When Bad Software Can Kill

bhoman writes "A wrist computer that tracks and calculates safe diving times and limits for SCUBA divers had a dangerous software bug that may have been covered up by company executives. This SF Chronicle Article details the problem, product, company, and some of the lawsuits. According to the Chron article, company execs tried to cover up and deny the problem for years, but their official website makes it look like they did a voluntary recall."

Comments

I wear an insulin pump

[Anonymous Coward]

And it has extensive safety measures built into it to prevent insulin over delivery. Obviously, when you put your life in the hands of a machine, you want to make sure it works, and that when it doesn't, you're notified. If a company is guilty of covering up a problem like this, I hope they get sued out of existence and the people guilty spend some time in jail.

Re:I wear an insulin pump

[fidget42]

I know some people will hate to hear this, but, like your insulin pump, maybe these types of devices should be considered medical devices. These things are not simple devides like a heart rate monitor, or bicycle trip computer. When you life is a product's hands you need someone like the FDA looking out for you.

Re:I wear an insulin pump

[CatPieMan]

However, your insulin pump probably has a warning (or the doctor who gave you the instruction on how to use it) that says if you do item A and item B, don't do item C.

As a certified diver (of about a year and a half), I know that they specifically say that you should never go flying less than 12 hours before you take a plane ride (even a small cesna), and, if you do multiple dives you should wait at least 24 hours.

This is not to say that the company was not at fault on this one, but, the divers themselves said that they finished the one dive at 10pm for a flight at 6:30am. I know that the absolute minimum is 4 hours (I did a flying after diving study with DAN), but, this is the limit of the dive tables and should NEVER be approached. All of the major certifying organizations will tell you this.

-CPM

Re:I wear an insulin pump

[jandrese]

I know that they specifically say that you should never go flying less than 12 hours before you take a plane ride (even a small cesna), I know that they specifically say that you should never go flying less than 12 hours before you take a plane ride (even a small cesna)

Man, layovers must be tough for you. :)

Re:I wear an insulin pump

[CatPieMan]

Oops, my bad, should be should never go flying less than 12 hours after diving for any length to any depth.

And, yes, I can't stand layovers - I generally like direct flights :).

-CPM

Re:I wear an insulin pump

[Paradise Pete]

Wouldn't it be easier to layoff the donuts, exercise, lose 100 pounds, and watch your diet?

I suppose you're trolling, but many fit people wear an insulin pump. Scott Verplank, for instance.

Re:I wear an insulin pump

[Anonymous Coward]

I have a young daughter with diabetes. We are just about to go onto MDI for a year or so, and then might consider going onto the pump in early teenage years.

Do you actually believe that the original poster wears an insulin pump by choice? Are you so misinformed as to think that lifestyle has anything to do with it? Do you understand that diabetics must pay very close attention to what they eat, far moreso than any casual "dieter" ever dreamed of?

I wouldn't wish diabetes on anyone. But in your case, I'd make an exception.

Re:I wear an insulin pump

[einer]

When you life is a product's hands you need someone like the FDA looking out for you.

The FDA should inspect my caribeaner? My car? My oven? Every electric appliance in my house requiring more than enough electricity to kill me?

Re:I wear an insulin pump

[Renli]

If your already diabetic no amount of watching your diet or exercising will replace the fact your body CAN'T make insulin so you need an external source.

And diabetes isn't only a "fat person" thing. My mother, a diabetic is actually, and has been since before becoming one, a tad bit under weight for her height. Both sides of her family had diabetics which put her at a much higher risk then normal.

christ your a tool

Re:I wear an insulin pump

[TaranRampersad]

As applications become more diverse, the role of traditional institutions such as the FDA grows more vague. Redefining them is a possible answer.

I think the proper answer is to highlight ethics in engineering again. I recall for Y2k, the Chinese supposedly had engineers riding on the planes at the stroke of midnight. Though maybe a bit harsh, such an act does bring the levity of the situation to people who often spend their time working on the product in an enclosed room.

In the case of the dive computer, I would hope that the engineers working on it actually dive, and understand the dangers normally involved with diving.

But... the U.S. Navy dive charts are still the best reference for the sport diver. The PADI certification requires that the diver understand diving, and not be reliant on dive computers - last time I checked.

This isn't an insulin pump. Dive certification is for people who wish to dive; it's a choice and those that make that choice need to understand the implications of the choice. Everything can screw up underwater. Divers should know that. With an insulin pump, the risks are different because people don't have a CHOICE to be diabetic or not; I would think that they are trained in the use of the pump... yet they must continue to monitor their blood sugar.

In essence, yes, there must be responsibility and accountability for equipment that we put our lives on the line with. But that doesn't mean we, as users, don't have some responsibility. Understanding how things work is important, especially if your life depends on it.

In this case, if these people did a cover up... They are liable for attempted murder, in my eyes.

Re:I wear an insulin pump

[LauraW]

If your already diabetic no amount of watching your diet or exercising will replace the fact your body CAN'T make insulin...

This is true for Type 1 diabetes, which often strikes children (where it's known as "juvenile diabetes") but can affect adults too. People with Type 1 diabetes are dependent on insulin injections or pumps.

Type 2 diabetics (like me) suffer from either "peripheral insulin resistance" (the insulin receptors in cells become harder to activate) or a moderate insulin deficiency. Since the insulin receptors mediate glucose transport into the body's cells, less insulin or faulty receptors mean more glucose stays in the bloodstream. Type 2 diabetes is sometimes, but not always, affected by weight and diet. (My doctor says that if I lost 50 pounds the diabetes would probably go away. She's even suggested weight-loss surgery a few times, but probably as a way of scaring me and emphasizing her point.)

Laura

Re:I wear an insulin pump

[tftp]

The FDA should inspect any device that gives you a medical advise. Your car does not do that, and neither does your oven. But if you have a calculator that tells you what food is safe for you to eat (or else you die), you'd better be sure it works.

Re:I wear an insulin pump

[mindstrm]

Yeah.. it's not like divers are taught that you use a computer to augment your diving, and that you should still fill out your dive tables or anything.

It's not like you aren't supposed to fly on a plane within 24 hours of diving, or anything.

It's not like every diver knows that the dive computers and dive tables are approximations, and that they can vary drastically for a number of reasons.

Pushing the absolute limits of what your computer says you are allowed is dumb.

I'm not saying the company is not responsible to a degree... they absolutely had an obligation to make their gear as safe as possible, and not informing the diving world that their gear had a flaw was totally unacceptable.

There is a large element of recklessness involved in this situation.

Re:I wear an insulin pump

[jerdenn]

The FDA should inspect any device that gives you a medical advise

It's a common misperception that the FDA inspects medical devices - in most cases, they do not. They merely inspect the paperwork that you provide them to prove that you did the device inspections yourself.
It's actually a relatively rare occurance that the FDA performs an onsight inspection.

-jerdenn

Re:I wear an insulin pump

[ncc74656]

I think the proper answer is to highlight ethics in engineering again. I recall for Y2k, the Chinese supposedly had engineers riding on the planes at the stroke of midnight. Though maybe a bit harsh, such an act does bring the levity of the situation to people who often spend their time working on the product in an enclosed room.

s/levity/gravity/g, perhaps?

Re:I wear an insulin pump

[EelBait]

Actually the Cesna would be more dangerous than a jet. Jets are typically pressurized to 8000 ft. whereas the Cesna is not pressurized. The rule is a 12 hour surface interval before a pressurized flight (or even a drive to the mountains), 24 hours for a non-pressurized flight.

Re:I wear an insulin pump

[TaranRampersad]

Quick! Someone mod him!

Re:I wear an insulin pump

[iawia]

Me too!

And the company that made my pump, disetronic, actually did notify me of a problem with the pump in february. They also detailed how to make sure you were not affected by the bug (I'm still not sure if it's a soft- or hardware bug, BTW), and where to send the reserve-pump so they could fix it.

Good service alltogether, I thought. No bug would be better, of course:-)

Re:I wear an insulin pump

[CharlesClarkson]

When you life is a product's hands you need someone like the FDA looking out for you.

Let me make sure I have this right. If my life is dependent on a machine, I should rely on a federal agency whose chief changes more often than the President. An agency so big that I am not even a number in their system. An agency influenced not just by my health concerns, but by politics, corporate lobbying, and a constantly changing budget.

Thank you, No. When my life's on the line I want quality in my corner.

Re:I wear an insulin pump

[Anonymous Coward]

Your information would be more credible if you knew how to spell the word site.

Re:I wear an insulin pump

[jerdenn]

Your information would be more credible if you knew how to spell the word site.

Perhaps.
However, my error makes the statement no less true.
To make up for my apparent lack of credibility, let me refer you to the following for more information: http://www.fda.gov/cdrh/devadvice/3122.html

Also, as a side note, I work for a very large medical diagnostics company.

-jerdenn

Re:I wear an insulin pump

[EvilTwinSkippy]

I am a Scuba Diver. When I go diving people look at me funny. First off, I have a little laminated dive table, and I scribble stuff on it, I think they call it a dive plan.

And then again, I always show up on deck with at least 500 lbs of pressure in my tank. I've had people tell me that I cold have gotten another few minutes on that air. And I wonder why my insurance company looks at me funny for diving. Geeze.

I have never trusted dive computers, mostly because they are useless if you are trying to plan your next dive. You have to adjust all of your calculations based on how much nitrogen you absorbed in the last 24 hours. The only reliable way is to bust out the tables.

At the most I'll use computers to give me the temperature at the bottom, dive time, and maximum depth. The time I always check with the guy with the clipboard and stopwatch on the surface.

Re:I wear an insulin pump

[cburley]

the Chinese supposedly had engineers riding on the planes at the stroke of midnight. Though maybe a bit harsh, such an act does bring the levity of the situation to people

s/levity/gravity/g, perhaps?

No; the planes brought the engineers up, i.e. it levitated them. Gravity would come into the picture only if there were serious Y2K bugs in the aircraft's computers.

;-)

Man...

[Azureflare]

This kind of story makes you want to stick your head in the sand and not buy any critical applications from corporations...Unfortunately, for some "leaders of industry," protecting image is more important than the safety of the users. Users are expendable; image is not.

Fortunately, there are still (I hope) some companies out there that are honest and worry about the safety of their users, particularly in life-critical applications.

What a slimy guy though, to prevent any notice of the fault from getting out, and firing managers for trying to get the word out! Man. Makes me angry. *Fumes*

Re:Man...

[Anonymous Coward]

Not much competition in this field. Unfortunately, this company is described as having the vast majority (75%) of the market and a recall of this product only would have measured in the hundreds. In this particular market, there just aren't (or weren't) any other companies honest or not.

Re:Man...

[Idarubicin]

This kind of story makes you want to stick your head in the sand and not buy any critical applications from corporations...

From whom would you buy your critical applications software (and hardware)? What if the guy down the street starts building them in his garage? Would you trust him? Would you trust your life with him?

Let's say he's very responsive to customer issues. Whenever there's a serious incident, he tracks down the bug in the software, issues a patch, and moves on. Unfortunately, there are a lot of bugs, and a lot of deaths, because he couldn't do proper QA by himself in his garage...

Well, you say, let him hire some QA people. Maybe a few marketing guys--he has to make a living, after all. Perhaps an engineer or two. Pretty soon, it starts to sound like he's running a *gasp* corporation.

You're right--directors and executives of companies that suppress reports of safety concerns should be drawn and quartered. To suggest that all corporations are reckless, deceptive, and grossly irresponsible is unfair.

Then there are some damned-if-you-do, damned-if-you-don't cases. I'm familiar with the Therac-25 accidents in the mid-1980s, but I'm not going to ask the pharmacy for cobalt-60 so I can do home radiotherapy. I have to accept that there is a probability that somewhere, someone screwed up--and my life might be at risk because of it, and there is little (if anything) I can do about it.

Re:Man...

[weston]

Your overal point is really good, but I want to nitpick one point and then jump off to a larger issue...

Well, you say, let him hire some QA people. Maybe a few marketing guys--he has to make a living, after all. Perhaps an engineer or two. Pretty soon, it starts to sound like he's running a *gasp* corporation.

Not necessarily. He could be running a sole proprietorship still, even though it likely wouldn't make much sense. He would probably at least change to an LLC, or perhaps he would pick another corporate form.

Why would he do this? For tax reasons, partially, but also... liability reasons. Protection from many kinds of liability is great -- it allows companies to take the financial risks necessary to get off the ground.

But here's the thing: I think a lot of people in the corporate world start to beleive a little bit too strongly in the abstractions surrounding the corporation. The relief from liability. The view of the customer/consumer as a revenue source. Once you start building up the abstraction of the corporation, that's the only relationship you have with them as course.... whereas the guy in his garage talks to each of his customers, has probably lived on the same street as them for a few years, and if he has any humanity, is going to feel some responsibility to them. Not to mention pride in his work (sometimes I think there's some of us hackers, for example, who'd be nearly as hurt by the fact that something we made failed in a critical way as the fact that it could threaten a life :).

Large organizations/corps aren't inherently evil, but they can easily breed this kind of behavior because they're inherently somewhat insular and abstracted from normal human realities.

Diving Computers

[aaarrrgggh]

There are two major diving computer companies with "original" systems-- UWATEC and SUUNTO. Uwatec (named in the suit) has been known for less conservative systems; they let a diver stay down longer.

This is attractive to people who do decompression diving, because it means that they don't have to hang out shivering at 5-10m with nothing to see as long at the end of the dive.

Suunto takes a different approach, has a more conservative model, and makes it easier to force your computer to be more conservative still. Most divers don't use that function, because it is contrary to their desire to have maximum bottom time.

Proper diving procedures recommend using two different computers, and always relying on the more conservative unit for your decompression limits. (Assuming that you are doing a computer-only dive and not a table dive.) When your life is at stake, you have to assume that equipment has problems, and act accordingly.

Re:Diving Computers

[skroz]

Agreed. Personally, (and according to PADI recommendations, I believe,) I don't trust computers at all. I have one, yes, but I still trust the tables a whole lot more. Someone recently showed me the wheel, which is apparently easier to screw up than the tables but far more accurate.

Checks and balances. I use the computer to make sure I'm doing the manual calclations correctly, and the manual calculations to keep the computer honest.

Then again, I'm strictly a recreational diver. Pros and semi-pros are a completely different story.

Re:Diving Computers

[Surazal]

DANG! If this is what you do as a hobbyist, I hate to see what the pros do. :^)

Re:Diving Computers

[SuperBanana]

Proper diving procedures recommend using two different computers, and always relying on the more conservative unit for your decompression limits.

Actually, for recreational, non-decompression diving(which represents the vast majority of recreational diving- technical diving is a whole other beast), PADI tells you to use the tables they give you on a waterproof card. You're supposed to plan your dive AHEAD OF TIME using the tables, and stick to the plan. You're not supposed to just grab a dive computer and jump in the water, for EXACTLY this reason- the computer could malfunction. Further, I'm pretty sure my PADI manual specifically said you should never use a dive computer to push the limits of no-decompression diving to get maximum bottom time, although it has been a LONG time since I went on a dive(and hence did a refresher course or studied my manual, both of which you should do after being inactive for a while).

Interstingly, I just found a google cache of a this page about a recall(or lack thereof) for the PADI dive table cards, while trying to find PADI's DAN(Diver Alert Network) site.

Ah- found it. There's another article here about it, including which tables(for concerned divers, seems to be tables printed in 2002-Jan 2003, check the site).

Re:Diving Computers

[Anonymous Coward]

Instead of self-indulgently frittering away your life as a stupid, self-righteous troll on an Internet message board, why don't you do something useful? Say, like killing yourself.

Re:Diving Computers

[Anonymous Coward]

Mod parent up!! +100 insightful

Re:Diving Computers

[Dr Rick]

Hmmm... first set of divers ended their dive at 10pm and had a flight the next day at 6:30am! Even under the most extreme 'gonzo diving' rules, you should have 12 hours between your dive and flight and most say 24 hours. Definitely relying a bit too much on the computer and not enough on common sense... As I learned, for the next 24 hours after diving the highest you should go is the height of a bar stool... Rick

Re:Diving Computers

[Tri]

The wheel isn't that much more accurate, and it's a lot easier to stuff up. It's very easy to put it out of alignment, and once you've done that, the results it will give you will be wrong.

The wheel isn't actually any more accurate than tables, it's just showing the same calculations in a different way.

And PADI does not recommend that you do not use computers.

And if you want to feel safe because you are using tables, use the US Navy Tables, and limit your ascent speed to 9 to 12 metres / minute, and you will actually be safer.

One of the main reasons people will use a computer, is because of the audio alarm you can hear when you exceed ascent rates (If you have a descent computer at least).

Re:Diving Computers

[lgftsa]

He forgot to mention that the divemaster manually checks everyone's calculations after each dive - and that's after each buddy pair checks each other's calculations first.

You have to remember that it doesn't matter why you're diving - sport, recreation, pro sport, commercial/industrial - it's all happening in a hazardous environment which the human body has no defences against.

What the dive tables[1] represent is a boundary to which most humans can push their bodies and not suffer a critical failure(embolism/bends/nitrogen narcosis[2]). Past that boundary, bad things happen. Some people don't reach that boundary before they happen. An identical stress applied to two people may not affect one person, but kill the other.

[1] Originally created by trial and error(diving and bending) by the US Navy, then becoming more accurate and conservative over time.

[2] NN is akin to getting high - and getting high is *NOT* a good idea when you're at 20m and breathing through a regulator! People who offer their regulators to passing fish, or loose track of time/depth die.

Re:Diving Computers

[pod]

They do the exact same thing. It's your life and health at stake here. If you don't value either then you should go diving by the seat of your pants and hope you make it out safely before your air runs out.

Re:Diving Computers

[Tri]

You can still plan your dive with a computer, by going into the diveplan mode, and seeing what the no-decompression limits are for the depth at which you intend to go.

In case of computer malfunction, you should immediatly abort the dive anyway, and the computer manuals are very clear on the fact that you must stay out of the water for a certain time.

Also, DAN has nothing to do with PADI, and they offer different recommendations.

Re:Diving Computers

[Anonymous Coward]

PADI tables are based on the US dive tables.

The US Navy tables are incredibly conservative in some respects (only once case of level II detectable bubbles using Doppler, and none of level III) and horribly unusable for others (recreational divers do NOT decent to a specified depth for a specified time and come right back up).

PADI tables are made for recreational diving, but do not allow for useful multilevel diving; the wheel is better for this, but still less than perfect.

A computer uses internal tables (differ from manufacturer) a pressure sensor and elapsed time device to "credit" time when you go shallower and "debit" time when you go deeper, calculating (supposedly) more accurately to allow you extended dive time than the "block" level tables.

I've owned Suunto Alpha and other models with no problems. Reconstruction with their software and comparing to PADI tables brings reasonable results.

Rodale's Scuba Mag has had this discussion before, and the Bikini Atoll Dive site will NOT allow certain computers to be used (guess which ones) due to shown inaccuracies (Bikini is a decompression dive).

Re:Diving Computers

[Anonymous Coward]

Don't forget about Central Nervous System Toxicity (CNS), the REAL killer at extreme depths.

Re:Diving Computers

[PurpleFloyd]

As someone studying for a private pilot's license, I can understand where the divers are coming from. Basically, if you screw up once, your life is over. This might not be the case every single time, but one mistake at the wrong time could easily end your life and put whatever bits of you rescuers could find in a little pouch 10 feet underground.

Thus, hobbyists and amateurs use methods very similar to those of the "pros"; both need to ensure the utmost level of safety. Most of the time that caution isn't warranted and things are fine without double-checking everything, but one time in a hundred or a thousand, you are very glad you did. Basically, the extensive checklists become second nature and take only a few minutes to perform; the small amount of time "wasted" is no trade-off at all considering what might otherwise happen.

Re:Diving Computers

[aaarrrgggh]

CNS is a lot easier to stay away from, as it is a function of O2 partial pressure. Unless you are going deeper than 60m, it's hard to have a problem with air.

Re:Diving Computers

[Surazal]

My comment was made in jest, though I can understand the seriousness of even doing this as a hobby.

Me, personally, I would love to be a hobbyist astronaut. Now THAT would be fun to brag about (and can you imagine the lookup tables for THAT!?). /tee-hee-hee :)

Re:Diving Computers

[dhartshorn]

Agreed. Dive the computer until it breaks. Then abort the dive and log it as if you dived the tables. The purpose of the computer is to give you more bottom time and shorter surface intervals, in particular when you are not diving square profiles.

Re:Diving Computers

[skroz]

Agreed on the nitrogen narcosis... might be fun above the surface, but pretty damn dangerous at depth. I've only been narc'd once, and it was at a depth of 120' right at the edge of the continental shelf. I remember getting a distinct feeling of flight, kinda cool at first. Then vertigo, then nausea. Imagine yarking into a reg'... gyah. Fortunately, I was spared that (potentially lethal) horror.

Re:Diving Computers

[ZeldorBlat]

[2] NN is akin to getting high - and getting high is *NOT* a good idea when you're at 20m and breathing through a regulator! People who offer their regulators to passing fish, or loose track of time/depth die.

Trying to bring a shipwreck to the surface is kind of funny, too.

Re:Diving Computers

[Colonel Blimp]

I've been diving for years and have a few hundred dives on my new computer. As for expecting the divemaster to manually check the calculations, it didn't happen on many of the dive trips I've been on. I can lie and say that as a super concientious diver I always used my tables in conjunction with the computer, but unfortunatly that didn't happen.

I consider myself a very conservative diver, last month I was going to do 3 tanks of Nitrox at 37% Oxygen, and as soon as I attached my regs and turned on the computer, it had just enough power to tell me that it was shutting down. It has a low battery warning, but since my last dive was 24 hours before, and it stays on until the safe to fly time is reached, it went dead. Rather than risk the possibility of Nitrox problems with a high O2 mix and not enough data on the depth, I switched to regular air (at a loss of some $$). The fact is, when you dive, you dive conservatively, and never push the limits, even if you have a computer. All divers need to remember that the #1 best computer you have is your brain.

One other story, I bought my Aeris computer, and it had a link to the PC to download data, but only in Windows 98. I called Aeris, and they stated that they didn't see the need to write a patch for it to work in XP....that made me feel just wonderful about the company.

Re:Diving Computers

[se2schul]

"Proper diving procedure" recommends not trusting a dive computer, but rather planning your dive before hand using some of the many software programs out there, and having your dive plan/schedule known before hand. Monitor your dive plan while underwater while using a depth gauge and bottom timer, instead of a complex, convoluted computer.

Computers are prone to fail underwater - bateries die, oring seals fail, and it's just a harsh environment in which to be trusting electronics.

To further complicate the problem, the bulhmann model that the computer uses produces horrible decompression stops. There are other decompression algorithms out there that produce much nicer shapes of decompression, like Eric Maiken's VPM (Varrying Permability Model).

To make matters worse, none of these algorithms truly model what is happenning inside the body - for example, they completely overlook the biochemical aspect of the dive.

We produce dive schedules using software, then massage the schedule to start the decompression stops deeper, extent time on any gas switch, and then shorten the shallow stops considerably. I did this just yesterday will doing deep dives on trimix (helium-based mix with lower oxygen content) while looking for new wrecks in the shipping channel.

Trusting a dive computer is insanity - use your brain instead.

Re:Diving Computers

[Sgt York]

I DM'd for about 3 years while in college, and we very rarely checked anybody's calculations unless we knew the person was new, uncomfortable, or had been dry a while.

We would typically announce the depths for places of interest, and state the bottom times for each; normally from memory. Anybody short on experience or clues would get a little extra attention and be steered from deep dives, but once again, we didn't make a habit of checking everybody's calculations.

As for NN, for those that don't know, getting narc'd is a very odd feeling. It's like have a "drunk/sober" light switch in your head. There was a HUGE deco chamber where I went to college, and they took us down once to get narc'd. Did it once by accident on an oil rig, too (what a way to find out your depth gauge is busted....said my max depth was 42' for that dive). A LOT more scary there.

Funny story....When we did the deco chamber, one guy brought along a bunch of condoms. We tied off the end at ~30m and let Boyle go to work...6 of us wound up walking across campus with condoms inflated to the size of Louisville Sluggers.

This is not lethal but ...

[Rosco P. Coltrane]

I had a friend in the US who underwent LASIK surgery. He told me that his wife, who was computer-savvy, and was watching him being operated on, saw a Win95 box dedicated to controlling the laser and the mount's stepper motors, and that the operator was repeatedly hitting ENTER to make that recurring message box with a red X disappear. She got worried but the surgery was already under way, so she didn't say anything.

Fortunately, his LASIK succeeded. Later on however, he went back to the hospital and asked about the operator's behaviour : the response was "well, we were worried at first, but that error message comes back every five minutes and the machine always works anyway".

Scary ...

Re:This is not lethal but ...

[RayOfLight]

This is obviously totally irresponsible on the part of those responsible for the tech being used for the operation. This really *is* scary!

Re:This is not lethal but ...

[iamhassi]

oh jesus! I had LASIK surgery and didn't even think to check the software running the machine. Mine turned out fine, but that scares the crap outta me now.

Re:This is not lethal but ...

[Anonymous Coward]

and are you going to tell us if you took them to court or not?! if they're ignoring errors and not even reading them, they're not doing their job. and if this is something that hasn't hurt anyone YET, what's stopping you from getting them under investigation?

don't be stupid, save people a lifetime of blindness.

Re:This is not lethal but ...

[Enonu]

Thanks for your insightful post. As somebody who's constantly considering lasic, but fearing that I would be the screwed .5% who's vision would be completely destroyed, this gives me an extra security check that I can perform before I opt for the surgery. I'll be asking:

* What software do you use?
* How do I get a safety report on this software for as long as it's been used?
* How many revisions/updates has it had in the past year?
* What's the underlying hardware and OS platform it runs on?
* What kind of training do the operators of this software have to go through.

If I get ANY BLANK stares or anything less than definitive answers, I'll be going somewhere else. If it's the difference between a place that charges $500 an eye and one that charges $1000 an eye, so be it.

Re:This is not lethal but ...

[pod]

Man, same here. I don't want anyone cutting my eyeball open and shooting lasers into my eyes while I'm only sedated JUST YET, but I've always said: I don't care how much it costs. Find me the most expensive place and take me there. I don't care if I have to pay Gimbel almighty himself to perform the surgery personally, I don't want to be taking ANY chances with something irreversible as lasic.

Re:This is not lethal but ...

[Greger47]

I've never understood the pretty laissez-faire attitude towards LASIK surgery in the states.

I've read several articles when journalist X went to the mall on the corner and had both his eyes done in a snap! Any everything was all smiles and thumbs up.

The normal procedure on this side of the pond is that after a thorough evaluation you get one eye done. After two followups to check that you everything went well and the eye is healing OK you zap the other eye.

Or as we say: Don't look into laser with your remaining eye!

Ofcourse, I'm sure you can find quacks here too...

Oh, and while we are at it, it fucking hurts like royal hell after the sedation wears off. Make sure to stock up on extra strength painkillers.

Re:This is not lethal but ...

[Anonymous Coward]

God, you guys were trolled. Hook-Line-Sinker. Some one posts a story (third-hand BTW) about Win95 and error messages during LASIK surgery, and your anti-Microsoft alarms blind you to a pretty ridiculous troll. Not only that but it was modded +5. Jesus Christ, it is no wonder this community is not taken seriuosly.

Re:This is not lethal but ...

[Rosco P. Coltrane]

err... that wasn't a troll, I really know that guy

Re:This is not lethal but ...

[Anonymous Coward]

oh jesus! I had LASIK surgery and didn't even think to check the software running the machine.

Don't worry. We at Microsoft would never take advantage of our customers to fit a retinal spy camera into your eyes. No sir!

Re:This is not lethal but ...

[pongo000]

Make sure you visit this site before ever laying down in that chair. A recent study (Feb. 2003, on the site) indicates between 10 and 20% of refractive surgery patients have complications, a number that is far above what the LASIK industry is touting as its failure rate.

Of particular interest are the stories concerning doctors who have overridden software safeguards and have continued the procedure, resulting in broken blades in the eyes and some other not-so-pleasant outcomes. Not strictly in the "bugs killling people" dept., but it does make you think whether you trust your eyes to a software developer.

Re:This is not lethal but ...

[nadaou]

If it's the difference between a place that charges $500 an eye and one that charges $1000 an eye, so be it.

The the take home point here is the $1200 dive computer WAS the best on the market, if($$ == best). See the problem?

Unfortunately for these poor folk, sometimes cheaper is better value.

And again, in case anyone missed it, redunancy is a good thing.

Re:This is not lethal but ...

[mosch]

You might also want to pay $10 for the doctor's choicepoint report. This will report their credentials and any sanctions. It's far from knowing about any complaints against the doctor, but before a surgery such as lasik, it'd probably be good to check for sanctions.

Haha

[Anonymous Coward]

I bet these execs thought "dead divers can't sue", so why bother.

Probability of punishment?

[Altima(BoB)]

On the issue of punishing companies for unsafe practices like this, sometimes it's 50/50. Depends how much sway they have. I'm not anti-capitalist über-left cynical jaded moron, but after reading Fast Food Nation recently, I don't have a whole lot of faith in the government's ability to control this kind of activity on a large scale. The government used to have a lot more power over companies since Theodore Roosevelt's time, but the book seems to point the finger at the Reagon era for the change.

Anyway, it wouldn't have been bad PR to admit a mistake, hell it's only human to make mistakes, even when something is as serious as this. The problem shouldn't have been there at all, but it was caught before anyone was hurt, so they should have just apologised and fixed it. Cover-ups make me sick.

Re:Probability of punishment?

[praksys]

More government control doesn't necessarily help that much.

Some of the most serious problems with defective products in recent history have occured when government was entirely in control. In some cases they screw up because, like business executives, they want to cut costs (providing HIV/AIDS infected blood for example). Sometimes they wind up killing people because they are too cautious. Scandals usually occur when actions kill people, not so much when inaction kills people (delays in FDA approval for new treatments cost thousands of lives).

If you think this is a problem with Capitalism then you should take a look at the sorts of things that went on in Communist countries like the USSR and still go on in places like Communist China.

Cover-ups make me sick.

I think that the only effective remedy for this sort of problem is greater transparency in both business and government. These kinds of problems thend to occur when the people involved think that they can get away with a cover-up.

Re:Probability of punishment?

[Cyberdyne]

On the issue of punishing companies for unsafe practices like this, sometimes it's 50/50. Depends how much sway they have. I'm not anti-capitalist über-left cynical jaded moron, but after reading Fast Food Nation recently, I don't have a whole lot of faith in the government's ability to control this kind of activity on a large scale. The government used to have a lot more power over companies since Theodore Roosevelt's time, but the book seems to point the finger at the Reagon era for the change.

Is the government's ability to "control this kind of activity" in question? According to the article: "The company weathered an investigation by the U.S. Consumer Product Safety Commission, which had inquired about the computer at the end of 1998 but dropped the proceedings many months later without announcing findings. Gilliam and other former Uwatec employees say the company misled the commission by sending it Aladins altered to remove the defect, but Johnson denies the charge." The government investigated - but presumably decided not to proceed. Perhaps because they were fooled by modified units (dumb: for the investigation, they should have bought units from stores like any customer!) No lack of authority or awareness - just a lack of ability on the investigator's part. My mother was legal advisor to the local Environmental and Consumer Protection Division; whenever they suspected anything, their first step was to buy the product in question, posing as ordinary customers. Simple government incompetence/indifference, rather than any structural problem...

Anyway, it wouldn't have been bad PR to admit a mistake, hell it's only human to make mistakes, even when something is as serious as this. The problem shouldn't have been there at all, but it was caught before anyone was hurt, so they should have just apologised and fixed it. Cover-ups make me sick.

According to the article, the coverup certainly made some divers sick:

The computers said they had plenty of time.

But the next day, about an hour into the flight, both men grew nauseous. Iazdi threw up and his fingers went numb. Skaggs' head and shoulder throbbed. They had the bends.

When the plane landed on a stopover in Charlotte, N.C., they rushed to the nearest recompression chamber, in Durham, more than 100 miles away. Shaking, terrified, they spent six hours in the high-oxygen, high-pressure atmosphere that forced deadly nitrogen bubbles from their bodies.

They survived, but the headaches, fatigue and numbness would never go away -

and they would never work again as divers.

Admitting to this fault would have been much worse than just PR; the compensation bill just from these two ex-divers, apparently crippled by this bug, would damage the company severely - and who would ever trust them again, knowing their products have crippled people without warning?!

Re:Probability of punishment?

[Anonymous Coward]

How will transparency work to stop this?

The CEO will just disclaim all invovlement "It was a mistake by an intern who has already been punished".

If Corporations want some of the benefits of personhood, then they MUST have drawbacks. The CEO MUST be held personally responsible for ANY actions taken by company employees (hey, they get the big bucks because it's "a risky job"). The CEO can devolve responsibility for some specific items to another C*O (bad hiring in their division), but for large errors, they at best get to chare tha pain (financial irregularities will be the responsibility of both the CFO and CEO).

Get government involved in corporations as much as they are with us humans. Personify a corporation by it's Officers.

Re:Probability of punishment?

[praksys]

How will transparency work to stop this?

The same way it does now, only more so. Nine times out of ten when companies are successfully prosecuted the crucial evidence is drawn from their own documents.

Get government involved in corporations as much as they are with us humans. Personify a corporation by it's Officers.

In fact the law already treats corporations as persons. A corporations is legally responsible for the actions of its employees, and both civil and criminal sanctions can be imposed on the corporation itself. What you want is something else. You want individual people to be held responsible for the actions of other individuals, or for the actions of corporations, even in cases where no direct responsibility can be proven. I think the courts would regard that as akin to collective punishment and would reject any such law as unconstitutional.

Re:Probability of punishment?

[john.r.strohm]

Unfortunately, this one was NOT caught before anyone was hurt.

Bob Raimo. Mitch Skaggs, and a few other guys are crippled for life because of those computers.

I know Raimo, slightly. He was one of the good guys. He almost became one of my regulator technicians, when it was getting hard to find a good Beuchat tech in Dallas. (You better believe you are trusting your life to your regulator technician: if he screws up, you stop breathing.)

MOD PARENT DOWN!

[Anonymous Coward]

This is slashdot... you have to be an anti-capitalist über-left cynical jaded moron to be here.

Re:MOD PARENT DOWN!

[Anonymous Coward]

Yeah! Sure! Sure! Have you used a malfunctioning medical device lately?!

If you have you would realize that this goes well beyond left/right nonsense!

Re:MOD PARENT DOWN!

[Pharmboy]

amen. As a conservative (read: pro business) individual, I am smart enough to know that in order for government to not smother corporations, they must act responsibly, and the punishments for violations of the public trust should be severe. That is the trade off.

We don't want government getting too involved with businesses, but we want them to kick them in the ass hard when they do something that not only can hurt/maim/kill someone, but also creates an adverse environment for corporations who DO act responsbibly.

In the end, you are correct: both left and right do not want companies to get away with 'hiding' a recall that could potentially hurt someone. That is not politics, its common sense. If they DID hide this recall or information about flaws in the product, they need to be taken out to the proverbial woodshed, even if it puts them out of business.

Re:MOD PARENT DOWN!

[Anonymous Coward]

Draconian punishments are normally a substitute for adequate detection rates.

Re:MOD PARENT DOWN!

[fanatic]

both left and right do not want companies to get away with 'hiding' a recall that could potentially hurt someone.

Unfortunately, your version of 'the right' is not the operative one. The businessman we see today would kill their own grandmothers to increase the value of their stock options. And the politicians they put in place want nothing more than to let them do it. Look at those scumbags Harvey Pitt and Michael Powell - thy can't move fast enough to sell us down the river.

Re:MOD PARENT DOWN!

[monoqlith]

> We don't want government getting too involved with businesses, With the current administration and congress, we don't have to worry too much about that, do we? Actually, I do want the government getting *more* involved with the state of business practices. A laissez-faire attitude always results in lack of business responsibility, liability, and concern for the consumer, which results in pain, death, and suffering. Any study of history should acknowledge this(read: The Irish Potato famine could have been averted of the imperialists in question had espoused a less laissez-faire attitude). Moreover, the amount of penetration corporations have within our government is sickening; corporations vicariously have more power here than in any other country. The consumer needs to be protected more vigorously, and to do that, the goverment needs to be more committed to checking corporate behavior. Things like this - blatant corporate oversights and resulting cover-ups - should never happen. >but we want them to kick them in the ass hard when they >do something that not only can hurt/maim/kill someone, >but also creates an adverse environment for corporations >who DO act responsbibly. Agreed. Unfortunately, corporations, at their highest levels, seem to be fraught with irresponsibility. What happened last year with ENRON, Worldcom, AOL, etc, made me quite angry. Executive greed is dangerous.

Re:MOD PARENT DOWN!

[Pharmboy]

i would disagree and say they are a suppliment that reduces the number of detections necessary. If you allow a group (corporations, in this case) to operate in an environment with a little regulation and oversite as possible, the threat of punishment that exceeds the crime acts as an incentive to keep people honest.

Speak softly and carry a big stick.

Re:MOD PARENT DOWN!

[Pharmboy]

Unfortunately, your version of 'the right' is not the operative one. The businessman we see today would kill their own grandmothers to increase the value of their stock options.

You have to keep it in perspective. Yes, some will, but the majority will not. Even with all the bad press, you have to realize that the truly criminal CEOs represent less than 1% of the CEO population. My view says that we punish this 99% and incentive to doing business right.

If there are no consequences, there is no change.

Re:MOD PARENT DOWN!

[Pharmboy]

My point is for government to become more involved when there is a problem, to view from a distance any then (and only then) become heavily involved when there is a breach of the public trust.

More regulations does NOT mean more safety or honesty. Reasonable oversite with STRONG penalties does.

Re:MOD PARENT DOWN!

[JuggleGeek]

This is slashdot... you have to be an anti-capitalist über-left cynical jaded moron to be here.

Obviously, I don't.

The main flaw of modern computer science.

[Krapangor]

Crappy coding style is caused by the main flaw of modern computer science: the failure to recognize the problem of correctness as a mathematical problem.
Everybody who has an university CS degree will agree with me that much time and effort is spend to encourage students to produce nice and correct programs. However this strategy is a failure so far. Again and again bugs, errors and other problems turn up more often these days in spite of the increased educational efforts.
This is because the CS community failed to accept the core of the problem: error in programs are a mathematical problem which must be attacked by mathematical methods. All modern approaches to correct code are indeed management orientated - take programming by contract, extreme programming etc.
But what does it mean that a program fails to execute correctly ?
It means that mapping induced by the program in the trajectory space doesn't agree with mapping induced by the specification. And that is a purely mathematical problem, ladies and gentlemen. The question if two mapping coincide is a basic mathematical question (the equivalence problem) which even dates back to Euclid and Platon.
So instead of throwing more and more management rubbish at poor CS graduates, people should analyze the mathematical structure of the problem and find there the answers they seek.

I think that it's very sad that CS people still ignore this issue and stick to their old established ways. Sometimes I believe this is not motivated by scientific arguments but a rather psychological inferiority complex: as mathematician have the reputation to be smart while CS people only count as code nerds, computer scientists tend to despise most mathematical approaches as "too academic" or "imfeasible".

Re:The main flaw of modern computer science.

[entrox]

Who are you? The apprentice of "PhysicsGenius"? That would at least explain the pseudo-intellectual gibberish you are writing.

That being said: what makes you believe that it was a programming error? If you had bothered to read the article instead of spouting some nonsense about mathematics and the "flaw of modern computer science", you would have seen that it was a design error, meaning the specification itself is in error. You can answer "the equivalence" problem, but if the specification is flawed you're going to get flawed code. Garbage in, garbage out.

Re:The main flaw of modern computer science.

[OldMiner]

I attend a small state university that is decidedly not renowned for its CS program. I'm coming up on my senior year. In no less than three class (Data Structure, Software Engineering, Algorithms) I have spent at least a week concentrating purely on proof of the correctness of an algorithm by various methods. Software Engineering took over a month on testing, primarily concentrating on mathematically rigorous proofs and automated tests (because a mathematically correct and proven algorithm can easily be implemented incorrectly). Pardon my insulting question, but when was the last time you attended college?

Re:The main flaw of modern computer science.

[aaarrrgggh]

For this specific problem, it was more that they modified an existing product to get it to market (in order to sell the company).

Your nitrogen uptake in diving is a function of the nitrogen partial pressure (79% in air, 60-75% with oxygen enriched air (nitrox). Making a computer calculate based on nitrox rather than air should be as simple as changing the O2 percentage. The problem is that at the surface, this computer still assumed you were still breathing O2 enriched air.

Good diving practices dictate a minimum 1-hour surface interval, and 24-hours before flying when using nitrox. Professional divers often push these limits, especially at the end of a trip when it is most dangerous.

Re:The main flaw of modern computer science.

[Anonymous Coward]

The size and complexity of most computer programs makes proving any property about them incredibly difficult. Proving the equivalence between a specification and an implemented program just is not feasible with today's technology, though research in model checking and software engineering are making advances.

The fundamental issue is that there's no way to prove that the specification itself is correct. After all, humans write specifications, just like humans write computer programs. Do you expect to mathematically prove that the specification is correct? If not, then you'll still be left with buggy software.

What this comes down to is that there are lots of ways to make software more reliable. Mathematical solutions help. So do, better compilers and programming languages. So do better software management principles. So do software patterns, and a dozen other things. But none of these is the silver bullet that's going to solve all our software reliability problems.

Re:The main flaw of modern computer science.

[almaw]

Oooooh, you're so wrong!

You can prove the correctness of a bit of code, but it's very hard, takes a long time and is highly skilled work. It becomes especially hard if you're trying to do it with a grammar for any real-world programming language and the code is anything approaching complex. For most real world cases it's simply imppossible.

Mathematical proof of a program's correctness is simply too hard and costs too much money to be applicable in the real world.

If you did a real CompSci course, such as the one I did at Cambridge University, you'll discover that "CS people" are very very far from being "code nerds". I was supervised by a couple of mathematicians for some courses who could code no Java, C++ or Perl (although one of them knew much ML). Proper Computer Science folk are seriously academic and embrace the mathematical side of the field. You can't write an optimising compiler without doing so, to name but one thing.

People don't "ignore this issue" - it's just virtually inapplicable to real world problems. Exteme programming is not "management rubbish". If you'd ever actually read a book about it and tried some of the methodology you'd appreciate that. You forget that the driving force for commerical products is pretty much how much it costs, against the feature set and speed. Provided it doesn't crash very often, that's Good Enough. Unless you're the sort of type who doesn't pay for Windows, I'd suspect most people would rather have a version for $100 that crashes once a month than a version for $1000 that crashes only once a year.

Get down off your pretentious high horse and get a clue.

Re:The main flaw of modern computer science.

[Anonymous Coward]

Seems to me that the problem in this case was a failure in requirements gathering (assuming nitrox after surfacing).. and not something that could have been fixed through a proof of correctness.

Re:The main flaw of modern computer science.

[Lemmy Caution]

That's the irony. Good management practices, including systematic diligence about assumptions, would have avoided this defect. The fact that the grandparent poster essentially thought "it compiles, it runs without crashing, and it's efficient" would mean that it worked and was ready to ship is the problem itself.

Re:The main flaw of modern computer science.

[mark-t]

That being said: what makes you believe that it was a programming error?

I believe the parent poster was generalizing, and not referring to this one particular incident.

You can answer "the equivalence" problem, but if the specification is flawed you're going to get flawed code.

And with that statement, you prove the parent poster correct. A flawed specification is nothing more than a logic problem, which will invariably draw on mathematical methods for its solution.

What is noteworthy is to realize that we are still running into problems with flawed software simply because no algorithm exists (or ever can exist) for finding the solutions to arbitrary math problems.

But just because we can't fix every problem doesn't mean that it's fruitless to use the methods we have to eliminate as many as we can.

Re:The main flaw of modern computer science.

[Anonymous Coward]

people should analyze the mathematical structure of the problem and find there the answers they seek.

Spoken like someone who's never, ever written any significant code. Toy problems in CS class don't count.

Hint #1: Programs are specified by human beings. More often than not, non-technical human beings. "Sure, Mr. Customer... we'll code that up for you. right away. All we need from you is a specification written in first-order predicate calculus or lambda calculus."

Hint #2: While it is possible to prove correctness for the aforementioned toy problems, that's just not happening when it comes to something the size of the Linux kernel or (God forbid) Windows XP. It's not even happening for Tux Racer or Gnutella.

Re:The main flaw of modern computer science.

[blair1q]

It's not a "failure to recognize."

It's a business decision.

People understand that mathematically proving a complicated computer program is an unprofitable task. It would be impossible to have software-controlled devices assisting in safety-critical situations if that were the absolute standard.

So those who adhere to standards apply a structured development organization and perform an acceptable level of inspection (i.e., proving), testing and documentation. If they do that correctly, then the government and courts will absolve them of most liabilities.

In the process, effectively almost all of the program is proved mathematically, though the proofs are done only in the eyes of an experienced inspector checking for "program correctness", and documented only as a mark on a checklist. If the inspector sees a construct that is likely to be dangerous, he should have it rewritten by the developer to be recognizably safe, or tested exhaustively by the tester.

It's not a perfect system, but it's enough until someone sues the government for allowing it to have holes.

Re:The main flaw of modern computer science.

[Anonymous Coward]

And that is a purely mathematical problem, ladies and gentlemen

You are sorely underestimating the problem. Mathematical problems have the convenience of being reducable to some minimal set of parameters without having to take the metal shavings and the grease and the skin pore plugs that accumulate on the mouse ball rollers into account. Complicated software projects are nondeterministic forests of unforseeable chaos.

You also appear to be assuming that a dichotomy exists with personality types - mathematicians and computer science people. That's not the case with the characters involved in producing a complicated peice of software. If you do some case studies or are ever yourself involved in a complex software production effort from concept to delivery, you will find that the people involved run the gamut from acedemics to engineers to MBAs, with many participants having some of the characteristics of others.

There's nothing wrong with elegant and mathematical design and testing approaches to the creation of software products, but if you believe that the creation of software is a purely mathematical problem, you are being naive. If you wish to convince anyone otherwise, you could start by pointing out a single example of a complex software product that is a "correct program" and was produced using any technique you wish.

A purely mathematical approach to the intractable problem of a generalized solution for the creation of a "correct program" would be wonderful, but monkeys are far more likely to take wing from your fundament.

Re:The main flaw of modern computer science.

[Anonymous Coward]

I have always wondered how my CS education would have altered if the major had been approached with a more thorough grounding in mathematics before doing any coding at all. Or, perhaps using a language that forced one to approach coding as a mathematical problem.

I now work for the same university I took my CS courses at. Its curriculum is very weak, in my opinion. It has been weakened by politics and in-fighting for years, and any good faculty that came through did not stay for very long, and the turkeys have roosted (so to speak). Now professors try to satisfy the latest buzzwords and think they can pick things up as they go along. They think because they have PhD's they can still remain relevant and effectively teach computer science by wrapping themselves in the current fads (Oh, you taught OOP in Smalltalk, better jump into Java now, even though you know squat about Java).

Now, with my 20/20 hindsight ;-) I think a much better approach for undergraduate computer science would be an immersion in matematics -- especially discrete mathematics, probability, statistics, calculus, linear algebra, etc -- for the first two years and only then start to compute and use a language that enforces rigid coding rules and helps to prevent sloppy coding. Then a strong base in algorithms.

Once you have that strong mathematical base it should be relatively trivial to add on the layers of computer language structure and directly applying this all of this base knowledge to problem solving using the tools of computer science!

One of my deepest regrets of my college years is that I was sure I knew everything, and knew what was best for my CS education: Learn C! Learn TCP/IP! Learn programming for GUI environments! Hells bells. I spent the following eight years trying to unlearn bad habits and learn the proper way to solve problems. Things that should have been built into my CS curriculum, rather than trying to make the students happy (C!) and give them real-world skills. Well, my C skills opened some doors, perhaps, but my job would have been much easier if I had been better prepared to solve complex problems first. Very luckily for me, none of my work revolved around any life-or-death scenarios or applications.

I really wish the approach they had for Ars Digita University had been known and (more importantly) accepted by my CS department when I was going for my undergraduate degree. I think I would be much more effective today.

Basically, learn the fundamentals fundamentally and well. Then try the fancy stuff.

Re:The main flaw of modern computer science.

[Anonymous Coward]

He's a troll. Probably a PhysicsGenius clone. The problem is that most of the people moderating the comments are so fucking stupid that they don't recognize pseudointellectualism when they see it. They read through his bullshit comment about computer science students feeling stupid and inferior compared to math students (which is in itself so laughably incorrect it should have stood out to them immediately), and off they go. Hey, he used big words..must be worth +5 Interesting!

Re:The main flaw of modern computer science.

[caluml]

If you don't like it, get an account, make some insightful/funny comments, get modded up, get some mod points, and mod as you see fit.
Damn whinging ACs.

Re:The main flaw of modern computer science.

[Beryllium Sphere(tm)]

I've never worked in an environment where the specifications and the infrastructure stayed constant long enough to finish a proof of correctness.

I've never worked in an environment where I was coding on top of something that was already proven correct.

I've never worked in an environment where the specification itself was proven correct. For example, the dive computer problem was that somebody didn't specify that the computer should count time at the surface as 79% nitrogen.

As a security geek, I'd be delighted to see perfectly correct code. There have been plenty of attempts to devise formal models of security, e.g. Bell-LaPadula and Clark-Wilson. Apply those all you want, but in real life zlib will have a buffer overflow, and the minimum-wage operator who needs a new refrigerator will sell information to the nice private detective.

Re:The main flaw of modern computer science.

[Anonymous Coward]

Okay..so let me get this straight, troll. (By the way, all you glue snorting moderators take a look at his posting history)

Computer science are studying under a flawed discipline, and think they're inferior to mathematician's..who, according to you, are also studying a flawed discipline.

Oh, and for you wonderful moderators out there who will probably troll -me- rather than the real troll with an account, let's see some of the other fun and exciting things this twit has been contributing:

Capitalism is responsible for dangerous Asian microwaves - http://slashdot.org/comments.pl?sid=60075&cid=5687 975

Don't watch evil anime - http://slashdot.org/comments.pl?sid=62599&cid=5847 630

Aristoteles and Platon - http://slashdot.org/comments.pl?sid=59832&cid=5674 634
(The above one is my personal favourite, because it illustrates that in his long career of trolling and pretending to be intelligent, he still hasn't learned the names of the fucking philosophers)

Bush should outlaw Star Wars - http://slashdot.org/comments.pl?sid=62129&cid=5818 386
(Interesting, if only to illustrate the fact that he's either insane, incredibly childish, or both)

Extinction isn't funny - http://slashdot.org/comments.pl?sid=64096&cid=5948 785
(This one's rather neat because he uses made-up words like phear and moralic, and flips out because of a distasteful joke..you couldn't cut through the irony with a chainsaw)

DirectFB rules - http://slashdot.org/comments.pl?sid=62675&cid=5852 088
(Basically just attacking X users, but if you read carefully, a keen eye might just be able to notice that even here, he has NO FUCKING CLUE WHAT HE'S TALKING ABOUT)

There. Did your work for you moderators, bunch of lazy fucks. Thanks for giving him enough karma points to continue on in the same way he always has.

Re:The main flaw of modern computer science.

[jvollmer]

as code nerds, computer scientists tend to despise >most mathematical approaches as "too academic" or >"imfeasible".

Mensa member, beware of the high IQ

A Mensa member who uses the term "imfeasible."
That's wonderful!

English major, beware of corrections

Re:The main flaw of modern computer science.

[g4dget]

It means that mapping induced by the program in the trajectory space doesn't agree with mapping induced by the specification.

You apparently aren't just a poor computer scientist, you are also an uneducated mathematician. Mathematicians understand that automated decision making does not reduce to proving the equivalence between a specification and a program. Decision making involves knowledge, uncertainty, validation, and many other factors. The people working on that in CS don't have all the answers, but they know a lot more than you apparently do.

Re:The main flaw of modern computer science.

[10am-bedtime]

you have a point (approaches congruent w/ mathematical rigor would help improve the software development process) although your presentation draws flames. next time, try to synthesize the half-steps taken by well-meaning but perhaps less incisive practioners instead of discarding them. for example, many of the extreme programming practices do indeed aim to close the mapping gap; you could have actually highlighted those efforts to shore your point.

enough of logos, how about pathos: using the word "sad" raises activation energy for acceptance of your point. perhaps it is a happy circumstance that so many people still have in front of them that "a ha!" moment when their brain flips from prescriptive to descriptive, imperative to functional, unordered to orderd, global to re-entrant. only when the knowing make fun of the ignorant can the situation be called "sad".

as for ethos: it is proper to expose this point at this time. no complaints from me in this respect. good luck next post.

Re:The main flaw of modern computer science.

[EvilTwinSkippy]

Where does a CS analysis take into affect human stupidity? How about freakish system failures, electrical surges, or those three-witches patterns of events that completely exceed the bounds of every parameter you have ever dreamed of?

I'll give you one hint: it doesn't, it hasn't, and it won't. Computer Science assumes that you can control all of the inputs. Having worked with real people in industry under real circumstances, I can tell you that all specifications dissolve on contact with the customer.

QED

Re:The main flaw of modern computer science.

[ratfynk]

Yes you lucky bum. Sounds like you are learning about real programming at a real college. Not .Net .processor bullshit.
Most cowboys that can hack out a Vis Basic exe,
and add flash to a web page think they are computer experts. Give em shit!

Re:The main flaw of modern computer science.

[DickBreath]

How about you just suck my dick and we'll call it even?

Sounds good to me.

Healthcare Software

[Anonymous Coward]

I have dealth with Healthcare Software for Pharmacy and Lab systems where a delay or missed processing of an order can be fatal to a patient. One thing I found before leaving that industry was that there was a massive migration of these systems from reliable-high uptime servers (VMS, Unix, Mainframe) to Windows client server enviroment. If you think that the Klez virus is bad in a regular office, try working in an enviroment where it brings down a server critical to patient care.

Re:Healthcare Software

[Vej]

You're saying that these computers were networked to a system that could be infected with a simple virus?

Seems that the problem isn't always the choice of machine but the choice of setup.

Re:Healthcare Software

[easychord]

I have worked on a similar system about 5 years ago.

I was more worried about bugs in the app, 4gl on Solaris, than server uptime. Saying that, when those solaris boxes went wrong they went wrong in a big way. Seemed to me that they caused more stress than Windows 2000, even though they had more uptime.

Guess the same would be true with Visual Basic and Microsoft SQL server, but the complexity and chances to mess up would be worse. I would be even more worried writing an X app in java with an open source RDMS..

Re:Healthcare Software

[DShard]

The same people you hate making IT decisions in your neck of the woods are making them in the healthcare industry, they are just a lot more liable.

Re:Healthcare Software

[Anonymous Coward]

Unfortunatly, it seems that "shares" are an MSCE's best friend. So yes it was easy to have an administration person, who opens all outside e-mail attachments, have a share to a report server which in turn is connected to a critical app feeding the report server (let the fun begin!!.)

Exposure.

[Renraku]

Exposure is a good fictional title about a certain floating-point bug in a mainstream CPU by a popular fictional chip maker. Doesn't matter if the software is perfect if the hardware isn't.

Parent is a GOATSE.CX link.

[Anonymous Coward]

Parent is a GOATSE.CX link. 'nuff said.

Ethics Lectures

[Poofat]

I've always wondered why the Engineers had to sit through the ethics lectures, and the Comp Sci people didn't. In this day and age, we are relying on automated systems and programs enough so that the people making them should be aware of the consequences of failure.

Re:Ethics Lectures

[iamhassi]

wrong. CS people have to sit through Ethics lectures too. In fact that's the first required class.

Re:Ethics Lectures

[Anonymous Coward]

What? I had to sit through ethics lectures when I took Comp Sci at Waterloo University in Ontario, Canada.
Maybe it's just the country... They take ethics pretty seriously up there.

Re:Ethics Lectures

[Anonymous Coward]

I can guarantee you, that in the early '90's, this dive computer was designed, build, and coded by engineers.

Re:Ethics Lectures

[smallpaul]

Do you really think that ethics can be taught in a lecture?

Re:Ethics Lectures

[Anonymous Coward]

My school has had CS ethics classes required from since the department was founded (about 35 years ago). I know that all other schools in my state generally have it as a requirement too. Where the hell did you go to school?

Re:Ethics Lectures

[Poofat]

Do you really think that ethics can be taught in a lecture?

Of course not, but it does help to show people that in reality, their mistakes can mean alot more than a few points deducted from a project.

Where I go to school, Comp Sci ethics classes/lectures are not required. This is not to say that they do not exist, but these things are compulsory in Engineering schools.

Re:Ethics Lectures

[Anonymous Coward]

Then your school is sub-par.

Re:Ethics Lectures

[smallpaul]

Of course not, but it does help to show people that in reality, their mistakes can mean alot more than a few points deducted from a project.

Think about what you are saying for a second. These guys are professional programmers, probably trained as engineers (after all these dive computers are hardware) but maybe not. They are working on software literally designed to save people's lives. And you think that they didn't know that "their mistakes can mean alot more than a few points deducted from a project?" We don't know a lot about the circumstances under which this code was created but I'm pretty damn confident that a few months of "ethics training" in university wouldn't have made a whit of difference.

To show the uselessness of ethics training: most politicians are lawyers and most lawyers will have taken ethics courses in college. Does this imply that most politicians are ethical? Or do you think that maybe your own personal moral fibre and the environment you work in is more important? Think about all of the ethically-trained engineers involved in chemical dumping and safety cover-ups!

Re:Ethics Lectures

[Anonymous Coward]

Maybe at YOUR school but not mine.

Re:Ethics Lectures

[philovivero]

It was just your school. The University of Kansas (eg) required CS majors to sit through an ethics course.

Re:Ethics Lectures

[Nanoda]

I dunno what institution of higher learning you went to, but mine has a "Computing Ethics" course as a requirement for CS.

It covers various ethical dilemmas (as I imagine Engineers do), and as someone else mentioned, goes over some of the more disastrous software creations. If you're interested, such lists usually include the Therac 25 (rollover bug, improper software re-use), the London Ambulance Service (Their newly-ordered, lowest-bidder Computer Aided Dispatch system caused massive problems), and the Ariane 5 rocket (overflow/improper error handling).

OTOH, I agree with you that people should know the conseqences (and likelyhood) of failure, as they clearly don't. There are loads examples on RISKS of people having laser surgery, needing some computerized medical device, and seeing gross examples that those using them have literally no idea the devices are misconfigured, warning of possible malfuctions, etc.

Re:Ethics Lectures

[Senjutsu]

I dunno what institution of higher learning you went to, but mine has a "Computing Ethics" course as a requirement for CS.

No, it isn't. I know what school I'm going to (it's the same as yours), and CMPUT 300 is not a requirement for a CS degree. It is only a requirement of the Specialization - Software Quality option. It is optional for all other programs, include Honours Comp. Sci.

Re:Ethics Lectures

[dtfinch]

I'm currently taking a class called "computer ethics and legal issues". It actually counts as a philosophy credit rather than a CS credit, and it's not required, but many of us take it anyway. The class involves two 10 page essays and the rest is lectures from two CS professors and a philosophy professor.

The philosophy professor in that class recently told us a joke: "What's the difference between IT professionals and lawyers? Lawyers have ethics." By this he meant that lawyers must take an oath to follow a certain code of conduct while IT professionals as a whole have no such requirement.

It's only a matter of time...

[craenor]

Until one of the software packages that controls the new-ish electronic traction, suspension and stabilization systems bugs out killing a family of 6 in their SUV.

The sad part is that for an error like this, multiple people will have to die or risk death before anyone will clue into what the error could be.

Re:It's only a matter of time...

[Anonymous Coward]

Don't be silly. How often do you see those gas-guzzling SUVs driving along with more than just the driver? Almost never. Your figure of 6 dead is an exaggeration.

Re:It's only a matter of time...

[Anonymous Coward]

The sad part is that for an error like this, multiple people will have to die or risk death before anyone will clue into what the error could be.

It seems more likely that isolating the cause of an accident to an electronic stabilization system wouldn't happen; it would be assumed that the driver just "lost control."

Re:It's only a matter of time...

[Anonymous Coward]

he didnt say hte six dead would be in the SUV...

Re:It's only a matter of time...

[Anonymous Coward]

The sad part is that for an error like this, multiple people will have to die or risk death before anyone will clue into what the error could be.

If they're all fucking assholes in their Navigators, Excursions, Escalades, X5s, M-class Mercedes, and Hummers (ESPECIALLY Hummers), there's nothing sad about it in the least.

In fact, these things should be encouraged-- all "critical software" development for "luxury" SUVs should be farmed out to Microsoft.

Re:It's only a matter of time...

[JJahn]

Well I hate to be cynical, but plenty of people die today on the roads with humans driving. A few more dying because of a software failure is bad but no worse than any other accident.

Shit happens afterall.

Re:It's only a matter of time...

[Anonymous Coward]

It's already happened I'm sure. There are SUV accidents every single day. However, like someone said, 6 killed insied the SUV ould be very rare and extreme; I've NEVER seen 6 people inside an SUV, not even in commercials.

tiny little blue screens of death!

[Anonymous Coward]

tiny little blue screens of death!

Missing Dive Equipment: A HyperIntelligent Dolphin

[Nova Express]

Of course they died, because they were missing the single most important piece of dive safety equipment: A hyperintelligent dolphin with miraculous capabilities of interspecies communication.

Flipper: Ennnhhhhhh! Ennnhhhhhh! (backs up)

Diver: What's that Flipper? There's a software bug in my wrist diving computer that could lead to my grisly death?

Flipper: Ennnhhhhhh! Ennnhhhhhh! (backs up)

Diver: Well thank God you told me! Otherwise I never would have known!

Flipper: Ennnhhhhhh! Ennnhhhhhh! (back up)

Diver: What? There's a Russian sub off the coast?

In short, never go diving without your near-omniscient dolphin.

the BMW on board computer runs windows

[the_2nd_coming]

I have not heard of any fatal problems but a S. Korean Official was locked into his car for 3 hours before finaly smashing the window to get out when the computer crashed .

Re:the BMW on board computer runs windows

[Anonymous Coward]

If you knew anything about BMWs, you'd probably know that the locks are not controlled by the computer and can ALWAYS be mechanically operated. Dumbass.

Re:the BMW on board computer runs windows

[Dirk Pitt]

Really? I guess cnet got the story wrong, then? They had to smash the windows with a sledgehammer to get him out, the doors would not unlock. But I guess you know everything about BMWs, smart guy.

BTW, moderators who modded down the original post, doesn't this qualify as "When Bad Software Kills"?

Re:the BMW on board computer runs windows

[Anonymous Coward]

Yes, but the BMW 5-series he was driving wasn't the one that runs Windows CE. That's the 7-series.

Re:the BMW on board computer runs windows

[MattCohn.com]

It's the first paragraph!!! THE FIRST PARAGRAPH!!!!

BMW has told CNETAsia that an electronic fault caused the problem, rather than a system crash of the car's Windows-based central computer, as other reports have speculated.

THE FIRST FUCKING PARAGRAPH!!!

Re:the BMW on board computer runs windows

[Dirk Pitt]

*Ahem*. The guy in the above post said that all BMWs could be unlocked manually. I disagreed. That's what I was responding to -- asshat.

As for your own blathering, two braincell point --
I suppose you're going to take anything BMW's PR people say as gospel? Prick.

Re:the BMW on board computer runs windows

[MattCohn.com]

I assumed you disagreed with the first part:


If you knew anything about BMWs, you'd probably know that the locks are not controlled by the computer


I see now that I was wrong, my appologies.

Not Good Enough!

[czion3]

Even a voluntary recall is not good enough. I'm sure not every scuba diver reads the San Francisco Chronicle to get this information. Money should be spent advertising the recall if there is no better way to get the word out.

Re:Not Good Enough!

[Anonymous Coward]

Money should be spent advertising the recall if there is no better way to get the word out.

Do you mean to say that not everyone reads slashdot?

Diving and Corporate Responsibility

[fdiskne1]

When I dive, I plan with a conservative dive table. Why risk your life just so you can stay underwater for another few minutes?

Corporations, by their very nature, don't care about their customers. All they care about is profits. Granted, some people within coporations may care about customers, but they have to follow the corporate rules.

Leeman and Ruchti (the founders of the company) ought to be thrown in jail for a long time and the company liquidated. All proceeds should be given to those harmed by their actions. I don't care that the current owners "didn't know" about the problems. It should serve as an incentive for future people/corporations that you will be held responsible for what your company does.

Re:Diving and Corporate Responsibility

[Tri]

If you got decompression sickness using a dive table, would you advocate that those responsible for making them should be thrown in jail too?

Dive tables are a mathematical model, just as computers are. They measure what you probably have in your body, but do not guarantee that you will not get bent. Every time you dive, you're taking a risk, and there is a possibility you will get bent.

Re:Diving and Corporate Responsibility

[fdiskne1]

True. Every time you dive you take a risk. I understand that and that's why I follow the tables conservatively. I could still get bent, but I'm willing to take that risk.

I would not advocate those making the tables be thrown in jail unless it had been proven that their tables were inaccurate and they covered up the problem. That's what happened in the case of these dive computers. When the problem with their computers was presented to them, they fired those wanting to fix the problem. They recklessly endangered people's lives and many people were injured because of their intentional actions. That's why they should be in jail.

Re:Diving and Corporate Responsibility

[EvilTwinSkippy]

Every time you dive, you're taking a risk, and there is a possibility you will get bent.

Amen to that. Diving is not safe. It is a sport and an art.

If you read the article, we are talking about less than 400 units. And we aren't even talking about consumer grade stuff, this was for Nitrox. I know nitrox divers. I also know that every stinking one of them trusts nobody's calculations but their own.

Perhaps the fear of untimely death and/or dismemberment will teach people that this is not about strapping equipment to your back and going "toodallyooo." It's a careful, calculated risk. An no one, not a computer, not a dive instructor, not yourself will ever gaurentee that you will survive the experience.

This is almost as funny as people expecting to survive with those goofy pony bottles. Some dive boats treat them like seat belts. (Grr.) Assuming that they work (anyone every really tested one?) you have a puff or two of air at depth with which to arrive at the surface. That doesn't sound like a particularly controlled surface. All you end up with is an extra piece of equipment to snag on the wreck.

(Or being the scrawny person I am, completely throw of my center of boyancy.)

Mandatory Open Source for life endangering apps

[Crashmarik]

I would have to say that the above is the best argument I have ever seen for open source software. If your life is on the line, if you may be damaged by software, then that software sourcecode should be forced to be open source. At the very least it would prevent weasly scumbags from thinking they could cover up their misdeeds, at best it might insure that companies would try and get the product right when peoples lives are at stake.

Blowing it all out of proportion!

[beyonddeath]

ok, I work at a dive shop in Toronto Canada, I am a certified rescue diver. No diver should _EVER_ rely strictly upon a dive computer, they should always have a backup depth and pressure gauge. Not only that but they should plan their dive using Naui or padi (or similar) dive tables and follow their plan. If at that point their computer thinks they can stay longer.. thats good but follow your plan anyway, better safe than sorry! The point is, get trained properly, and use ur brain not a computer to do the thinking.

Re:Blowing it all out of proportion!

[Warin]

Exactly!

I havent dived in 13 years, and when I was last active Dive computers were just coming into vogue for the well heeled diver. But it was drummed into us over and over again that computers can fail or give inaccurate results. So always plan using a table and stick to it.

A computer might be a nice accesory, but if your life can count on precision, double check everything with a table!

Re:Blowing it all out of proportion!

[Anonymous Coward]

A rescue diver named 'beyonddeath'...

Re:Blowing it all out of proportion!

[Anonymous Coward]

The sad thing is that computers are supposed to be precise at these things. The failure was something a 1st-year comp sci student would have been able to catch by drafting up a test plan. Uwatec failed to take into account something so commonplace and simple... The fact that divers breathe air when they surface, rather than wasting the nitrox in their tanks.

Re:Blowing it all out of proportion!

[garrett791]

The point of having a computer is that it maximizes bottom time by calculating air consumption continuously (calculus vs algebra, if you will). Thus, you'd expect to stay down longer than the tables would let you. I agree that it's better safe than sorry and probably a good idea to at least consult a dive table to find a ballpark figure, but there's no point in shelling out $200 for a computer if you're not going to reap any benefit.

FWIW, I'm also a certified rescue diver.

Re:Blowing it all out of proportion!

[Tri]

No it doesn't. A computer maximises bottom time, by calculating how much nitrogen is going in and out of different ``tissue groups'' in your body, and calculating how saturated those tissue groups are.

When you reach a certain level of saturation, the computer has calculated that if you take any more nitrogen in, you will not be able to outgas it safely in time, if you ascend at a normal speed, hence giving you a decompression stop.

The few computers that do use air consumption in their calculations, only use it to make the model more concervative when your air consumption is going up (ie, a sign of stress).

Re:Blowing it all out of proportion!

[aaarrrgggh]

With repetitive diving, it is arguable that you are actually safer with a computer over the tables. With the type of diving mentioned in the article (reverse-profiling), you are definately better off (with a computer that compensates for that type of thing).

The product in question is an air-integrated computer. For people not familiar with diving, that means that your tank pressure, depth, time, and no-decompression limits are all coming from a single device.

There are real safety benefits with air-integrated computers-- divers can compare their no-decompression limits with their remaining air time, and look to optimize both parameters. Sadly, getting bent is less of a concern for most divers than running out of air.

I personally dive with an air-integrated computer (Suunto Cobra). My backup device is Stinger (wristwatch dive computer)-- I used to have a Citizen bottom-timer-- depth and dive time integrated. I worked as a divemaster for a couple years.

The logic here is that you need to abort a dive immediately if your computer fails, but if you still know depth and time, you can fudge your way through things when you are working. Not pretty, but it can at least get you through a dive.

Everybody has their opinion, and it all comes down to risk. I personally make my computer more conservative, and push that limit, so I know I have some kind of safety factor. (Actually, one computer is set conservatively, and the other normal-- so I can actually tell where I stand with my buffer.)

Re:Blowing it all out of proportion!

[EvilTwinSkippy]

Amen brother. Anyone relying on a machine to tell them they are pushing the limit is asking for trouble. Gift wrapped trouble, in double boxes wrapped in gauze with slight perfume scent.

People, there is a difference between accuracy an precesion. Yes, the computer can measure information far more precisely than the tables. That doesn't really make the answer any more accurate. Besides, where in the computer's calculations does it take into account death or debiliation?

Why not use a computer that understands life, death, and that people back on the shore will miss you terribly if something goes wrong. That computer is your brain.

Re:Blowing it all out of proportion!

[cfulmer]

Ok, so I'm a diving professional. Apart from what I've read, I don't know the exact details of the case. However, this definately seems to be one of those cases where they were all at fault.

The physics of what diving does to your body is not yet fully understood. Sure, we have models that tell you what your body should and should not be able to handle, but they're only approximations and their accuracy can vary widely by your body composition, your level of exhaustion, your level of hydration and so on. (Partying all night and drinking would be a very bad thing to do. Your computer doesn't count how many drinks you had or how late you stayed up.) Some of the factors are probably yet-to-be-discovered. To my knowledge, no computer yet even has a way of monitoring those variables, yet alone modeling them.

In any case, here are some mistakes that it appears the divers made:

1. Making increasingly deeper dives. This is exactly the opposite of what you're supposed to do -- taking your deepest dive first. By increasing the dive depth, you allow nitrogen to build up in your system. Their second dive (which they aborted) was likely shallower than their third dive.

2. Extremely short surface interval -- the surfacing to replace camera lights.

3. Flying merely 8 1/2 hours after diving. After (presumably) several consecutive days of diving, a full day would have been more appropriate.

What would have made more sense? I would have finished the second dive and just not taken pictures and would have waited an additional day between diving and flying. There's a lot to do in Miami that doesn't require going 100 ft under water.

If the software was bad and the company knew it but didn't do anything about it, then they deserve what they get. *BUT*, had the divers acted more reasonably, they'd still be diving today.

ABS Breaking Systems

[nurb432]

Don't forget about these little modules, that *most* of us in society today bet our safety on, putting our very lives in the hands of the developers. So many people just dont even realize they are there, or what they are doing.. zero clue..

Even if you drive an old vehicle that doesn't have these things, the guy next to you, or behind, in that huge SUV you probably does.

Airplanes too, its bad for one to fall out of the sky due to bad code...

Re:ABS Breaking Systems

[phillymjs]

I actually had a little trouble with an ABS system a few years back, on a '94 Pontiac Grand Am. The system failed in such a way that once in a while when I would apply the brakes, the pedal would sink all the way to the floor without doing anything to slow the vehicle... the brakes were just plain not there. I would immediately let up on the pedal and reapply the brakes, and then they would work.

Luckily, the first time this happened I was slowing from about 25mph to turn into a parking lot, with no other traffic around-- otherwise things might have been more, shall we say, interesting.

I was stunned when the service people told me that the failure of the ABS could take out the brakes entirely. One can just imagine the kind of lawsuit that could have been unleashed, had my brakes gone out at a truly inopportune time-- like if a little kid ran out in front of my car, or I were unable to stop at an intersection and ended up getting t-boned by a speeding 18-wheeler as a result.

~Philly

Re:ABS Breaking Systems

[ishmaelflood]

Hmmm. Are you sure that was a software failure? It sounds to me more like a hydraulic failure in the master cylinder, in which case you should have had at least one warning light and probably a very loud buzzer. The little zizz the pump gives when you 'key on' is a pressure check.

Even if the pump fails you would still have unassisted braking - the pedal would be rock solid.

There is no way the software can disable that mechanical circuit,on thinking about it. Sorry, you had a mechanical or hydraulic issue, not a control system problem.

Re:ABS Breaking Systems

[phillymjs]

Hmmm. Are you sure that was a software failure? It sounds to me more like a hydraulic failure in the master cylinder, in which case you should have had at least one warning light and probably a very loud buzzer.

Only going by what they told me. And there was never a buzzer or warning light indicating any kind of failure.

Even if the pump fails you would still have unassisted braking - the pedal would be rock solid.

That's what I thought until they told me otherwise. The first few years I owned that car, there were so many stupid things wrong with it that I didn't question that the failure of ABS had the potential to take out the whole system.

Re:Missing Dive Equipment: A HyperIntelligent Dolp

[Anonymous Coward]

Fuckin' dolphins - think they're it cos they can breathe underwater and go 'Ennnhhhhhh!'

Pfffffft......

I took Lassie diving once - did she help out? Did she hell....

Re:Use *your* brain,

[beyonddeath]

why waste my time... im passin engrish!

Abstract State Machines?

[Pizaz]

If i understand you correctly, I believe there are people, institutions working on this. Do a search for "abstract state machine" Should return a few links like...
http://research.microsoft.com/fse/asml/
http://www.eecs.umich.edu/gasm/

If at all possible don't rely on software...

[26199]

I imagine they teach all CS undergraduates about the THERAC-25, and how simple safety measures like hardware interlocks are much, much more reliable than software...

In this case, couldn't you check dive times against a book or something to make sure you're not completely off the mark?... what about something to measure nitrogen levels? Anything so you're not relying purely on software... (or, as someone has already suggested, you could use two completely different pieces of software).

Re:If at all possible don't rely on software...

[Anonymous Coward]

Here's a more in-depth paper. It's an absolutely chilling story.
http://sunnyday.mit.edu/therac-25.html

Re:If at all possible don't rely on software...

[EvilTwinSkippy]

Holy shit. All that code, and the only decided to install a foot-pedal AFTER 6 people died.

That was a chilling story. Party because I keep thinking of all the times I would tell users: no you are crazy, the software can't do that. It turns out that the way they were using it the software COULD do it.

Every system I now have verified by an independent expert: my wife. If there is any flaw in the system, she finds it. Every developer needs to marry a skeptic. Someone who uses the software in a manner completely unintended by the developer.

Cry on the testbench. Laugh in deployment.

MOD PARENT DOWN!

[Anonymous Coward]

He's not insightful, he's wrong. Ethics lectures are mandatory in Comp Sci.

Looks like the "padi dive tables" are your friend

[zakezuke]

I don't dive much, but I still have my padi dive table.

"For flying up to 8,000 feet after diving: Less then one hour TBT (Total bottom time) , wait 4 hours; less then 4 hours TBT, wait 12 hours." *PADI tive tables (C) 1983

[where TBT = RNT Residual nitrogen time) + Actual Bottom time ]

I dont have my padi manual onhand to estimate how long the folks were down as my table doesn't cover flight, only covers up to 24hours reccomended desaturation time, and doesn't cover this Nitrox stuff.

http://www.stud.ntnu.no/~playboy/diving/diving.h tm l

My old PADI book wouldn't cover Nitrox either, so if I were to use it, I would have no choice but to accept their information as fact, or buy new tables.

My favourite story about dangerous bugs...

[sopuli]

The story has been around for a while (core memory...), and I'm not sure whether it's an UL or not, but here goes:

Six or seven years ago, I worked with a fellow with the very British
name of Ken Appleby. He had a Spitfire, I had my '74 B, and we used
to motor out to Pickwick's Pub and throw darts after work on occasion.

Ken used to work for Lucas in the UK, specifically for a division
of Lucas that did military electronics. My favorite of his stories
was about the time he had been working on a computer-controlled
torpedo. It used magnetic core memory to store the programs, which
had the advantage of being very non-volatile as well as not susceptible
to EMP discharge.

So Ken got to ride on the boat for the first test of the torpedo that
used the computer with his program in it. Somewhere out in the North
Sea, on an R. N. cutter, Ken and his crew launched the first ever run
of this new weapon, and Ken learned a new respect for debugging...

The program was supposed to make the torpedo shoot off the boat, dive
to a depth at which it couldn't be easily detected, then circle
toward the target, climb to striking depth, and hit the target. There
were on-board sensors to detect sea level, and the torpedo was supposed
to travel at a preset distance below sea level, with constant feedback
keeping it on track.

Somehow, somewhere, Ken had multiplied one of the 3D coordinates by
a negative number, and this error soon propagated through the
transformation matrix (the mathematical construct that models 3D
space), with predictable results.

Within instants of hitting the water, the torpedo -- instead of
sinking out of visible range -- blasted up and out from the water in
a great silver fountain, then continued skipping across the surface of
the blue like some sort of deranged wingless flying fish. Worse yet,
instead of circling toward the target, it circled all right, but began
to return to the ship that launched it. Fortunately it was not armed,
but they still detonated the self-destruct on it rather than let it
slice through their ship at 50 knots or whatever rate it travelled.
Because of the non-volatile core memory, Ken was able to debug the
program from what the Royal Navy frogmen could recover from it, and
he fixed the problem for Rev 2.0.

But I must admit that the image of the torpedo, splashing happily
above the surface of the water like an aroused porpoise, is one that
returns to me in idle moments such this. What else would a Lucas
torpedo do but try to fly?

Re:My favourite story about dangerous bugs...

[Renraku]

I remember a terrible bug with some microwaves from 'back in the day'. They had the usual 'convenience' panel with the usual numbers and the usual preset timers for different meals. However, this one upon selecting 'chicken', would not only set the timer for 65535 seconds, but wouldn't shut off if the door was opened. I know these units were recalled, but I always press 'cancel' before opening the door, just because of this story.

Re:My favourite story about dangerous bugs...

[The Monster]

terrible bug with some microwaves . . . wouldn't shut off if the door was opened.

It is to prevent exactly this sort of nonsense that every Microwave I've ever seen the inside of (nice to have the schematic glued inside the case) has either three or four (this more on commercial models) redundant 'interlock' switches that prevent the unit from generating radiation with the door open. The first 2/3 switches are 'normally open' but held closed by the spring that engages the door latch. The last switch is 'normally closed' but held open by the door being shut, and is designed to short the current that would normally flow through the MW emitter straight to neutral, blowing the fuse if the other switches fail to disengage the current between the time the latch is disengaged and the door actually starts to open.

Re:My favourite story about dangerous bugs...

[Renraku]

Yeah, most microwaves like to have some kind of safety switch, however, this was one that didn't. It was 'hush-hush' in the late 80's..

Re:My favourite story about dangerous bugs...

[Anonymous Coward]

Of course, you need to be intimately familiar with "The Prince of Darkness," Lucas, to get the punchline...

-A 1980 MGB driver

Re:My favourite story about dangerous bugs...

[green1]

our old microwave went one step better, not only did it have multiple interlocks (I can't remember how many... but there were a few in there when I disected it after it died) but it also had a lock on the door making it impossible to open the door while the microwave was in operation, somehow I always trusted that a whole lot more than the solution of the microwave turning off when you open the door...

of course that was, in the end, one of the downfalls of that particular unit as it started to die, some bug in the system developed such that every so often it wouldn't stop cooking at the end of the cooking time, and pressing stop wouldn't stop it either, and as it had locked the door for safety, you couldn't open the door to turn it off either, only way to stop it when that happened was to either run down to the basement and hit the circuit-breaker, or heave the monster off the shelf (with the food still inside, usually something like soup if you had to do this) and unplug it.

Re:My favourite story about dangerous bugs...

[slamb]

of course that was, in the end, one of the downfalls of that particular unit as it started to die, some bug in the system developed such that every so often it wouldn't stop cooking at the end of the cooking time, and pressing stop wouldn't stop it either, and as it had locked the door for safety, you couldn't open the door to turn it off either, only way to stop it when that happened was to either run down to the basement and hit the circuit-breaker, or heave the monster off the shelf (with the food still inside, usually something like soup if you had to do this) and unplug it.

No, that's not one of the downfalls of the unit. Your story demonstrates exactly why that final safeguard was necessary. It caused what would otherwise have been a huge safety hazard to instead be an annoyance. Would the other approach (something that hopefully switches off the magnetron instead of preventing the door from opening) have worked? Maybe, but you don't know that, and it's good that you don't.

Re:My favourite story about dangerous bugs...

[Anonymous Coward]

Hehe, that's not even good for an urban legend...

Re:My favourite story about dangerous bugs...

[green1]

actually upon inspection of the unit we found out that the magnatron had shut down at the end of the cooking time, it was just that the fan kept going and the light stayed on and the door locked, leaving the appearance of it still cooking, (and an inability to get at the food)
looking at the simple ways the interlocks were built though I'm confident that they would have stopped the magnatron had the door been opened, the machine did however prevent us from testing that.

but yes, it did instill more confidence than the new microwaves.

Re:Looks like the "padi dive tables" are your frie

[CatPieMan]

They also by their own admitance did their deeper dive later. This also is quite contrary to all of the PADI stuff that I have been taught.

For anyone who doesn't know-- taking the deeper dive second tends to help you get the bends faster (it is similar to the reasons you always start off the night drinking the drink with the highest alcohol content).

There is also some recommendation about not doing more than 3 dives in one day without at least a 1 hour surface interval.

I have been using a Suuanto Stinger for about a year (this is the same one that the British Navy divers use). It has never let me down. But, I also never push it to the limits, nor have I ever done more than three dives in one 24-hour period.

-CPM

Mod parent up !!

[Anonymous Coward]

At Slashdot you have to be an anti-capitalist über-left cynical jaded moron to be here.

Scuba dive the right way

[Anonymous Coward]

I had a scuba instructor for my first certification, Di Dieter, who had experience diving with Coustou (hope I spelled that right), he also dove the Andrea Doria on several occasions, and basically has been around. I'm sure he's had thousands of dives, perhaps approching or even exceeding the ten thousand mark, under his belt (close to forty years of diving, multiple daily dives, several hundred dives a year, including a grueling dive schedule with Coustou, and he's a dive instructor). He's a no-nonsense guy with a good dose of common sense, and has little patience with screwups.

He did it right. He taught us to dive the navy dive tables, one up, one over, plus a safety margin. This was when the recreational tables had just come out. My friend and I dove for some years after that, and never had a problem. At that time, dive computers were out for a few years, and all the dive shops, through their "train with really expensive gear so you buy it" training programs had all their students diving with computers throughout their training.

Di Dieter did it right. He trained us with the old fashioned, and RELIABLE mechanical guages, waterproof clocks/watches, and tables on waterproof material. No computers.

While computers can extend dive times because you don't spend all your time at maximum depth, you also increase risk in doing so. Whether you decide to use the dive computers or not, you should ALSO have the mechanical pressure and depth guages, and manually calculate your dives.

Solely relying on a computer for diving is sheer stupidity and absolutely reckless. The minimal increase in bottom time is not worth the risk of an embolism, or the bends, which can be a debilitating condition for the rest of your life, or even fatal.

Do it right. Manually calculate your dive, and rely on your brain, not a computer, to stay safe and not risk your life. Bring that fancy computer with you if you want, but don't trust it over basic guages.

And Di, if you're reading this, this is the dude with the 43 lbs of lead on his weight belt! Hope you're still diving. And enjoying life. Peace.

Re:Scuba dive the right way

[Durindana]

Hmmm....

As another reply said, relying solely on a computer isn't proper training, period. That's the case with NAUI and, I expect, the other major groups, but it's hard to say to what extent standards might be relaxed in certain places.

But more originally, I feel obligated to point out something that's close to "stupidity and absolutely reckless": diving while weighing so much you require 43 pounds of weight to get underwater.

An average male in decent shape should require no more than 15 pounds, maybe 20 or 25, to get down, even in a full drysuit. Women have naturally higher body fat, but they still shouldn't need anything close to 40 pounds. Most rec divers should need much less, with a wetsuit.

You're pushing the boundaries of one of the biggest risk factors for getting bent: overweight. You were aware fat absorbs nitrogen faster than any other tissue compartment, right? There really is a significant percentage increase of N2 absorption by overweight people - enough to make relying on the tables questionable.

Hate to be a dick, and yes, I've dived with folks who wore two belts cause they couldn't fit all their lead bars/steel shot on one. But ignoring a significant risk factor just doesn't make sense. It's like diving while drinking, or diving with asthma - or relying on a computer and not checking against the tables.

Re:Scuba dive the right way

[JaredOfEuropa]

"While computers can extend dive times because you don't spend all your time at maximum depth, you also increase risk in doing so. Whether you decide to use the dive computers or not, you should ALSO have the mechanical pressure and depth guages, and manually calculate your dives.

Solely relying on a computer for diving is sheer stupidity and absolutely reckless. The minimal increase in bottom time is not worth the risk of an embolism, or the bends, which can be a debilitating condition for the rest of your life, or even fatal."

I disagree. Just like computers, mechanical gauges are subject to failure especially when not maintained properly (rental gear from a dodgy dive shop). Computers are not inherently more unsafe than tables: they use the same models and are usually more conservative than the dive tables. Using a computer is really just like taking the Wheel with you underwater and working out a multilevel dive profile as you go along.

The danger in diving does NOT come from relying on computers, but on pushing your limits. Whether you usually dive until the Remaining Bottom Time on your computer reaches 0, or usually plan dives using the tables to pressure group Z, you are diving to the absolute limits... and your risk will be greater in both cases. Remember that your personal limit may actually be lower than the tables or computer indicate, that is why dive organisations recommend you avoid the table or computer limits. I think you'll find that most cases of divers contracting the Bends were pushing their limits, using tables and/or computers. I have never heard of someone contracting the Bends by using only a computer to plan his dives, staying well within its limits. The case mentioned in the article was different: in this case it was a computer error, and from the sound of it these divers were pushing the limits anyway.

By the way: the dive tables suffer from some of the same problems as the computers: recently, PADI recalled a number of dive tables because of a misprint.

Re:Scuba dive the right way

[Anonymous Coward]

Jacques-Yves Cousteau

Re:Scuba dive the right way

[Anonymous Coward]

You're pushing the boundaries of one of the biggest risk factors for getting bent: overweight. You were aware fat absorbs nitrogen faster than any other tissue compartment, right? There really is a significant percentage increase of N2 absorption by overweight people - enough to make relying on the tables questionable.

I'll repeat it, although I've covered this in my parent post. My dive partner and I were taught good diving practices, and basic diving common sense by my instructor, Di Dieter. We were trained using Navy dive tables. But no one, not even him, as he instructed us, used the actual dive times set for a physically fit navy diver. One up, one over was what HE used, as a physically fit diver, for no decompression dives. He gaves us the basics, filled us with what experience he could during an open water certification course, during training dives, and during subsequent advanced courses. Everyone in those courses was given the tools to follow, and the dive "sense" to decide on the best safety practices to follow.

What did I, and my dive partner take away from this training? Yes, my weight was an issue with Di. But he gave me the tools to make the proper decisions in regards to safe dive times and practices. What was the result? My partner, who was in excellent physical condition enough to be considered equal in condition to a navy diver, and I would start our dive plan as a "one up, one over" baseline. Then depending on all of the variables and possible emergencies that we could possibly think of, we lowered dive times further. This resulted in shorter dives than anyone else on the dive boat every time. While I know this wasn't what my dive partner would have wanted, he never said a word, accepting the reduced bottom times without question. And as for the lead, increased surface area of a 1/4 inch wet suit is a large factor, as well as the weight. Big guy, big suit. During training, that $250 for the suit was a killer, but I had the other gear because someone loaned me the gear. So rather than cut the suit for a custom fit, we folded the legs and arms over, which added to the lead requirement because no material was subtracted, and you are aware of the floatation of a wet suit. I'm more practical now, and would cut the suit in a minute. But since I haven't dived in years, I have a dive suit with less than 50 dives on it, and it still has full length, uncut, arms and legs.

In addition to the bottom times, we always included a safety stop at 15 feet to the dive plan. And where possible and where safe (like a shore dive, slack water with lots of divers around including several rescue divers that knew us and we knew they were keeping an eye on us on a boat dive), we usually burned through the rest of our tanks at our safety stops. And on the boat dives that Di Dieter was on, he made sure to have extra tanks at the 15 foot depth, and deeper for deeper dives, which we would use for our safety stops, being sure not to burn to much air in case they were needed for emergencies.

Yeah, the divers in the article didn't follow good diving practices. Diving deeper later was one of the mistakes, among many. But where an equipment malfunction ends the dive short, do you blow your vacation? That's probably what led them to make an improper decision on making another dive, deeper. But I wonder if the result would have been different if they had made several safety stops at 15, 30, and possibly other levels, being sure to spend a sufficient amount of time at each stop. That's what I would have done, as I do on every dive, even though every dive is a no decompression dive.

The article didn't specify, but I'm sure it would have mentioned if a helicopter had taken them the 100 miles to the re/decompression chamber. They had symptoms that no one could mistake for anything but the bends, yet they drove? Didn't they have the DAN insurance for an airlift? Is that insurance still available? Why weren't they airlifted with a

Re:Scuba dive the right way

[Anonymous Coward]

By the way: the dive tables suffer from some of the same problems as the computers: recently, PADI recalled a number of dive tables because of a misprint.

I posted the parent post. And I have a response in to someone else. PADI may have recalled their dive tables, but as I stated and explained in the parent and another post, we didn't use PADI tables, but used actual Navy dive tables, and use reduced times for our own situation as explained in the other posts.

So I did brought my navy tables with me underwater. And I used the waterproof card on the surface as well for pre and post dive calculations. But one thing I didn't do is to rely on that card without checking it. I looked it up in the open water certification manual that I received for my training class, and confirmed that the numbers were the same. And then I looked them up in a dive periodical as well. So I checked two additional sources, and confirmed that the numbers matched completely and entirely for the entire table, before relying on it for my first training dive.

Had anyone who purchased a misprinted PADI table done the same, they would have found the error, and then did the necessary research or phone calls/letters to find out what numbers were/are correct.

So in my situation, even if I had received tables with a misprint, I would have known it prior to the dive. And in any event, I had two sets of everything from the beginning. Lights (actually more than two for evening/night dives), pencils, knives, tables, slate, strobes, more than two light sticks, etc. On boat dives, a spare net, snorkel, mask, booties, fins, straps, and more in one of my dive bags. The only thing that I can think of that I didn't have a spare or backup of was the reel with string on it used for cave diving, which I used on every dive. I did have spare string for it though.

So once again, a misprinted dive table would not have affected me. And today, with the internet, it's even easier to check the accuracy of the dive table card that you take on your dives. So there's even less excuse today than there was ten or fifteen years ago or more.

Uh, have you ever used Z?

[arevos]

Attacked by mathematical methods?! I've just spent another 4 hours revising Z, a horribly evil formal language designed to almost exactly the system you propose. Unfortunately, it doesn't work, at least not for the vast majority of software programmed.

I don't know about most other CS students, but the reason I despise mathematical formal proofs in computer is because they are infeasible, and, frankly, you're more likely to make a mistake with the math then you are with the code, once the project gets big enough.

Have you ever used formal methods such as Z to prove your software? Believe me, it's not something you'd do willingly. The only possible uses for mathematically proved software is with simple, but important code, like in an ATM, for example. Anything larger and it all falls apart.

My point is that mathematical methods aren't the answer. Even my lecturer on this subject, who co-wrote the language, would use such techniques on a large software project. You'd have to be insane.

Re:Uh, have you ever used Z?

[YoJ]

Actually, any sort of type system that is checked at compile time is a "formal method" that proves things about the program. In this case the properties are simple things like "no function is applied to the wrong number of arguments", or "no pointer is dereferenced that does not point to a valid object".

You might argue that this type of proof is in a different level entirely than using Z, but verification can happen in varying degrees. Even a Z specification might not talk about the hardware used to execute the program. Also, types can conceivably encode any mathematical property, it's just that existing languages have simple types.

The thing that is true is that manual proof systems for code are almost never used, even by the people who create them. Automatic proof systems are much more practical and have a real possibility of wide adoption. Think of it as making compilers smarter. I would love it if my compiler could look at a function I just wrote and give me an error like, "this function will not terminate if passed directed graphs with cycles, which might be produced as input in the following way..."

Re:Uh, have you ever used Z?

[Anonymous Coward]

Note: The attitude you demonstrate is exactly what the original poster was so trollishly complaining about. Z has been designed by very smart people to solve certain kinds of problems, and it has been used to solve real (if limited) practical problems. Try to grok the good points in their formal approach, without too much prejudice. In real-life projects, the use of formal methods can range from full-scale formal proofs of LIMITED ASPECTS of the projects, to rigorous thinking about the properties of the software and the specification. With practice, thinking about the formal properties of the objects you're working on becomes second nature and won't slow you down -- on the contrary, you'll get along a lot faster at the end.

Re:Uh, have you ever used Z?

[arevos]

I started off ambiguous to Z, but now I rather do dislike it. I can see it being used for systems like ATMs, pacemakers, and other important, but small, pieces of software. I'll even accept you could check some limited functionality of a large project with it.

But above a certain size it just falls apart, as all it does is add an extra layer in your product developement cycle, which means more room to make mistakes. For most software, I can't see the point of Z at all. Fortunately, I don't have to like it, just to do it. And so far on my courseworks I've performed pretty good :)

Besides, after 15 weeks studying this stuff, I think I deserve a little bitching time (don't even get me started on the rubbish known as Java :).

Re:Uh, have you ever used Z?

[arevos]

I have no objection to automatic formal systems! A smart compiler that could tell me whenever I screw up my code would be perfect. I just don't want to do it manually :)

RISKS in the modern world

[ColaMan]

If you're interested in the hazards of software in the real world check out the risks forum.
They take submissions from people about faults and errors in software (and related meatware) that put lives at risk.A weekly digest can be found here.

It's a good read, especially browsing through the archives. eg:

"A woman drowned during a flood when the elevator she was riding in incorrectly sensed a fire alarm and went to the ground floor which was underwater."

"Three people killed when a computer glitch caused a 16-inch pipeline to rupture, dumping 237,000 gallons of petrol."

and so on. Makes you a little paranoid. Now I know why indemnity insurance is so high these days.

Re:RISKS in the modern world

[Anonymous Coward]

Here's a slashdot on this very topic

http://ask.slashdot.org/article.pl?sid=02/10/26/ 22 23230&mode=thread

Re:SCAT

[Anonymous Coward]

No sir, I don't like it.

Too much corn.

I know it's a nasty joke...

[botzi]

yeah, well, I shouldn't say it, but I can't do nothing with being an idiot and all..........

Airplanes too, its bad for one to fall out of the sky due to bad code...

Uuuuuuuh, may be 11.09 was a bug??????;o)...........

Re:I know it's a nasty joke...

[Anonymous Coward]

wtf is 11.09?

Oh, 9/11?

fucking commie foreigner!

Re:I know it's a nasty joke...

[Anonymous Coward]

Which accident was flight 1109?

Re:Mandatory Open Source for life endangering apps

[The Bungi]

Please explain how this problem would have been averted by allowing the divers that use these devices to look at the embedded software.

Go on, enlighten some of us.

Re:Mandatory Open Source for life endangering apps

[subaquatique]

Someone mod the parent up, this is a very good point.
However, there is a lot of code in these types of critical systems that the companies are going to want to keep that way (competitive advantage etc.).
Could you force them to open up only the safety critical code?

Sometimes it IS lethal

[Anonymous Coward]

This has happened in the past:

Search Google for the Therac_25.

A series of interlocking problems in software and hardware damaged and outright killed one patient.

http://courses.cs.vt.edu/~cs3604/lib/Therac_25/T he rac_1.html

Re:Sometimes it IS lethal

[MattCohn.com]

I read that a while back during another slashdot article on bugs... and that is the scariest thing I have ever read, hands-down, period.

hmmm reminds me of a sun ad

[minus_273]

where the diver gets a blue screen on one of those :-p

Re:Scuba dive the right way, update

[Anonymous Coward]

Upon further reflection, I've changed my mind. Actually, it's a good idea to bring a dive computer with you. So if you take a bends hit, you can blame the computer and sue the company.

Should have thought of that before!

Re:no

[Anonymous Coward]

and pussies!

Re:Missing Dive Equipment: A HyperIntelligent Dolp

[Poeir]

Dolphins can't breathe underwater, they're mammals. They can just hold their breath for a very long time, like whales.

Responsability

[DeepBlueDiver]

Even if they were pros, the injured divers made a rookie mistake.

Diving is really, really wonderful and very safe if you follow proper security measures. But like in many other activities there are always some risks involved, and it is YOUR responsabiliy to do all you can to minimize this risks.

You never trust your computer alone, you always doble check with the tables, and you memorize the tables, just in case. Ok, calculations with Nitrox are more difficult than with air, but anyway after a while you should develop some mental aproximations to right values based on experience.

I mean, I would never accept a "5 hours to fly safely" time, after 3 dives in a row (RTFA). No matter what computer says it, I'll relax in the sun for at least 12 hours before even getting close to an airport.

On the other hand, Uwatec executives should be impaled on air tanks, and dragged to Bonaire, Cozumel, or any other location full of divers year round, where we can take turns torturing them for years before killing them and feeding their corpses to the sharks.

There were just less than 400 defective computers, this could have been solved quite easily.

Previous Slashdot on "Killer" software and Therac

[Anonymous Coward]

http://ask.slashdot.org/article.pl?sid=02/10/26/22 23230&mode=thread

Say it with me brutha:

[Have Blue]

When Software Attacks, Next On FOX!

A Little Common Sense

[Anonymous Coward]

Did they have to buy the Microsoft diving watch?

Or was it what ever one else was wearing?

PADI=Put Another Dollar In

[Anonymous Coward]

PADI covers "Enhanced Air" diving in yet another certification. That's why it isn't in the regular book. You may also pay for such gems of certification as "boat diver", "deep diver" and my personal favorite "altitude diver".

Put Another Dollar In training indeed.

Re:PADI=Put Another Dollar In

[Anonymous Coward]

...so, have you been to Koh Tao? All PADI really cares about is selling the certification cards...

Re:PADI=Put Another Dollar In

[zakezuke]

To be honest... I took my course in like 1985/1986 or so. I don't know how long consumer enhanced air have been around. The only form of enhanced air I was familar with was that helium mix used on trully deep sea dives

Re:PADI=Put Another Dollar In

[Colonel Blimp]

There are 2 nitrox classes under PADI, one is a short course for nitrox using a computer, and a much longer course (recommended) where you learn the hows and whys of nitrox and how to calculate using nitrox tables. Didn't make it to Koh Tao last time I was in Samui, the weather wasn't so hot, but I did Phuket last month. Love Thailand, amazing dives and I have some fantastic u/w photos from the trip.

Re:PADI=Put Another Dollar In

[aaarrrgggh]

Here, here on Thailand. Spent two years diving there (mostly east coast). Is that where the put another dollar in comes from? I know that's where I first heard it...

Re:PADI=Put Another Dollar In

[Colonel Blimp]

About a year and a half ago I did a liveaboard to the Similans and half the divers got food poisioning (including the divemaster). I went back last month, and redid the trip, but none of the same crew. Then I did a 3 tank dive and one of the DM's was on food poisioning boat, she remembered everything, its a small world. Thailand is heaven.

Re:Mandatory Open Source for life endangering apps

[Pete (big-pete)]

Please explain how this problem would have been averted by allowing the divers that use these devices to look at the embedded software.

Well I think that when the managers first raised the issue that there was a problem with the device it could have been checked and verified by a neutral party. Instead the company just said they were making up stories to drag the company down after they were fired...

If the problem could have been proven to exist then the company may have been forced to recall the product earlier, and less people would have needed to have their lives put at risk.

-- Pete.

How about...

[kkith]

some of these bugs.

asking for trouble

[g4dget]

Anybody who relies on a dive computer to avoid the bends is just asking for trouble. Dive computers are useful as an additional safety measure, but you should always calculate your dive profiles by hand. "Closely spaced dives" are particularly problematic and should either be avoided entirely, or you should include a big extra safety margin. Unless this guy did all that and kept meticulous dive logs, I think his lawsuit has no merit, even if the computer was completely broken.

Dive tables and dive computers are rough guides, but there are far too many variables to be able to make any guarantees.

Beyond that, "the bends" may cause all sort of really unpleasant permanent injuries, but, while they can be fatal, that is fairly unusual.

Safety engineering is holistic

[Beryllium Sphere(tm)]

Almost any piece of code could be safety critical. Bad UI could mislead people. Low-level sensor and chipset interface code could cause critical bugs by omission, if it failed to work around some stupid hardware bug. Every line of arithmetic would need to be checked for overflows and roundoff errors. Then you'd need to open-source the requirements and the design documents, because verification is not the same thing as validation. Seems unlikely that limited disclosure would make a big difference.

Just imagine

[SpacePunk]

How many people a beowulf cluster of these can kill!

Fight Club

[Kefabi]

Companies are out to make money.

Take the expected number of products that customers have that will fail and harm/kill someone, then multiply that by the average settlement. You end up with what your company can expect to pay from all the court cases from people dying with whatever product a company sells.

If this is cheaper than doing a recall, the company won't do a recall. Even when the company knows people will die from their shitty products

That's what Fight Club says, though I think most companies these days will do a recall anyway, in an effort to avoid bad PR as well.

Ford/Firestone didn't do too well by not doing a recall for a long time. Yeah, they might have expected to lose less money by not doing a recall, but the massive amout of bad PR that came around (people started noticing they were more likely to die on the things) ended up doing a lot worse damage to the bottom line than a recall.

Re:Fight Club

[Anonymous Coward]

"That's what Fight Club says..."

It's nice that you've unplugged your brain and rely on hollywood to tell you about the world...

MY brain is telling me not to talk to you anymore,so don't bother responding...

Simple Answer

[Anonymous Coward]

I learned from the RIAA and the MPAA, that any one who codes has no ethics. So you see your lectures would be useless.

Another fatality from software/hardware interface

[unfortunateson]

I would love to find some attribution to this, I believe I remember reading it in Computerworld in the mid-'80s:

A manufacturer of particle accelerators for treating cancers had a unit, that due to a software bug, would occasionally blow a fuse. It wasn't considered important enough to track down, since you could just reset the machine, and it'd be fine.

Until they upgraded the equipment for a higher power unit, with the same software. The radiation dose killed a patient.

This came up originally under the subject of software malpractice.

Therac 25

[TheToasterBoy]

Anybody remember ther Therac 25? It was a medical radiation machine, and killed a handful of people, due to a firmware bug...

Therac 25 Investigation

ToaterBoy

wellduh

[Anonymous Coward]

Welll duuuuh

your thinking of the therac

[Indy1]

do a google search for it......Lots of information out about it

heres one link i found super fast
http://courses.cs.vt.edu/~cs3604/lib/Therac_ 25/The rac_1.html

Re:Mandatory Open Source for life endangering apps

[ComputerSlicer23]

How about this, the software has to be held in escrow for the particular revision of the software I have. It has to build the binary I have, and this has to be verified by a third party.

When a lawsuit comes up, I file for the escrowed copy to be given to my lawyer under an NDA where upon they can have it examined by experts in the field of computer science and diving. The first person who figured out that the software might have had a bug, might have figured all this out.

That's a more viable solution to corporate nature. The only problem is that the process of escrowing it, means they are afraid a bug might exist, which creates an image problem. So it's not likely to happen, but more likely then open sourcing the software.

Having it as Open Source would have meant the bug could have been announced in public anonymously, and verified by people in the public. This is exactly the same as security via obscurity in encryption. You want security, not security by obscurity. It's mearly a matter of time until the obscurity becomes clear, and your data is now in the clear.

The problem here is that everyone who knew, was liable for a lawsuit for defamation and would have to defend themselves in a court of law. That's not very cheap. Putting out an e-mail, on a mailing lists, or thru the popular channels that divers use (magazines, flyers at the shops), would have been easy had the software been available to the public for examination.

I like open source and think it's great for the great software I get for essentially free. For specific applications however, the peer review and transparency are a wonderful thing. They can easily be accomplished without the GPL, or BSD licenses. Open source isn't a magic bullet, but I'll bet the manager resigning and announcing to the public that someone should peer review the software for a specific flaw, would have saved a lot of pain and suffering.

I'll bet word of a specific flaw that is provable by experts, that could explained to the divers so they can understand:

"The computer assumes when you come up for air, you are breathing the enriched oxygen, if you aren't the computer is wrong!"

I don't know dick about diving, but even I know about the bends and how bad it is, and what it does to you, and I'd understand the problem if somebody told me the above. I bet news like that would travel fast in diving circles. It might ruin the corporation, but it'd save lifes.

Open source isn't a magic bullet, but some transparency would have mitigated the number of people put at risk.

Kirby

Re:Mandatory Open Source for life endangering apps

[ocelotbob]

Read the story. The company denied there was a flaw. Were the code open, a third party without financial interest could be brought in to audit said code and say without a doubt that there was a flaw and that the code was unsafe.

I have...

[dunham]

My class project was specifying an X11 window manager in Z.

Z has it's place (and Lotos, which the class also covered), but I don't think it applies to general purpose programming.

Assuming that you have the tech to check if your program matches the spec, and the spec is somewhat consistent, you still don't know if your spec matches what you want - so you're back to the original problem but in a slightly different language.

I have, however, been quite impressed with what the compiler group at stanford has done. The system is not 100% perfect (e.g. false positives), but it's detected a lot of real errors in real software (linux and bsd kernels) without too much noise.

As for run-time checking, I'm particularly impressed with valgrind. Whenever I suspect that a C/C++ program is breaking because I did something stupid, I use valgrind to find the fault.

That said, I think using safer programming languages, with GC and either dynamic or static typed (per your religion) would greatly improve the quality of software.

Re:I have...

[arevos]

Z has it's place (and Lotos, which the class also covered), but I don't think it applies to general purpose programming.

*Mutters something about Z's place being in /dev/null* :)

True, I can see some uses for Z, which is more than my housemate will admit to. Though after this course, I will never, ever, ever touch that pseudo language ever again.

That link you gave certainly seemed very interesting. I'm probably doing my third-year project in C++, and I've done quite a bit of work in the language before. I remember one pointer error in some software I wrote that actually worked 100% of the time on my machine, but had sporadic performance on other people's. Actually, the code in question was completely fubarred, as I had started to change something, then forgotten about the half-finished code later on. It only worked because the pointer just happened to overflow onto the piece of memory that contained the right data.

Valgrind, as well, seems interested when I googled it. Actually, I'll probably use this for my project, if I find it's not too much trouble to set up. Any extra safety checks will only count in my favour, and buggy code is really quite annoying anyway.

That said, I think using safer programming languages, with GC and either dynamic or static typed (per your religion) would greatly improve the quality of software.

Agreed, I use Perl whenever I can these days, which can be quite neat and elegant if done. And then there's CPAN, which is another really big plus. Though if I were working in a group, I'd probably prefer Python :)

hmm

[Anonymous Coward]

makes me glad that i'm being cheap right now and still using dive tables and analog gauges...

Evil

[CptChipJew]

Corporations covering up stuff like this?

I guess this gives new meaning to the cliche "How low can they be?"

Re:Evil

[exspecto]

I believe the cliche you're going for is: "How low can they go?"

It's ok, I know english isn't your first language.

Comment removed

[account_deleted]

Comment removed based on user account deletion

Lucas weapons?!?

[Anonymous Coward]

I drive a 1970 MGB so I know all about Lucas electrics. Now you're telling me they did weapons too?!? Oh, good grief!

Re:Lucas weapons?!?

[titzandkunt]

Well they're bound to be dangerous to somebody.

T&K.

Re:Lucas weapons?!?

[Eevee]

The almost mandatory Lucas jokes:

Q: What are the three headlight setting on a Lucas -designed car?

A: Dim, flicker, and off.

Q: Why do the British drink warm beer?

A: Because Lucas made refrigerators too.

Q: Why didn't Lucas make televisions sets?

A: They couldn't figure out from where the oil should be leaking

Re:Lucas weapons?!?

[Anonymous Coward]

The leaking oil is a feature to counteract the rust injected at the factory during manufacture of all British cars.

Why just the engineers?

[Halo-]

In my experience, it is seldom the engineers who make the ethic calls. (Sure, about code reuse, etc...) In the engineers in this article actually did raise objections, but weren't listened to.

The simple truth is that management will decide what type of product is shipped. Great engineers with shitty management still equals trouble,

Re:Why just the engineers?

[HeyLaughingBoy]

The simple truth is that management will decide what type of product is shipped. Great engineers with shitty management still equals trouble,

And vice versa. An excellent mananger (yes, /. such things exist on this planet!) won't know the product is bad unless the engineers say so. Although in this particular case management was at fault, it's really dumb to assume all management is stupid. Most mgrs are actually fairly bright and can make intelligent decisions when engineers properly communicate product issues to them. Ultimately the product is the responsibility of the corporation not the individual. If you decide to not say something because historically no one paid any attention to you, then you have just become the weak link in the quality chain.

Re:Why just the engineers?

[Halo-]

Of course it is stupid to assume all managers are dumb. I have had the priviledge of working with some great ones.

The most telling remark I've ever heard from a senior management-type was "Well, development is a cost-center after all..." Meaning that we lost money that the sales team made. The idea that there would be nothing to sell without development and support seemed to have never crossed this guy's mind.

To me, the problem is that managers in the tech industry seldom have background in the skills they are managing. Their development teams are interchangable parts, and if a task is deemed too ambitious, the solution is simply to swap in a better part. Too often this "better" part is simply a team lead by an engineer without the good sense to stand up and protest.

If the customer asks for a faster car, redesigning the engine might make sense. If the customer asks for a car which get 1000 miles to the gallon and flies, no amount of redesign is gonna help.

I realize I've strayed a bit from the topic of simple defects being covered up, but I think there is a common thread...

Reminds me eerily of the Therac-25 incident

[Anonymous Coward]

We read a lengthy paper on this in a software engineering course. This equipment was responsible for delivering massive radiation doses and killing quite a few people. The biggest mistake that they made was removing the hardware interlocks and relying soley on software.

Operators that reported malfunctions would just keep hitting keys when the machine seemed to malfunction and were reported to say "it always does this" when an error message would appear.

I'd suggest that anyone interested in how not to engineer software for life critical applications read the (quite lengthy) paper.

Re:Mandatory Open Source for life endangering apps

[Anonymous Coward]

Commercial source escrow should be mandatory. Some sort of oversite agency would ensure compliance and safety of the source. The agency database of source code would be encrypted and released to the public every year. They keys would be released after 75 years or after copyright has expired. Or when something like this happens.

Same here.

[BoomerSooner]

When a software bug can kill, you've got to test, test, test, test, test, test, test, ....

Unfortunately my boss just want's it out the door! Lol, I guess when he's out of a job (me included), I can look back and say I told you so! (Not a good concilation prize by any stretch.)

It can happen to anyone

[Anonymous Coward]

Bug or no bug, pushing the limits when you dive can get bent... dive computers operate by constantly measuring your depth and time to tell you what ammount of nitrogen your body has absorbed. They are doing a calculation based on some research or formula that says at this depth and time 99.99% of people don't get bent. There is no way for the computer to know that you're 55 years old and have poor circulation or that you're seriously dehydrated because you were drinking the night before the dive.

Over the last few years, diving equiptment has become much more reliable and diver training standards have been seriouly reduced. People don't take seriously the consequences of diving deep for long periods of time. The guy in the article dismissed the diving he was doing by calling it 'baby-diving'... there is no such thing.

A few years ago, a buddy of mine and I were doing some deep diving (on Suunto Vypers). We were right at the limits of our computers (in fact mine kicked over into decompression mode). We both did the same basic dive profile, she got type II dcs (bad neurological symptoms) and I was perfectly fine. Fortunately we were able to get her to a recompression chamber and her symptoms were sucessfully treated, but it was very dicey for a while...

Anyways, my point is that bug or no bug in the software, you need to be responsible and understand the fundamentals behind diving, not just trust the number that the computer tells you.

-Dan

Dive computers = false sense of security

[Dolphinzilla]

In my experience as a diver for the last 15 years, I have seen many divers who rely on dive computer technology to get closer to the edge and get more bottom time, longer dives, deeper dives, etc. The original "paper" dive tables were based on the experience and testing by U.S Navy diver's and are VERY conservative. The advent of widespread use of dive tables for recreational diving resulted in diving being a lot safer. The advent of computerized tables has promoted a false sense of security to the diver (kind of like having a radar detector in car - you might avoid more tickets, but you may speed more also) - I myself have dove profiles I would never have attempted based on the dive tables but the computer "said" it was OK so we did it. Here is a story about a dive computer specifically designed to be used with mixed gas diving (nitrox) adding yet another element of risk over regular diving. I think that dive computers should come with a waiver that says "if you trust you life to this device you do so at your own risk". Based on what the story said I would never have gone flying so soon after diving using regular dive tables - they threw the dice and lost, and now they want to pretend that what they were doing was risk free and the dive computer caused all the problems - Its nice that the dive computer maker is recalling the units to make them more conservative. Too bad those divers didn't buy the "common sense" computer too.

Re:Dive computers = false sense of security

[miles_thatsme]

I think you've overstated things with your title. To be sure, these guys were pressing their luck. A nitrox dive, a bounce-dive (or sawtooth dive profile), flight shortly thereafter... But the question is not whether using tables are inherently safer than computers, but the same question factoring in how often people will profile their dives. I'm a divemaster and the frequency that I manually profiled dives and carefully logged each was poor before I got a computer. In my view the principle is the same in any discipline: learn your basic principles (long division) before you rely on gear to do it for you (calculator). If your electronic calculation is grossly out of whack, you will know it.

Re:Dive computers = false sense of security

[Asic Eng]

Well, the dive computer (assuming it works) will give a more accurate representation of the amount of nitrogen absorbed. So if you go to depth A remaining there for time T1 and then depth B with time T2 (dive 1) it will register that differently than staying at depth A for time T1+T2 (dive 2).

For the following I'm assuming here that A is deeper than B.

If you use the table for dive 2, you'd pretend it was dive 1. In this case you'd have a greater saftey margin.

However if you dive dive 1, your saftey margin would theoretically the T1+T2be the same, using both methods.

If you were to use a dive computer which provides a greater saftey margin, but based on your actual dive profile, your saftey margin for dive 1 could actually be greater.

Having said that, I admit that a dive where you spend only a part of the time at the max depth is a lot more likely. I think that dive computers will do a better job with a slow descent though (diving in groups can cause waiting time), so there might be another potential saftey advantage.

Re:Dive computers = false sense of security

[k98sven]

As a sidenote, I'd say that people generally give far too much credit to anything with a digital readout...
people belive that computers are infallible.. or at least very accurate.
(perhaps it's the fault of digital wristwatches, which do happen to be quite accurate for their size and cost)

Teaching physics, I often have to tell the students to use common sense instead of blindly trusting the meter.

For instance, in the lab we have digital slide calipers with no less than three(!) digits after the decimal point.
Obviously, the real precision is nowhere near one micrometer (just look at how a real micrometer is built and you'll see what I mean) but the students will nevertheless assume it has that precision unless you tell them otherwise.

Once, a group of students hadn't zeroed the caliper properly, and all their readings were off by 3 cm, an error which should've been obvious as the measured object was only 10 cm.
(The calipers also have an plain ruler-scale on it as well.)

It all just goes to show that fancy digital gadgets will almost always win over common sense.

By extension: Ford Pinto

[Kappelmeister]

This kind of story makes you want to stick your head in the sand and not buy any critical applications from corporations...Unfortunately, for some "leaders of industry," protecting image is more important than the safety of the users. Users are expendable; image is not.

So you're saying you're not going to ever drive a car again?

Computer applications aren't the only life-critical products we depend on. You put your life in the hands of corporations every minute of the day. How are you going to make sure your house is structurally sound? Buy open-source lumber and build it yourself? Are you going to keep eating food which has been prepared by corporations?

But as you, the Pinto history and others point out, corporations will only care about the lives of their consumers to the point at which it becomes economically favorable to do so. If it's cheaper to settle 10 probable death cases than issue a recall for the faulty product, they settle. The value of human life doesn't factor in. Today's cars only sell themselves on safety because it has become economical to do so, i.e., consumers value safety and demand it from their products.

This is why we need government oversight. I'll tell you what makes me want to put my head in the sand: how we are not funding the oversight agencies enough to do their job. We just passed two tremendous tax cuts in three years; I don't know where the cuts are going, but I feel like people take safe food and transportation for granted around here. I hope at least the sand is clean.

And how do you know the specification is corrrect?

[haverford]

All that mathematical methods allow you to do is prove that code satisfies a specification. Unfortunately, in most application domains, generating a rigorous specification is not significantly easier or less error-prone than just writing code.

I think it's very sad when CS people fail to notice this obvious fact.

Typo

[arevos]

Even my lecturer on this subject, who co-wrote the language, would use such techniques on a large software project.

Um, I mean: wouldn't use such techniques on a large software project.

Tables, Computers, and Estimation

[gasp]

Also as a certified diver (1994) I know that tissue nitrogen saturation is highly dependent on the individual and a multitude of complex factors. There are tables for very general estimations, which have to be very conservative to be useful at all to a diverse group of individuals diving in a variety of circumstances.

Dive computers allow the use of less conservative "tables" by applying the algorithms to sensor data. By applying actual depth/time/gas data to the algorithmic tables a diver can dive more agressive profiles, and also have the convenience of having the calculations automated in real time.

The 'no flying within 12 hours' and similar rules are simple conservative safeguards, and don't assume much at all about dive profiles. Also, it's not just a rule against flying, driving home via a route that elevates you a few thousand feet above your dive elevation can result in the same effects. (I live and dive at sea level, but I can't drive more than a few miles in any direction without significantly increasing my elevation.)

The alleged problem with the computer in question (if I understood the story correctly) is that the program assumed the diver continued breathing nitrox while surfaced between dives. That's a considerable problem, since it provides incorrect data. Even worse, it's an anti-conservative error.

Nitrox diving is an inherently more agressive attempt to increase dive profile limits. I am not personally a nitrox diver, but I understand the principles. I certainly don't want my computer to base it's calculations on an air mixture I'm not breathing between dives.

There is no rational excuse for knowingly allowing such an error to go unreported or fixed.

Re:Tables, Computers, and Estimation

[aaarrrgggh]

Technically, the computers aren't less conservative, they just calculate your no-deco time based on all tissue compartments, and don't make assumptions about repetitive dives like the table. The increased bottom time is more of a function of the exact depths.

The doppler-validated algorithms actually have considerably less bottom time than the PADI tables.

Re:Missing Dive Equipment: A HyperIntelligent Dolp

[Anonymous Coward]

In australia , we've got an animal that is just as intelligent as that dolphin. He's called "skippy" (the bush kangaroo)

Skippy can use radios, crack safes, mow down bad guys with machine guns..

Fully relying on a dive computer is stupid.

[ChrisKnight]

Yes, it is bad that this computer has a bug that can result in over-saturation of Nitrogen. But anyone who relies on their dive computer ONLY, and doesn't do a hand table, when 'diving aggressivly' is being a fool. Would you drive straight into a building becuase your GPS says it should be a road and you are just too stubborn in your reliance on computers to believe your eyes?

Dive computers are a convenience, but they shouldn't be a replacement for using your brain and planning safe dives.

One person in this thread mentioned the safties in their insulin pump. I'm willing to bet that they still own a glucose tester and a few spare syringes, because they aren't going to put their lives in the hands of one piece of hardware.

-Chris

Okay.

[mindstrm]

Yes companies should be responsible.

But these divers were being stupid.

I'm a novice diver, but the concepts are not hard to understand:

You don't fucking dive within 24 hours of taking an airplane ride.

You don't push the limits of your gear. Computers ESTIMATE the nitrogen in your blood; every person's metabolism is different, the exact same conditions can kill one person and have no effect on another.

DIVE TABLES. Many divers still use dive tables.. sure, your computer is great.. but you USE your dive tables, plan your dive, know roughly what you are going to do.

These guys pushed it, with dangerous consequences. Is the computer company at fault? Partly. But let's not forget these guys were doing unsafe stuff in the first place. The dive computer is a tool, not a God.

The article mentions "Nitrox lets you go where you can't normally go". That's BS. Nitrox is used so you can stay down LONGER, usually on shallower dives. This is compounded because Nitrox has a higher than normal oxygen content, and oxygen becomes toxic under pressure... so the depth of a nitrox dive is limited.

Let me guess....

[Anonymous Coward]

American company was it?

Narcosis, no`

[mindstrm]

Narcosis has nothing to do with dive tables... only with depth. The rough figure is 30 meters... I think narcosis at 20 meters is rare if not impossible. All you have to do if you experience narcosis is ascend to a depth where you realize that fish can breathe water, and you can't.

When you learn to dive, you usualy do a deep dive to a) show you what depth you start to experience narcosis and b) learn what it feels like, so you can recognize it when you are diving.

Re:Narcosis, no`

[lgftsa]

Neither do embolisms - both were examples of failures of the human body. Unfortunately, when I wrote and edited my message, I mixed up several points which are unrelated.

Oh well, c'est la vie.

Re:Narcosis, no`

[Tri]

Narcosis at 20m is certainly possible, it's just usually mild... It will probably not be strong enough to make you want to give your regulator to a fish, but your brain will not be working at full speed, and it will take you more work to do things which are simple at the surface.

In case anyone missed it

[mindstrm]

O2 enriched air == enriched air == nitrox == reduced nitrogen air (effectively).

The feature divers like is the reduced nitrogen, not the increased O2. You don't "breathe slower" or anyhting because of the extra O2.

So when a diver is at the surface, they generally breathe real air, not tank air, (to conserve tank air, and because it's more relaxing/takes less effort). This air counts towards your nitrogen level... if it is assumed you are still breathing nitrox between dives, the numbers will come out wrong, the error getting more severe the longer you are out. (Dive computers aern't used just for one dive, they are continuous... telling you when you can dive safely again, and for how long, at what depth, etc)

Just for the record

[mindstrm]

Current diving training STILL trains you to use tables, not computers. They specifically tell you that computers are a nice tool, and very useful, but that you MUST know how to do things the normal way. That means: Watch, pressure guage, and dive tables. Pencil & Slate.

What these divers did was NOT indicative of how diving schools train nowadays by any means.. they pushed it, doing many things that dive schools make a BIG point of discouraging.

Dive computer is a backup for me too

[John3]

I'm just a recreational diver as well, and I use my dive computer primarily as a record keeping device. It's an easy way to track my times and depths over two dives for later entry into my dive log. For dive time calculations, I use the tables. It's conservative, but I'd rather miss a few minutes of bottom time and be healthy than rely on the calculations in the computer.

It sounds to me like the market for these computers was agressive divers...people who were trying to push the limits of safe dive times. That means the company should have been even more vigilant of there calcuation methodology, especially considering the price those computers went for.

And as far as fly time, NAUI recommends 24 hours wait time after a dive before flying...extremely conservative, but one again I prefer to be safe (especially since it's a hobby!).

Re:Dive computer is a backup for me too

[Balp]

Using tabels or not I see as dependent of the dive place. In some areas it's rater easy to go down to the botton at one deep stay down there and then after wards acend to a safty stop and directly up getting something that is close to the nice square dives that the tabkles count after.

Most of my dives take a long time to decend along the botton to the dive depth. The computer take this into account, then we fiollow some kind of wall out at the deciede deep. Then we turn and coose a different deep back along the wall to end the dive slowly accedning along the bottom, getting a swimning security stop of four to five minits.

This type of dive sites wouldnt get long dive times using the PADI table. Having 13 minits when reaching 26 meters isn't that fun.

My conservative suunto (with extra conervative setting for the cold water give me arbout 5 minits more bottom time, thats a big differance. Then using this slow multilevel acents that are almost inpossible to plan with the wheel unless to have extreem good knowledge of the dive site. it's hard to do multilevel dives that way.)

I'm a scuba diver

[Daimaou]

I'm an avid scuba diver, but I have never been keen on using the dive computer for this very reason; rather I go for the manual method even though you supposedly cut your dive time down.

Having worked in software for many years, I have yet to see a perfect program, and I have never wanted to trust my life and/or health to the programming and testing skills of someone else.

Bad software can kill when......

[PS-SCUD]

It makes a Patriot missile battery not recognize you as friendly.

Re:Mandatory Open Source for life endangering apps

[The Bungi]

How about this, the software has to be held in escrow for the particular revision of the software I have.

You can escrow the source without making it available. I can't see how your example makes a point for open source.

Diving Computers vs. Dive Tables.

[fmaxwell]

Don't forget that, for years, the PADI dive tables were Navy Dive Tables. For a very good history of dive tables, click here. Dive tables are based on the same theories and technology as dive computers. The biggest difference is that they are more prone to human error than are dive computers.

It's great to say "plan your dive and dive your plan", but people are fallible. Your buddy may go a little deeper than he/she intended. You may, because of narcosis, get confused about the maximum time or depth. You or they might have problems that slightly delay your ascent. If you plan to go to 90 feet and you drop a video camera to the bottom at 110, unless you're Bill Gates, you're probably going to go get the camera and cut the dive short. So much for the plan. (I've been a diver for over fifteen years. I've seen everything from divers getting entangled in wrecks to outright equipment failures. Don't reply with some macho explanation of how you can foresee and prevent every error. You can't and if you believe that you can, then you need to stop diving until your ego and testosterone stop affecting your reasoning.)

My buddy and I each bought dive computers at the same time. I made it a point to choose dive computers from different manufacturers so that a sofware flaw in one would not put us at undue risk. We stick close together and always use the more conservative of the two computer readings. Had one of us had a UWATEC computer, we would have noticed the problem immediately when comparing the two computers.

Re:Diving Computers vs. Dive Tables.

[hughk]

I thought that the PADI tables are not the same as USN tables. They are based on them, but are far more conservative (i.e., less time at any depth) than the navy tables. Indeed, PADI warn recreational divers to stay clear of tables for professional purposes. Another point is that the USN tables assume a younger and fitter diver. PADI has to use a tissue model for a much wider range of body types (for non divers here, the amount of nitrogen held by different types of tissue, i.e., muscle, fat, is variable).

However, that last bit you say about trying to dive with a buddy with a different computer is one of the best ideas. I also plan my dive with the PADI wheel which gives a third level of checking.

Re:Diving Computers vs. Dive Tables.

[fmaxwell]

I thought that the PADI tables are not the same as USN tables.

They are not the same as the Navy tables, however, they were initially very close.

Another point is that the USN tables assume a younger and fitter diver. PADI has to use a tissue model for a much wider range of body types (for non divers here, the amount of nitrogen held by different types of tissue, i.e., muscle, fat, is variable).

Also true. Although earlier PADI tables were simply USN tables with more conservative times rather than being based on scientific research into nitrogen uptake of various tissue types.

However, that last bit you say about trying to dive with a buddy with a different computer is one of the best ideas.

So many diving couples make the mistake of getting matching dive computers when that is, in fact, the last thing that you want. The two divers profiled in the story both used the defective UWATEC dive computers. Had either of them had a different model, they would probably have recognized the problem before it was a life-threatening danger.

Like you, I also believe in backups. I have three ways to measure my depth: Computer, analog depth gauge, and Citizen watch with depth gauge. I time the dive using both the watch and the computer. I take waterproof dive tables with me in the pocket of my BC. And that's not even counting the duplication that I get when my buddy has her computer, watch, and depth gauge.

Diving gear is life-support equipment. I find it disgusting when dive shops peddle regulators, consoles, tanks, and BCs based on color coordination rather than on design, construction, and reliability.

Re:Diving Computers vs. Dive Tables.

[geekoid]

I would like to state, I know nothing about the dive industry.

However, I have been in the software industry in other fields.

It has been my experience to see several different companies using the same 3rd party code, or using the same contract company, which usually means the code betwwen each of the contract companies clients is very much the same.
Hell, I've seen pharmacutical software 'retuned' for financial needs.
Could multiple companies that make dive computers be using the same algorthym? how would you know if they did?

If a create 'gee-whiz bang' dive software, and sold it cheaper then it cost to develop in house, would many companies opt to liscense my software?

Re:Diving Computers vs. Dive Tables.

[fmaxwell]

Could multiple companies that make dive computers be using the same algorthym?

Algorithm, yes. Actual code, sometimes. The way that one can tell is that the "shared" systems have similar, or identical displays. Remember, these are not dot-matrix displays. They are custom LCDs with fixed digit and character placement and size.

There are also operational similarities having to do with how one recalls dives, changes displayed info, etc. The documentation on "shared" dive computers is often the same.

Really, they are like cars: You can tell looking at a Pontiac Firebird and a Chevy Camaro that it's basically the same car.

Plan your dive, dive your plan...

[dvd_tude]

... is what they hammer on in the courses, for good reason: simply put, you can die or be a cripple for life if you screw up. (My course? NAUI in 1976, taught by a Coast Guardsman at Alameda Naval Air Station. No wussy computers then.)

The main benefit of computers is that they simplify the task of figuring safe repetitive dives. In theory they can also give a more accurate plan based on accumulated nitrogen load, and thus allow more bottom time than a strict tables dive. Some computers even include a planning function which provides a simulation of a dive profile, based on its calculated estimate of your N2 load from prior recent dives.

But... the computers can fail. Think about it: you're relying on a relatively low-cost piece of electronic hardware, immersed in saltwater under pressure. There's lots of direct and indirect failure modes... not only could its seal or battery fail, it could be knocked loose, bitten by something etc.

And don't forget user error: if it's like most gizmos you could have forgotten to push the button to start it. Or, worse, you pushed it at depth and so the reading is too shallow.

God forbid it should have a software error like the early Aladdin evidently did.

To protect yourself, prior to your dive you should already have figured out your basic safe dive profile and bottom time given your nitrogen load. Manual tools like the PADI Wheel are used to do this. Then, you have: a watch, a backup gauge, and a buddy (who functions as a redundant set of gear.)

Once you're in the water your plan, your mechanical depth gauge, your watch and your buddy are your friends: they will save your ass (or at least your dive) if that fancy gizmo on your wrist decides to go tits-up at depth.

Yes, I have and use a computer. But I still do a 'sanity check' of the proposed dive using a manual tool like the PADI Wheel or the tables. Actually, if you're like most recreational 'vacation' divers who dive with divemasters, the divemaster does that check for you in case YOU screw up.

More rant: these newer 'air-integrated' computers scare me even more. I won't use one. I recently saw one fail, and the guy fixed the pressure transponder using a spring from a ball-point pen (bragging about 'MacGyvering' the thing) and then DIVED ON IT! Nuts!

My take on the guys who got bent on the early Aladdin is that they were pushing it, relying solely on the computer and doing 'closely-spaced' (repetitive) dives. Had they used manual backup and a lick of commonsense for time-to-fly they would not have gotten the bends.

As pros they should have known better. Yet to my mind they're not much smarter than those Moskito lobster divers I saw marking time in Roatan's hyperbaric chamber at Anthony's Key. Rather than placing faith in an etherial deity like la Moskita, they placed their unquestioning trust in a piece of software. The result is the same: they came up bent.

(Read more about the Moskito epidemic of decompression sickness here.)

- dvd_tude

Disclaimer

[RighteousFunby]

This reminds me of the old disclaimer that came with Windows 95 and up that the software shouldn't be used in situations where lack of stability would mean megadeaths (i.e nuclear facilities).

So THAT'S the real cause of Chernobyl! Microsoft!

Re:Disclaimer

[Anonymous Coward]

In Soviet Russia, software crashes you?

Modded down in flames!!!

extremely wrong

[DiveX]

You are a 'certified rescue diver'? That has as much weight in the diving community as saying you are 'Network +' certified in a room full of CCNPs. You are positively wrong.
The dive computer uses algorithms to calculate the amount of nitrogen going into and out of the tissue compartments. Different pressures affect the rate you on and off gas. If you drop to 100 feet, you are absorbing gas quickly. If you then ascend to 80 feet, you will off-gas some of the absorbed nitrogen at one rate and yet still on-gas nitrogen at a different rate. Ascend again and the same thing occurs, off gas some of the previous nitrogen and still on gas nitrogen at another rate. This is called 'multi-level' diving. Tables assume you are at the deepest depth for the whole dive. If you were to do a square profile (descend, stay at one depth, and then do a straight ascent) then a dive computer has a lesser no-decompression limit than the table would. What you have confused is a dive computer that is air integrated. that may, as a feature, have a different display that calculates your given air consumption and figures out how long you may stay at depth before reaching a reserve point (generally 500 psi). That is simple algebra, but decompression algorithms are a lot more complicated.

I should know, I teach this several times a month as a current and experienced dive instructor (check my profile) and use this information weekly on my technical dives to wrecks where we (my dive group) consider anything above 200 feet to be shallow. I have been on most of the sites that the article mentioned in passing (Florida caves [look at my web site]), the Andrea Doria, U-boats, etc.

Dive computers may be used to help avoid decompression, but not for decompression diving. I generate my own tables for any technical dive. Most people commenting here so far seem just to be newbie divers themselves. It is like someone that just finished a VB class starts spouting off about C++.

Most divers don't know how to properly ascend and decompress as it is. for the laymen, think of it like a soda bottle that is slightly agitated with dissolved gases (CO2). You would slowly open the bottle until there is a slight release in pressure and then close it; allows gasses to equalize, and then open, stop, repeat. You are allowing the gas to escape slowly enough that bubbles do not form. In the case of diving and human bodies, it is to prevent nitrogen from forming bubbles. Most divers just do direct ascents too quickly or a quickly stop at 15 feet before hitting the surface. The best way to ascend is to do a full stop (assuming a deep dive) at 40 feet for 15-20 seconds, stop at 30 feet for 30-60 seconds, stop at 20 60 seconds, and a stop at 10 for 120-180 seconds. this allows the nitrogen time to slowly come out at a slow rate; i.e. like opening the coke bottle slowly so it doesn't spill over.

If you decompress properly, then flying isn't a big deal. The general problem with flying after diving is the reduced pressure. You are going at a reduced pressure (most commercial craft will pressurize to no more than 8000 feet) so the nitrogen currently in the body comes out more quickly.

Re:extremely wrong

[aaarrrgggh]

Do you dive with BSAC divers? They really trust them Aladdin's, especially for deco diving. There is nothing wrong with using a computer to tell you your deco time, but you should always plan a deco dive. You can make custom tables on a PC, and back that up with your dive computer.

Sadly, most people don't even know how to use computers. My girlfriend's computer got bent last month, and she couldn't figure out what she did wrong. People just don't pay attention to what their computer is telling them!

(BTW, if you are diving deeper than 60m, that is strictly in the realm of technical diving, ideally done with trimix to avoid narcossis and O2 toxicity issues. A special level of conservatism is required for that type of diving.)

Re:extremely wrong

[se2schul]

BTW, diving to 59m on air is a delusion of safety.

Better to dive trimix for any dive below 30m. It increases your cognitive faculties so much that it's worth the extra cost. I also feel better after a helium dive than an air/nitrox dive to shallow depths.

I hate the feeling of being impaired while I dive. A 30/30 (30% oxygen, 30% helium) is a great mix for 30m. Between that and 60m, I dive 21/35. I follow all of GUE's standard mixes

Just as I wouldn't drive drunk, I would't dive deep on air.

Re:extremely wrong

[DiveX]

60m on air? you are quite a bit away from clufullness if you think that point is the limit of air. I don't dive below 120ft (40m) on air, hell rarely below 100ft (33m) on air. Anything below that needs trimix. People that trust dive computers for deco diving are strokes. don't listen to strokes and don't dive with strokes. BSAC divers are also the ones that kill themselves on the Buddy Inspiration rebreathers more often than anyone else.

Re:extremely wrong

[aaarrrgggh]

I don't recommend anybody dive to 60m on air, but it is within the limits of O2 toxicity. Everybody has to know their own limits as far a nitrogen narcosis goes... personally I am comfortable down to 42m on air. Much deeper than that... and all my normal diving practices go out the window... it's too cold for me!

Serious decompression diving should be done with proper tables. Get-out-of-jail-free decompression (less than five minutes at 5m), based on risk factors associated with your specific dive or series (a la Suunto RGBM), is still within the recreational realm.

I found myself in that situation a few months back, because of multiple day diving and a short surface interval (40min) after a deep dive. Although the tables let me ascend directly to the surface, I like having my computer tell me that maybe I should do a quick decompression stop, just to stay safe.

Re:extremely wrong

[se2schul]

" Everybody has to know their own limits as far a nitrogen narcosis goes" is just ridiculous. It's like me saying that I feel comfortable driving after 7 beers, but everyone has a different limit. Don't drive impaired and don't dive impaired. It's that simple. Helium is a nicer gas to decompress from. It does less damage to your body than nitrogen. There is less breathing resistance at depth so you don't have to use regs with high IP's to get good performance. It provides mental clarity necessary to do deeper dives. You feel better after diving high helium. As far as 60m ok for O2 toxitiy, you're pushing it IMO. We don't dive ppo2's of 1.4+ on the bottom. We dive ppo2's of closer 1.0 or 1.1. You're already going to be giving your lungs a beating with high ppo2's on deco, so we don't do it on the bottom. The stuff you're saying sounds like from a TDI or IANTD manual. Just because those agencies recommend it, it doesn't mean that it is the best option. ss

Re:Missing Dive Equipment: A HyperIntelligent Dolp

[Isao]

Wasn't Flipper played by Lassie in the television series?

Here's a solution..

[Anonymous Coward]

Stop bitching and whining about diving. Do what you want to do, and accept the risks involved. We all write faulty software on purpose. Why? It's called job security. If it worked perfectly the very first revision you put out, you couldn't make any money on upgrades and your boss would probably fire you because he/she got what they wanted.

All of this complaining, and no one around here wants to write their own diving computer software. You'd think that at least some /. readers are divers!

Corporate Death Penalty Needed

[that _evil _gleek]

As long corporations can figure out when it's cheaper to just go-ahead and let a few people die, some will. There needs to be a 3 strikes your company is dissolved law.
No more company, all assets sold, stockholders get whats left over, after all debts payed (as usual). Corporate officers and board members prohibited from serving in either capacity in any corporation for a period of at least 2 years. Don't worry if they don't actually have enough cash to cover that, they can always get real jobs...

At one point in our history, it actually required an act of Congress to incorporate, it isn't a right its more like a drivers license, the only thing Congress would need to do is care.

Re:Corporate Death Penalty Needed

[Anonymous Coward]

WTF would that do? Make a new company and buy the assets cheap?

i agree.

[rebelcool]

the type of code necessary for safety critical systems is really unsuited to open source. safety code is built with formal verification, then scientific lab testing. These 2 things are ill suited to the open source development model, for 2 reasons.

1. they're boring. I find it unlikely there are many scuba diving programmers with a specialty in algorithm verification willing to devote the months of formal verification necessary. Even less likely is one with a decent test lab.

2. They require specialized expertise. Especially when it comes to developing a test methodology. Since every combination of variables cannot be tested in any system of complexity, one must pick and choose the likeliest combinations and extrapolate behaviors from those. Again, people who are good at that tend to be rare and very well paid for doing it (its tedious). Not something someone is simply going to volunteer their time on.

Safety critical systems are one of those things where you simply cannot give the code out and expect that to make a difference. It's less about the code itself than about experience in designing and validating safety systems. The code is merely a means to the end.

air traffic control software

[wadiwood]

I guess I just have to add dive software to my list of things I won't work on. The other two that have been on my list for a long time have been air traffic control and missile guidance. At least I don't think the Arms guys are going to let me program their missiles to launch out of the earth's gravitational field and make for the sun (or some other star). At least the dive software can't kill so many people so quickly.

Maybe we could program the flight controls of big aircraft so that they are equipped with GPS maps of where they cannot fly or land, like central business districts.

Ie if the pilot tries to fly at a skyscraper the autopilot takes over and redirects the plane. Hmm. Be good if we could make it work properly.

Re:air traffic control software

[Anonymous Coward]

Maybe it would have helped if the Merkins wouldn't have been so damn arrogant! You cannot piss of the world during decades, and expect that nothing ever will come back.

Re:Pinto

[ishmaelflood]

"The value of human life doesn't factor in. " yes it does, that Pinto page (which was pretty good actually) even had a figure in there, $200k, I think. You may not like it but the current cost of an American life is about 4 million bucks.

Supposing the perceived benefit had been 100 times the cost of the injuries, not 2.5 times? Would that be acceptable?

I think they made a cost/benefit decision (wrong, as it turned out), and they got hammered for it. But their logic was correct.

We don't live in a world of fluffy bunnies and chocolate houses. Safety costs. At some point there is an engineering change to a product that is not worth making, even though it will save a life.

In some respects we have gone to the opposite extreme. Holden in Australia have fitted side airbags. They sold these things for two years, so that is 60000 vehicle years, before one went off in an accident.

Cost to society 80000*600 dollars= 48 million dollars. life saved: 2, possibly.

Even if they carry on crashing at the same rate for ten years it is very hard to believe that they will have been worth fitting.

Incidentally you would be amazed by the number of people who think that airbags are more important than antilock brakes, apparently they still want to have the accident, just not get their nose broken when it happens.

And of course it is very hard to get even slightly het up about safety when the morons won't wear safety belts.

Lasik

[ishmaelflood]

I have two friends who have had laser eye surgery, one, very succesfully so far, the other somewhat less so.

Things they don't tell you

1) Your eye is stll going to change shape with age, so your prescription will change, so you will have to have it redone in 5 years or so (less if you want to keep driving without glasses)

2) If you indulge in any activities involving pressure (eg scuba diving) or lack of (eg mountaineering) then there is a risk that your eye will deform and render you temporarily unfocussed until normal pressure is restored.

3) the scars cause massive internal reflections and this will affect your night vision when driving.

4) you may need to have tune-ups. two in one friend's case.

5) Cross infection risks means that it is wiser to have each eye done at different times.

I'm not a big fan.

Re:Lasik

[ccmay]

I'm not a big fan.

Me neither. I've thought long and hard about it, but finally decided that it's not worth the risk. I make my living with my eyes.

What works well for me is ordinary spectacles for work and daily wear, with disposable contact lenses for occasional use. I put them in before I swim, ski, scuba, go out for an evening with my wife, etc. Then before I go to bed, I discard them. Never a problem.

-ccm

Anti Lock Brakes

[ishmaelflood]

or as we call them ABS.

These are software driven just like vehicle stability systems (in fact VSS is just ABS hardware with a few more sensors).

We don't seem to have a plague of rogue software killing occupants because, guess what, we really try to be careful with this stuff. The FMEA for ABS software is huge, and detailed. How many of you guys ever have to do an FMEA? or even know what one is?

Here's a funny war story (I know everyone involved, this happened).

The wheel speed is picked up via a sensor on a 40 tooth tone wheel. Cars without ABS don't have tone wheels. Someone asked, what will happen if a non-ABS wheel gets onto an ABS car?

Mechanic fits non-ABS wheel to car. Development engineer drives off, hits brakes at 10 kph, no prob.

same at 20, same at 30

same at 40

same at 50

same at 70

Drives up to 80 kph hits the brakes, one wheel locks, the car slews sideways into a bank and rolls up on two wheels.

Engineer needs new undies.

What had happened was that the sensor could pick up the back of the wheelstuds. There are 5. The software assumed that the car was travelling at the speed of the slowest wheel, so the non-ABS wheel was the vehicle speed. Our ABS is disabled below 9 kph to ensure that you can stop the car, on some surfaces it will only inch to a halt unless you lock the wheels.

So, at 80 kph the ABS realised it was supposed to work, activated, saw one wheel almost stopped, released the brakes on that wheel, and locked the other one. Hilarity ensued.

Weren't you

[ishmaelflood]

guys complaining about black boxes in cars last week?

that's what they are for. Debugging software. Now all we need is a black box to debug the drivers.

Tables = false sense of security

[Llywelyn]

The Tables written up by the military are based on a young seaman who is in good condition, using normal air, with no known medical conditions, doing exactly the depth we are talking about for exactly the times we are talking about.

Tell me one diver who actually does that? I know and associate regularly with rescue divers, dive masters, and a crop of other experienced divers--none of them are young, fit seamen in the military form of good condition and none of us do exactly the depths we say we will--some err shallow, some are a few feet deep.

It is also based on averages and says nothing about how you will personally react.

I was talking to my Advanced Open Water (PADI) instructor the other year (long overdue, I probably have over 100 dives) and he had a woman he was training at one point who was doing just the open water tests for the basic certification. Nothing deeper than about 20 feet all day, did everything correctly, didn't stay too long, ate right, wasn't overly stressed, &c. Never left the "A" category on a PADI dive table.

She got bent.

Furhter, we don't know that absorbtion is the same on repeated dives. We don't even know quite how absorbtion works (though we have a few equations that help). If you do more than 2 or 3 dives, throw your computer out since it is worthless for that day--the tables are no better in this regard.

The point is this: whenever you dive, you are taking a risk. We have tables and computers which lend to us a false sense of security but there are no guaruntees. You can stay about 98+% confident diving within the tables, you can stay in about the same range diving on most computers, but you never, ever even approach 100% confidence any more closely.

Computers track your actual depth--not the one you planned (whether it be deeper or shallower). Thus they can actually be far more accurate and still let you get your dives in without a difficulty. They keep a record of useful information--their best guess at how much nitrogen you've absorbed (see above, its a guess), your maximum depth, bottom time, and a variety of other things for you. This is conveinant more than anything else and, while they may not be as conservative as dive tables, they do increase my bottom time while still keeping me in that range of "as certain as anything else."

You throw the dice every single time you step into the water. Don't think that tables are any better or worse than the computer--they both lend a false sense of security.

Re:Tables = false sense of security

[Dolphinzilla]

I agree with you 100%, diving has many risks. My point was that by taking the conservative nature of the tables out of the equation (which don't easily allow profiles which recoup residual nitrogen time during the dive) that a diver taking a chance has a greater probability of screwing up. As someone pointed out in another post (and you mentioned above) the divers health has a tremendous amount to do with how he will react to breathing gas under high preassure at depth. Until I read this article I didn't know that they made a dive computer specifically for Nitrox diving - I have always considered Nitrox to be something that Sport divers should stay away from - balancing the risk of the bends with oxygen toxicity seems insane just so you can spear a few more fish or take a few more photographs.

They apologize for "any inconvenience"

[Blademan007]

At the bottom of their recall web page:

"We apologize for any inconvenience this may have caused you."

Now *that* is an understatement...

Re:They apologize for "any inconvenience"

[Anonymous Coward]

I'm in Davey Jones' locker, you insensitive clod!

QA != high quality product.

[lukme]

In fact, of the companies I have work in, the one with the highest quality product was the smallest and the one without any QA people.

Re:Mandatory Open Source for life endangering apps

[Oscar_Wilde]

Yes! And then we could have a Beowulf cluster of diving computers! Or diving computer webservers! Or a diving computer that can be used to control your TV!

(sorry but someone was going to say it)

and to think Gimpel's Lint.

[lukme]

I believe that Gimpel's PC-Lint/flexeLint was doing the memory checks in 1996, at least the NULL pointers and double deletes.

I wonder what the difference is between Gimpel's algorithm and the standford algorithm?

Flying after diving

[TFloore]

Simply as a point of information...

Speaking as a certified diver that does dive nitrox (and I love diving happy gas!) I'll point you to DAN for guidelines for flying after diving. You mention them, but perhaps didn't get a full information exposure there.

And if you don't know DAN (Divers Alert Network) you really should look them up. They are a non-profit research organization for scuba divers, and they offer diving insurance. It's worth getting. 1 Dive Table #3 deco in a hyperbaric chamber will run you an absolutely awful amount of money (about $25,000) and is not covered by any "normal" insurance.

Anyway, DAN's current guidance for flying after diving is not terribly clear. But you are right, for a single dive, they currently suggest a minimum of 12 hours before flying. Or, as another person notes, before any change to a higher elevation (defined as "more than 3000ft elevation change" just like the definition for high-altitude diving). For repetitive diving, the current guidance is "not less than 18 hours" and the longer the better.

And that "minimum is 4 hours" you mention depends on the source. The US Navy says 2 hours, after a single no-deco dive. Though, I'll agree, that's a little crazy for my tastes.

And diving nitrox doesn't seem to have any influence on time to safe flying after diving, beyond the obvious that you might have absorbed less nitrogen. This guidance assumes you are diving close to the limits of either tables or computers, and therefore you end the dive at the same nitrogen-loading whatever gas you are breathing.

Re:Flying after diving

[LauraScudder]

When I got certified, we were living above 1500 ft. and my first instructor told us to wait at least 6 hours to drive up there. Then during our advanced certification, we had this ex-navy seal as our intructor, and he told us that 2-3 hours would be perfectly fine. I think a major problem with the flying after diving times given by DAN are so unclear and constantly undercut by more agressive diving organizations that it gives many divers the sense that they can and should push the limits more than is actually recommendable. The official numbers of 12 hours and 24 hours get beaten into you well enough during certifications, sure, but then as soon as you talk to other divers it's another story.

Still, a macho pushing the limits culture is no excuse for hiding a clear product defect that causes injuries. All these cases of corporate cover-up are just starting to make me sick. What happenned to responsibility and customer trust in corporate America?

You are 100% correct - however

[lukme]

lets face it, if you are given an imcomplete spec and someone's life depends on the code you are producing, wouldn't you like to be able to say that you did everything in your power to show that your code is complient to the spec.

Additionally, whenever you are designing, coding and testing, you also need to be aware of the limitations of the spec and make sure you understand the logic behind it and everything is consistant and makes sense.

Computer and dive tables

[TFloore]

Yeah.. it's not like divers are taught that you use a computer to augment your diving, and that you should still fill out your dive tables or anything.

I routinely do dive profiles that my dive tables say I should get bent on. My computer knows better, because it knows the actual depth profile I dive, and not just the max depth and total dive time.

Almost any dive profile on a wall will do this. You start deep, and drift slowly more shallow as you go, and you can do a nice hour-long dive with a max depth of about 80ft, and an average noticably shallower than that.

Yes, you can do this with a multi-level dive table, with a wheel or similar. I've done that. You know how much trouble that is? And how difficult it is to know, for a sloping wall dive, exactly how long you'll spend at any particular depth looking at coral? Yes, plan your dive, and dive your plan. But realize that you aren't a robot, and don't dive like one.

Multilevel dive planning is for deco diving where your computer can't handle it, and, incidentally, you *have* to know deco times ahead of time so you can hang stage bottles at the right depth.

But that dive profile above, for a normal set of dive tables, diving with a computer, will almost always end with your tables telling you that you went into deco. Because all it uses is max depth and total bottom time.

It's not like every diver knows that the dive computers and dive tables are approximations, and that they can vary drastically for a number of reasons.

Yeah, and the tables are approximations, too. Actually, they are statistical representations, and state that 98% of divers that stay within these guidelines will not get DCS, with some confidence bound. Yes, diving tables, you can still be that unlucky 2% that does everything right and gets bent anyway. Sometimes it's just not your day.

Pushing the absolute limits of what your computer says you are allowed is dumb.

No. You do research, you find out what algorithm your computer uses, how conservative or liberal it is, how it was modified from standard industry-published algorithms, and you pick a computer that works the way you want it to. And then you dive within the bounds the computer sets, so long as those bounds pass your internal bullshit detector. (You *do* have an internal bullshit detector, right?) But diving close to those bounds is not "dumb" it is simply using your equipment to the limits you are comfortable with.

There is a large element of recklessness involved in this situation.

Can't disagree with that at all. Finishing a dive at 10pm and flying at 6:30am the next morning is not safe.

Re:Computer and dive tables

[instarx]

But diving close to those bounds is not "dumb" it is simply using your equipment to the limits you are comfortable with.

Being comfortable and being dumb are two very different things. Pushing the absolute limit set by your dive computer IS DUMB, and if you are comforatable with that then it is VERY dumb. You give the reasons not to push the limits yourself. 1)Every person is different, 2)the dive tables that the PC programming is based upon is an approximation, 3)as is the programming itself.

You have a pretty fine-tuned bullshit detector if you can tell the difference safe and not safe when pushing the limits of a dive computer. One problem with this particular computer was that it gave the right results MOST of the time, but in certain situations it gave very wrong results (short, frequent dives). No one's bullshit meter would have detected the problem with these dive computers that gave reasonable results 99% of the time and then totally screwed you the other 1%. Neither is there any way you could have "researched" the algorithms in this particular computer to determine its accuracy because the error came from a hidden programmning error. So I think we return to the original idea - pushing the limits of any dive computer is very dumb.

The bigger issue here for /.ers is that because of its digital readout too much importance was probably given to the dive computer's implied precision. I'm sure it said it something like it was safe to fly after 6 hours and 18 minutes. Digital readouts imply greater accuracy than is often actually present, whether it is regarding a safe number of minutes to fly displayed on a dive computer or milliseconds until your cake is ready on the microwave. Placing one's life on th eline using this implied but non-existent accuracy is very dumb. All that apparent accuracy is totally useless given your original parameters were wild-ass guesses and approximations to begin with.

Re:Computer and dive tables

[TFloore]

The bigger issue here for /.ers is that because of its digital readout too much importance was probably given to the dive computer's implied precision.

This, I admit, is one personal bitch of mine.

At work, we deal with a few safety numbers, standoff ranges and things like that. One of our magic standoff ranges is 91.44 meters. It's a really interesting number, and you have a lot of confidence in it... until you look at it again. And realize that 91.44meters just happens to be 100yards. And that this magic safety numebr was probably just someone saying "well, 100yards sounds about right" and someone else blindly converted it to that exact distance in meters.

And suddenly you have a lot less confidence in that safety number.

Incidentally, I still maintain that diving your computer to its limits is safe. (You notice a bit of a contradiction there???) However, I also do seriously slow ascents when diving close to limits on a computer, and instead of a 3 minutes at 15ft safety stop, I'll do 3 minutes at 30ft, and 5 minutes at 15ft, and a slower ascent rate than officially recommended (60ft/minute at greater than 60ft, and 30ft/minute at less than 60ft, is the official guidance).

I may be crazy, but I'm not stupid. Or at least I won't admit to it. :)

Re:Computer and dive tables

[seaan]

Pushing the absolute limit set by your dive computer IS DUMB...

It all depends on the context, as a previous poster stated there is an element of choice here. You choose the computer, and you choose the settings in the computer. For example I've set my computer (a Cobra) to use the most conservative setting (of 3 choices). Does that mean I'm dumb to use the maximums provided by that mode? Same concept applies to choice of computers.

When I first heard about this several months ago (I heard about it from RISKS), I started thinking about how I as an intelligent person could detect and counter this type of software bug.

I agree with the point about trusting the computer's readouts about safe time to fly. Obviously in the case of the people flying after diving, they violated the standard cautions about air travel. For instance the latest NAUI recommendation is to not fly at least 12 hours after a single dive, and to wait at least 24 hours after multiple dives. Recent articles in DAN have been more conservative, and recommend at least 24 hours. People should not let a dive computer override those recommendations.

But a number of other divers were injured after a more typical procedure of doing multiple dives per day. I suspect, but am not sure that some of these incidents could have mitigated by common sense. They usually involved 4 or more dives in a day. While 4+ dives a day obviously can be done safely, I think common sense should indicate that you don't want to push the absolute limits here.

I think the best prevention method is to still use the charts. If you did a wall dive starting steep and going shallower, you can still use the charts as a basis - check and see what the chart results would be if you were a column or two better. While this would be a risky practice for pure chart diving, I believe this would be a useful information supplement to make sure that your computer is working within normal parameters.

Air in the system...

[Anonymous Coward]

... he is EXACTLY describing what happens when you have an air bubble somewhere in the hydraulic system.

Re: Air in the system...

[ishmaelflood]

Yes, air in the system is an error state for the hydraulics. Your point is?

knowing your equipment

[orange]

sheesh - talk about guessing.
Has anyone actually taken out their computers alongside their tables and actually compared the dives you can do with each.
On the same profile, and consequently the same depth at the same time, I could never get the same dive on my computers (2, yeah, I would never trust just one) that I can get on tables.
All the computer does is give me credit for when I'm not as deep as what the table say.

Re:knowing your equipment

[orange]

Replying to my own post :)

Come to think of it, My Mosquito has failed on me once :)
Put me into dive mode for the whole weekend (Till I could get the thing back to the distributors on Monday).
They simply changed the battery :) I know of one other person who also had this happen to them. Anyone know of any others who've had similar problems?

The cost benefit of a $1200 dive computer?

[Anonymous Coward]

I have only done one dive in my life, a resort dive to only roughly 30 feet but isn't the added dive time gained by $1200, the stated cost of this computer, better spent on more tanks using a conservative dive profile based on the established tables rather than a fancy-smancy dive computer?

More generally...

[pretty_penguin]

I've often wondered where individual responsability ends and collective (governmental) responsability begins. In this respect, the more dangerous passtimes (scuba, skydiving, bungee, etc) are an especially difficult case. And any scuba- or skydiver will all admit they're accepting a certain risk inherent to their sport. They're simply doing stuff our bodies were never meant to do (deep diving, flying).

On the other hand, one does tend to take for granted, for example, supervised or standardized testing procedures / quality control to be in place regarding such products as airbags in cars, and as was mentioned in earlier posts, medicinal equipment. And a lot of this goes for guns, too, though i don't mean to start an NRA/regulation flamewar here.

Manufacturers of gear in the more critical fields are definitely aware that consumers expect them to adopt adequate safety measures. Does this make the cover-up worse? In principle, I'd say yes. But legally, I dunno (IANAFL) ... Of course, once you plunge in, that's your own decision. And my diving instructor did in fact tell us, even with all these fancy computers around these days, know your dive tables and multilevel wheel. Plan the dive and dive the plan.

But one does wonder, who should start initiatives to protect such specific consumers? Organisations of peers (PADI, in this case)? Government? Or is it, in the end, as simple as: every man for himself? Seems to me that these scattered, fragmented suits that the article mentions, are bound to be less effective than a collective effort could be.

Electronics in skydiving too

[CvD]

In skydiving there are 2 electronic devices (made with hardware chips with software on them) similar to the dive computers: audible altimeter and automatic activation device (AAD).

An audible altimeter is mounted in your helmet next to your ear, it beeps when you reach a certain altitude so you know its pull time. It is meant as a backup to your wrist altimeter, but a lot of skydivers these days rely on their audible as their primary altimeter, with their wrist as secondary, because it is more convenient. An audible will remind you no matter what which altitude it is, while a wrist altimeter is a passive device, requiring you to look at it. When this device fails, you have a possibly dangerous situation. There are still a number of things that have to happen before someone bounces, but it can happen.

One of the things that prevents people from hurting themselves after they don't hear their audible or they're unconcious or whatever, is an automatic activation device. This is a small computer which sits in your rig (the backpack which houses your parachute and reserve) and monitors air pressure and pressure changes. You switch it on at the beginning of the day and it will monitor the air pressure continuously from then on. If it determines you are still in freefall at 750 feet, it will deploy your reserve parachute.

This is also a device which, when it fails, will probably mean someone dies. Of course, the AAD is like a safety net for a circus trapeze artists. A trapeze artist does their thing while considering the safety net not to be there. Same for skydivers. The AAD really is a last resort measure, and you never act as if it were there. So for a situation where an AAD is needed to arise, things have already gotten pretty out of hand. Statistically, the chance that the AAD will also fail at that moment is very small.

Of course, if don't have an AAD installed, not hearing your audible is a lot more dangerous. In most countries more advanced skydivers are allowed to jump without one.

So, although these devices are designed to save lives, when they fail, then could kill. It is not as extreme as an insulin pump or a dive computer, of course, where your life depends on it working correctly.

Most popular audible: Larsen & Brusgaard ProTrack

Most popular automatic activation device: Airtec Cypres

Cheers,

Costyn.

No, you are extremely wrong

[se2schul]

Anyone who does "technical" diving knows that computers are completely inadequate for the job.

You can plan multi-level dives using software the same way you generate deco schedules for your tech dives.

A dive computer is merely a crutch for those that don't understand decompression. It promotes diving without adequately planning your dive. It can produce very unsafe schedules especially for bounce dives by saying that no deco is needed when you clearly need some. Not if, but when it fails, the user is left without a proper understanding of deco, and they are left doing an ascent without confidence that they will come out of the water safely.

The problem with dive organizations like PADI (Put Another Dollar In ;-) is that they certify divers with ego-boosting titles like Dive-Master or Mater-Scuba Instructor and they have a TON of useless certifications like Boat Diver. What's next, Knife Diver? Advanced Knife Diver with the 6" blade specialty? The problem is that a Master Scuba Knife Diving Instructor who doesn't understand deco himself tells his students that they need a dive computer. Who can say 'NO' to this Knife Diving GOD? Now you have a ton of divers who don't understand deco enough to recognize when their overpriced dive computer (which is less reliable than Win 98) gives out bad information.

The only computer I trust while diving is my brain.

Re:No, you are extremely wrong

[EvilTwinSkippy]

I thought PADI was "Pay and Die Instanty". (Not to be confused with Not Another Useless Instructor (NAUI)

Re:No, you are extremely wrong

[Anonymous Coward]

...or NAUI - Not Another Underwater Idiot.

Actually, there is a big difference between NAUI and PADI. NAUI Tech advocates the use of helium for deeper diving. They encourage a gear configuration and system like DIR (see GUE or WKPP and with Weinke's RGBM tables, the deco is much better than what most agencies advocate.

PADI, on the other hand, with their RecTec program, encourages deep air diving (diving while impaired), and they have no consistent standards for equipment configuration. The suggestions and requirements they have are ridiculous in comparison to NAUI Tec.

For the absolute best in training though, visit GUE to see their training standards.

Re:No, you are extremely wrong

[EvilTwinSkippy]

Preaching to the Choir. I'm a NAUI cardholder myself. I've been through my OpenWater, Advanced, and Wreck "Survey" certs. Was my self-depricating humor that convincing?

The dive shop I normally use has switched from NAUI to PADI, at least for their basic courses. For the record I don't see that as a "Good Thing. My sister came out of her basic course with absolutely no bouyancy control. She was Mary Poppins the first time she hit salt water. Granted we all were a bit off that dive. I lost a weight belt and had to spiderman back up the anchor line. I also dropped a tank on my foot helping someone up the ladder.

I know that my NAUI course required 2 ocean dives before I even got my C-Card. I also remember a hell of a lot of time in the pool getting used to the equipment.

Another tale of mistrusted application

[SiggyRadiation]

I used to be an applicationmanager for a few Hospital-Information-System applications. A few years ago there was a large news-item about a hospital administrering blood of the wrong blood-type to a patient, killing him.

The cause of it was a software-flaw: the bloodbank-software had a duplicate-entry system. Analyst A enters the bloodtype, analyst B enters the bloodtype. If the two matches then we are satisfied.
The checking-system did not check. The analysts entered different values but no alarm-bells were ringing.

This did not happen at the hospital where I worked, but we also used the same software.

I checked the buglists... and there it was... bug # 12345 date: half-a-year-ago. Bug: application does nog check inconsistent entries. Stunning... absolutely stunning.

There is a programmer / accountmanager who has now found out (the hard way) that programming medical applications is a serious business. And that if he scaled the priority of this bug up, a life would have been saved. This company was quite sluggish in it's reactions to bugs and it took quite something to get a bug classified as top-priority. I don't know what the priority of this bug was, but it was too low.

Nice detail is that the hospital was found to be the responsible party, because the bug was known and they did not implement temporary manual/alternative checks into their process.

Siggy

I disagree.

[ccmay]

the type of code necessary for safety critical systems is really unsuited to open source. safety code is built with formal verification, then scientific lab testing.

I don't agree with you. This dive computer had a design error, not a programming error. All the algorithm verification in the world wouldn't have caught this error. But if the code had been published open source, maybe someone would have caught the erroneous assumption that a diver on the surface would continue to breathe the Nitrox mixture instead of taking out his regulator and breathing normally.

It may be true that open source as a method of creating the code would be inefficient. But publishing the source so anyone could review it might have avoided a tragedy.

-ccm

software certified for use in life-or-death-situat

[Anonymous Coward]

Does anyone out there know of any compiler
development system that doesn't have a
disclamer in the license agreement?

You know the disclamer..."software is
provided for entertainment value only,
and is not to be used in situations where
loss of life or bodily harm can occur.

Not responsible for any damages. But we
will replace the CD's if something really
bad happens!"

Re:Mandatory Open Source for life endangering apps

[ComputerSlicer23]

Duh, the dictionary definition of escrow is precisely that nobody gets access until certain terms are met, escrow isn't open source. That's why later in the post, I say that this is more likely then having it open sourced.

I switched gears, from the fourth paragraph on, assume I'm talking about the software being open sourced. For phrase "Having it Open Source", subsitute "Having it Open Source instead of Escrow would be much better because: ", and read the rest of the comment.

That three paragraphs is a simple example of why having the source available under certain condictions is good. It being open source is vastly superior to escrow (from the perspective of the consumer), because you don't have to jump thru the legal hoops to break the escrow. You just grab your copy of the source, and find somebody to audit it.

Essentially, if it had been open source, the manager could have anonymously tipped anybody to check the source for a very specific flaw. Nobody has to break escrow, or is violation of the NDA, and a large corporation, or a gov't body could have fought the defamation case, instead of them crushing one of their former employees for defamation (even though they are correct, they'd probably lose in court).

Open source has a lot more transparency, which is very good in this case.

Kirby

Shhh!

[TW Burger]

As a spokeperson of the anti-capitalist über-left cynical jaded morons I inform you we greatly resent being outed.

Re:Mandatory Open Source for life endangering apps

[HeyLaughingBoy]

Don't be ridiculous.
I presently develop software for a medical device. At last check we had around 500kloc running on custom hardware that costs the customer about $80,000 per instrument. What possible benefit could there be to Joe Random Developer seeing the code without having intimate knowledge of the design requirements and the hardware? For that matter, how could he change anything without having the hadware to test it on?

If you want to improve safety, insist on better scrutiny by outside agencies a la CE, UL, CSA, (or in our case, all of the above as well as the US FDA) to certify the software, but saying that Open Source is a solution is just silly.

Re:Mandatory Open Source for life endangering apps

[Crashmarik]

Remember the pentium FDIV bug ?

Improper use of dive computers

[EvilTwinSkippy]

Every SCUBA diver is taught to never rely on the computer. Then again, we are also taught to never come up on an empty tank either, but that's never stopped anyone now has it?

Now while we are taught to worship the dive tables, I do know that in practice many divers don't use it. Generally the dive operator has already worked out the tables for you if you are on a party baot.

Another note, the computer is essentailly a lump reading temperature, time, and depth until the alarm bells go off telling you to get the hell to the surface. If someone is diving and relying on a piece of equipment to do that for them, he or she does not belong in the water.

For the record, I do scuba dive, I do use tables, and I do always arrive on the surface with 500 psi in the tank. I am a bit of a killjoy.

Re:Missing Dive Equipment: A HyperIntelligent Dolp

[EvilTwinSkippy]

Funny, on my last snorkle trip to the Islands, I had in improptu tour guide in the form of a dolphin. He just tailed the boat and then played with us when we got in the water.

The dive boat guys had never seen anything like it.

E-Navigation - also a possible killer?

[Anonymous Coward]

I know someone who worked on a navigation/mapping program that I will not mention. Out of the user feedback that has come in, I can assume that software like this could also be considered life-threatening.
Example 1: A bus that used the software was routed to roads with low bridges. Oh, something should be added to the trip parameters eh?
Example 2: A new feature was added to allow for footpath trips... and people have been routed to walk along busy highways without a sidewalk. Oops.

i was diving before the goat got bent

[LifesABeach]

i am a experienced diver.

i started diving before the goat got bent. in the mid '70's the navy bent the goat at 1 atomosphere, it took about 30 days.

if the suits say their product is not bogus, then let them prove it by 'demoing' it under the conditions that the law suit is about.

valgrind

[dunham]

Mutters something about Z's place being in /dev/null

At the very least there is the "generate thesis topics" use. :)

valgrind just wraps the executable (you use it like strace). The way it works is quite impressive - it's an x86->x86 dynamic translater, which instruments the code.

It also has "skins" that allow you to plug in different checks. In addition to the memcheck, there is a cachegrind skin which does a cache miss profile of your application (marks up code with # of each type of cache miss). And you can make your own. You write a function that takes a basic block of risc code and returns your augmented version.

The downside is that it's x86 Linux only. And porting to another processor would be major work.