Storing energy as hydrogen and burning it in a car later is 3x less efficient than storing it in batteries. Hydrogen makes no sense. Get a battery electric vehicle instead.
From the summary: "A prisoner could just as easily read the works of Vonnegut or Heinlein and claim it as his holy book, and demand accommodation of Bokononism or the Church of All Worlds [citing Kurt Vonnegut's Cat's Cradle and Robert A. Heinlein's Stranger in a Strange Land]. "
I don't get it -- so inventing a religion from science fiction authors Kurt Vonnegut or Robert Heinlein would be bogus. But inventing a religion from science fiction writer L. Ron Hubbard yields a viable and constitutionally protected religious practice. What's the difference?
far deeper in fact, than we've ever cored. That number must be wrong -- I'm guessing it should read 200m. It's in the original story, I know, but it just can't be right.
2.5%, huh -- I'm not impressed. So basically if we all stopped flying it would have just a tiny effect on net anthropogenic CO2 production. Sounds like we should concentrate our efforts on other more profligate industries first and worry about building electric airliners in 50 years.
I guess that I don't understand people's privacy objections here. Those people who got free BlackBerries are well aware of the monitoring. Legally, either party may record a conversation and save it and provide it to whomever they want (Though this varies by state). It's the responsibility of the BlackBerry owner to make sure that their friends know the situation -- and based on the last drug-text, they do.
The bigger question that should be in a/. poll soon, is: "I would give a researcher all of your phone data, text, and other information, in exchange for a free:
There's plenty of oxygen on Titan. The whole crust is made out of water ice. True there is no free molecular oxygen, but neither was there on Earth before about a billion years ago.
As for life on Titan, the suggestion is that there might be an opportunity when the liquid water beneath Titan's 50-km-thick ice crust bubbles to the surface (a "cryovolcano"), or when a meteor impact leaves a patch of melted local bedrock (which is water ice, so the patch would be a lake). When liquid water from one of these sources combines with the organics in the atmosphere, who knows what happens. But it better happen fast -- the whole thing freezes over in 10^4 years!
Dunno anything about these folks' rings, but I got my wife an engagement ring with Martian basalt in it. Thankfully she is also a nerd, and in fact studies the Moon and Mars for her research. Otherwise I don't recommend this tactic, as it's likely to get you slapped rather than engaged . . .
I don't understand the problem, here. All data from NASA planetary missions are made public 1 year after they are taken. Here, you can go download them and use them for whatever you like at the Planetary Data System . There's a group of enthusiastic amateurs that use and interpret the raw data at UMSF , among other places. You're welcome to use these data and do science with them and publish them, scooping other scientists. Believe me, there's plenty of science left to be done in there.
Alan Stern is the precise antithesis of a clueless project manager. He is, in fact, a planetary scientist who continues to actively contribute to the scientific community. He took this job because HIS mission to Pluto, New Horizons, on which he is the principal investigator, did end up on budget and on time, and he thinks that the total amount of science would be maximized if others did the same. He's right. On the astrophysics side there isn't money left for hardly any science at all these days, what with the Hubble-successor James Webb Space Telescope hoovering up any dollar not glued down. What Alan Stern is doing makes sense from the standpoint of maximizing the science return from a fixed yearly budget.
[the STS is] the only manned launcher the USA has so they've got to work with it until Orion becomes available.
This misses the point. The problem is that NASA told congress that they could indeed keep flying the shuttle while developing Orion, for an extra $1B per year. Congress said, "great. keep flying the shuttle, develop Orion, and do it without the $1B." NASA is not getting enough money to do both. The point of retiring the shuttle is to free up that ~$6B/year and spend it on the next-generation launch system, Orion, instead. We can't do both without a significant increase in budget, which is just not going to happen.
As for not having American access to the Station in the interim, we'll just have to deal with paying the Russians. Unless the NASA COTS system works out. Elon Musk over at SpaceX may very well have his Dragon capsule and Falcon 9 launch vehicle ready about that time to take over from the Shuttle.
However you may have a point about the cost/benefit ratio. For the price of a shuttle launch to repair Hubble (~$1B), you could just about build and launch a new one on an unmanned rocket. If there were a concerted program to launch a virtually identical 2-meter telescope every 4 years with different instrumentation on it, that program would be better and cheaper than continuing to repair Hubble. However, congressional whims being what they are, such a program would inevitably get cut after its first mission, obviating the savings. Hence NASA has opted to continue to repair and update Hubble instead.
JWST may be the political successor of Hubble, but it will not replace its capabilities. JWST operates only in the infrared; Hubble's primary contributions are in the visible (and the UV). These spectral coverages are complementary. The launch of JWST (after it finishes hoovering up what's left of the NASA astrophysics budget) will not cause Hubble to become obsolete.
Sure, adaptive optics allows ground-based 'scopes to do SOME of the things that only Hubble could previously do. However, anything requiring high-contrast imaging, photometric stability, or spectral uniformity still greatly benefits from Hubble. Given that astronomers request 10 times as much time on Hubble as there actually is, there's still plenty of science that only it can do.
Ahhh -- vacuum-insulated thermoses are effective because the vacuum is held within a metal vessel. The metal is chosen such that it has a very high reflectivity and, necessarily then (since T+R+A=1 and E=A at each wavelength), a low emissivity. Hence the purpose of such a thermos is to inhibit radiation since "blackbody" radiation assumes an absorptivity of 1 (A=1, hence E=1) and for lower emissivities it is less effective.
However, I certainly concede that under some circumstances, such as the LN2 that you describe, conduction can be more effective than radiation. Much of the energy in that case turns into latent heat as your body heat boils the N2, turning it to gas.
All this means is that the clothes will cool down to a very low temperature first, before you do. Then you'll be radiating to them instead of to space. Like another poster suggested, the best solution would be a space blanket, which has a very low emissivity and high reflectivity. Hence the whole "space" blanket thing.
Wrong. As you sit in front of your computer, you exchange heat with your environment in three ways simultaneously: (1) conduction, (2) convection, (3) radiation.
The part you are referring to is heat transfer mechanism (1), conduction, as your body heats cooler air molecules around you. Mechanism (2), as occurs when those heated air molecules rise toward the top of the room making room for cooler ones, also requires air.
However, mechanism (3), the most effective of the three, does not require any medium at all. You, like all baryonic matter, emit electromagnetic radiation with frequencies and intensities as described by blackbody radiation, dependent on temperature. An object twice as hot gives of 16 times as much heat in radiation per unit time.
Normally, when sitting in front of your computer, you are radiating like mad, and so losing heat. However, so are the walls of your apartment. Those walls, being nearly the same temperature as you are, heat you to a large degree, making up for the heat that you are losing to radiation. Hence if, on a cold night, you are walking down a hallway in which one wall has a fireplace behind it, you immediately notice how warm the wall is without coming anywhere near it.
Considering that the "walls" in space are the 2.73K cosmic microwave background radiation, and that a person's temperature is more like 300K, you would radiate 10^8 times more energy than your receive. You'd freeze in a hurry.
Now, if there's a star heating you from one side, this can partially make up the difference. You still get the one-side-super-hot and one-side-super-cold problem, then, like the surface of Earth's moon writ small.
What about predictions for precipitation? The author claimed that he was motivated by a washed-out waterpark visit. Variations in the high temp by 3 degrees don't really matter a lick -- what matters is if it predicts sun and you get rain, or vice versa. How accurate are those "20% chance of rain" predictions really? Inquiring slashdot readers want to know!
While North Korea has built a nuclear weapon (well, the one test was a fizzle, it seemed, but they are at least close), and while they have built missles that can strike South Korea and Japan (but not yet the U.S.), they have not yet put the two together. In order to get a bomb onto a missile, or even an airplane for that matter, it has to be a lot smaller a lighter than the ones that the North Koreans have so far. So THAAD can't help defend from them -- yet, anyway. It's not clear yet how long it will be before the North Koreans have something that's deliverable.
I don't know where this 1 meter stuff came from. The actual full sampling of HiRISE is 30cm, a factor of 6 greater than HRSC, and a factor of 3 better than MOC. Be careful when comparing "sampling" to "resolution" -- they are not the same thing. HiRISE has taken the HiROAD, so to speak, by not trumpeting their 30cm sampling but instead claiming 1-meter imaging scales. Don't hold that against them when comparing to other teams that publish their best sampling.
The other real advantage of this camera is that it returns 14-bit images -- this means that they get dynamic range such that you can see details well, with good S/N, EVEN IN SHADOW, while keeping the well-lit stuff from saturating. Truly awesome. On Friday, when those images come down, 20,000 by 60,000 with awesome signal-to-noise, full dynamic range, and 30cm surface sampling, you will agree that this is a large forward step for Martian surface science.
What this means to me is that after 20 years, they're still writing the same games that they always did, but just with better graphics. Because those better graphics are so much more expensive to produce, nobody is willing to take a chance on a *truly* new and innovative game concept. _Spore_ being a possible exception.
I think 30 is old. I just turned 29, and am starting to realize that I am old. *sigh* At least it seems that there are things old people can do that young people can't -- be an astronaut, for instance:)
Slashdot Mirror
Didn't Dilbert suggest this back in 1998.
Storing energy as hydrogen and burning it in a car later is 3x less efficient than storing it in batteries. Hydrogen makes no sense. Get a battery electric vehicle instead.
From the summary: "A prisoner could just as easily read the works of Vonnegut or Heinlein and claim it as his holy book, and demand accommodation of Bokononism or the Church of All Worlds [citing Kurt Vonnegut's Cat's Cradle and Robert A. Heinlein's Stranger in a Strange Land]. "
I don't get it -- so inventing a religion from science fiction authors Kurt Vonnegut or Robert Heinlein would be bogus. But inventing a religion from science fiction writer L. Ron Hubbard yields a viable and constitutionally protected religious practice. What's the difference?
far deeper in fact, than we've ever cored. That number must be wrong -- I'm guessing it should read 200m. It's in the original story, I know, but it just can't be right.
I do believe you have won the comments section for this article ;). Thanks to everyone else for playing!
2.5%, huh -- I'm not impressed. So basically if we all stopped flying it would have just a tiny effect on net anthropogenic CO2 production. Sounds like we should concentrate our efforts on other more profligate industries first and worry about building electric airliners in 50 years.
I guess that I don't understand people's privacy objections here. Those people who got free BlackBerries are well aware of the monitoring. Legally, either party may record a conversation and save it and provide it to whomever they want (Though this varies by state). It's the responsibility of the BlackBerry owner to make sure that their friends know the situation -- and based on the last drug-text, they do.
The bigger question that should be in a /. poll soon, is: "I would give a researcher all of your phone data, text, and other information, in exchange for a free:
(1) dumb phone
(2) BlackBerry
(3) iPhone
(4) RAZR smart phone
(5) CowboyNeal "
The other problem, I think, is a lack of oxygen.
There's plenty of oxygen on Titan. The whole crust is made out of water ice. True there is no free molecular oxygen, but neither was there on Earth before about a billion years ago.
As for life on Titan, the suggestion is that there might be an opportunity when the liquid water beneath Titan's 50-km-thick ice crust bubbles to the surface (a "cryovolcano"), or when a meteor impact leaves a patch of melted local bedrock (which is water ice, so the patch would be a lake). When liquid water from one of these sources combines with the organics in the atmosphere, who knows what happens. But it better happen fast -- the whole thing freezes over in 10^4 years!
Dunno anything about these folks' rings, but I got my wife an engagement ring with Martian basalt in it. Thankfully she is also a nerd, and in fact studies the Moon and Mars for her research. Otherwise I don't recommend this tactic, as it's likely to get you slapped rather than engaged . . .
I don't understand the problem, here. All data from NASA planetary missions are made public 1 year after they are taken. Here, you can go download them and use them for whatever you like at the Planetary Data System . There's a group of enthusiastic amateurs that use and interpret the raw data at UMSF , among other places. You're welcome to use these data and do science with them and publish them, scooping other scientists. Believe me, there's plenty of science left to be done in there.
Evidently you are a Windows user with a small penis length, then, I infer :)
- a FreeBSD server admin with 250-days uptime
Alan Stern is the precise antithesis of a clueless project manager. He is, in fact, a planetary scientist who continues to actively contribute to the scientific community. He took this job because HIS mission to Pluto, New Horizons, on which he is the principal investigator, did end up on budget and on time, and he thinks that the total amount of science would be maximized if others did the same. He's right. On the astrophysics side there isn't money left for hardly any science at all these days, what with the Hubble-successor James Webb Space Telescope hoovering up any dollar not glued down. What Alan Stern is doing makes sense from the standpoint of maximizing the science return from a fixed yearly budget.
This misses the point. The problem is that NASA told congress that they could indeed keep flying the shuttle while developing Orion, for an extra $1B per year. Congress said, "great. keep flying the shuttle, develop Orion, and do it without the $1B." NASA is not getting enough money to do both. The point of retiring the shuttle is to free up that ~$6B/year and spend it on the next-generation launch system, Orion, instead. We can't do both without a significant increase in budget, which is just not going to happen.
As for not having American access to the Station in the interim, we'll just have to deal with paying the Russians. Unless the NASA COTS system works out. Elon Musk over at SpaceX may very well have his Dragon capsule and Falcon 9 launch vehicle ready about that time to take over from the Shuttle.
However you may have a point about the cost/benefit ratio. For the price of a shuttle launch to repair Hubble (~$1B), you could just about build and launch a new one on an unmanned rocket. If there were a concerted program to launch a virtually identical 2-meter telescope every 4 years with different instrumentation on it, that program would be better and cheaper than continuing to repair Hubble. However, congressional whims being what they are, such a program would inevitably get cut after its first mission, obviating the savings. Hence NASA has opted to continue to repair and update Hubble instead.
JWST may be the political successor of Hubble, but it will not replace its capabilities. JWST operates only in the infrared; Hubble's primary contributions are in the visible (and the UV). These spectral coverages are complementary. The launch of JWST (after it finishes hoovering up what's left of the NASA astrophysics budget) will not cause Hubble to become obsolete.
Sure, adaptive optics allows ground-based 'scopes to do SOME of the things that only Hubble could previously do. However, anything requiring high-contrast imaging, photometric stability, or spectral uniformity still greatly benefits from Hubble. Given that astronomers request 10 times as much time on Hubble as there actually is, there's still plenty of science that only it can do.
Ahhh -- vacuum-insulated thermoses are effective because the vacuum is held within a metal vessel. The metal is chosen such that it has a very high reflectivity and, necessarily then (since T+R+A=1 and E=A at each wavelength), a low emissivity. Hence the purpose of such a thermos is to inhibit radiation since "blackbody" radiation assumes an absorptivity of 1 (A=1, hence E=1) and for lower emissivities it is less effective.
However, I certainly concede that under some circumstances, such as the LN2 that you describe, conduction can be more effective than radiation. Much of the energy in that case turns into latent heat as your body heat boils the N2, turning it to gas.
All this means is that the clothes will cool down to a very low temperature first, before you do. Then you'll be radiating to them instead of to space. Like another poster suggested, the best solution would be a space blanket, which has a very low emissivity and high reflectivity. Hence the whole "space" blanket thing.
Wrong. As you sit in front of your computer, you exchange heat with your environment in three ways simultaneously: (1) conduction, (2) convection, (3) radiation.
The part you are referring to is heat transfer mechanism (1), conduction, as your body heats cooler air molecules around you. Mechanism (2), as occurs when those heated air molecules rise toward the top of the room making room for cooler ones, also requires air.
However, mechanism (3), the most effective of the three, does not require any medium at all. You, like all baryonic matter, emit electromagnetic radiation with frequencies and intensities as described by blackbody radiation, dependent on temperature. An object twice as hot gives of 16 times as much heat in radiation per unit time.
Normally, when sitting in front of your computer, you are radiating like mad, and so losing heat. However, so are the walls of your apartment. Those walls, being nearly the same temperature as you are, heat you to a large degree, making up for the heat that you are losing to radiation. Hence if, on a cold night, you are walking down a hallway in which one wall has a fireplace behind it, you immediately notice how warm the wall is without coming anywhere near it.
Considering that the "walls" in space are the 2.73K cosmic microwave background radiation, and that a person's temperature is more like 300K, you would radiate 10^8 times more energy than your receive. You'd freeze in a hurry.
Now, if there's a star heating you from one side, this can partially make up the difference. You still get the one-side-super-hot and one-side-super-cold problem, then, like the surface of Earth's moon writ small.
What about predictions for precipitation? The author claimed that he was motivated by a washed-out waterpark visit. Variations in the high temp by 3 degrees don't really matter a lick -- what matters is if it predicts sun and you get rain, or vice versa. How accurate are those "20% chance of rain" predictions really? Inquiring slashdot readers want to know!
While North Korea has built a nuclear weapon (well, the one test was a fizzle, it seemed, but they are at least close), and while they have built missles that can strike South Korea and Japan (but not yet the U.S.), they have not yet put the two together. In order to get a bomb onto a missile, or even an airplane for that matter, it has to be a lot smaller a lighter than the ones that the North Koreans have so far. So THAAD can't help defend from them -- yet, anyway. It's not clear yet how long it will be before the North Koreans have something that's deliverable.
Firebombing of Tokyo killed in the 100,000 range, IIRC.
I don't know where this 1 meter stuff came from. The actual full sampling of HiRISE is 30cm, a factor of 6 greater than HRSC, and a factor of 3 better than MOC. Be careful when comparing "sampling" to "resolution" -- they are not the same thing. HiRISE has taken the HiROAD, so to speak, by not trumpeting their 30cm sampling but instead claiming 1-meter imaging scales. Don't hold that against them when comparing to other teams that publish their best sampling.
The other real advantage of this camera is that it returns 14-bit images -- this means that they get dynamic range such that you can see details well, with good S/N, EVEN IN SHADOW, while keeping the well-lit stuff from saturating. Truly awesome. On Friday, when those images come down, 20,000 by 60,000 with awesome signal-to-noise, full dynamic range, and 30cm surface sampling, you will agree that this is a large forward step for Martian surface science.
What this means to me is that after 20 years, they're still writing the same games that they always did, but just with better graphics. Because those better graphics are so much more expensive to produce, nobody is willing to take a chance on a *truly* new and innovative game concept. _Spore_ being a possible exception.
I think 30 is old. I just turned 29, and am starting to realize that I am old. *sigh* At least it seems that there are things old people can do that young people can't -- be an astronaut, for instance :)