Heavy water is D2O, D being deuterium, or an isotope of hydrogen that has 1 extra neutron. Heavy water is used as a moderator in the breeder reactors that convert/purify barely-fissionable U-235 into U-238. The only other material that can act as an appropriate moderator is super-pure graphite, but the Nazi's found heavy water easier to produce, so they used that.
The only other alternative is to not use a breeder reactor, but instead to try and extract the U-238 directly from the uranium ore (in which it is present in VERY low concentrations). However, this approach requires enourmes complexes, noxious chemicals, and complicated pressure systems. This is a much more expensive method, but technically simpler if you haven't yet discovered how to build an effective breeder reactor. This was also the method used by the americans to build their first bombs.
I'll believe that when you back it up with evidence, because I've done a fair amount of reading on this subject and I've never heard that angle before...
Would you please stop shamelessly plugging something that it is obvious tha YOU are selling on EBay? I'm getting really tired of finding these posts everywhere...
I believe that this practice also applies in the US, though only at birth. IANAL, and this is only IIRC, but the law says that the parents can't choose a name that will be detrimental to the kid. The only time i've heard of this being invoked was when a couple of scientologists wanted to name their kid SN13686141637117x or something like that.
This system would also have the added advantage of making people pay actual $ for keeping code red-infected machines online (or some other worm that scans the net in volume). Not to mention that it would helpo draw the problem to the attention of users who don't know better.
What I'm proposing is a relatively safe science mission that uses know technologies and proven capabilities that could capture the imagination of the public. Asteroids. While we know a great deal about the meteorites that strike out earth, we do not know as much about the large asteroids that inhabit our solar system. This mission would investigate these asteroids.
Phase one would be completely unmanned. A vehicle, perhaps prepared in orbit by the ISS, would travel to the asteroid belt or some nearby asteroid, capture the asteroid, and return with it to earth orbit. The the requirements for this would really push the envelope of what our current technologies are capable of, and would expand and improve our familiarity with the mechanics of space operation.
Phase two involves the process that occurs after the asteroid has been returned to earth orbit. I envision the ISS becoming a central base for a team of geologists and other scientists who routinely make EVA spacewalks to the asteroid, performing numerous science experiments and taking samples that are returned to the ISS or earth for analysis. This phase would also be very succesful in the media's eyes as it has the potential to produce excellent pictures and videos of humans at work in space. Though you might not think that the media should not be our primary purpose in space, it will be absolutely neccesary to capture the public's imagination and to build a feeling of adventure.
The final, third phase depends on the size of the asteroid. There are numerous possibilities for it after the science has been conducted on it in orbit. It could either be completely dissasembled in orbit, put on a trajectory to burn up in earth's atmosphere, or left in orbit. However, it could also be put on a trajectory to impact with the moon in a known location, allowing us to for the first time in history to study an asteroid impact in great depth. This could also provide justification for another moon mission to set up equipment beforehand and study the impact crate afterwards.
The key to the success of this mission lies in its modularity. If, after phase 1 conditions here on earth have changed, one need not appropriate enourmous amounts of $$$ from congress for phase two. Same goes for phase three. This will make the mission a much more attractive proposition to the financiers.
I would love to see this happen. Any comments on it from the rest of the/. crowd?
Germany invaded Poland and FDR tried hard to get us involved in that, which we eventually did get involved in.
Not because of anything you (americans) did. Even after the Japanese bombed Pearl Harbour there were serious questions about whether the US would enter the war in Europe. It is entirely possible that they would have limited the war only to the pacific theatre if Hitler hadn't declared war on them. Many Americans forget that it was the Germans who declared war, not the US.
He wrote a package that happened to incorporate some OCR libraries that someone else wrote. He didn't claim to write the OCR libraries. Also, without his package, the OCR libraries wouldn't be applied to defeating this securtity.
US vs. Canada Drug testing vs. no drug testing private health vs. public health
Coincidence? NO! This is the one important difference that you are leaving out: the US has private medical insurance where Canadian medical insurance is public. I'll save the debate on the merits of each for later, but it does come down to this. In the US, it is not uncommon for employees to recieve health benifits as part of their job (in Canada it's obviously not neccesary). If an employee is a drug user, there is a far higher chance that they will eventually make claims on the company's health insurance. As well, keep in mind that nicotine (from smoking), will show up for as long as a week after the last cigarette.
The thing is, it's extremely easy to convert from celcius to kelvin and back (just add/subtract ~273 degrees) because the units are the same order of magnitude. Thus, it is perfectly acceptable to define both scales as standards. To conver from Celcius to Farenheight however not only involves addition and subtraction, but also converting the magnitude of the unit (1 deg. F != 1 deg. C).
As for all the other units, using imperial is just a boneheaded and stubborn refusal to accept a more universal and practical system.
Of course Canadians are smarter than Russians. Also smarter than a fair few yanks and a lot of the rest of the world. And just to round it out, we're not the least bit egotistical to boot!
We all know of the american astronaut deaths: 3 - Apollo 1 fire 7 - Challenger 7 - Columbia
What about Russian deaths? I've heard it mentioned that they lost 3 cosmonauts on the return from orbit in the '70s, but haven't seen any evidence to back it up. How many russians died in the quest for space? (IMHO, they were more succesful than the americans in terms of leaping the first hurdles)
Also, another poster mentioned scientists who died in the service of the space program. I'd like to know and remember every man who gave his life for what I believe to be humanity's final frontier.
Feel free to blow huge holes into it. All right, I'll take my best shot.
Firstly The ore processing station can be broken down into two parts: the mining and the processing. a) The mining: exactly what 'ore' will you mine? I can't say for sure but I don't believe that there are very valuable mineral deposits confirmed on the moon or the asteroid belt. As well, transporting the ore from the moon or the asteroid belt will costs $$ and the efficiency of your system. We already have a very effective and efficient mining industry here on earth that is nowhere near depleting useful construction resources. If you are mining precious metals in space, you will have to bring them down to earth in order to convert them into useful construction materials which will only be brought up again. A nice way of paying for the entire venture, but again, efficiency would be paramount. b) If you are mining titanium or aluminium in space, fine - I can't comment on how those are processed b/c I don't know anything about it. But I would venture to guess that these are fairly complicated processes requiring many chemicals and machines which would, again, have to be lifted into space - when we already have these processing facilities here on earth. However, if you are mining Iron for the purpose of turning it into structural steel, you are SOL in space. Steel production requires tons of coal, as well as air (It's quite an interesting process actually). These are two things you will definitely NOT find in space.
So really, the mining prospects in space doesn't look too good or profitable. Why bother developing a huge, complicated, risky system when we have equivalent capabilities here on earth? It would actually be cheaper to pay to lift stuff up in the short term (next 20 years) - Even with our current lifting systems.
Now proposition 3: the space station. One word: why? Your entire argument seems to be that we need to make space economically self-sustaining in order for space development to occur. In truth, there aren't many manufacturing processes that require or would benifit from zero-G or a vacuum (which are the only economic benifits of space). The only real benifit comes from preventing environmental damage. However, our current society still thinks that raping the planet is an acceptable buisiness model, and it continues to be profitable. For manufacturing, unless you stay with basic refining, you're going to need to haul materials up only to - you guessed it - haul them back down. The simple economics of it just don't make sense.
So now that I've stated why I don't believe your proposition would work, want to hear mine? Government agencies such as NASA should NOT be concentrating on what we do in space (except for purely scientific missions like mechanical probes), but on how we get there. If the government can develop a launch vehicle (not neccesarily rockets, think ground-based linear induction motors (rail guns), gauss launching systems, or airplane launched payloads) that costs only a few $/kilo, then you are in buisiness. If you make space venture-capitalism low risk then you will get all kinds of investment. The best part? the launch system is controlled by the government, so you can still regulate to what goes up. When you (as a human) can catch a ride to LEO for ~$1000, then space development will take off.
There are sometimes when you don't want to heighten your senses. In fact, sometimes it's exactly the opposite. I once went out with a girl who smoked and... ugh... i have never had a more disgusting kiss.
Actually, there's a fairly interesting piece up on the TIME website where they discuss the three most probable (in their opinion) causes for the crash. Their 3 leading suspicions are improper piloting leading to a roll which caused structural breakup, the heat tiles that fell of during launch, and the possibility that what little fuel is reserved for the maneuvering engines ignited somehow.
They also toss some juicy quotes like: "The shuttle was built as a space truck, and then the International Space Station was built to give it something to do. Both programs are likely to suffer as a result of this disaster. " and "it's unlikely that NASA will undertake any further shuttle missions or any other manned space flights for the next two years."
It's quite a simple and obvious scheme really. The RIAA has hired someone to build this virus which effectively DDOSes the entire 'net. All of the P2P filesharing networks slow to a halt, and suddenly all of those people who were planning to download + burn the music for their superbowl party tommorrow have to actually buy it.
Actually, it wouldn't surprise me *too* much to learn that this is the case...
Transparent plastic bags have two key differences from a steel trashcan:
1) They're transparent (you can see what's in them) 2) They don't fragment into thousands of little bits of flying steel (that can co straight through a person) when they blow up
Neither of these makes the shopping carts an impossible target, but they make them much less attractive. As well, the carts are sometimes manned...
I'm thinking that it would be easier to get some guy to release several bags of nails/washers/ball bearings which would go zooming towards the magnet at really high speeds - completely irrespective of anyone or anything that gets in their way.
Slashdot Mirror
Heavy water is D2O, D being deuterium, or an isotope of hydrogen that has 1 extra neutron. Heavy water is used as a moderator in the breeder reactors that convert/purify barely-fissionable U-235 into U-238. The only other material that can act as an appropriate moderator is super-pure graphite, but the Nazi's found heavy water easier to produce, so they used that.
The only other alternative is to not use a breeder reactor, but instead to try and extract the U-238 directly from the uranium ore (in which it is present in VERY low concentrations). However, this approach requires enourmes complexes, noxious chemicals, and complicated pressure systems. This is a much more expensive method, but technically simpler if you haven't yet discovered how to build an effective breeder reactor. This was also the method used by the americans to build their first bombs.
I'll believe that when you back it up with evidence, because I've done a fair amount of reading on this subject and I've never heard that angle before...
Would you please stop shamelessly plugging something that it is obvious tha YOU are selling on EBay? I'm getting really tired of finding these posts everywhere...
I believe that this practice also applies in the US, though only at birth. IANAL, and this is only IIRC, but the law says that the parents can't choose a name that will be detrimental to the kid. The only time i've heard of this being invoked was when a couple of scientologists wanted to name their kid SN13686141637117x or something like that.
This system would also have the added advantage of making people pay actual $ for keeping code red-infected machines online (or some other worm that scans the net in volume). Not to mention that it would helpo draw the problem to the attention of users who don't know better.
What I'm proposing is a relatively safe science mission that uses know technologies and proven capabilities that could capture the imagination of the public. Asteroids. While we know a great deal about the meteorites that strike out earth, we do not know as much about the large asteroids that inhabit our solar system. This mission would investigate these asteroids.
/. crowd?
Phase one would be completely unmanned. A vehicle, perhaps prepared in orbit by the ISS, would travel to the asteroid belt or some nearby asteroid, capture the asteroid, and return with it to earth orbit. The the requirements for this would really push the envelope of what our current technologies are capable of, and would expand and improve our familiarity with the mechanics of space operation.
Phase two involves the process that occurs after the asteroid has been returned to earth orbit. I envision the ISS becoming a central base for a team of geologists and other scientists who routinely make EVA spacewalks to the asteroid, performing numerous science experiments and taking samples that are returned to the ISS or earth for analysis. This phase would also be very succesful in the media's eyes as it has the potential to produce excellent pictures and videos of humans at work in space. Though you might not think that the media should not be our primary purpose in space, it will be absolutely neccesary to capture the public's imagination and to build a feeling of adventure.
The final, third phase depends on the size of the asteroid. There are numerous possibilities for it after the science has been conducted on it in orbit. It could either be completely dissasembled in orbit, put on a trajectory to burn up in earth's atmosphere, or left in orbit. However, it could also be put on a trajectory to impact with the moon in a known location, allowing us to for the first time in history to study an asteroid impact in great depth. This could also provide justification for another moon mission to set up equipment beforehand and study the impact crate afterwards.
The key to the success of this mission lies in its modularity. If, after phase 1 conditions here on earth have changed, one need not appropriate enourmous amounts of $$$ from congress for phase two. Same goes for phase three. This will make the mission a much more attractive proposition to the financiers.
I would love to see this happen. Any comments on it from the rest of the
Germany invaded Poland and FDR tried hard to get us involved in that, which we eventually did get involved in.
Not because of anything you (americans) did. Even after the Japanese bombed Pearl Harbour there were serious questions about whether the US would enter the war in Europe. It is entirely possible that they would have limited the war only to the pacific theatre if Hitler hadn't declared war on them. Many Americans forget that it was the Germans who declared war, not the US.
That's the best way I've ever seen to get away with alchohol you're not supposed to have.
Don't know if my parents will fall for it though...
You are really thick aren't you.
He wrote a package that happened to incorporate some OCR libraries that someone else wrote. He didn't claim to write the OCR libraries. Also, without his package, the OCR libraries wouldn't be applied to defeating this securtity.
Why do I waste my time with trolls? Why?!
US vs. Canada
Drug testing vs. no drug testing
private health vs. public health
Coincidence? NO! This is the one important difference that you are leaving out: the US has private medical insurance where Canadian medical insurance is public. I'll save the debate on the merits of each for later, but it does come down to this. In the US, it is not uncommon for employees to recieve health benifits as part of their job (in Canada it's obviously not neccesary). If an employee is a drug user, there is a far higher chance that they will eventually make claims on the company's health insurance. As well, keep in mind that nicotine (from smoking), will show up for as long as a week after the last cigarette.
The thing is, it's extremely easy to convert from celcius to kelvin and back (just add/subtract ~273 degrees) because the units are the same order of magnitude. Thus, it is perfectly acceptable to define both scales as standards. To conver from Celcius to Farenheight however not only involves addition and subtraction, but also converting the magnitude of the unit (1 deg. F != 1 deg. C).
As for all the other units, using imperial is just a boneheaded and stubborn refusal to accept a more universal and practical system.
Of course Canadians are smarter than Russians. Also smarter than a fair few yanks and a lot of the rest of the world. And just to round it out, we're not the least bit egotistical to boot!
We all know of the american astronaut deaths:
3 - Apollo 1 fire
7 - Challenger
7 - Columbia
What about Russian deaths? I've heard it mentioned that they lost 3 cosmonauts on the return from orbit in the '70s, but haven't seen any evidence to back it up. How many russians died in the quest for space? (IMHO, they were more succesful than the americans in terms of leaping the first hurdles)
Also, another poster mentioned scientists who died in the service of the space program. I'd like to know and remember every man who gave his life for what I believe to be humanity's final frontier.
Feel free to blow huge holes into it.
All right, I'll take my best shot.
Firstly The ore processing station can be broken down into two parts: the mining and the processing.
a) The mining: exactly what 'ore' will you mine? I can't say for sure but I don't believe that there are very valuable mineral deposits confirmed on the moon or the asteroid belt. As well, transporting the ore from the moon or the asteroid belt will costs $$ and the efficiency of your system. We already have a very effective and efficient mining industry here on earth that is nowhere near depleting useful construction resources. If you are mining precious metals in space, you will have to bring them down to earth in order to convert them into useful construction materials which will only be brought up again. A nice way of paying for the entire venture, but again, efficiency would be paramount.
b) If you are mining titanium or aluminium in space, fine - I can't comment on how those are processed b/c I don't know anything about it. But I would venture to guess that these are fairly complicated processes requiring many chemicals and machines which would, again, have to be lifted into space - when we already have these processing facilities here on earth. However, if you are mining Iron for the purpose of turning it into structural steel, you are SOL in space. Steel production requires tons of coal, as well as air (It's quite an interesting process actually). These are two things you will definitely NOT find in space.
So really, the mining prospects in space doesn't look too good or profitable. Why bother developing a huge, complicated, risky system when we have equivalent capabilities here on earth? It would actually be cheaper to pay to lift stuff up in the short term (next 20 years) - Even with our current lifting systems.
Now proposition 3: the space station.
One word: why? Your entire argument seems to be that we need to make space economically self-sustaining in order for space development to occur. In truth, there aren't many manufacturing processes that require or would benifit from zero-G or a vacuum (which are the only economic benifits of space). The only real benifit comes from preventing environmental damage. However, our current society still thinks that raping the planet is an acceptable buisiness model, and it continues to be profitable. For manufacturing, unless you stay with basic refining, you're going to need to haul materials up only to - you guessed it - haul them back down. The simple economics of it just don't make sense.
So now that I've stated why I don't believe your proposition would work, want to hear mine?
Government agencies such as NASA should NOT be concentrating on what we do in space (except for purely scientific missions like mechanical probes), but on how we get there. If the government can develop a launch vehicle (not neccesarily rockets, think ground-based linear induction motors (rail guns), gauss launching systems, or airplane launched payloads) that costs only a few $/kilo, then you are in buisiness. If you make space venture-capitalism low risk then you will get all kinds of investment. The best part? the launch system is controlled by the government, so you can still regulate to what goes up. When you (as a human) can catch a ride to LEO for ~$1000, then space development will take off.
Um, ah...
There are sometimes when you don't want to heighten your senses. In fact, sometimes it's exactly the opposite. I once went out with a girl who smoked and... ugh... i have never had a more disgusting kiss.
That was after the Challenger explosion...
Actually, there's a fairly interesting piece up on the TIME website where they discuss the three most probable (in their opinion) causes for the crash. Their 3 leading suspicions are improper piloting leading to a roll which caused structural breakup, the heat tiles that fell of during launch, and the possibility that what little fuel is reserved for the maneuvering engines ignited somehow.
They also toss some juicy quotes like: "The shuttle was built as a space truck, and then the International Space Station was built to give it something to do. Both programs are likely to suffer as a result of this disaster. " and "it's unlikely that NASA will undertake any further shuttle missions or any other manned space flights for the next two years."
Actually, Mach eighteen... that's 18x the speed of sound.
t ml
Taken from http://spaceflightnow.com/shuttle/sts107/status.h
Thank you! You just made my day.
Um, actually the war of 1812 did start in 1812. June 19th to be precise.
Holy crap! This is serious...
:-)
Someone should file an incident report form!
It's quite a simple and obvious scheme really. The RIAA has hired someone to build this virus which effectively DDOSes the entire 'net. All of the P2P filesharing networks slow to a halt, and suddenly all of those people who were planning to download + burn the music for their superbowl party tommorrow have to actually buy it.
Actually, it wouldn't surprise me *too* much to learn that this is the case...
Transparent plastic bags have two key differences from a steel trashcan:
1) They're transparent (you can see what's in them)
2) They don't fragment into thousands of little bits of flying steel (that can co straight through a person) when they blow up
Neither of these makes the shopping carts an impossible target, but they make them much less attractive. As well, the carts are sometimes manned...
Are you serious?
Can you back this up?
OTOH, I think i just got succesfully trolled...
I'm thinking that it would be easier to get some guy to release several bags of nails/washers/ball bearings which would go zooming towards the magnet at really high speeds - completely irrespective of anyone or anything that gets in their way.