Deleting data is really really hard. If one is storing large amounts of data it is difficult to put a system in place which can prove that every copy in your posession has been deleted. Think about the work of sifting through thousands of write-once offline backups, be it tapes or CDs or whatever, locating the data, copying the original minus the data and destroying the originals. If that's not hard enough, what about data that's not in discrete files. Say there's a PostgreSQL database that's zipped and spans a thousand peices of physical media. The only way to delete a record is to load the whole database then redump it. And don't forget about regenerating all the index files. And dealing with obsolete file formats.
This sounds like a stupid problem, but in reality it is really tough to delete something and be certain that you've got it all.
The real news is that 20% of the watermelon crop is currently thrown out due to cosmetic issues. I don't understand why shape and surface issues would disqualify the fruit from use in processed foods. Such as watermelon juice, fruit salads, sweeteners, etc. If true (and the article did not provide citations, this represents a stunning waste.
> Given the size differential between the first and later stages, the earlier post is > somewhat justified in calling LOX and kerosene the primary fuel for Saturn V.
But most of the delta-v comes from the final two stages. Velocity at first staging was 9,900 km/h. Final velocity was 39,000 km/h. Source: http://www.braeunig.us/space/specs/saturn.htm
I work for Google, and I gotta tell you, it's a pain to have to research an answer and type up a page of results within 0.17 seconds of a user hitting the Search button. Someone help!
> The problem is, I think, simply a decrease in volume for fuel. [...] > Then there is also the problem of foam acting chemically with the fuel or oxidizer. [...] > Anyway, that's my best guess.
Good guesses. Reality is stranger.
The tank is made of aluminum alloy. Very thin metal. At supersonic speeds, the tank would heat up. The increased temperature would cause the walls to become weaker, and the tank would buckle and rupture. By putting the insulation on the outside, they keep the metal of the tank walls super-cooled. Neat idea. The Delta rockets do the same thing.
Another reason is that if you think foam falling off the outside of the tank is bad, just imagine what foam falling off the inside would do. yup, it would get sucked through the engines. The turbopumps which inject fuel into the main engines are high-energy bombs, just waiting for an excuse to fly apart. So rockets (like Atlas and Saturn) with internal insulation require filters on the fuel lines to make sure they don't ingest any foam.
> He's previously said that the film will feature a whole new cast and ship;
That has the potential to be very good. The writers would have the freedom to kill off or transform any crew members they wish, not just the ones wearing red shirts. With everyone and everything (including the ship) potentially expendable, it could be a wild ride with lots of plot reversals.
It also has the potential to be very bad. Many viewers don't realise how much the regular Trek actors influence the show by keeping an independent reality check on their characters. Multi-season arcs in TNG were actually actor driven (like Troi quietly disliking Worf for most of the show).
So while it might be a great movie, it might be Trek only in name. We'll have to wait and see. Too bad it will be an odd number movie.
A lot of posts here will no doubt be saying something along the lines "see, this is what happens when you outsource". Well, think about it from an investigator's point of view. If money was transferred illegitimately from a US customer to somewhere in the US, it would be much harder to figure out what was going on than if it was being sent to India. By outsourcing the call center to India, it has made the origin of this sort of fraud much easier to detect.
I'm a system administrator and most of my customers are in the UK. So when I'm investigating an incident on our servers, and the logs show some activity from Brazil, it makes my job a lot easier.
Posted by "Drunkenbatman". On "drunkenblog.com". Defending "desicanuk". Quotes people from "Delicious Monster", "DaringFireball" and "Unsanity". Submitted to "slashdot.org" by "tabkey12".
Two questions:
How do we expect to be taken seriously with pseudonyms like this?
How many/.ers didn't even blink while reading the intro?
Of course look who's talking; Odo, a fictional shapeshifter... <sigh>
And ISPs are going to search for fingerprints in encrypted downloads how exactly?
It would be relatively easy for the next generation of P2P applications to add very basic encryption. Possibly based on a captcha (just a regular zip file encrypted against the random letters contained in a gif).
Or will the MPAA's next trick be to purchase legislation banning encryption.
> There is no robot to send up to bring it down. They want to be able to command it down [...] BTW my father worked on pointing and control on Hubble. I'm no expert, but I've spent many nights asking him a lot of questions about Hubble.
Oh man, you seriously need to have another chat with your dad. Hubble can point itself in any direction thanks to its gyros. But it doesn't have any engines. It couldn't deorbit itself if it wanted to. They have full control over where Hubble looks, but not where it goes. To deorbit Hubble you need a robotic deorbit module (aka a rocket).
HUBBLE ROBOTIC VEHICLE DEORBIT MODULE (HRVDM)
Contract Award Date: DTD 092404
Contract Award Number: CNT NNG05EA01C
Contract Award Amount: AMT $330,578,914
Contractor: TO Lockheed Martin Space Systems Company
[Off topic] While Googling for the above I found this generated ad:
Find HUBBLE DEORBIT MODULE at eBay
Looking for hubble deorbit module? eBay has great deals on new and used electronics, cars, apparel, collectibles, sporting goods and more. If you can't find it on eBay, it probably doesn't exist.
http://www.eBay.com
When do they intend to deorbit Hubble? As I understand it, the first thing expected to die on Hubble are the gyroscopes. One needs three gyros to point the scope at a celestial target. The deorbit module will definitely have its own pointing system (used for docking, among other things). Which means the mere presence of the deorbit module would fix Hubble. So what's their criteria for dropping Hubble into the Pacific?
> Computers are made up of meltable parts. By melting the computers down, would it not be possible to skim off various useful elements and compounds at certain depths?
Four problems I can think of off the top of my head:
Computers are not meltable. Circuit boards don't melt (at least not at any reasonable temperature). So there's going to be a lot of debris.
Melting computers would require a lot of energy. Weigh the environmental costs of burning a ton of coal vs burrying a dozen computers.
The resulting pools of liquid wouldn't be very pure. Not if one is relying on gravity to do the separation. To do a better job you'd need to use a centrifuge. Note that many chemicals of different densities like to bond to each other.
Plastics and other low-temperature volatiles would vapourize before one melted steel. So you'd be venting toxic fumes. That means you'd need a big air-purification system.
Just some thoughts. I'm sure others will think of others. But it's an interesting suggestion.
> The proposed NCRA legislation covers both monitors and computer chasses, as well as a "computer with a central processing unit and monitor integrated in a single device," or a laptop.
Where (and how) do they draw the line? Desktop computer > laptop > palmtop > wristwatch > implant... maybe it would be better to charge by mass or percentage value (a laptop != a Cray).
I'm not criticising goal of this law, just curious how an arbitrary line is drawn. Arbitrarily is my guess.
The US would never partner with the Chinese. Not while the US shuttle is grounded. And once it is flying, they won't need to partner with them. The Chinese know this. Having to rely on the Russians to get to the space station is embarrasing enough, but dropping to third place thanks to the Chinese would be too much.
On the other hand, the Chinese have (so far) been very good a keeping the operation of their space program separate from issues of national pride. They launch misions when they are ready, not in time for some politico's birthday or scheduled speech. Linking the two was one of the reasons the Russians never made it to the Moon and one of the reasons the Americans lost Challenger.
My question would be whether the replacement tiles are actually new, or whether they've just been sitting in a warehouse for 40 years like most of the other shuttle spare parts.
Yes, they are new. One can't stock spare tiles since each is tile different. Not only are the tiles not interchangable, the orbiters don't have compatible tile layouts. So they are custom built as needed. Until recently they were manufactured by the original facility in Palmdale, California. This made sense since the shuttles were built there. A couple of decades after they stopped building shuttles, Nasa realised that it would make sense to move the tile manufacturing facility to Florida, right next to the orbiter processing facililties. As soon as they completed this new facility, hurricane Frances swept through Florida and ripped the roof off. So Nasa is currently considering whether to reopen the old Palmdale facility.
Note that "tiles" != "RCC panels". The former are cheap, the latter cost nearly $1m each. Nasa has spares of these (at least they are interchangable between shuttles), but new ones can still be built by Lockeed Martin. Though the staff are starting to look a little old...
That is indeed a lot of gadgets. But the other (missing) half of the statistic is how long will these devices last? Will the all be thrown out next year, making this a running cost? Or will they be in use for years to come, making this a capital cost?
The calculator on my desk was purchased in 1972. The PC I'm writing this on was bought in 1999. Both are expected to last me for many more years to come. My fear is that the $113.5b figure in the article is mostly the result of people burning money for no reason.
Not always. NASA was given a blank cheque in the 60s to get a man to the Moon. With the advantage of hindsight, we can see that NASA managed the project extremely well and there was very little waste. Contrast this with NASA's subsequent accomplishments once the blank cheque expired: decades of waste.
Sometimes a blank cheque is just what's needed to get something accomplished efficiently. Apparently not in this case though.
Slashdot Mirror
Deleting data is really really hard. If one is storing large amounts of data it is difficult to put a system in place which can prove that every copy in your posession has been deleted. Think about the work of sifting through thousands of write-once offline backups, be it tapes or CDs or whatever, locating the data, copying the original minus the data and destroying the originals. If that's not hard enough, what about data that's not in discrete files. Say there's a PostgreSQL database that's zipped and spans a thousand peices of physical media. The only way to delete a record is to load the whole database then redump it. And don't forget about regenerating all the index files. And dealing with obsolete file formats.
This sounds like a stupid problem, but in reality it is really tough to delete something and be certain that you've got it all.
The real news is that 20% of the watermelon crop is currently thrown out due to cosmetic issues. I don't understand why shape and surface issues would disqualify the fruit from use in processed foods. Such as watermelon juice, fruit salads, sweeteners, etc. If true (and the article did not provide citations, this represents a stunning waste.
> Given the size differential between the first and later stages, the earlier post is
> somewhat justified in calling LOX and kerosene the primary fuel for Saturn V.
But most of the delta-v comes from the final two stages.
Velocity at first staging was 9,900 km/h. Final velocity was 39,000 km/h.
Source: http://www.braeunig.us/space/specs/saturn.htm
I work for Google, and I gotta tell you, it's a pain to have to research an answer and type up a page of results within 0.17 seconds of a user hitting the Search button. Someone help!
> The problem is, I think, simply a decrease in volume for fuel.
[...]
> Then there is also the problem of foam acting chemically with the fuel or oxidizer.
[...]
> Anyway, that's my best guess.
Good guesses. Reality is stranger.
The tank is made of aluminum alloy. Very thin metal. At supersonic speeds, the tank would heat up. The increased temperature would cause the walls to become weaker, and the tank would buckle and rupture. By putting the insulation on the outside, they keep the metal of the tank walls super-cooled. Neat idea. The Delta rockets do the same thing.
Another reason is that if you think foam falling off the outside of the tank is bad, just imagine what foam falling off the inside would do. yup, it would get sucked through the engines. The turbopumps which inject fuel into the main engines are high-energy bombs, just waiting for an excuse to fly apart. So rockets (like Atlas and Saturn) with internal insulation require filters on the fuel lines to make sure they don't ingest any foam.
That has the potential to be very good. The writers would have the freedom to kill off or transform any crew members they wish, not just the ones wearing red shirts. With everyone and everything (including the ship) potentially expendable, it could be a wild ride with lots of plot reversals.
It also has the potential to be very bad. Many viewers don't realise how much the regular Trek actors influence the show by keeping an independent reality check on their characters. Multi-season arcs in TNG were actually actor driven (like Troi quietly disliking Worf for most of the show).
So while it might be a great movie, it might be Trek only in name. We'll have to wait and see. Too bad it will be an odd number movie.
I'm a system administrator and most of my customers are in the UK. So when I'm investigating an incident on our servers, and the logs show some activity from Brazil, it makes my job a lot easier.
Two questions:
- How do we expect to be taken seriously with pseudonyms like this?
- How many
/.ers didn't even blink while reading the intro?
Of course look who's talking; Odo, a fictional shapeshifter... <sigh>And ISPs are going to search for fingerprints in encrypted downloads how exactly?
It would be relatively easy for the next generation of P2P applications to add very basic encryption. Possibly based on a captcha (just a regular zip file encrypted against the random letters contained in a gif).
Or will the MPAA's next trick be to purchase legislation banning encryption.
Oh man, you seriously need to have another chat with your dad. Hubble can point itself in any direction thanks to its gyros. But it doesn't have any engines. It couldn't deorbit itself if it wanted to. They have full control over where Hubble looks, but not where it goes. To deorbit Hubble you need a robotic deorbit module (aka a rocket).
For more information, see this page:
[Off topic] While Googling for the above I found this generated ad:
When do they intend to deorbit Hubble? As I understand it, the first thing expected to die on Hubble are the gyroscopes. One needs three gyros to point the scope at a celestial target. The deorbit module will definitely have its own pointing system (used for docking, among other things). Which means the mere presence of the deorbit module would fix Hubble. So what's their criteria for dropping Hubble into the Pacific?
Four problems I can think of off the top of my head:
- Computers are not meltable. Circuit boards don't melt (at least not at any reasonable temperature). So there's going to be a lot of debris.
- Melting computers would require a lot of energy. Weigh the environmental costs of burning a ton of coal vs burrying a dozen computers.
- The resulting pools of liquid wouldn't be very pure. Not if one is relying on gravity to do the separation. To do a better job you'd need to use a centrifuge. Note that many chemicals of different densities like to bond to each other.
- Plastics and other low-temperature volatiles would vapourize before one melted steel. So you'd be venting toxic fumes. That means you'd need a big air-purification system.
Just some thoughts. I'm sure others will think of others. But it's an interesting suggestion.Where (and how) do they draw the line? Desktop computer > laptop > palmtop > wristwatch > implant ... maybe it would be better to charge by mass or percentage value (a laptop != a Cray).
I'm not criticising goal of this law, just curious how an arbitrary line is drawn. Arbitrarily is my guess.
On the other hand, the Chinese have (so far) been very good a keeping the operation of their space program separate from issues of national pride. They launch misions when they are ready, not in time for some politico's birthday or scheduled speech. Linking the two was one of the reasons the Russians never made it to the Moon and one of the reasons the Americans lost Challenger.
Yes, they are new. One can't stock spare tiles since each is tile different. Not only are the tiles not interchangable, the orbiters don't have compatible tile layouts. So they are custom built as needed. Until recently they were manufactured by the original facility in Palmdale, California. This made sense since the shuttles were built there. A couple of decades after they stopped building shuttles, Nasa realised that it would make sense to move the tile manufacturing facility to Florida, right next to the orbiter processing facililties. As soon as they completed this new facility, hurricane Frances swept through Florida and ripped the roof off. So Nasa is currently considering whether to reopen the old Palmdale facility.
Note that "tiles" != "RCC panels". The former are cheap, the latter cost nearly $1m each. Nasa has spares of these (at least they are interchangable between shuttles), but new ones can still be built by Lockeed Martin. Though the staff are starting to look a little old...
The calculator on my desk was purchased in 1972. The PC I'm writing this on was bought in 1999. Both are expected to last me for many more years to come. My fear is that the $113.5b figure in the article is mostly the result of people burning money for no reason.
Not always. NASA was given a blank cheque in the 60s to get a man to the Moon. With the advantage of hindsight, we can see that NASA managed the project extremely well and there was very little waste. Contrast this with NASA's subsequent accomplishments once the blank cheque expired: decades of waste.
Sometimes a blank cheque is just what's needed to get something accomplished efficiently. Apparently not in this case though.
Yes. Real techs just stick their tongue in the video port and jiggle a paperclip in the keyboard port. Only amateurs need dedicated hardware.