Tell that to the people of Missouri. In 2000 they voted for a man three weeks dead (Gov. Mel Carnahan) rather than elect John Ashcroft to the Senate. To quote a recent episode of The West Wing, sometimes "there are worse things than being dead."
Since I was unable to read the article, I have but one question. WHo is funding this?
NASA has awarded a three-year contract to Honeybee Robotics. The total bill is $750,000. That's only $250k per year. Not chump change, but really a drop in NASA's budget. There's a significant potential return on their investment. Yes, they need to focus on whatever their priorities are, but they can't keep the blinders on and ignore promising new technology that might be used on the next mission--it's like saying, "We're still getting data from Voyager, so we better not think about designing Galileo, Cassini, or any other probes."
Why not spend some of that money exploring our own planet. There are expansive depths of the oceans that have life forms we have yet to discover, same goes for the rainforests. Why not procure some tax dollars and explore them.
For the record, NASA does spend quite a bit of money on research projects directed at the earth. There are a lot of surveys that are only practical from orbit. Further, I agree with you--some research funds could be very well spent on investigating our forests, and there's some truly fascinating (and potentially useful) stuff in the depths of our oceans.
But--there's always a but. That sort of research isn't part of NASA's mandate. Asking why NASA doesn't direct funding to oceanic exploration is like asking the Department of the Interior to help manage the Australian Outback. If you think that NASA is spending too much on developing techniques for future planetary exploration, then write to your congresscritter and demand that the appropriate amount of funding be transferred to another research agency.
I agree with you on that point--you cannot effectively censor the internet. However, in the example you cite, there at least must exist some offline planning. It's a little bit more difficult to plan violent or otherwise criminal acts. It becomes more challenging to create a 'spontaneous' violent protest.
Criminal acts will always be committed, in meatspace and cyberspace, by all manner of people--clever and otherwise. At least this legislation would address the most egregious instances of inciting criminal activity on the web.
I don't think anyone on Slashdot will suggest that the sort of legislation proposed will be a panacea, but it can't hurt to provide a regulated framework within which already existing laws can be enforced. If they're going to shut down a server, at least there will be law on the books that specifically describes circumstances under which such action is permitted--and law that is subject to constitutional scrutiny.
An interesting side issue: I would think that this sort of activity is already prohibited under existing law. Props to the Australian government if they're merely codifying de facto policies so that everyone knows what the rules are. Jeers if they're trying to overreach the equivalent meatspace jurisdiction because FUD says violent protestors are inherently more dangerous on the internet than in real life (how's that again?) I suppose I'm saying/. ought not jump to conclusions about the proposal--wait until the bill is before Parliament, then read it. (Yes, I know...getting/.ers to read raw legislation is even harder than getting them to read the articles they reply to. Alas.)
How can somebody make an honest joke (about somebody) and not get penalized.
IANAL, but common law in most countries has built up a set of principles by which defamation lawsuits are judged. Generally, the limits of acceptable comment are much broader when discussing a bona fide public figure, like a politician. It is accepted (in both common sense and common law) that politicians will be subject to scrutiny (and ridicule) within reasonable bounds. Satire is almost always acceptable, in part because on television shows like Royal Canadian Air Farce it is obvious that humour is intended, and remarks should not be taken as gospel truth.
In the media, different countries have different standards for news reporting. In the United States a plaintiff must show malice on the part of his or her defamer--very difficult, which is why so much sensationalistic crap can be published as "news". In Canada, the bar is lower--the news source must demonstrate that they had reasonable grounds to publish their (otherwise defamatory) assertions. In other countries, YMMV. In all cases, there is (or should be) a responsibility to separate fact from opinion from humour.
I've been to the land down under, and it's one of the more fascist countries I've visited. They are even worse than the US.
How did this get modded Interesting, rather than Flamebait? If one reads the article, one finds that Australia has decided to pull the plug on websites that are used to organize violent protests. Such websites are illegal in the United States as well, however the legal tests for shutting down such sites are stricter in the US. The First Amendment does not protect speech that advocates specific criminal acts. That's why you're not allowed to put Wanted: Dead or Alive posters of abortion doctors on your web site. Similarly, posting notices to the effect of, "The WTO is meeting in Seattle next week, bring your Molotov cocktails" would also be illegal.
Only very specific threats are typically considered unprotected speech, however. You can publish bomb recipes in the States, or make general calls for revenge, that might be unacceptable in other jurisdictions. Australia has chosen to accept a slightly broader definition of what constitutes inciting violent or criminal activity. Slight difference in degree, not a difference in kind. Many other countries (Canada, for one) have similar policies. (And, IIRC, Canada is usually reviled on Slashdot for being a Socialist/Commie/pinko nation, rather than a Fascist one.)
They are the country the most wiretaps per citizen.
They are the country with the most reported wiretaps per person. I'm sure that the FBI, CIA, and NSA are just models of honesty and transparency about that sort of thing, since they're such good USAPATRIOTs. Ahem.
China is Australias morst important trading partner. Now wonder some strange ideas come back from China.
Canada is the United States' biggest trading partner. I'd love to know what strange ideas Americans are getting by that route.
I concur with the physics, btw, but you're really overestimating the resilience of our civilisation.
For the record, I often think it a stretch to describe this mess as a 'civilization' anyway. But to address your point--I think that the problems caused by this occurrance will be alleviated somewhat by it's relatively slow onset. Sure, the poles flipping is a very rapid thing on geologic timescales, but we're still talking decades or more.
Communications won't collapse--most long-haul lines are based around fibre now, which is essentially impervious to solar radiation. Satellites infrastructure might take a bit of a hit, but I don't see the iminent collapse of the GPS system. (Since the U.S. military really can't do without it, they'll find a way to keep it working. Kind of a hand-waving argument, but you can bet your ass that they'll get whatever appropriations they want from Congress.) Retaining GPS and transoceanic fibre will mean that international finance and trade will be pretty much unaffected.
Climate change is a different beast altogether. Nobody knows exactly what form it will take, if it happens at all. The world already overproduces food--we just don't distribute it very well. I suspect that we will see exactly what we've seen for most of this century--the developed world will survive in relative comfort, while Third World nations willl starve.
As to health effects--again, a big question mark. It depends on dose of solar radiation, but I'm heartened by the fact that these flips have happened fairly frequently without being accompanied by mass extinctions. Cancer rates will go up somewhat. Wealthy nations will probably develop preventive medicines to cut down on the effect.
In short, day to day life probably won't be seriously affected for most people. We'll get some weird weather, and have to develop some interesting technological solutions in some areas, and--oh, yes--low lying cities may have to build dikes or be evacuated. But that's about it. Not the end of civilizaiton.
Alternately, I advocate giving every person on earth a little bar magnet to carry around, along with detailed instructions as to how it ought to be oriented to maintain an artificial planetary magnetic field.
I seem to recall a Mr. Bean episode along these lines. He wanted to paint his apartment, but was too efficiency-minded (read: lazy--I'm sure there are a lot of coders out there who can relate) to pick up a paintbrush.
The obvious solution was to place the can of paint in the middle of the room, and add a small explosive charge. Before detonating the can, ensure that all of the objects in the room that are not meant to be painted are coated in newspaper. Oh, and make sure that nobody enters the room while the fuse is burning. It will lead to much hilarity, yes, but also human silhouettes that will have to be hand painted later.
If anybody tries/has tried this, I implore them to please post links to photos.
I've worked plenty of places where IS and IS only were allowed to install ANY software.
In one of my previous workplaces, we had a policy like that. We finally got tired of waiting for the IS guys to install software for us, so we spliced a second PS2 connector on to one of our keyboards. Worked great for extracting the admin's password on his next visit. Probably illegal, but it meant that we were actually able to start getting work done again.
(Moral of story: any network on which there exist computers that are not physically secured--is insecure.)
It's a waste of Hubble time. There's real science to be done.
Second reason:
The sunlit moon is way too bright. You'd cook all the expensive and highly sensitive optics. If you examine a new moon, maybe you could get away with it, but such a moon is still illuminated by the full sunny side of the earth. I wouldn't want to try it. Also, pointing towards the dark face of the moon is also pointing the Hubble very close to where the sun would be in its sky...
Third reason:
The Hubble's resolution isn't good enough. Depending on the wavelength you work at, the moon's distance at the time, and the assumptions you choose to make in your calculation, the Hubble could resolve objects no smaller than twenty to eighty metres in size--much larger than any of the artifacts left at the moon landing sites. You might have better luck with the Keck telescopes in Hawaii, but they too are busy being used for real science. Any hoax believers aren't going to be convinced by a smudge, which is all you'd see even with the Kecks--if you could see anything at all.
Please stop being lazy and Google for it yourself. The original poster is quite correct. The human eye is most sensitive to green light. Going from red (632 nm) to green (532 nm) there is an approximately fourfold increase in sensitivity. That's why green laser pointers are starting to appear, despite their cost. Novelty value, certainly, but also because a laser pointer limited to a safe power is four times more visible in green than in red.
My guess is that it is because green does not re-transmit as far in distance as red does. Red has a longer wavelength and so can travel further without absorption. You don't want your enemy to be able to see you as well, right?
The eye can resolve finer variations in contrast and brightness in green than in red, as well--hence the use of green displays in night vision scopes. Incidentally, it doesn't matter at all what colour your night vision scopes' display is from the enemy's point of view. Night vision devices are almost always passive devices that collect existing light. As long as they are properly fitted, they aren't directing any radiation--red, green, visible, invisible--outward, so there's nothing to see.
There was a study done about what would be better to use for star watching: green or red.
For amateur astronomers, red LED flashlights are available. They are used because even a fairly bright red LED is perceived as relatively dim by the eye, so your eyes don't lose their dark adaptation every time you check your star charts.
As an aside to anyone here who works with near-IR lasers...you know that a 200 mW diode laser at 670 nm (very red) looks no brighter than a 5 mW HeNe (red, 632 nm)--indeed, it looks quite a bit dimmer after all those burn spots start occluding your vision. Wavelength matters just as much as power when talking about perceived brightness.
The only thing stopping the USA from kicking the arse of everyone that opposes them around the world, including the Chinese and the Europeans is that the USA can't replace combat losses of personel;
Um. Sure. Absolutely. An invasion can be deemed successful if the conquering power is too afraid to send armed troops into the 'vanquished' nation.
Really, the only thing stopping the USA from kicking the arse of everyone else would have to be the nuclear weapons belonging to other nations. And the chemical weapons. And the biologicals, God forbid. Oh--and six billion people, most of whom might take exception to any potential arsekicking. Granted, taking on the entire world all at once is unlikely in the extreme. Still, there's a half dozen or more nations (UK, Russia, China, India, etc.) that could mount a significant attack on the United States. They would lose, but after such a conflict the United States could certainly not be said to have won...
The notion of mutually assured destruction loses its deterrent effect once one side expects to be razed and burned anyway. Oh, and MAD doesn't deter people who don't care about their own destruction anyway, as long as they can get a chance to bloody the U.S. a bit.
Remember the kid in school that would always say, "My ball, my rules"?
Yes, but most kids don't say, "My ball, but you can make an exact copy of it, for free, for your own use. You can play with your ball with whatever rules you want. You can take my basketball and turn it into a baseball, or a golf ball, or a Calvinball, or a shuttlecock, to meet your own needs. You can give away as many copies of my ball--or your derivative ball--as you want, to whomever you want. You can play with as many--or as few--other players as you wish."
"Oh, and if you like my ball, and you want to contribute to improvements--maybe a more durable covering, a prettier finish--I welcome your suggestions, but I won't be bound by them. It is my ball, after all."
First point--this question has been posed on/. before; I've even replied to it before.
The short answer is no. It won't work.
Optics designed for use with high-power laser systems are fragile and extremely costly. Also, they work extremely badly if they get dirty. Even if you could prepare a material sufficiently reflective to protect a shell under ideal circumstances (an iffy proposition at best) you're screwed if there's dust or smoke about--both common on a battlefield. I've seen some very expensive (nominally high-power) optical elements ruined (burned, cracked, shattered) because a little bit of fluff settled on them in a beam path.
That being said, I feel a bit cheated because I recently took a bunch of online courses from Columbia University. At about $1000/credit, it kinda bothers me that people can get something similar for free (of course, you can't get a degree this way).
And you've abdicated any right to complain with your own comment. The only reason that universities may charge exorbitant rates as they see fit is because they are permitted to grant credit towards degrees. You're not paying for the subject matter. You're paying for the piece of paper at the end (oh, yes--the live professor is worth something, but the actual value of his or her pedagogy varies wildly.)
Saying, "I have a degree from Cornell" carries significantly more weight than, "I have read all of the online materials without attending any classes or earning any credits." The cost of the courses is what you pay for the university's seal of approval--they are willing to attest to your knowing the material that you assert you know.
Also--quit whining. You now have access to a tremendous free resource that's not polluted with the quantity of misinformed crap that poisons most of the rest of the 'net. Enjoy it. Use it.
You must not have read the specs very closely, or compared it with other models, or read many reviews.
I dunno, it seems that the parent poster didn't read the article. From THG:
Even more annoying is the fact that Dell documents this energy-saving feature neither on its German- language homepage nor anywhere in the handbook. The English homepage, in the meantime, features a footnote: "Power management features limit processor speed when running on battery." This is pretty well hidden, however.
So right off the top, if you're German, then Dell isn't even going to tell you that they're selling you a desktop processor that's automatically crippled when running on battery. If you're English-speaking, then you still have to have very good eyes. The "power management features" quote is buried in a fine-print footnote at the bottom of the technical specs page. Further, nowhere on the pages for the Speedstep 250N is the actual slower clock speed noted. At what point is the footnote no longer sufficient? On battery power, the processor drops to 0.7 volts and 300 MHz. Can I complain yet? I'm getting great battery life, after all...
The parent poster is correct--when making a major purchase, it is a good idea to read product reviews. What we have here, however, is a case of deliberately deceptive (and possibly fraudulent) marketing. It's like advertising an automobile as a V8--but four of the cylinders stop firing whenever you're not in your driveway. If Dell is going to advertise a 2.2 GHz notebook, then it should be able to function as a 2.2 GHz notebook even when it's not on my desk at home. Dell should reasonably be expected to realize that their notebook computers are going to frequently be used on battery power--the clock speeds cited should be 2.4/1.2 GHz at the top of the page, not 2.2 GHz with a tiny footnote. Anything less--even if barely legal--is still slimy.
As an aside, many Toshiba and Compaq laptops allow you to change a control panel setting to say, "Damn the batteries, full speed ahead!" or words to that effect. Consumers familiar with this friendlier incarnation of SpeedStep may be in for a rude surprise.
Now who's being outrageous and attacking with a blanket statement.
Moderators! Why are you modding up posters who didn't get the ironic humour in the first place?
I suppose it's +1, Insightful for people who didn't get the original joke...
Re:how do you stop the damn thing...
on
Antimatter Space Drive
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· Score: 4, Informative
Don't bother decelerating. You want to stop a probe? Put a planet in the way. Just make sure you gather (and transmit) lots of data--really fast--on the way down. Or do a flyby. Or aim really carefully and put yourself into an orbit about some object of interest.
Some of the Russian Venera and Luna probes took the first approach--deliberately crashing into Venus or the Moon, respectively. NASA's Voyager craft did a tremendous amount of good science with just flybys. Galileo (the spacecraft, not the Italian scientist) dropped a probe into Jupiter's atmosphere and then settled into two years of orbiting the planet.
The only advantage to using an antimatter/matter reaction as a propellant is the sheer efficiency of the reaction. You get a lot more push out of a lot less 'fuel'.
The problem is that it will still be decades (if not centuries...if ever) before we will be able to produce the quantities of antimatter necessary to have antimatter as the sole fuel of a large spacecraft.
One idea being considered (by NASA, among others) is to use small amounts of antimatter as a sort of igniter for conventional fusion reactions. Sure it's a smaller specific impulse than pure antimatter, but fusion still gets you way more bang for the buck than chemical rockets. And early calculations suggest that a vanishingly small amount of antimatter would be sufficient. (Still much more than the current annual production of the stuff, however.)
Either way, for moving a really large craft, antimatter (or at least conventional nuclear) technology will be necessary. It's prohibitively expensive to loft a significant amount of reaction mass to space--antimatter becomes a lot less expensive when you factor in the hundred plus dollars per pound we pay to put something in low earth orbit.
Would more capacitors in a device reduce the need for an immediate (sustained) power source, if we're talking about short bursts?
Emphatically, yes. Actually, for nearly all pulsed lasers, there's almost no other way to get to a high power--and pulsed lasers are by far the 'big guns' (pardon the expression) of the laser world. Using capacitors allows one to deliver a very large amount of energy in a very short time, which works just great for a weapon, as long as you aim the thing accurately.
It's also possible to shorten already short laser pulses using nonlinear optics, but that's beyond the scope of this post.;)
Lasers work by creating an inversion of atoms into an excited state and then releasing that exciting energy in a burst. But exciting the atoms obviously takes energy and, by E=mc^2, it takes a LOT. Industrial and scientific lasers can manage this by being plugged in to a dedicated power supply capable of delivering the gigawattage required for even small lasers, but a soldier in the field clearly doesn't have the luxury of an outlet needed to power his weapon.
Okay, I'll bite. Where does E=mc^2 come into this? I've worked with lasers for a number of years, and I have yet to see any of my lasing medium converted directly to energy. Lasers operate by kicking atoms into an excited state (usually an excited electronic state) and then emitting light when excited atoms relax back to ground state.
For the record, small lasers don't require "gigawattage" to operate. I have a laser pointer that runs on one AA battery--I'll be giving a talk using it in a couple of hours. A laser designed for a weapons application would be larger. Still, I could assemble a carbon dioxide laser that could start fires from several hundred feet away and still be light enough to carry--and operate for a while on a moderately hefty battery back.
Granted, I couldn't destroy missiles with it, but the article discussses lasers that are mounted on aircraft or vehicles, or are part of fixed installations. You don't need a large power supply for even an extremely powerful laser if it only fires the very short pulses (microseconds or nanoseconds) that would be most useful for military purposes.
Slashdot Mirror
Tell that to the people of Missouri. In 2000 they voted for a man three weeks dead (Gov. Mel Carnahan) rather than elect John Ashcroft to the Senate. To quote a recent episode of The West Wing, sometimes "there are worse things than being dead."
Gaaaaack! Must...control...fists...of...death.
The plural of a word should never, ever, ever be made by adding an apostrophe and an 's'.
End rant.
NASA has awarded a three-year contract to Honeybee Robotics. The total bill is $750,000. That's only $250k per year. Not chump change, but really a drop in NASA's budget. There's a significant potential return on their investment. Yes, they need to focus on whatever their priorities are, but they can't keep the blinders on and ignore promising new technology that might be used on the next mission--it's like saying, "We're still getting data from Voyager, so we better not think about designing Galileo, Cassini, or any other probes."
Why not spend some of that money exploring our own planet. There are expansive depths of the oceans that have life forms we have yet to discover, same goes for the rainforests. Why not procure some tax dollars and explore them.
For the record, NASA does spend quite a bit of money on research projects directed at the earth. There are a lot of surveys that are only practical from orbit. Further, I agree with you--some research funds could be very well spent on investigating our forests, and there's some truly fascinating (and potentially useful) stuff in the depths of our oceans.
But--there's always a but. That sort of research isn't part of NASA's mandate. Asking why NASA doesn't direct funding to oceanic exploration is like asking the Department of the Interior to help manage the Australian Outback. If you think that NASA is spending too much on developing techniques for future planetary exploration, then write to your congresscritter and demand that the appropriate amount of funding be transferred to another research agency.
Criminal acts will always be committed, in meatspace and cyberspace, by all manner of people--clever and otherwise. At least this legislation would address the most egregious instances of inciting criminal activity on the web.
I don't think anyone on Slashdot will suggest that the sort of legislation proposed will be a panacea, but it can't hurt to provide a regulated framework within which already existing laws can be enforced. If they're going to shut down a server, at least there will be law on the books that specifically describes circumstances under which such action is permitted--and law that is subject to constitutional scrutiny.
An interesting side issue: I would think that this sort of activity is already prohibited under existing law. Props to the Australian government if they're merely codifying de facto policies so that everyone knows what the rules are. Jeers if they're trying to overreach the equivalent meatspace jurisdiction because FUD says violent protestors are inherently more dangerous on the internet than in real life (how's that again?) I suppose I'm saying /. ought not jump to conclusions about the proposal--wait until the bill is before Parliament, then read it. (Yes, I know...getting /.ers to read raw legislation is even harder than getting them to read the articles they reply to. Alas.)
IANAL, but common law in most countries has built up a set of principles by which defamation lawsuits are judged. Generally, the limits of acceptable comment are much broader when discussing a bona fide public figure, like a politician. It is accepted (in both common sense and common law) that politicians will be subject to scrutiny (and ridicule) within reasonable bounds. Satire is almost always acceptable, in part because on television shows like Royal Canadian Air Farce it is obvious that humour is intended, and remarks should not be taken as gospel truth.
In the media, different countries have different standards for news reporting. In the United States a plaintiff must show malice on the part of his or her defamer--very difficult, which is why so much sensationalistic crap can be published as "news". In Canada, the bar is lower--the news source must demonstrate that they had reasonable grounds to publish their (otherwise defamatory) assertions. In other countries, YMMV. In all cases, there is (or should be) a responsibility to separate fact from opinion from humour.
How did this get modded Interesting, rather than Flamebait? If one reads the article, one finds that Australia has decided to pull the plug on websites that are used to organize violent protests. Such websites are illegal in the United States as well, however the legal tests for shutting down such sites are stricter in the US. The First Amendment does not protect speech that advocates specific criminal acts. That's why you're not allowed to put Wanted: Dead or Alive posters of abortion doctors on your web site. Similarly, posting notices to the effect of, "The WTO is meeting in Seattle next week, bring your Molotov cocktails" would also be illegal.
Only very specific threats are typically considered unprotected speech, however. You can publish bomb recipes in the States, or make general calls for revenge, that might be unacceptable in other jurisdictions. Australia has chosen to accept a slightly broader definition of what constitutes inciting violent or criminal activity. Slight difference in degree, not a difference in kind. Many other countries (Canada, for one) have similar policies. (And, IIRC, Canada is usually reviled on Slashdot for being a Socialist/Commie/pinko nation, rather than a Fascist one.)
They are the country the most wiretaps per citizen.
They are the country with the most reported wiretaps per person. I'm sure that the FBI, CIA, and NSA are just models of honesty and transparency about that sort of thing, since they're such good USAPATRIOTs. Ahem.
China is Australias morst important trading partner. Now wonder some strange ideas come back from China.
Canada is the United States' biggest trading partner. I'd love to know what strange ideas Americans are getting by that route.
For the record, I often think it a stretch to describe this mess as a 'civilization' anyway. But to address your point--I think that the problems caused by this occurrance will be alleviated somewhat by it's relatively slow onset. Sure, the poles flipping is a very rapid thing on geologic timescales, but we're still talking decades or more.
Communications won't collapse--most long-haul lines are based around fibre now, which is essentially impervious to solar radiation. Satellites infrastructure might take a bit of a hit, but I don't see the iminent collapse of the GPS system. (Since the U.S. military really can't do without it, they'll find a way to keep it working. Kind of a hand-waving argument, but you can bet your ass that they'll get whatever appropriations they want from Congress.) Retaining GPS and transoceanic fibre will mean that international finance and trade will be pretty much unaffected.
Climate change is a different beast altogether. Nobody knows exactly what form it will take, if it happens at all. The world already overproduces food--we just don't distribute it very well. I suspect that we will see exactly what we've seen for most of this century--the developed world will survive in relative comfort, while Third World nations willl starve.
As to health effects--again, a big question mark. It depends on dose of solar radiation, but I'm heartened by the fact that these flips have happened fairly frequently without being accompanied by mass extinctions. Cancer rates will go up somewhat. Wealthy nations will probably develop preventive medicines to cut down on the effect.
In short, day to day life probably won't be seriously affected for most people. We'll get some weird weather, and have to develop some interesting technological solutions in some areas, and--oh, yes--low lying cities may have to build dikes or be evacuated. But that's about it. Not the end of civilizaiton.
Alternately, I advocate giving every person on earth a little bar magnet to carry around, along with detailed instructions as to how it ought to be oriented to maintain an artificial planetary magnetic field.
The obvious solution was to place the can of paint in the middle of the room, and add a small explosive charge. Before detonating the can, ensure that all of the objects in the room that are not meant to be painted are coated in newspaper. Oh, and make sure that nobody enters the room while the fuse is burning. It will lead to much hilarity, yes, but also human silhouettes that will have to be hand painted later.
If anybody tries/has tried this, I implore them to please post links to photos.
In one of my previous workplaces, we had a policy like that. We finally got tired of waiting for the IS guys to install software for us, so we spliced a second PS2 connector on to one of our keyboards. Worked great for extracting the admin's password on his next visit. Probably illegal, but it meant that we were actually able to start getting work done again.
(Moral of story: any network on which there exist computers that are not physically secured--is insecure.)
It's a waste of Hubble time. There's real science to be done.
Second reason:
The sunlit moon is way too bright. You'd cook all the expensive and highly sensitive optics. If you examine a new moon, maybe you could get away with it, but such a moon is still illuminated by the full sunny side of the earth. I wouldn't want to try it. Also, pointing towards the dark face of the moon is also pointing the Hubble very close to where the sun would be in its sky...
Third reason:
The Hubble's resolution isn't good enough. Depending on the wavelength you work at, the moon's distance at the time, and the assumptions you choose to make in your calculation, the Hubble could resolve objects no smaller than twenty to eighty metres in size--much larger than any of the artifacts left at the moon landing sites. You might have better luck with the Keck telescopes in Hawaii, but they too are busy being used for real science. Any hoax believers aren't going to be convinced by a smudge, which is all you'd see even with the Kecks--if you could see anything at all.
Um, you mean the speed of dork, don't you?
You put a cord on it!
Does it still work?
Please stop being lazy and Google for it yourself. The original poster is quite correct. The human eye is most sensitive to green light. Going from red (632 nm) to green (532 nm) there is an approximately fourfold increase in sensitivity. That's why green laser pointers are starting to appear, despite their cost. Novelty value, certainly, but also because a laser pointer limited to a safe power is four times more visible in green than in red.
My guess is that it is because green does not re-transmit as far in distance as red does. Red has a longer wavelength and so can travel further without absorption. You don't want your enemy to be able to see you as well, right?
The eye can resolve finer variations in contrast and brightness in green than in red, as well--hence the use of green displays in night vision scopes. Incidentally, it doesn't matter at all what colour your night vision scopes' display is from the enemy's point of view. Night vision devices are almost always passive devices that collect existing light. As long as they are properly fitted, they aren't directing any radiation--red, green, visible, invisible--outward, so there's nothing to see.
There was a study done about what would be better to use for star watching: green or red.
For amateur astronomers, red LED flashlights are available. They are used because even a fairly bright red LED is perceived as relatively dim by the eye, so your eyes don't lose their dark adaptation every time you check your star charts.
As an aside to anyone here who works with near-IR lasers...you know that a 200 mW diode laser at 670 nm (very red) looks no brighter than a 5 mW HeNe (red, 632 nm)--indeed, it looks quite a bit dimmer after all those burn spots start occluding your vision. Wavelength matters just as much as power when talking about perceived brightness.
Um. Sure. Absolutely. An invasion can be deemed successful if the conquering power is too afraid to send armed troops into the 'vanquished' nation.
Really, the only thing stopping the USA from kicking the arse of everyone else would have to be the nuclear weapons belonging to other nations. And the chemical weapons. And the biologicals, God forbid. Oh--and six billion people, most of whom might take exception to any potential arsekicking. Granted, taking on the entire world all at once is unlikely in the extreme. Still, there's a half dozen or more nations (UK, Russia, China, India, etc.) that could mount a significant attack on the United States. They would lose, but after such a conflict the United States could certainly not be said to have won...
The notion of mutually assured destruction loses its deterrent effect once one side expects to be razed and burned anyway. Oh, and MAD doesn't deter people who don't care about their own destruction anyway, as long as they can get a chance to bloody the U.S. a bit.
Yes, but most kids don't say, "My ball, but you can make an exact copy of it, for free, for your own use. You can play with your ball with whatever rules you want. You can take my basketball and turn it into a baseball, or a golf ball, or a Calvinball, or a shuttlecock, to meet your own needs. You can give away as many copies of my ball--or your derivative ball--as you want, to whomever you want. You can play with as many--or as few--other players as you wish."
"Oh, and if you like my ball, and you want to contribute to improvements--maybe a more durable covering, a prettier finish--I welcome your suggestions, but I won't be bound by them. It is my ball, after all."
The short answer is no. It won't work.
Optics designed for use with high-power laser systems are fragile and extremely costly. Also, they work extremely badly if they get dirty. Even if you could prepare a material sufficiently reflective to protect a shell under ideal circumstances (an iffy proposition at best) you're screwed if there's dust or smoke about--both common on a battlefield. I've seen some very expensive (nominally high-power) optical elements ruined (burned, cracked, shattered) because a little bit of fluff settled on them in a beam path.
I dunno. I can think of several people off the top of my head for whom any money spent educating them was clearly wasted.
My list begins with several Fox executives...
And you've abdicated any right to complain with your own comment. The only reason that universities may charge exorbitant rates as they see fit is because they are permitted to grant credit towards degrees. You're not paying for the subject matter. You're paying for the piece of paper at the end (oh, yes--the live professor is worth something, but the actual value of his or her pedagogy varies wildly.)
Saying, "I have a degree from Cornell" carries significantly more weight than, "I have read all of the online materials without attending any classes or earning any credits." The cost of the courses is what you pay for the university's seal of approval--they are willing to attest to your knowing the material that you assert you know.
Also--quit whining. You now have access to a tremendous free resource that's not polluted with the quantity of misinformed crap that poisons most of the rest of the 'net. Enjoy it. Use it.
I dunno, it seems that the parent poster didn't read the article. From THG:
Even more annoying is the fact that Dell documents this energy-saving feature neither on its German- language homepage nor anywhere in the handbook. The English homepage, in the meantime, features a footnote: "Power management features limit processor speed when running on battery." This is pretty well hidden, however.
So right off the top, if you're German, then Dell isn't even going to tell you that they're selling you a desktop processor that's automatically crippled when running on battery. If you're English-speaking, then you still have to have very good eyes. The "power management features" quote is buried in a fine-print footnote at the bottom of the technical specs page. Further, nowhere on the pages for the Speedstep 250N is the actual slower clock speed noted. At what point is the footnote no longer sufficient? On battery power, the processor drops to 0.7 volts and 300 MHz. Can I complain yet? I'm getting great battery life, after all...
The parent poster is correct--when making a major purchase, it is a good idea to read product reviews. What we have here, however, is a case of deliberately deceptive (and possibly fraudulent) marketing. It's like advertising an automobile as a V8--but four of the cylinders stop firing whenever you're not in your driveway. If Dell is going to advertise a 2.2 GHz notebook, then it should be able to function as a 2.2 GHz notebook even when it's not on my desk at home. Dell should reasonably be expected to realize that their notebook computers are going to frequently be used on battery power--the clock speeds cited should be 2.4/1.2 GHz at the top of the page, not 2.2 GHz with a tiny footnote. Anything less--even if barely legal--is still slimy.
As an aside, many Toshiba and Compaq laptops allow you to change a control panel setting to say, "Damn the batteries, full speed ahead!" or words to that effect. Consumers familiar with this friendlier incarnation of SpeedStep may be in for a rude surprise.
How do you have vaporware in a vacuum?
Moderators! Why are you modding up posters who didn't get the ironic humour in the first place?
I suppose it's +1, Insightful for people who didn't get the original joke...
Some of the Russian Venera and Luna probes took the first approach--deliberately crashing into Venus or the Moon, respectively. NASA's Voyager craft did a tremendous amount of good science with just flybys. Galileo (the spacecraft, not the Italian scientist) dropped a probe into Jupiter's atmosphere and then settled into two years of orbiting the planet.
The problem is that it will still be decades (if not centuries...if ever) before we will be able to produce the quantities of antimatter necessary to have antimatter as the sole fuel of a large spacecraft.
One idea being considered (by NASA, among others) is to use small amounts of antimatter as a sort of igniter for conventional fusion reactions. Sure it's a smaller specific impulse than pure antimatter, but fusion still gets you way more bang for the buck than chemical rockets. And early calculations suggest that a vanishingly small amount of antimatter would be sufficient. (Still much more than the current annual production of the stuff, however.)
Either way, for moving a really large craft, antimatter (or at least conventional nuclear) technology will be necessary. It's prohibitively expensive to loft a significant amount of reaction mass to space--antimatter becomes a lot less expensive when you factor in the hundred plus dollars per pound we pay to put something in low earth orbit.
Emphatically, yes. Actually, for nearly all pulsed lasers, there's almost no other way to get to a high power--and pulsed lasers are by far the 'big guns' (pardon the expression) of the laser world. Using capacitors allows one to deliver a very large amount of energy in a very short time, which works just great for a weapon, as long as you aim the thing accurately.
It's also possible to shorten already short laser pulses using nonlinear optics, but that's beyond the scope of this post. ;)
Okay, I'll bite. Where does E=mc^2 come into this? I've worked with lasers for a number of years, and I have yet to see any of my lasing medium converted directly to energy. Lasers operate by kicking atoms into an excited state (usually an excited electronic state) and then emitting light when excited atoms relax back to ground state.
For the record, small lasers don't require "gigawattage" to operate. I have a laser pointer that runs on one AA battery--I'll be giving a talk using it in a couple of hours. A laser designed for a weapons application would be larger. Still, I could assemble a carbon dioxide laser that could start fires from several hundred feet away and still be light enough to carry--and operate for a while on a moderately hefty battery back.
Granted, I couldn't destroy missiles with it, but the article discussses lasers that are mounted on aircraft or vehicles, or are part of fixed installations. You don't need a large power supply for even an extremely powerful laser if it only fires the very short pulses (microseconds or nanoseconds) that would be most useful for military purposes.