Genetically modified cells and viruses often mutate. scientists aren't certain, but they suspect that modification produces a less stable genetic code.
In the case of HIV, the virus is ALREADY extremely mutation-prone. If I remember correctly, the reverse transcriptase enzyme (the one that makes the initial-infection copy) averages more than one error per copy.
The virus compensates for this by having TWO copies of its genome - not so much for error correction as to have a significant chance of having a working version of each enzyme when it has infected a cell. (This also lets it form hybrids when two different versions infect the same cell.)
The result is that it actually evolves resistance to the antibodies the body throws at it during the course of the infection. And also that the infection is slow - but eventually overwhelms the immune system with a mob attack of divergent versions of the virus. A typical late-stage patient may have three or more viable variant populations, each capable of infecting other people.
If they ARE using pieces of the AIDS virus in their construct, I certainly hope one of the changes they made is replacing this error-prone enzyme with a more accurate one from another virus.
I think they can fairly be described as an embedded software vendor that supplies Linux platforms, rather than an "embedded Linux vendor".
Right on.
They haven't switched. (At least they haven't if the management is on the ball.) They've just added a new product line. Maybe it will pick up. Meanwhile the old standby is still there. Take your pick. Whichever way the market goes they're in the game.
NASA uses VXWorks, it is one of thir best customers. They are very conservative, wont switch to linux.
When you've spent billions hardening a technology to extremes of reliability, a single failure costs you hundreds of millions and maybe several lives, and the technology you've hardened is more than adequate for the next job, you'd be a fool to switch.
You switch when the job can't be done without a switch, or when the benefits (including risk reductions) outweigh the costs and risks.
It's when you're starting from scratch that older and newer technologies are on a nearly level playing field. When an old tech is in place and performing well the new one needs to have a BIG advantage to displace it.
Such practices mutate thousands of unknown mutated genes for every beneficial gene they produce. Nobody ever checked if if 1/10 or 1 percent of the general population was allergic to a protein in a mutated food plant.
You're missing the point on the concern about allergies.
It's not that a new allergen might be created. Nearly ANYTHING can be allergenic - either directly or in complex with something else in the body. New compounds are being "invented" by mutation all the time. Forcing some mutations into a few plants in a lab is not even a drop in the bucket.
The concern is that there are a lot of compounds that are allergenic AND PERVASIVE in certain food plants. When someone becomes allergic to them, essentially the only effective treatment is to avoid them. (As of the last time I checked, desensitization does NOT work on the branch of the immune system that mediates food allergies.)
But these protiens are often useful: Some of them are the biological warfare agents the crop plants use against the parisites they are resistant to. Copying them into other species of crop plants can confer the resistance. Very useful.
But if you copy, say, a corn allergen to wheat, and sell the modified wheat AS wheat, how is someone who is allergic to it supposed to avoid it. Look at the label: It says "wheat". No corn ingredients (not even the dozen or so that don't sound like corn but are). Ought to be safe, right?
And with engineered wheat containing this corn allergen (and probably several others) immune to a range of pests (so no expensive pesticides are needed to keep its yeilds up), it will soon displace the non-engineered corn from commercial farming. So people with corn allergies won't be able to eat wheat, either.
Heck, how can they even FIGURE OUT that it's a CORN allergy? Scratch tests don't work. You need to do an elimination diet. Where do they start? Just meat? (What if the cattle were corn-fed? Many plant protiens appear in the meat in enough concentration to affect the taste and smell, which is no more sensitive than the immune system.)
Repeat with transferring wheat allergens into corn. Then play three-way musical genes with potatoes. Then add more plants to the mix.
Eventually, if you're allergic to ANY crop plant you're allergic to ALL crop plants. Then what do you eat?
Or are you trying to breed out people who get food allergies? (I suppose that's one way to reduce the population to the handfull that could be fed without the use of pesticides, fertilizers, OR gene-engineered crops.)
It's a shame, NetBSD I can understand, there may be some confusion when both BSDs use the same "daemony" logo style, but the other BSDs have all moved away from beastie.
IMHO NetBSD should dress the daemon as a retiarius.
That's the "Net-man" - the unarmored net-and-trident wielding gladiator of the Roman games.
(In competition with the Secutor (the sword-and-shield guy) the Retiarius has a significant advantage.)
And either selective availablity or local jamming will be turned on the first time somebody uses GPS to fly a cruise missile in the president's window and land it on his desk (or something equivalent).
Probably local jamming or some variant, since differential GPS enables the land-on-the-desk stunt even with selective availablity turned on. (That WAS what it was invented for, after all.)
IMHO differential GPS is the real reason it was turned off. SA was no longer performing its intended mission, while SA was making GPS less useful and/or more expensive for the civilian infrastructure.
Lighthouses have been obsolete since radar came to be. GPS is hardly the starting point for this.
As a boater I can tell you that neither radar nor GPS makes lighthouses obsolete. Nor did LORAN before them.
Sure, if you've got it and its working you can tell where you are. Within a football field if selective-availability is on, much better if it's off.
And the big commercial ships have them and they're usually working.
And the small commercial ships in well-to-do countries (like fishing boats for instance) may have them and they may be working.
And the more well-to-do pleasure-boaters may have them and they may be working.
But there are a LOT of boats out there that DON'T have them. The BULK of them, if you're talking numbers.
Fishermen may not have them - and may have other things to deal with than watching a screen. Most pleasure boats are small fry, not millionaires' giant toys. (A small ocean-capable cruising sailboat, for instance, may be considerably less expensive than an RV of a similar size.)
Even if they have them, any bets whether they're working when you're coming in after a month at sea, two years after they were purchased? Salt spray is HELL on electronics, and gets into everything.
And even when they do have them, and they are operating, a boater may think he's far out to sea when he's actually almost onto a hidden hazard, and not be looking. (A lighted nav marker, among other things, is the idiot-light of boating.)
Saying GPS obsoletes lighthouses is like saying GPS-based navigation systems for cars obsolete stop signs, curve signs, and the blinking lights associated with them.
Data? If you live in one of the 4 UMTS markets you can receive faster data transmitions through your Cingular service then through your cable modem.
I'd love to do that. But I don't.
The cell site is just TDMA. No data (other than digitized voice), period. And as of the last time I checked (a couple weeks ago) there were NO plans at Cingular to EVER upgrade it - even to voice-only GSM - just as AT&T had no such plans before the merger.
(I'll try again from time to time as the merger shakes out and gets organized.)
It's right on the edge of their TDMA coverage, far off the edge of their GSM coverage, and they're not planning to expand either - even to convert it to GSM as they retire TDMA. Verizon has no plans to extend coverage to that area, either. (With the AT&T/Cingular cell and a roaming agreement, they apparently consider it adequately covered.)
Since there's only a handfull of retirement homes and the intersection of two not-heavily-traveled highways, it's probably too sparse for 'em. (If the area zoned for a new subdivision ever develops they might change their mind. But in that case I'd be losing much of the view I built there to get, selling the house at an inflated price, and moving further out.)
I recently built a vacation/retirement house in a remote area (where I could get a landline but can't get DSL or cable internet) and got cellphones to use during the construction project - then decided to try using them with a cell socket rather than installing a landline. Didn't work as well as I'd like.
My phone is an older Nokia model and the service AT&T (now Cingulair) wireless. That company is the only carrier available in the area - and no GSM, just TDMA (and maybe AMPS but I can't tell for sure).
The Cell Socket works reasonably well for voice calls.
It provides charging current when the cellphone is ON hook, but stops when the phone is engaged in a call. (Apparently the power brick is too small to power the cellphone and POTS-emulator line at the same time.)
The Cell Socket doesn't provide a dial tone. Instead (if you pick up the POTS phone when the cellphone is plugged in and ready) it provides a series of three beeps. Apparently these emulate the three beeps you get at the front of an intercept recording. My guess is that this is intended to keep people form trying to use modems and FAX machines with the Cell socket.
I tried programming a modem to use it (ignoring the wait-for-dialtone). But even at the lowest speed setting it would not work with the TDMA cellphone service.
(I hear you can get 1200 baud or so through an AMPS cellphone connection. Unfortunately, my phone was a Nokia with AT&T firmware, and (as far as I can tell) those (at AT&T's insistence) can not be forced to make an AMPS call when a digital carrier is available. So I couldn't test that.)
So it's good for:
- Making long distance calls on your cheep cell plans comfortably.
- Eliminating your long-distance carrier on your landline.
- Using your cellphone anywhere in a house when there's only a few good spots for the signal.
- Putting voice-only service into a remote location, where a landline would be expensive to run (or used too little to justify the expense when you already have a cellphone).
But it's not good for:
- Data
- FAX
- Long calls with little time between them to recharge the cellphone battery.
Most of the items on Hubble are designed to be replaceable in orbit, which is why a robot is able to be designed to replace exactly the things you identify.
Apparently, though, the gyros were not among the pluggable items (which is why somebody got the bright idea to put a new set in a pluggable "experiment" package.)
This leads me to believe that much of the other non-experiment infrastructure was in the same boat: Permanently installed to save weight or simplify design, with spares adequate to the expected mission lifetime in place, ready to be switched in. The expected near-term end-of-life of the Hubble is due to progressive failure of gyros. If they were as easily pluggable as the expeirments there wouldn't be a suggestion to include them in an experiment package.
My suggestion is that any future design should have "In order to support easy service for an indefinite project life, everything that CAN be pluggable IS pluggable, even if it carries a nontrivial weight penalty" as an explicit design principle.
Good engineering practice includes learning from past mistakes.
One of the suggestions for fixing the hubble's gyros was to include gyros in an experiment package. This got me to thinking:
Why are the gyros not a plugin item?
Why is the plugin not to essentially the same standard as the experiments.
While the primary optical path (including covers) and any docking connections and the like are a one-of and optimally should be special-purpose structures, virtually all the rest of the telescope's infrastructure - gyros, computers, batteries, etc. - could be built into pluggable modules. (Even attitude / station-keeping thruster assemblies and their tankage could be puuggable.)
Perhaps the replacment could be designed that way?
Making things pluggable would reduce the on-station time for service missions - whether repair, upgrade, experiment-change, or replace-consumables. It would also simplify building unmanned robotic service vehicles for the telescope, and reduce the likelyhood failure in robotic service missions.
A special agent is a federal investigative employee who has powers of arrest and is usually armed. This is "special" when compared to the powers of an ordinary federal employee, not to other agents within the FBI.
Only the powers of arrest part is "special". A mind-boggling range of government employees have federal permission to carry guns. (And this permission, like post-office driving rules, overrides state laws.)
This was apparently first noticed when an airport security employee leaked the list of agencies whose members could carry thorugh airports. In 1997, according to a GAO study (the source for info in this libertarian party press release) the nubmer of agencies was 45 and the number of gun-toters approaching 60,000 and had grown by over 2,400 in the previous year. I've heard nothing to indicate that the number has not continued to climb since then.
Some non-law-enforcement worker categories:
Poultry inspectors. Disaster aid workers. IRS auditors.
Some agencies with "special agents":
Small Business Administration NASA Department of Education U.S. Fish & Wildlife Service Department of Veterans Affairs
The Energy Department has access to machine guns and other agencies can summon tanks and military helicopters.
According to the Western Journalism Center these agencies have SWAT teams:
The National Park Service the Department of Health & Human Services
Re:An admission
on
Blink
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· Score: 2, Interesting
When I first saw the title The Power of Thinking without thinking , my first reaction was to reword the title in my head to The Power of Voting Republican.
Which is what comes from making a knee-jerk reaction rather than actually thinking about it - you got the parties flopped. B-)
On most issues both Liberals and Conservatives want the same things: Peace, prosperity, justice. The main ways they differ on how to get them - and how they think about it.
Liberal ideology encourages making snap judgements on an emotional basis. (Notice the substution of "I feel..." for "I think..." in their rhetoric.) Their policies (when they think about them at all) are based on either direct action to solve perceived problems by pushing in the desired direction, or indirect action to suppress something that is conceptually associated with the problem. And they treat people as members of classes - dealing with all the members of the class on the bases of the steretypical member's behavior. All of these approaches have a common thread: "Damn the side effects."
Conservative ideology, on the other hand, promotes thought about problems. The targets are largely the same. But the solutions take into account the unintended consequences of directly attacking the problem - which are often a cure far worse than the disease.
Conservatives are often people who were liberal in their younger years. They TRIED the simple solutions and found out that they made things worked. Then they thought about THAT, and came up with (or signed on to) other approaches - that were counter-intuitive but actually made things better rather than worse.
Thus the Winston Churchill quote: "If you're not a liberal at 20, you have no heart. If you're not a conservative at 40, you have no brain."
Unfortunately a lot of people either never find out that some "obvious" solutions don't work or never learn to think, and thus get stuck at 20. B-(
I learned to program with GWBasic, QBasic, TurboPascal, Modula-3 - none of which made it into the chart...
I learned with MAD (given your handle there ought to be a joke there somewhere).
MAD - Michigan Algorithm Decoder - was a rather powerful language sometimes described as algol-like, contemporary with Fortran II, which compiled into object (or assembler) for the IBM 70x/70xx series.
It was quite powerful. It had complex numbers, matrix types and operations. Particularly useful to me was that it let the user define new types, new operators, and rules for the code generator to support them. It also could show you, inline in your listing, the assembler code generated to support each line - invaluable for learning what was going on, and optimizing, and often handy for debugging.
A lot of useful work was done using this language in the '60s and '70s in the University of Michigan (where it originated) and a number of other places - several other universities, the auto industry, etc.
It died when the 709x series was replaced by the 360 series (although a low-key effort was made to produce a 360 version).
Part of the problem was that some of the language features depended on being able to pass a second, hidden, address in each argument to its own routines on certain functions while still being compatable with the Fortran-supporting subroutine library. This would have been surmountable.
The main killer was that the University had built its own timesharing system for the 360 series (MTS) while waiting for IBM to get its act in gear with TSS, and this had cought on and become production, not just at umich but at many other places. The U didn't have the budget to simultaneously support MTS, a language, its library, the "data concentrator" terminal server, and Dr. Dave's "fuzzball" routers for the early internet.
In the absense of a compatible language on the new machines the still-in-production applications were ported to languages that WERE available, relieving the pressure to support MAD, and the language was allowed to die.
[...] how are they expecting us to believe that this new tech isn't reverse-engineered UFO tech?
Obviously (from the names) we're talking about the "transtator" of Star Trek fame.
Bones (or Kirk, or some other crewperson or person from another of the fleet) must have lost another communicator on one of the trips back in time to Earth, as he did on that Mob-run planet in _A Piece of the Action_.
Are you sure you don't mean Electrical Discharge Machining? Do a google for EDM and machining to find tons of links. Also you left out an important part in your proposed plans: a capacitor. The resistors feeds power to the capacitor and limits the amount of current drawn when the arc fires. Also, very handy if you don't want your PS to melt down if you create a short accidentally.
Could be. But if you have a capacitor you don't need the switch (except to control the resistance by controlling the number of resistors in circuit). Instead you have a relaxation oscilator, with the repetition rate and gap voltage controlled by the gap. And I'd think it would tend to spot-weld when you shorted out.
Now you've got me wondering whether I just missed the cap and you're right, or if there's two variants on a theme. (I did the motion control on that project rather than the sparker control.) Your description certainly makes the resistors make more sense.
I'll see if I can look up the guy I worked for (who designed the spark supply) and check with him. (Probably won't be able to do it in time to follow up here, though.)
This technology is nothing new. My father built systems to do R&D and production using Electro Chemical Machining. [...]
Items used every day may have under gone this process, turbine fan blades, air bag explosive chambers, hard drive motors (meow), test sabot rounds for tanks.
Are you sure those are all built by electrochemical machining? I suspect some of them are built by its close relative: electrodynamic machining.
Electrochemical machining is reverse electroplating. It pulls metal atoms out, not just from the cut, but from the surrounding metal that is intended to remain, changing its properites.
Electrodynamic machining is a spark to the workpiece through a dilectric solution (typically water or oil). It can cut through anything that can be made to conduct. (You do diamonds by flashing a bit of metal over them for the initial contact. As you're removing diamond, the surface that's left has a microscopic layer that is converted to graphite to keep you going.)
Three sorts of tools:
- Use the end of a wire as a drill. (Feed the wire as the end erodes.)
- Use the side of a wire as a bandsaw. (Feed the wire in the inches-per-minute range so the cutting edge is always smooth and of a known size.)
- Make a graphite electrode in the shape of the hole you want and burn your way in. (Graphite doesn't erode much at all. Replace as needed.)
Cutting action: The spark vaporizes a path through the dilectric and melts a tiny pit in the workpiece. (Polarity is chosen so most of the melting is on the workpiece.) When the spark stops the channel collapses and the shockwave blasts the molten material out of the pit before it can re-harden. Repeat at a rate in the kilohertz range. Spark generally forms at the shortest space, which is where you want to remove the most metal, giving you a mirror finish.
(This effect was originally discovered in Russia about WW II when an engineer tried increasing the life of ignition "points" by putting them in an oil bath to cool them. They disintegrated within hours. It's also why you always use a brush to run current around a lubricated ball- or roller-bearing instead of passing it through the bearing: The effect would destroy the bearing surfaces in a similarly short time.)
The cut-away material ends up as a contaminant in the dilectric. So you pump that through a filter to clean it out.
Motion control is paramount: You sense the spark voltage to tell how far you are from the workpiece and use it for feedback, advancing or backing up to keep your spark path at the correct length.
Contaminants (especially chips) sometimes short the gap, so you back out until you clear it and can spark again. Sometimes you end up machining away the chip. Sometimes you may have to back far - even completely - out of a cut to clear the contaminant from your gap. This may mean retracing your path around several turns. (In the shaped-carbon-rod drill-in mode you also run the rod in little circles and/or back-and-forth it now and then to pump the dirty dilectric out and clean stuff in.)
You're CONSTANTLY backing-and forthing. MOST of your tool motion is back-and-forth, a small fraction is motion into the workpiece as the cut advances. So you MUST use an integer motion-control algorithm that retraces its steps exactly (or within an LSB or so) and doesn't accumulate roundoff err. Any accumulated roundoff, even a TINY bit, quickly walks you out of your path and into the workpiece, shutting you down.
The device is essentially a big power supply, a resistor, a switch, a voltage measurement peripheral, a computer, a motion table, and a dilectric pump/filter. Most of the energy ends up in the resistor. You do it that way as the easy way to control the spark's waveshape. The switch might be a bunch of paralleled FETs on a big heatsink. The resistor might be a bunch of foot-long power resistors, with a fan blowing on them so you can run them far beyond their normal ratings, carefully wired to minimize parasitic inductance.
That's the bulk of the specialized knowlege you'd need to build one, as they were about 15-20 years ago (when I did software for one).
[...] however, at anything about 40mph or so, rider lean is essentially worthless to affect the lean angle of the vehicle. Keith code has proven this by welding the steering to a fixed straight position on one of his track bikes and inviting disbelievers to ride it on a track in a straight line at speed, lean as hard as they can, and the bike continues to go straight.
Wrong test.
The wheel must be free to swivel in response to the gyroscopic forces to let the bike turn. The small gyroscopic force turns the wheel with respect to the frame, while the turned wheel turns the bike. Welding it to the bike completely overcomes this effect, and the gyroscopic effect simply stresses the forks, which leaves the wheel with miniscule offset.
The right test is to take your hands off the grips.
Of course it doesn't tell you whether the wheel is turning due to a gyroscopic effect or something else. But the point is that leaning turns the wheel and the angled wheel turns the bike.
Trevor mentions that you control speed by leaning forward/backward and steer by twisting your body. This is appropriate for low speeds.
But as with a bicycle or motor cycle, at higher speeds you can steer by leaning. For instance:
- Lean right.
- Force on the axle is translated to motion 90 degrees offset in the wheel's direction of rotation, causing the wheel to gradually precess to the right, gradually turning the vehicle.
Twisting continues to work but differently - in reverse and one stage of integration removed:
- Gently push forward on the right handlebar, as if turning left. (There should be a body-twisting motion to produce an equivalent on the unicycle.)
- Force on the axle is translated to motion 90 degrees offset in the wheel's direction of rotation, causing the wheel to gradually precess to lean progressively more to the right. (Stop pushing the handlebars when you're tilted as much as you want.)
- Tilting the wheel moves the center of gravity to the right, causing the vehicle and rider's weight to apply a force on the axle, as with the "lean right" case above.
- When you've turned far enough, gently push forward on the LEFT handlebar (or do the opposite body-twist) to undo the lean.
This only works at moderate-to-high speeds, when the gyroscopic effect is adequate. And it works at much lower speeds on a motorcycle than a bicycle due to the greater gyroscopic effect from the heavy wheels. (It's hard to get a bike going fast enough to do this.)
Try it out on a motorcycle: Find a nice flat, straight, country road with good pavement and no traffic. Get moving maybe 25 MPH, and balanced well enough that you can open your hand around the handgrip and steer by leaning. Once you've got that working, try just barely touching the back of one handle to push it forward.
Once you get the hang of it you can use it to perform extremely abrupt turns on the 'cycle. A stiff push causes the cycle to suddenly drop into a steep bank and begin a tight turn. A stiff push the other way pops it back upright and traveling straight. The banking is just right to keep you stuck to your seat and turning at a constant rate while applying no twisting force to the handlebars. Very relaxed while performing extreme manouvers, since the only muscular effort is used when you CHANGE your RATE OF TURN. (But don't overdoit and break traction or you'll go down.)
So THAT's what the maintenance crew / army was riding (on the under-road access paths) in Heinlein's _The Roads Must Roll_.
Maybe RH can stop spinning in his grave now that tech is catching up to his earliest stories.
Good work, Trevor!
Re:Wow, this is great news for criminals everywher
on
Cell Phone On A Chip
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· Score: 1
No longer will they have to keep their 10 sim cards on a keychain and swap them into their phone. Now they can just have 10 phones [...]
Note that this is how much of the middle-east terrorist networks were mapped. Some of the players had separate SIM cards for each contact - but made the mistake of using them in the same phone.
Since the phone's serial number and the SIM's serial number were both sent to the network, and the spy satellites snooped the network transmissions, the US intelligence community was able to map who was talking to whom, and when, and build a very accurate map of the command structure.
Eventually the terrorists figured out that the NSA was listening and that the physical phone (and its location) could be tracked. So they started using separate phones, and moving between calls when relaying messages, or avoiding cellphones altogether. After which the US was able to talk about what it had been doing without worrying about breaking it by revealing it (since it had already been broken by the terrorists' behavior change).
Of course that puts ordinary crooks on notice that this capability is available, encouraging them to use separate phones.
Sure, cheaper phones will make it easier for crooks. But they make it easier for ALL communication. (Including people REPORTING crooks - cheaper cellphones means more people have them when they need them.) IMHO the benefits to the general population far outweigh any slight easing of criminal communication.
[...] global problems effect all of us (air, water, fish all travel internationally). There's more to earth than USA and Canada:)
Quite.
But the media coverage and activist "scientific" prononcements here, where we can CHECK them, is extremely biased usually just plain wrong. And what I've seen of similar media coverage and activist "scientific" pronouncemnts in European countries, on those occasions where I could check them, were at least as bad (and usually worse, though that might be "law of small numbers" from my limited sample of checkable reports.)
So why should I (or you) trust this one any more than the rest?
At least we now have the blogosphere, so we can get our truth squads on the job.
(With such posts as my previous one just for an early shot across their bow. B-) )
But don't take MY word for it either. Let's get some certifiable experts on the job.
Seems like everyone and his uncle is coming up with a ****-ster type site.
I hear Napster was named that because it was the author's nickname. (He tended to carry a napsack everywhere he went.)
Of course once Napster caught on big and received major media attention, nearly everybody doing a peer-to-peer application who needed/wanted a large user community to make it useful, would name it "(something)ster" to attract user attention and create the appropriate mindset.
Slashdot Mirror
Genetically modified cells and viruses often mutate. scientists aren't certain, but they suspect that modification produces a less stable genetic code.
In the case of HIV, the virus is ALREADY extremely mutation-prone. If I remember correctly, the reverse transcriptase enzyme (the one that makes the initial-infection copy) averages more than one error per copy.
The virus compensates for this by having TWO copies of its genome - not so much for error correction as to have a significant chance of having a working version of each enzyme when it has infected a cell. (This also lets it form hybrids when two different versions infect the same cell.)
The result is that it actually evolves resistance to the antibodies the body throws at it during the course of the infection. And also that the infection is slow - but eventually overwhelms the immune system with a mob attack of divergent versions of the virus. A typical late-stage patient may have three or more viable variant populations, each capable of infecting other people.
If they ARE using pieces of the AIDS virus in their construct, I certainly hope one of the changes they made is replacing this error-prone enzyme with a more accurate one from another virus.
I think they can fairly be described as an embedded software vendor that supplies Linux platforms, rather than an "embedded Linux vendor".
Right on.
They haven't switched. (At least they haven't if the management is on the ball.) They've just added a new product line. Maybe it will pick up. Meanwhile the old standby is still there. Take your pick. Whichever way the market goes they're in the game.
Now they're a two-trick pony.
NASA uses VXWorks, it is one of thir best customers. They are very conservative, wont switch to linux.
When you've spent billions hardening a technology to extremes of reliability, a single failure costs you hundreds of millions and maybe several lives, and the technology you've hardened is more than adequate for the next job, you'd be a fool to switch.
You switch when the job can't be done without a switch, or when the benefits (including risk reductions) outweigh the costs and risks.
It's when you're starting from scratch that older and newer technologies are on a nearly level playing field. When an old tech is in place and performing well the new one needs to have a BIG advantage to displace it.
Such practices mutate thousands of unknown mutated genes for every beneficial gene they produce. Nobody ever checked if if 1/10 or 1 percent of the general population was allergic to a protein in a mutated food plant.
You're missing the point on the concern about allergies.
It's not that a new allergen might be created. Nearly ANYTHING can be allergenic - either directly or in complex with something else in the body. New compounds are being "invented" by mutation all the time. Forcing some mutations into a few plants in a lab is not even a drop in the bucket.
The concern is that there are a lot of compounds that are allergenic AND PERVASIVE in certain food plants. When someone becomes allergic to them, essentially the only effective treatment is to avoid them. (As of the last time I checked, desensitization does NOT work on the branch of the immune system that mediates food allergies.)
But these protiens are often useful: Some of them are the biological warfare agents the crop plants use against the parisites they are resistant to. Copying them into other species of crop plants can confer the resistance. Very useful.
But if you copy, say, a corn allergen to wheat, and sell the modified wheat AS wheat, how is someone who is allergic to it supposed to avoid it. Look at the label: It says "wheat". No corn ingredients (not even the dozen or so that don't sound like corn but are). Ought to be safe, right?
And with engineered wheat containing this corn allergen (and probably several others) immune to a range of pests (so no expensive pesticides are needed to keep its yeilds up), it will soon displace the non-engineered corn from commercial farming. So people with corn allergies won't be able to eat wheat, either.
Heck, how can they even FIGURE OUT that it's a CORN allergy? Scratch tests don't work. You need to do an elimination diet. Where do they start? Just meat? (What if the cattle were corn-fed? Many plant protiens appear in the meat in enough concentration to affect the taste and smell, which is no more sensitive than the immune system.)
Repeat with transferring wheat allergens into corn. Then play three-way musical genes with potatoes. Then add more plants to the mix.
Eventually, if you're allergic to ANY crop plant you're allergic to ALL crop plants. Then what do you eat?
Or are you trying to breed out people who get food allergies? (I suppose that's one way to reduce the population to the handfull that could be fed without the use of pesticides, fertilizers, OR gene-engineered crops.)
It's a shame, NetBSD I can understand, there may be some confusion when both BSDs use the same "daemony" logo style, but the other BSDs have all moved away from beastie.
IMHO NetBSD should dress the daemon as a retiarius.
That's the "Net-man" - the unarmored net-and-trident wielding gladiator of the Roman games.
(In competition with the Secutor (the sword-and-shield guy) the Retiarius has a significant advantage.)
Selective availability has been turned off, [...]
And either selective availablity or local jamming will be turned on the first time somebody uses GPS to fly a cruise missile in the president's window and land it on his desk (or something equivalent).
Probably local jamming or some variant, since differential GPS enables the land-on-the-desk stunt even with selective availablity turned on. (That WAS what it was invented for, after all.)
IMHO differential GPS is the real reason it was turned off. SA was no longer performing its intended mission, while SA was making GPS less useful and/or more expensive for the civilian infrastructure.
Lighthouses have been obsolete since radar came to be. GPS is hardly the starting point for this.
As a boater I can tell you that neither radar nor GPS makes lighthouses obsolete. Nor did LORAN before them.
Sure, if you've got it and its working you can tell where you are. Within a football field if selective-availability is on, much better if it's off.
And the big commercial ships have them and they're usually working.
And the small commercial ships in well-to-do countries (like fishing boats for instance) may have them and they may be working.
And the more well-to-do pleasure-boaters may have them and they may be working.
But there are a LOT of boats out there that DON'T have them. The BULK of them, if you're talking numbers.
Fishermen may not have them - and may have other things to deal with than watching a screen. Most pleasure boats are small fry, not millionaires' giant toys. (A small ocean-capable cruising sailboat, for instance, may be considerably less expensive than an RV of a similar size.)
Even if they have them, any bets whether they're working when you're coming in after a month at sea, two years after they were purchased? Salt spray is HELL on electronics, and gets into everything.
And even when they do have them, and they are operating, a boater may think he's far out to sea when he's actually almost onto a hidden hazard, and not be looking. (A lighted nav marker, among other things, is the idiot-light of boating.)
Saying GPS obsoletes lighthouses is like saying GPS-based navigation systems for cars obsolete stop signs, curve signs, and the blinking lights associated with them.
Data? If you live in one of the 4 UMTS markets you can receive faster data transmitions through your Cingular service then through your cable modem.
Also: UMTS is metered at a penny a megabyte if you use it for anything other than browsing on your cellphone's screen.
Bluetooth, cable-from-the-phone, or plugging the authorization card into a different phone or device all start the meter.
Data? If you live in one of the 4 UMTS markets you can receive faster data transmitions through your Cingular service then through your cable modem.
I'd love to do that. But I don't.
The cell site is just TDMA. No data (other than digitized voice), period. And as of the last time I checked (a couple weeks ago) there were NO plans at Cingular to EVER upgrade it - even to voice-only GSM - just as AT&T had no such plans before the merger.
(I'll try again from time to time as the merger shakes out and gets organized.)
It's right on the edge of their TDMA coverage, far off the edge of their GSM coverage, and they're not planning to expand either - even to convert it to GSM as they retire TDMA. Verizon has no plans to extend coverage to that area, either. (With the AT&T/Cingular cell and a roaming agreement, they apparently consider it adequately covered.)
Since there's only a handfull of retirement homes and the intersection of two not-heavily-traveled highways, it's probably too sparse for 'em. (If the area zoned for a new subdivision ever develops they might change their mind. But in that case I'd be losing much of the view I built there to get, selling the house at an inflated price, and moving further out.)
I got one of these about a year ago.
I recently built a vacation/retirement house in a remote area (where I could get a landline but can't get DSL or cable internet) and got cellphones to use during the construction project - then decided to try using them with a cell socket rather than installing a landline. Didn't work as well as I'd like.
My phone is an older Nokia model and the service AT&T (now Cingulair) wireless. That company is the only carrier available in the area - and no GSM, just TDMA (and maybe AMPS but I can't tell for sure).
The Cell Socket works reasonably well for voice calls.
It provides charging current when the cellphone is ON hook, but stops when the phone is engaged in a call. (Apparently the power brick is too small to power the cellphone and POTS-emulator line at the same time.)
The Cell Socket doesn't provide a dial tone. Instead (if you pick up the POTS phone when the cellphone is plugged in and ready) it provides a series of three beeps. Apparently these emulate the three beeps you get at the front of an intercept recording. My guess is that this is intended to keep people form trying to use modems and FAX machines with the Cell socket.
I tried programming a modem to use it (ignoring the wait-for-dialtone). But even at the lowest speed setting it would not work with the TDMA cellphone service.
(I hear you can get 1200 baud or so through an AMPS cellphone connection. Unfortunately, my phone was a Nokia with AT&T firmware, and (as far as I can tell) those (at AT&T's insistence) can not be forced to make an AMPS call when a digital carrier is available. So I couldn't test that.)
So it's good for:
- Making long distance calls on your cheep cell plans comfortably.
- Eliminating your long-distance carrier on your landline.
- Using your cellphone anywhere in a house when there's only a few good spots for the signal.
- Putting voice-only service into a remote location, where a landline would be expensive to run (or used too little to justify the expense when you already have a cellphone).
But it's not good for:
- Data
- FAX
- Long calls with little time between them to recharge the cellphone battery.
Most of the items on Hubble are designed to be replaceable in orbit, which is why a robot is able to be designed to replace exactly the things you identify.
Apparently, though, the gyros were not among the pluggable items (which is why somebody got the bright idea to put a new set in a pluggable "experiment" package.)
This leads me to believe that much of the other non-experiment infrastructure was in the same boat: Permanently installed to save weight or simplify design, with spares adequate to the expected mission lifetime in place, ready to be switched in. The expected near-term end-of-life of the Hubble is due to progressive failure of gyros. If they were as easily pluggable as the expeirments there wouldn't be a suggestion to include them in an experiment package.
My suggestion is that any future design should have "In order to support easy service for an indefinite project life, everything that CAN be pluggable IS pluggable, even if it carries a nontrivial weight penalty" as an explicit design principle.
Good engineering practice includes learning from past mistakes.
One of the suggestions for fixing the hubble's gyros was to include gyros in an experiment package. This got me to thinking:
Why are the gyros not a plugin item?
Why is the plugin not to essentially the same standard as the experiments.
While the primary optical path (including covers) and any docking connections and the like are a one-of and optimally should be special-purpose structures, virtually all the rest of the telescope's infrastructure - gyros, computers, batteries, etc. - could be built into pluggable modules. (Even attitude / station-keeping thruster assemblies and their tankage could be puuggable.)
Perhaps the replacment could be designed that way?
Making things pluggable would reduce the on-station time for service missions - whether repair, upgrade, experiment-change, or replace-consumables. It would also simplify building unmanned robotic service vehicles for the telescope, and reduce the likelyhood failure in robotic service missions.
A special agent is a federal investigative employee who has powers of arrest and is usually armed. This is "special" when compared to the powers of an ordinary federal employee, not to other agents within the FBI.
Only the powers of arrest part is "special". A mind-boggling range of government employees have federal permission to carry guns. (And this permission, like post-office driving rules, overrides state laws.)
This was apparently first noticed when an airport security employee leaked the list of agencies whose members could carry thorugh airports. In 1997, according to a GAO study (the source for info in this libertarian party press release) the nubmer of agencies was 45 and the number of gun-toters approaching 60,000 and had grown by over 2,400 in the previous year. I've heard nothing to indicate that the number has not continued to climb since then.
Some non-law-enforcement worker categories:
Poultry inspectors.
Disaster aid workers.
IRS auditors.
Some agencies with "special agents":
Small Business Administration
NASA
Department of Education
U.S. Fish & Wildlife Service
Department of Veterans Affairs
The Energy Department has access to machine guns and other agencies can summon tanks and military helicopters.
According to the Western Journalism Center these agencies have SWAT teams:
The National Park Service
the Department of Health & Human Services
When I first saw the title The Power of Thinking without thinking , my first reaction was to reword the title in my head to The Power of Voting Republican.
Which is what comes from making a knee-jerk reaction rather than actually thinking about it - you got the parties flopped. B-)
On most issues both Liberals and Conservatives want the same things: Peace, prosperity, justice. The main ways they differ on how to get them - and how they think about it.
Liberal ideology encourages making snap judgements on an emotional basis. (Notice the substution of "I feel..." for "I think..." in their rhetoric.) Their policies (when they think about them at all) are based on either direct action to solve perceived problems by pushing in the desired direction, or indirect action to suppress something that is conceptually associated with the problem. And they treat people as members of classes - dealing with all the members of the class on the bases of the steretypical member's behavior. All of these approaches have a common thread: "Damn the side effects."
Conservative ideology, on the other hand, promotes thought about problems. The targets are largely the same. But the solutions take into account the unintended consequences of directly attacking the problem - which are often a cure far worse than the disease.
Conservatives are often people who were liberal in their younger years. They TRIED the simple solutions and found out that they made things worked. Then they thought about THAT, and came up with (or signed on to) other approaches - that were counter-intuitive but actually made things better rather than worse.
Thus the Winston Churchill quote: "If you're not a liberal at 20, you have no heart. If you're not a conservative at 40, you have no brain."
Unfortunately a lot of people either never find out that some "obvious" solutions don't work or never learn to think, and thus get stuck at 20. B-(
madprogrammer writes:
No teaching/learning languages?
I learned to program with GWBasic, QBasic, TurboPascal, Modula-3 - none of which made it into the chart...
I learned with MAD (given your handle there ought to be a joke there somewhere).
MAD - Michigan Algorithm Decoder - was a rather powerful language sometimes described as algol-like, contemporary with Fortran II, which compiled into object (or assembler) for the IBM 70x/70xx series.
It was quite powerful. It had complex numbers, matrix types and operations. Particularly useful to me was that it let the user define new types, new operators, and rules for the code generator to support them. It also could show you, inline in your listing, the assembler code generated to support each line - invaluable for learning what was going on, and optimizing, and often handy for debugging.
A lot of useful work was done using this language in the '60s and '70s in the University of Michigan (where it originated) and a number of other places - several other universities, the auto industry, etc.
It died when the 709x series was replaced by the 360 series (although a low-key effort was made to produce a 360 version).
Part of the problem was that some of the language features depended on being able to pass a second, hidden, address in each argument to its own routines on certain functions while still being compatable with the Fortran-supporting subroutine library. This would have been surmountable.
The main killer was that the University had built its own timesharing system for the 360 series (MTS) while waiting for IBM to get its act in gear with TSS, and this had cought on and become production, not just at umich but at many other places. The U didn't have the budget to simultaneously support MTS, a language, its library, the "data concentrator" terminal server, and Dr. Dave's "fuzzball" routers for the early internet.
In the absense of a compatible language on the new machines the still-in-production applications were ported to languages that WERE available, relieving the pressure to support MAD, and the language was allowed to die.
[...] how are they expecting us to believe that this new tech isn't reverse-engineered UFO tech?
Obviously (from the names) we're talking about the "transtator" of Star Trek fame.
Bones (or Kirk, or some other crewperson or person from another of the fleet) must have lost another communicator on one of the trips back in time to Earth, as he did on that Mob-run planet in _A Piece of the Action_.
Are you sure you don't mean Electrical Discharge Machining? Do a google for EDM and machining to find tons of links. Also you left out an important part in your proposed plans: a capacitor. The resistors feeds power to the capacitor and limits the amount of current drawn when the arc fires. Also, very handy if you don't want your PS to melt down if you create a short accidentally.
Could be. But if you have a capacitor you don't need the switch (except to control the resistance by controlling the number of resistors in circuit). Instead you have a relaxation oscilator, with the repetition rate and gap voltage controlled by the gap. And I'd think it would tend to spot-weld when you shorted out.
Now you've got me wondering whether I just missed the cap and you're right, or if there's two variants on a theme. (I did the motion control on that project rather than the sparker control.) Your description certainly makes the resistors make more sense.
I'll see if I can look up the guy I worked for (who designed the spark supply) and check with him. (Probably won't be able to do it in time to follow up here, though.)
This technology is nothing new. My father built systems to do R&D and production using Electro Chemical Machining. [...]
Items used every day may have under gone this process, turbine fan blades, air bag explosive chambers, hard drive motors (meow), test sabot rounds for tanks.
Are you sure those are all built by electrochemical machining? I suspect some of them are built by its close relative: electrodynamic machining.
Electrochemical machining is reverse electroplating. It pulls metal atoms out, not just from the cut, but from the surrounding metal that is intended to remain, changing its properites.
Electrodynamic machining is a spark to the workpiece through a dilectric solution (typically water or oil). It can cut through anything that can be made to conduct. (You do diamonds by flashing a bit of metal over them for the initial contact. As you're removing diamond, the surface that's left has a microscopic layer that is converted to graphite to keep you going.)
Three sorts of tools:
- Use the end of a wire as a drill. (Feed the wire as the end erodes.)
- Use the side of a wire as a bandsaw. (Feed the wire in the inches-per-minute range so the cutting edge is always smooth and of a known size.)
- Make a graphite electrode in the shape of the hole you want and burn your way in. (Graphite doesn't erode much at all. Replace as needed.)
Cutting action: The spark vaporizes a path through the dilectric and melts a tiny pit in the workpiece. (Polarity is chosen so most of the melting is on the workpiece.) When the spark stops the channel collapses and the shockwave blasts the molten material out of the pit before it can re-harden. Repeat at a rate in the kilohertz range. Spark generally forms at the shortest space, which is where you want to remove the most metal, giving you a mirror finish.
(This effect was originally discovered in Russia about WW II when an engineer tried increasing the life of ignition "points" by putting them in an oil bath to cool them. They disintegrated within hours. It's also why you always use a brush to run current around a lubricated ball- or roller-bearing instead of passing it through the bearing: The effect would destroy the bearing surfaces in a similarly short time.)
The cut-away material ends up as a contaminant in the dilectric. So you pump that through a filter to clean it out.
Motion control is paramount: You sense the spark voltage to tell how far you are from the workpiece and use it for feedback, advancing or backing up to keep your spark path at the correct length.
Contaminants (especially chips) sometimes short the gap, so you back out until you clear it and can spark again. Sometimes you end up machining away the chip. Sometimes you may have to back far - even completely - out of a cut to clear the contaminant from your gap. This may mean retracing your path around several turns. (In the shaped-carbon-rod drill-in mode you also run the rod in little circles and/or back-and-forth it now and then to pump the dirty dilectric out and clean stuff in.)
You're CONSTANTLY backing-and forthing. MOST of your tool motion is back-and-forth, a small fraction is motion into the workpiece as the cut advances. So you MUST use an integer motion-control algorithm that retraces its steps exactly (or within an LSB or so) and doesn't accumulate roundoff err. Any accumulated roundoff, even a TINY bit, quickly walks you out of your path and into the workpiece, shutting you down.
The device is essentially a big power supply, a resistor, a switch, a voltage measurement peripheral, a computer, a motion table, and a dilectric pump/filter. Most of the energy ends up in the resistor. You do it that way as the easy way to control the spark's waveshape. The switch might be a bunch of paralleled FETs on a big heatsink. The resistor might be a bunch of foot-long power resistors, with a fan blowing on them so you can run them far beyond their normal ratings, carefully wired to minimize parasitic inductance.
That's the bulk of the specialized knowlege you'd need to build one, as they were about 15-20 years ago (when I did software for one).
[...] however, at anything about 40mph or so, rider lean is essentially worthless to affect the lean angle of the vehicle. Keith code has proven this by welding the steering to a fixed straight position on one of his track bikes and inviting disbelievers to ride it on a track in a straight line at speed, lean as hard as they can, and the bike continues to go straight.
Wrong test.
The wheel must be free to swivel in response to the gyroscopic forces to let the bike turn. The small gyroscopic force turns the wheel with respect to the frame, while the turned wheel turns the bike. Welding it to the bike completely overcomes this effect, and the gyroscopic effect simply stresses the forks, which leaves the wheel with miniscule offset.
The right test is to take your hands off the grips.
Of course it doesn't tell you whether the wheel is turning due to a gyroscopic effect or something else. But the point is that leaning turns the wheel and the angled wheel turns the bike.
Trevor mentions that you control speed by leaning forward/backward and steer by twisting your body. This is appropriate for low speeds.
But as with a bicycle or motor cycle, at higher speeds you can steer by leaning. For instance:
- Lean right.
- Force on the axle is translated to motion 90 degrees offset in the wheel's direction of rotation, causing the wheel to gradually precess to the right, gradually turning the vehicle.
Twisting continues to work but differently - in reverse and one stage of integration removed:
- Gently push forward on the right handlebar, as if turning left. (There should be a body-twisting motion to produce an equivalent on the unicycle.)
- Force on the axle is translated to motion 90 degrees offset in the wheel's direction of rotation, causing the wheel to gradually precess to lean progressively more to the right. (Stop pushing the handlebars when you're tilted as much as you want.)
- Tilting the wheel moves the center of gravity to the right, causing the vehicle and rider's weight to apply a force on the axle, as with the "lean right" case above.
- When you've turned far enough, gently push forward on the LEFT handlebar (or do the opposite body-twist) to undo the lean.
This only works at moderate-to-high speeds, when the gyroscopic effect is adequate. And it works at much lower speeds on a motorcycle than a bicycle due to the greater gyroscopic effect from the heavy wheels. (It's hard to get a bike going fast enough to do this.)
Try it out on a motorcycle: Find a nice flat, straight, country road with good pavement and no traffic. Get moving maybe 25 MPH, and balanced well enough that you can open your hand around the handgrip and steer by leaning. Once you've got that working, try just barely touching the back of one handle to push it forward.
Once you get the hang of it you can use it to perform extremely abrupt turns on the 'cycle. A stiff push causes the cycle to suddenly drop into a steep bank and begin a tight turn. A stiff push the other way pops it back upright and traveling straight. The banking is just right to keep you stuck to your seat and turning at a constant rate while applying no twisting force to the handlebars. Very relaxed while performing extreme manouvers, since the only muscular effort is used when you CHANGE your RATE OF TURN. (But don't overdoit and break traction or you'll go down.)
A self-balancing power unicycle.
So THAT's what the maintenance crew / army was riding (on the under-road access paths) in Heinlein's _The Roads Must Roll_.
Maybe RH can stop spinning in his grave now that tech is catching up to his earliest stories.
Good work, Trevor!
No longer will they have to keep their 10 sim cards on a keychain and swap them into their phone. Now they can just have 10 phones [...]
Note that this is how much of the middle-east terrorist networks were mapped. Some of the players had separate SIM cards for each contact - but made the mistake of using them in the same phone.
Since the phone's serial number and the SIM's serial number were both sent to the network, and the spy satellites snooped the network transmissions, the US intelligence community was able to map who was talking to whom, and when, and build a very accurate map of the command structure.
Eventually the terrorists figured out that the NSA was listening and that the physical phone (and its location) could be tracked. So they started using separate phones, and moving between calls when relaying messages, or avoiding cellphones altogether. After which the US was able to talk about what it had been doing without worrying about breaking it by revealing it (since it had already been broken by the terrorists' behavior change).
Of course that puts ordinary crooks on notice that this capability is available, encouraging them to use separate phones.
Sure, cheaper phones will make it easier for crooks. But they make it easier for ALL communication. (Including people REPORTING crooks - cheaper cellphones means more people have them when they need them.) IMHO the benefits to the general population far outweigh any slight easing of criminal communication.
[...] global problems effect all of us (air, water, fish all travel internationally). There's more to earth than USA and Canada :)
Quite.
But the media coverage and activist "scientific" prononcements here, where we can CHECK them, is extremely biased usually just plain wrong. And what I've seen of similar media coverage and activist "scientific" pronouncemnts in European countries, on those occasions where I could check them, were at least as bad (and usually worse, though that might be "law of small numbers" from my limited sample of checkable reports.)
So why should I (or you) trust this one any more than the rest?
At least we now have the blogosphere, so we can get our truth squads on the job.
(With such posts as my previous one just for an early shot across their bow. B-) )
But don't take MY word for it either. Let's get some certifiable experts on the job.
Looks like nobody saw my sig, and got the joke.
Now that you point it out, it IS funny. B-)
Napster, Bellster, Dogster, Crapster, Slapster..
Seems like everyone and his uncle is coming up with a ****-ster type site.
I hear Napster was named that because it was the author's nickname. (He tended to carry a napsack everywhere he went.)
Of course once Napster caught on big and received major media attention, nearly everybody doing a peer-to-peer application who needed/wanted a large user community to make it useful, would name it "(something)ster" to attract user attention and create the appropriate mindset.