Has been litigated, and charges are forthcoming. Yasir Esam Hamdi has a hearing about ten miles from where I am now on Tuesday, and will probably be released...next?
If he will be realeased after a hearing, doesn't that say something about the validity of the charges against him? If there is insufficient evidence to hold him, why was he held for 3+ years without a trial?
I'm not honestly contesting that people like Richard Reed should be in jail, but I think it is wrong that they had to argue all the way up to the Supreme court just for the basic rights afforded most other criminals. You will note that this admisnistration fought in every court to prevent such rights being afforded to these guys. That's not right.
They're enemy combatants, and are being held outside the United States. The US courts do not have jurisdiction over the matter.
The Supreme Court disgarees with that statement. And you should be ashemed of yourself for supporting something that so blatantly violates the spirit of the Constitution.
Don't get your reading materials from the government, and you won't have a problem.
They can also look at purchase records from bookstores, and subpoena internet records. Where else am I supposed to obtain reading materials, pray tell?
any time you deal with the state you have to assume that you will be violated
That's not the Constitution I have learned about.
You can be a cynic, but you shouldn't defend what you know in your heart is wrong.
Why five? Wouldn't one lost liberty be enough to cause concern?
In any case how about: the right to a trial (Jose Padilla), the right to a lawyer (Shoe-bomber dude), the right to call witnesses (the so-called 20th hijacker), the right to hear evidence presented by the prosecution (the Gitmo detainees), the right to not have the government know what you read (at least not without getting a warrant; Patriot Act), freedom of assembly and to protest (e.g. in Central Park).
Actually i find the concept to authenticate against what you are very insecure.
That's one problem. Another is that you can never change that authentication token, the way you can change passwords or keys. Imagine a scenario where you work at the airport and
the Evil Terrorists (tm) manage to get a copy of your fingerprint (can be done with latex gel and an eraser) or retinal scan and can use it to access something important. The only secure response is to deny access to anyone with a fingerprint that looks like yours, forever. So either you never work again, or you get to have a special password system just for you (and all the other ID-theft victims). But of course, at that point primary security rests with the password system; which you miight as well just use in the first place.
Biometric security systems strike me as being very similar in spirit to the various copy-protection schemes out there that the RIAA loves; they sound intimidating and high-tech, but are really poorly thought-out and only good to keep out amateurs, while serving to make all our lives more difficult. I wonder if our security guys really do think that al-Qaida really is a bunch of amateurs? Are they?
As for biometric passports - why in Ashcrofts name would you keep the biometric information on the passport as opposed to in a central database? If your ATM card didn't rely on a central server the banks would have been cleaned out long ago.
I have no doubt that professional forgers, being the third oldest profession (bureaucrat being the second, and we all know what the first is), could sooner or later figure out how to encode the biometric information. In other words, the passport has to be considered insecure and information on it shouldn't be trusted.
Now, if you don't keep the fingerprint scan on the passport, why make a big fuss about "biometric" passports? Deliberate misinformation? Or is it a two-step scheme where the retinal scan is too big to transmit, so a copy is stored on the passport and e.g. a hash on the central server to verify the integrity of the passport?
Of course, you can still hump it across the Rio Grande, biometric passport or no biometric passport. So now we have to start checking people inside the country as well as at the border.
Sooner or later this road leads only one place: frequent random searches of all citizens and demands for "Your paperz, bitte" anywhere, anytime.
Perhaps I miscalculated in thinking that slashdot would be a good place to submit this news to.
Don't feel too bad. Most Slashdotters are out on the town on a Saturday night; it's just the losers who are still posting. As for the moderators - no-one understands how it ends up being what it is, but the leading theory is that most moderators are under the influence of some pretty serious drugs while moderating.
Seriously though, congratulations on first plasma. I visited LDX about 8 months ago and you've certainly made much progress since then. However, you might want to make it clear that this doesn't mean that fusion is just around the corner. As far as I understand, the LDX concept is a bit of a dark horse; keeping the superconducting magnet cold in the presence of the plasma is challenging, no? I know they talk about a refrigerator, but that has never been demonstrated...
Anyway, I look forward to hearing about the
plasma properties and confinement...
First of all - I am a space scientist, primarily I work with un-manned missions.
Second, I am saying that un-manned missions have benefitted from the money spent on manned spaceflight. NASA exists primarily because people have the dream of going into space; without that dream un-manned spaceflight would be a sounding rocket program, at best. Therefore it is counter-productive (not to mention stupid) for space scientists to attack manned spaceflight.
Third, I am saying that an honest appraisal of the value of any form of space science holds a hard truth, and that is that most people would not fund it purely for the science.
Forth, even from a purely scientific point of view, it is questionable if space science is so much more productive than other sciences that it deserves the incredible amounts of money spent on it. As we say at JPL, one space dollar equals 100 ground dollars. Is the science that much better?
Does space science save lives? Does it even prolong life? Does it make life better? Or is it just entertainment?
First off, the medium that the oceanic explorers travelled on was also the one that could sustain them. They could pull their food out of the ocean. Space is the opposite - exposure to the native environment is fatal.
Sorry Cousteau, but un-protected immersion in the North Atlantic will kill you in minutes.
Ask yourself this: Considering it will cost billions to send people to the moon versus the millions it cost sending unmanned flights, exactly what scientific experiment could those people do that an unmanned flight could not do?
Considering it will cost billions of dollars to send even an un-manned flight anywhere, ask yourself this: isn't the money better spent learning how to extend human life? Isn't all of space science a total waste? Please enlighten me why we need to spend my hard-earned tax money on that stuff at all.
I think I see his point. We already know enough to know that there really isn't anything worth sending people to.
Uh-huh. We've sent a dozed guys to a rock 300,000 km away, and sent out probes for 30 years, and we're determined that space is boring. There is clearly nowhere to go. We've mapped all of space. Sure.
Sorry to piss in your beer, Einstein, but space is kinda BIG. I highly doubt that we have ruled out the possibility of worthwhile destinations.
To put it in 15th Century terms, it's kinda like Columbus having looked into his bed-pan in the morning and decided he'd explored all the oceans and there was clearly no reason to even get out of bed.
IAARS (I AM a Rocket Scientist), so I am going to share my opinion...
What's really annoying about this guy is that he seems to think that un-manned spaceflight will somehow benefit if manned spaceflight is scaled back. Of course, that's nonsense. Cut manned spaceflight and I will bet you a donut to a Delta VH that within a decade NASA will cease to exist. This guy, who benefitted professionally to a huge extent from the existence of manned spaceflight programs, now
has the nerve to turn around and bite the hand that (probably quite literally) fed him. That's annoying. And it hurts all of space science in the long run.
On a dollar-for-dollar basis space research of any kind (manned or unmanned) is pretty much a total waste of money. Some examples will help: the Hubble Space Telescope cost something like 2 billion. That's about 20 times the cost of the Keck Telescope, and it is about neck-and-neck when it comes to scientific output between the two. When it comes to planetary exploration - can you honestly say that there have been spin-offs that are useful here on Earth? I mean, let's be honest here: the science return from space research is all pretty trivial. Between us, who really gives a sh*t about some radiation belts around the Earth? A few power-line operators maybe, but it's not like they need a detailed understanding of the Earths bow-shock to operate, now is it? As for the rest of it - well, pretty pictures of Saturn are nice and all, but who really cares? They're ice and dirt, and have absolutely no impact on our daily lives. None whatsoever.
Some would argue that certain kinds of science can only be done from space, things like far-infrared, or X-ray observations. But those missions have in effect been subsidized to the tune of billions by other, less worthy missions. If you had to factor in the development cost of heavy-lift boosters into the cost of developing the Chandra X-ray observatory, it would have cost $20 billion or more. I doubt that would have been seen as worthwhile science.
In terms of improving human life, wouldn't the billions spent on un-manned space exploration be better spent curing disease through the NIH? Or a tax-cut. I mean, tax -cuts and de-regulation make more ultra-billionaires; if they want to fund space research privately then they can do that, and the free market will reward it accordingly (if in fact it is worthwhile).
Only a true naif would think that science is funded for scientific reasons alone, and Dr. van Allen has an inflated sense of his own importance when it comes to national funding priorities.
Sciences like physics were funded because physiscists know how to make very, very large bombs. Bio-medical science is funded because people don't want to die. Everything else is pretty much not funded, or lives off of the table-droppings from the big sciences. And the big sciences are not funded because Congress has a love for deep knowledge.
By somehow pretending like his particular kind of science is more worthy than other science, he's starting a discussion that by all rights should hurt all of space science. In other words: Jim, SHUT UP. We've got a good gig going here, and you're messing it up.
Gun manufacturers are not responsible for the actions of the people that use their products, but P2P vendors are?"
Yeah, but what good will P2P do you when the King of England starts pushing you around? Well? That's what I thought.
Actually, as any experienced grass-roots activist, political dissident, resistance fighter, insurgent, terrorist or law enforcement officer knows, the key to successfully opposing those in power is a secure communications network. Encrypted P2P comes pretty close to that. That may be part of the reason it's being outlawed.
No. Most of the work is getting to a velocity of 8 km/sec.
No!? So sure, are you?
Yes, actually. The physics of that calculation is trivial. Also, "work" has a well-defined meaning in physics, so strictly speaking that sentence is perfectly true.
Clue alert - he wasn't talking about energy. Try actually reading his post to discover he was talking about work to solve engineering problems, not how much fucking energy it takes to attain oribital velocity.
Clue alert - engineering difficulty is closely related to energy in situations like these. With orbital velocities comes a whole range of new problems related to hypersonic aerodynamics, heating, flight control, structural design, etc etc. Look, SpaceShipOne uses hydraulic-boosted (if even that)manual flight controls, and relies of passive stability to maintain the correct flight attittude. You couldn't get away with that for a Shuttle. It also doesn't have a heatshield the way the Shuttle does (it has some re--inforcement, but not even within an order of magnitude). The rocket on SpaceShipOne has a total impulse of maybe 1 km/sec, and the corresponding mass fraction of the vehicle devoted to fuel is maybe 20%. The rest can go to building a robust vehicle; on the Shuttle the mass fraction of fuel has to be closer to 90%. SpaceShipOne doesn't have cryogenic fuels, and the associated issues.
I can go on and on, but hopefully by now you've grokked that these are two very different machines, and SpaceShipOne is as close to orbit as climbing Mt. Greylock is to climbing Mt. Everest.
1) is most of the work of 2) It gets you out of the atmosphere - now all you have to do is get going FAST while you're out there.[...]But once you've got a device capable of 1) it's a LOT less than doubling the engineering to upgrade it for 2).
No. Most of the work is getting to a velocity of 8 km/sec. That's 90% of the required total energy. Getting to altitude is 10%. So SpaceShipOne is 10% of the way to orbit (in terms of energy).
The additional difficulty of going into orbit is considerably greater than twice the effort: you have to carry 10 times the fuel fraction, and you have to be capable of re-entry, on-orbit maneuvering, etc etc.. It's a lot harder than just going up in a big arc for 5 minutes.
SpaceShipOne is a lot closer to a Cessna than it is to a Space Shuttle. Seriously.
I know this is going to cost me a lot of karma, but it has to be said: the Linux solutions to Office incompatibility are still not good enough. I collaborate with many folks who use Word exclusively for writing papers. It's hard/impossible to get figures, tables and equations to display properly in OOffice. I haven't even gotten to the point where I'd try using a calendar or similar program. Just basic, everyday word-processor files cause more problems than they should in this day and age.
Fix that and maybe Linux will have a shot on the desktop. Of course, I know that will never happen - for no fault of Linux developers, mind you. Microsoft knows that their very existence hangs on their lock on Office compatibility. If they lose that they are dead. So they will make sure that doesn't happen.
Although I've never published in Nature, publishing in the Astrophysical Journal (ApJ) costs ~$250 PER PAGE for the author... I'm sure Nature is at least as expensive.
Actually, publishing in Nature is free, unless you have big color prints.
This is why NASA spends so much effort marketing what they have done -- for instance, providing free, beautiful pictures that consist entirely of false-color images that have been tweaked by hand to look attractive...they're more a credit to the artistic nature of the postprocessors than to the people doing the research itself.
I think that is very insulting. Do you really believe that it is more of a feat to
adjust some color scales than it is to
send a spacecraft to another planet at distances of 300 million miles or more, have it operate without any repairs for years at a atime, survive the heat & cold of space, the forces of re-entry, launch etc etc.? The images are generally false-color composites, true. But they are not "retouched". The difference is between one of choosing how to remap wavelengths your eye can't see into colors it can see, and flat-out changing images. JPL does the former, and not the latter.
So all NASA has to do is make significant public underestimates of their mission potentials. That way, after completing, say, 10% of their expected work, they can announce that the mission "is a success".
That's not how things are done. I don't think you even begin to grasp how challenging some of this stuff is - the rover team was ecstatic when both rovers worked (the bets in my group were for at least one loss). Then there is the issue with dust accumulation on the solar panels, and thermal cycling. Nobody I know thought that the rovers would last this long, and it remains to be seen if they will make it to winter.
You have to rememeber that many of these missions are selected after competitions among various university and industry groups. This means that you have to sell a mission to the review boards; you can't do that if you under-promise. If you only claimed you could do 10% of what you think you could actually do, then some other group is going to propose a mission to do 20% of what is possible - and they will look much better on paper and so get chosen. And these proposals are not secret, so NASA can't turn around and tell the public that mission will do less than it proposed for.
The result is NASA tends to define success criteria close to what is reasonably expected based on some pretty detailed mission analysis work.
Another point to remember is that the mission probability of success is like a chain - no stronger than the weakest link. Which means that there are almost always a few events that have all the risk (launch, landing); once past those there isn't much that can kill a spacecraft, at least not until old age starts to set in. And one thing about JPL - their stuff is built to last. That's why the mission achievements are bimodal - either failure, or way longer life (and greater success) than expected.
Here's an idea - blow the crap off with compressed air.
Gee. I'm sure everyone at JPL is kicking themselves right now wishing they'd thought of that. I mean, clearly it's such a brilliant, amazing idea that only some/. troll could think of that. Maybe it turns out that the tradeoff between the 10 kg spent on a compressed air bottle vs. 10 kg of science instruments is such that it's better to go with the instruments... hmm?
Just think of all the children that could have been fed with this $400 million.:( Or all the landmines that could be removed. Instead, we get playtoys for stupid white men. Micheal Moore needs to do his next expose on "science".
Some children were fed out of that $400 million. Where do you think the money goes? To pay for the roughly 10,000 engineers, scientists & technicians who in one way or another worked on the mission. Even rocket scientists have children.
Micheal Moore needs to do his next expose on "science".
Or maybe he should discuss the appalling state of education in this country. Not to mention a discussion of how spending on basic research help bring health & wealth to the world in general.
You'll note that I said, "human history." This is significantly less time than 100,000 years. Less than 10,000 unless you count cave paintings.
Funny, I certainly do count cave paintings. In any case, your statement is deliberately vague - I'd suggest using a real number that can be pinned down.
So the amount of plutonium actually released into the environment would be conspicuously small, yes?
No. Particularly if the reaction is a fizzle, the fraction of plutonium actually "burned" is quite small. Work out the energetics for yourself - it can be less than a percent. But in any case, much of the danger from fallout is from fission products: iodine, cesium etc etc.
I would imagine that a 1 kiloton blast would be much cheaper, less detectable, and easier to produce with non-nuclear material
Do you seriously think you could bring in a thousand tons of high explosive to downtown Manhattan without being discovered? You'd need to sneak a freight train down there...
If you really wanted to make a good dirty bomb, why not use conventional materials with an arsenic payload
Not really, because arsenic needs to be ingested to be really lethal. Co-57 does its work from a distance. And then there is the issue of people-s irrational reaction to radiation, as opposed to chemical poisons.
It also gives them the technology for isotope separation, since as you point out, the plant also contains a separation facility.
So? Why wouldn't they use chemical separation?
You misunderstand. As things are now, only a few countries have separation facilities. Today, if a country wants to separate plutonium they have to build a separate plant. That is subject to discovery, and is not a widely available technology. With the IFR you are proposing to provide ready-made separation technology and facilities to every country with a nuke plant. That simplifies the problem for proliferators - they just have to run a few processes undetected, rather than hide an entire plant. As for survival of the personnel - not every country or group has the same desire to preserve human life.
Part of the reason Pu-240 is considered unsuitable for weapons is the fact that the pit would be warm; this causes problems in designing a compact warhead suitable for ICBM use. But it's not much of a problem for a terrorist bomb, and can be dealt with for air-droppable bombs that say North Korea might use.
Regarding neutron embrittlement, check out this link for an interesting discussion. Note that he's talking about thermal reactors, and note that the solution tended to be to reduce the fast neutron flux onto the reactor vessel. However, that approach is not viable with a fast reactor, where you need the fast neutrons, particularly if you are going to be burning actinides. Neutron emrittlement hasn't caused any accidents to date (that I know of), but it remains a design issue with fast reactors. That's one of the reasons there have been so many prototype fast breeders, and so few production reactors of that type.
As far as the claim, "Every fast-neutron sodium reactor design ever built has had some serious accidents related to sodium," this is false.
Let's see: The Seawolf had a sodium accident. The Lagoona Beach reactor had a block of the sodium channels and a partial meltdown. The Phoenix reactor had sodium problems. So did the Soviet BN-300 and BN-600 reactors. Even the Soviet Rorsat reactors (Na-K eutectic) had leaks. Of course, every light-water reactor ever built has leaks too. The difference is that when sodium leaks you have a fire, when water leaks you don't.
Unfortunately this fails to take into account the amount of spent fuel sitting in pools at nuclear plants. This is fuel as well and still retains approximately 98% of its energy potential.
Yes, but all the reactor fuel ever spent only amounts to less than 50 years' worth of power. So even if you can use the remaining 98%, that's only 2500 years. Hardly "all of human history". And that's ignoring growth in energy consumption, as well as inefficiencies in the process. Both of which will drastically reduce the estimate.
You are rather stuck - if the fraction of total energy available from spent fuel is large, then
that implies that there isn't much more available to be mined. In any case, fission energy resources are not sufficient to power current society for more than a few thousand years. Humans have existed for >100,000 years.
As far as plutonium goes, the plutonium that is most useful to power generation (the heat-generating isotopes) are precisely the kind of plutonium you don't want for weapons...[]spent fuel from a nuclear reactor designed solely for power generation has never before been used by any country to make a nuclear weapon
I understand the difference between Pu-240 and Pu-239. However, the fact that it hasn't (officially) been done in no way proves that it can't be done. It's mostly a matter of implosion speed, and if you are willing to accept a fizzle, it's not even that hard. A fizzle will still be a very powerful dirty bomb, and would cause a huge disruption to any metropolitan area so hit. With modern implosion designs it is quite likely that you could get a very significant yield from IFR plutonium; imagine what a 1kt explosion in downtown Manhattan would do.
There are two issues related to non-proliferation. The first is terrorism, the second is states acquiring nuclear weapons. In the first case, terrorists would be very happy to have IFR-grade plutonium even for just a dirty bomb (the Pu-240 actually makes it more of a problem). As far as states acquiring nuclear weapons - an IFR gives them access to a neutron source suitable for blanket breeding (note that blanket breeding can produce any grade of Pu you wish, including very low Pu-240-content stuff). It also gives them the technology for isotope separation, since as you point out, the plant also contains a separation facility. That can hardly be good. It's a nasty tradeoff: if you centralize the separation/recycling then you have fuel and plutonium transports that are vulnerable to terrorism. If you move the separation out to the plants then you are giving sensitive technology to potential proliferators. Either way you're inviting trouble.
That website you linked to is not particularly balanced in its advocacy of nuclear power. There are some serious issues with fast neutron reactors. The first is that the neutron flux has a tendency to damage the reactor materials (look up "neutron embrittlement"), and this problem is worse for fast reactors than for thermal ones. Second, while you do extend the fuel supply, you only do so by a factor of 50 or so (i.e. out to maybe 2000 years). That is not longer than all of human history. Using Thorium might help a bit, but not really all that much.
Third, their sodium reactor design is a safety nightmare - the sodium gets activated, and is of course highly flammable. Every fast-netron sodium reactor design ever built has had some serious accidents related to sodium. That should be telling... The use of lead-bismuth reactors might be an improvement, but those have issues too. Fourth, the plutonium created in an IFR can actually be used to make a bomb, despite what they say. It may, or may not, contain large amounts of Pu-240. In the latter case it will require special care, but you can still make a serviceable bomb (including, but not limited to, so-called dirty bombs). Mind you, any nuclear reactor (this goes for fusion, too) can serve as a source of neutrons to irradiate uranium to make plutonium (the "breeder blanket" approach). Non-proliferation is a pretty serious problem no matter what; I think the solution there has to be some pretty strict international controls.
It's fair to say that the IFR is not a great solution. But a solution is definitely needed.
Slashdot Mirror
If he will be realeased after a hearing, doesn't that say something about the validity of the charges against him? If there is insufficient evidence to hold him, why was he held for 3+ years without a trial?
I'm not honestly contesting that people like Richard Reed should be in jail, but I think it is wrong that they had to argue all the way up to the Supreme court just for the basic rights afforded most other criminals. You will note that this admisnistration fought in every court to prevent such rights being afforded to these guys. That's not right.
They're enemy combatants, and are being held outside the United States. The US courts do not have jurisdiction over the matter.
The Supreme Court disgarees with that statement. And you should be ashemed of yourself for supporting something that so blatantly violates the spirit of the Constitution.
Don't get your reading materials from the government, and you won't have a problem.
They can also look at purchase records from bookstores, and subpoena internet records. Where else am I supposed to obtain reading materials, pray tell?
any time you deal with the state you have to assume that you will be violated
That's not the Constitution I have learned about. You can be a cynic, but you shouldn't defend what you know in your heart is wrong.
Name five you've lost.
Why five? Wouldn't one lost liberty be enough to cause concern?
In any case how about: the right to a trial (Jose Padilla), the right to a lawyer (Shoe-bomber dude), the right to call witnesses (the so-called 20th hijacker), the right to hear evidence presented by the prosecution (the Gitmo detainees), the right to not have the government know what you read (at least not without getting a warrant; Patriot Act), freedom of assembly and to protest (e.g. in Central Park).
ROTFLOL!!! Mod parent up. :P
That's one problem. Another is that you can never change that authentication token, the way you can change passwords or keys. Imagine a scenario where you work at the airport and the Evil Terrorists (tm) manage to get a copy of your fingerprint (can be done with latex gel and an eraser) or retinal scan and can use it to access something important. The only secure response is to deny access to anyone with a fingerprint that looks like yours, forever. So either you never work again, or you get to have a special password system just for you (and all the other ID-theft victims). But of course, at that point primary security rests with the password system; which you miight as well just use in the first place.
Biometric security systems strike me as being very similar in spirit to the various copy-protection schemes out there that the RIAA loves; they sound intimidating and high-tech, but are really poorly thought-out and only good to keep out amateurs, while serving to make all our lives more difficult. I wonder if our security guys really do think that al-Qaida really is a bunch of amateurs? Are they?
As for biometric passports - why in Ashcrofts name would you keep the biometric information on the passport as opposed to in a central database? If your ATM card didn't rely on a central server the banks would have been cleaned out long ago. I have no doubt that professional forgers, being the third oldest profession (bureaucrat being the second, and we all know what the first is), could sooner or later figure out how to encode the biometric information. In other words, the passport has to be considered insecure and information on it shouldn't be trusted.
Now, if you don't keep the fingerprint scan on the passport, why make a big fuss about "biometric" passports? Deliberate misinformation? Or is it a two-step scheme where the retinal scan is too big to transmit, so a copy is stored on the passport and e.g. a hash on the central server to verify the integrity of the passport?
Of course, you can still hump it across the Rio Grande, biometric passport or no biometric passport. So now we have to start checking people inside the country as well as at the border. Sooner or later this road leads only one place: frequent random searches of all citizens and demands for "Your paperz, bitte" anywhere, anytime.
Don't feel too bad. Most Slashdotters are out on the town on a Saturday night; it's just the losers who are still posting. As for the moderators - no-one understands how it ends up being what it is, but the leading theory is that most moderators are under the influence of some pretty serious drugs while moderating.
Seriously though, congratulations on first plasma. I visited LDX about 8 months ago and you've certainly made much progress since then. However, you might want to make it clear that this doesn't mean that fusion is just around the corner. As far as I understand, the LDX concept is a bit of a dark horse; keeping the superconducting magnet cold in the presence of the plasma is challenging, no? I know they talk about a refrigerator, but that has never been demonstrated...
Anyway, I look forward to hearing about the plasma properties and confinement...
Second, I am saying that un-manned missions have benefitted from the money spent on manned spaceflight. NASA exists primarily because people have the dream of going into space; without that dream un-manned spaceflight would be a sounding rocket program, at best. Therefore it is counter-productive (not to mention stupid) for space scientists to attack manned spaceflight.
Third, I am saying that an honest appraisal of the value of any form of space science holds a hard truth, and that is that most people would not fund it purely for the science.
Forth, even from a purely scientific point of view, it is questionable if space science is so much more productive than other sciences that it deserves the incredible amounts of money spent on it. As we say at JPL, one space dollar equals 100 ground dollars. Is the science that much better? Does space science save lives? Does it even prolong life? Does it make life better? Or is it just entertainment?
Sorry Cousteau, but un-protected immersion in the North Atlantic will kill you in minutes.
Considering it will cost billions of dollars to send even an un-manned flight anywhere, ask yourself this: isn't the money better spent learning how to extend human life? Isn't all of space science a total waste? Please enlighten me why we need to spend my hard-earned tax money on that stuff at all.
Uh-huh. We've sent a dozed guys to a rock 300,000 km away, and sent out probes for 30 years, and we're determined that space is boring. There is clearly nowhere to go. We've mapped all of space. Sure.
Sorry to piss in your beer, Einstein, but space is kinda BIG. I highly doubt that we have ruled out the possibility of worthwhile destinations. To put it in 15th Century terms, it's kinda like Columbus having looked into his bed-pan in the morning and decided he'd explored all the oceans and there was clearly no reason to even get out of bed.
What's really annoying about this guy is that he seems to think that un-manned spaceflight will somehow benefit if manned spaceflight is scaled back. Of course, that's nonsense. Cut manned spaceflight and I will bet you a donut to a Delta VH that within a decade NASA will cease to exist. This guy, who benefitted professionally to a huge extent from the existence of manned spaceflight programs, now has the nerve to turn around and bite the hand that (probably quite literally) fed him. That's annoying. And it hurts all of space science in the long run.
On a dollar-for-dollar basis space research of any kind (manned or unmanned) is pretty much a total waste of money. Some examples will help: the Hubble Space Telescope cost something like 2 billion. That's about 20 times the cost of the Keck Telescope, and it is about neck-and-neck when it comes to scientific output between the two. When it comes to planetary exploration - can you honestly say that there have been spin-offs that are useful here on Earth? I mean, let's be honest here: the science return from space research is all pretty trivial. Between us, who really gives a sh*t about some radiation belts around the Earth? A few power-line operators maybe, but it's not like they need a detailed understanding of the Earths bow-shock to operate, now is it? As for the rest of it - well, pretty pictures of Saturn are nice and all, but who really cares? They're ice and dirt, and have absolutely no impact on our daily lives. None whatsoever.
Some would argue that certain kinds of science can only be done from space, things like far-infrared, or X-ray observations. But those missions have in effect been subsidized to the tune of billions by other, less worthy missions. If you had to factor in the development cost of heavy-lift boosters into the cost of developing the Chandra X-ray observatory, it would have cost $20 billion or more. I doubt that would have been seen as worthwhile science.
In terms of improving human life, wouldn't the billions spent on un-manned space exploration be better spent curing disease through the NIH? Or a tax-cut. I mean, tax -cuts and de-regulation make more ultra-billionaires; if they want to fund space research privately then they can do that, and the free market will reward it accordingly (if in fact it is worthwhile).
Only a true naif would think that science is funded for scientific reasons alone, and Dr. van Allen has an inflated sense of his own importance when it comes to national funding priorities. Sciences like physics were funded because physiscists know how to make very, very large bombs. Bio-medical science is funded because people don't want to die. Everything else is pretty much not funded, or lives off of the table-droppings from the big sciences. And the big sciences are not funded because Congress has a love for deep knowledge.
By somehow pretending like his particular kind of science is more worthy than other science, he's starting a discussion that by all rights should hurt all of space science. In other words: Jim, SHUT UP. We've got a good gig going here, and you're messing it up.
Yeah, but what good will P2P do you when the King of England starts pushing you around? Well? That's what I thought.
Actually, as any experienced grass-roots activist, political dissident, resistance fighter, insurgent, terrorist or law enforcement officer knows, the key to successfully opposing those in power is a secure communications network. Encrypted P2P comes pretty close to that. That may be part of the reason it's being outlawed.
JPL is part of NASA, it's just run by the folks from UC
Actually, JPL is run by Caltech for NASA. Funding for JPL comes from NASA.
No!? So sure, are you?
Yes, actually. The physics of that calculation is trivial. Also, "work" has a well-defined meaning in physics, so strictly speaking that sentence is perfectly true.
Clue alert - he wasn't talking about energy. Try actually reading his post to discover he was talking about work to solve engineering problems, not how much fucking energy it takes to attain oribital velocity.
Clue alert - engineering difficulty is closely related to energy in situations like these. With orbital velocities comes a whole range of new problems related to hypersonic aerodynamics, heating, flight control, structural design, etc etc. Look, SpaceShipOne uses hydraulic-boosted (if even that)manual flight controls, and relies of passive stability to maintain the correct flight attittude. You couldn't get away with that for a Shuttle. It also doesn't have a heatshield the way the Shuttle does (it has some re--inforcement, but not even within an order of magnitude). The rocket on SpaceShipOne has a total impulse of maybe 1 km/sec, and the corresponding mass fraction of the vehicle devoted to fuel is maybe 20%. The rest can go to building a robust vehicle; on the Shuttle the mass fraction of fuel has to be closer to 90%. SpaceShipOne doesn't have cryogenic fuels, and the associated issues. I can go on and on, but hopefully by now you've grokked that these are two very different machines, and SpaceShipOne is as close to orbit as climbing Mt. Greylock is to climbing Mt. Everest.
Not if your goal is actually getting into orbit, it isn't.
No. Most of the work is getting to a velocity of 8 km/sec. That's 90% of the required total energy. Getting to altitude is 10%. So SpaceShipOne is 10% of the way to orbit (in terms of energy). The additional difficulty of going into orbit is considerably greater than twice the effort: you have to carry 10 times the fuel fraction, and you have to be capable of re-entry, on-orbit maneuvering, etc etc.. It's a lot harder than just going up in a big arc for 5 minutes.
SpaceShipOne is a lot closer to a Cessna than it is to a Space Shuttle. Seriously.
Fix that and maybe Linux will have a shot on the desktop. Of course, I know that will never happen - for no fault of Linux developers, mind you. Microsoft knows that their very existence hangs on their lock on Office compatibility. If they lose that they are dead. So they will make sure that doesn't happen.
Probably something like the -log [deuterium].
Ph.D. = doctor of philosophy.
Actually, publishing in Nature is free, unless you have big color prints.
I think that is very insulting. Do you really believe that it is more of a feat to adjust some color scales than it is to send a spacecraft to another planet at distances of 300 million miles or more, have it operate without any repairs for years at a atime, survive the heat & cold of space, the forces of re-entry, launch etc etc.? The images are generally false-color composites, true. But they are not "retouched". The difference is between one of choosing how to remap wavelengths your eye can't see into colors it can see, and flat-out changing images. JPL does the former, and not the latter.
So all NASA has to do is make significant public underestimates of their mission potentials. That way, after completing, say, 10% of their expected work, they can announce that the mission "is a success".
That's not how things are done. I don't think you even begin to grasp how challenging some of this stuff is - the rover team was ecstatic when both rovers worked (the bets in my group were for at least one loss). Then there is the issue with dust accumulation on the solar panels, and thermal cycling. Nobody I know thought that the rovers would last this long, and it remains to be seen if they will make it to winter.
You have to rememeber that many of these missions are selected after competitions among various university and industry groups. This means that you have to sell a mission to the review boards; you can't do that if you under-promise. If you only claimed you could do 10% of what you think you could actually do, then some other group is going to propose a mission to do 20% of what is possible - and they will look much better on paper and so get chosen. And these proposals are not secret, so NASA can't turn around and tell the public that mission will do less than it proposed for.
The result is NASA tends to define success criteria close to what is reasonably expected based on some pretty detailed mission analysis work.
Another point to remember is that the mission probability of success is like a chain - no stronger than the weakest link. Which means that there are almost always a few events that have all the risk (launch, landing); once past those there isn't much that can kill a spacecraft, at least not until old age starts to set in. And one thing about JPL - their stuff is built to last. That's why the mission achievements are bimodal - either failure, or way longer life (and greater success) than expected.
Gee. I'm sure everyone at JPL is kicking themselves right now wishing they'd thought of that. I mean, clearly it's such a brilliant, amazing idea that only some /. troll could think of that. Maybe it turns out that the tradeoff between the 10 kg spent on a compressed air bottle vs. 10 kg of science instruments is such that it's better to go with the instruments... hmm?
Just think of all the children that could have been fed with this $400 million. :( Or all the landmines that could be removed. Instead, we get playtoys for stupid white men. Micheal Moore needs to do his next expose on "science".
Some children were fed out of that $400 million. Where do you think the money goes? To pay for the roughly 10,000 engineers, scientists & technicians who in one way or another worked on the mission. Even rocket scientists have children.
Micheal Moore needs to do his next expose on "science".
Or maybe he should discuss the appalling state of education in this country. Not to mention a discussion of how spending on basic research help bring health & wealth to the world in general.
Dumbass.
Hmm. Is that some kind of back-up in case the real universities don't admit you?
Funny, I certainly do count cave paintings. In any case, your statement is deliberately vague - I'd suggest using a real number that can be pinned down.
So the amount of plutonium actually released into the environment would be conspicuously small, yes?
No. Particularly if the reaction is a fizzle, the fraction of plutonium actually "burned" is quite small. Work out the energetics for yourself - it can be less than a percent. But in any case, much of the danger from fallout is from fission products: iodine, cesium etc etc.
I would imagine that a 1 kiloton blast would be much cheaper, less detectable, and easier to produce with non-nuclear material
Do you seriously think you could bring in a thousand tons of high explosive to downtown Manhattan without being discovered? You'd need to sneak a freight train down there...
If you really wanted to make a good dirty bomb, why not use conventional materials with an arsenic payload
Not really, because arsenic needs to be ingested to be really lethal. Co-57 does its work from a distance. And then there is the issue of people-s irrational reaction to radiation, as opposed to chemical poisons.
It also gives them the technology for isotope separation, since as you point out, the plant also contains a separation facility.
So? Why wouldn't they use chemical separation?
You misunderstand. As things are now, only a few countries have separation facilities. Today, if a country wants to separate plutonium they have to build a separate plant. That is subject to discovery, and is not a widely available technology. With the IFR you are proposing to provide ready-made separation technology and facilities to every country with a nuke plant. That simplifies the problem for proliferators - they just have to run a few processes undetected, rather than hide an entire plant. As for survival of the personnel - not every country or group has the same desire to preserve human life.
Part of the reason Pu-240 is considered unsuitable for weapons is the fact that the pit would be warm; this causes problems in designing a compact warhead suitable for ICBM use. But it's not much of a problem for a terrorist bomb, and can be dealt with for air-droppable bombs that say North Korea might use.
As far as the claim, "Every fast-neutron sodium reactor design ever built has had some serious accidents related to sodium," this is false.
Let's see: The Seawolf had a sodium accident. The Lagoona Beach reactor had a block of the sodium channels and a partial meltdown. The Phoenix reactor had sodium problems. So did the Soviet BN-300 and BN-600 reactors. Even the Soviet Rorsat reactors (Na-K eutectic) had leaks. Of course, every light-water reactor ever built has leaks too. The difference is that when sodium leaks you have a fire, when water leaks you don't.
Unfortunately this fails to take into account the amount of spent fuel sitting in pools at nuclear plants. This is fuel as well and still retains approximately 98% of its energy potential.
Yes, but all the reactor fuel ever spent only amounts to less than 50 years' worth of power. So even if you can use the remaining 98%, that's only 2500 years. Hardly "all of human history". And that's ignoring growth in energy consumption, as well as inefficiencies in the process. Both of which will drastically reduce the estimate. You are rather stuck - if the fraction of total energy available from spent fuel is large, then that implies that there isn't much more available to be mined. In any case, fission energy resources are not sufficient to power current society for more than a few thousand years. Humans have existed for >100,000 years.
As far as plutonium goes, the plutonium that is most useful to power generation (the heat-generating isotopes) are precisely the kind of plutonium you don't want for weapons...[]spent fuel from a nuclear reactor designed solely for power generation has never before been used by any country to make a nuclear weapon
I understand the difference between Pu-240 and Pu-239. However, the fact that it hasn't (officially) been done in no way proves that it can't be done. It's mostly a matter of implosion speed, and if you are willing to accept a fizzle, it's not even that hard. A fizzle will still be a very powerful dirty bomb, and would cause a huge disruption to any metropolitan area so hit. With modern implosion designs it is quite likely that you could get a very significant yield from IFR plutonium; imagine what a 1kt explosion in downtown Manhattan would do.
There are two issues related to non-proliferation. The first is terrorism, the second is states acquiring nuclear weapons. In the first case, terrorists would be very happy to have IFR-grade plutonium even for just a dirty bomb (the Pu-240 actually makes it more of a problem). As far as states acquiring nuclear weapons - an IFR gives them access to a neutron source suitable for blanket breeding (note that blanket breeding can produce any grade of Pu you wish, including very low Pu-240-content stuff). It also gives them the technology for isotope separation, since as you point out, the plant also contains a separation facility. That can hardly be good. It's a nasty tradeoff: if you centralize the separation/recycling then you have fuel and plutonium transports that are vulnerable to terrorism. If you move the separation out to the plants then you are giving sensitive technology to potential proliferators. Either way you're inviting trouble.
Third, their sodium reactor design is a safety nightmare - the sodium gets activated, and is of course highly flammable. Every fast-netron sodium reactor design ever built has had some serious accidents related to sodium. That should be telling... The use of lead-bismuth reactors might be an improvement, but those have issues too. Fourth, the plutonium created in an IFR can actually be used to make a bomb, despite what they say. It may, or may not, contain large amounts of Pu-240. In the latter case it will require special care, but you can still make a serviceable bomb (including, but not limited to, so-called dirty bombs). Mind you, any nuclear reactor (this goes for fusion, too) can serve as a source of neutrons to irradiate uranium to make plutonium (the "breeder blanket" approach). Non-proliferation is a pretty serious problem no matter what; I think the solution there has to be some pretty strict international controls.
It's fair to say that the IFR is not a great solution. But a solution is definitely needed.