In general, pilots tend to prefer old-school analog dials and needles to digital readouts. Especially in high-performance aircraft. It's a heck of a lot easier to look at a needle and say, "oooh, that one's getting close to the red part," than to look at an LCD and say, "73. what does 73 mean? is that close to too high, or close to too low, or just right?"
Thus, when they rip out the old dials to put in computer screens, the computer screens display digital versions of the same old dials, because that's the way the pilots like it. (there was an article on/. a year or two ago on this in the space shuttle. but i'm too lazy to bother even thinking about finding it.)
And a CRT/LCD has a lot more that can go wrong than does a mechanical dial (considering that most of the data is gathered in a mechanical fashion anyways). Meaning that if you can have the exact same info displayed on a mechanical dial or on a picture of a mechanical dial on a digital display, replacing the dial with the digital makes no sense whatsoever.
It doesn't do any real damage when your computer crashes, so it's perfectly fine to "upgrade" to the latest whiz-bang, bleeding-edge, doesn't-actually-work technology. When an airplane travelling at super-sonic speeds crashes, it does a lot more damage, so it pays to consider your upgrades a little more carefully.
Hey, there are plenty of engineers who *do* get off on those things. The problem is that the people with money get off more on things which go fast and blow up things, thus allowing them to keep other people from getting money.
And now we *know* you're not one. Or, if you are, you're perhaps an EE. I know *I* don't want you designing airplanes. Get yourself a fluid dynamics text if you don't believe me.
Almost right...Speed of sound varies with temperature (see my post down a little ways). If you assume constant pressure, then yes, speed of sound varies with density (ideal gas law: pv = RT). But density decreases with altitude, and thus so does sound speed. Mach 5 is about 3700 mph at STP; as you go up, this would *decrease*, not increase.
Actually, the speed of sound varies with local conditions:
The speed of sound a is defined as (gamma * R * T)^.5, where gamma is the ratio of specific heats (1.4 for air at reasonable temperatures), R is the gas constant (universal gas constant divided by molecular weight; 287 J/kg-K for air), and T is the local temperature. At standard atmospheric temperature and pressure (STP), a = 346 m/s. Mach 5 = 5 * a, or roughly 3700 mph at STP.
One consequence of this is that you can travel at a higher mach number while going the same speed if the local temperature is lower. As you go up to higher altitudes, temperature decreases, so the sound of speed decreases. For air-breathing vehicles, though, this can cause a problem, because local pressure also decreases significantly with altitude...*trails off in an irrelevant tangent*
The 99.9998% figure doesn't really have to do with money being made (or not made), but is the portion of works out of print by the time the copyright expires. Money can still be made off of those works after copyright expires--it's just that it can be made by a lot more people.
Doesn't it depend on who is considered to be on which side? In many European countries, I believe, "conservatives" share many positions with America's "liberals" and vice versa. Which way does NZ define them?
Well, according to a presentation I saw by some NASA engineer at the University of Michigan earlier this year, the Space Shuttles are only 25% into their predicted lifespan. Meaning they think they can get decades more out of them. I don't particularly agree, but it looks like they'll have to at least try...
They used maneuvering thrusters to keep the probe in orbit around Eros until they decided to land it...That's part of the life cycle estimate for an object in orbit around a body; how much fuel are you willing to devote to keeping it there? Even orbits around Earth decay over time; every satellite up there will reenter eventually.
Of course, this begs the question, "why's the moon still up there?" All right, so maybe there *are* stable orbits. But we don't have anything to put in orbit that we expect to use in 100 years, so we don't bother perfecting the process of putting stuff there.
Yep...When the Lunar Prospector finished its mission they crashed it into the Moon's south pole in an attempt to kick up water vapor that could be observed from earth...They didn't find any, but the chance of finding any was given at about 10%, assuming that there was some there to find. But it was a good try...
Well, this is true. By the time it got near enough that we could pluck it out of space easily, we would have already gone out, grabbed an asteroid, and towed it into low-earth orbit (what the space shuttle travels at) with a craft designed for such an activity (large-scale sample return...yum) for ease of study. Okay, maybe not. But, at any rate, by the time NEAR got back, the only thing it would be useful for is sticking in the Smithsonian.
There's no reason to bring it home. Better to just use and abuse it where it is. See how much we can do with it before the fuel runs out and the camera gets destroyed. Hmmm....Do we need all four solar panels to run the instrumentation? If we oriented it so that one of them was stuck in the dust, we could scoot along and dig little trenches; see if we kick up anything interesting to take pictures of. (and, in space, *everything* is interesting to take pictures of)
They're also talking about a sample-return mission from Mars (in about ten years), missions to Europa, and setting up a sort of GPS/communications network around Mars to coordinate movements of and data return by various Mars rovers. They're not exactly lying down on the job.
Right now I think NASA is focusing on the unix method of "do one thing and do it well", with the added requirement of "do it cheaply". This mission was meant to go out to the asteroid and take pictures of it, run spectrographic analysis, etc. Your basic ranged sensing package.
I'm sure sending some sort of rover/sample return mission to an asteroid can be expected in the relatively near future. It wouldn't be too much different from the Stardust mission, which is currently on its way to collect material from the tail of the comet Wild-2 and return it to Earth (in 2006).
Right now, though, they're just playing with the last bit of functionality from a defunct piece of equipment. Recall the Lunar Prospector probe, which they crashed into the moon after its mission had been completed, on the off chance that the plume of debris it kicked up would show signs of water. It's a matter of, "we could leave this floating in space forever, or we could try this one last thing before we abandon it." I have to give them credit; they've done some pretty cool things with spacecraft that weren't meant to do them.
I imagine lack of fuel, for one thing...Spacecraft tend to not carry much more fuel than absolutely necessary; NEAR is probably running on fumes right now. The kind of maneuvering they're doing (setting it down and taking off again) take a negligible amount of fuel , compared to changing orbits to rendezvous with Earth again.
According to David Brin's The Uplift War, male dolphins have been trying to get frisky with female human researchers for as long as such have existed. We just couldn't understand them under we made them sentient...
okay, so it's not a real good source of info. so what?
Please tell me you're not calling him a criminal based on these two acts. Think of his actions as walking down the street, noting that the door to some random house was standing open, and continuing along his way. And then being brought in for questioning in relation to a burglary at that house which occurred hours before he passed by. Seeing that there is a vulnerability is not a crime. It is only using that vulnerability that is wrong.
please tell me why you need to...
Please tell me why you need to read Slashdot. Answer: you don't./. doesn't provide you with food, oxygen, water, or shelter, and that's really about all you *need*. Lack of necessity is perhaps the worst reason I've ever heard to not do something. The guy is curious; there's no reason whatsoever to punish someone for harmless curiousity.
As far as I remember, it was only military service.
Actually, it was any civil service whatsoever. In the words of Heinlein himself:
The criticisms are usually based on a failure to understand simple indicative English sentences, couched in simple words...Their failures to understand English are usually these:
1. "Veteran" does not mean in English dictionaries or in this novel solely a person who has served in military forces. I concede that in commonest usage today it means a war veteran . . . but no one hesitates to speak of a veteran fireman
or veteran school teacher. In STARSHIP TROOPERS it is stated flatly and more than once that nineteen out of twenty veterans are not military veterans. Instead, 95% of voters are what we call today "former members of federal civil service."
2. He/she can resign at any time other than during combat -- i.e. 100% of the time for 19 out of 20; 99%+ of the time for those in the military branches of federal service.
3. There is no conscription. (I am opposed to conscription for any reason at any time, war or peace, and have said so repeatedly in fiction, in nonfiction, from platforms, and in angry sessions in think tanks. I was sworn in first in 1923, and have not been off the hook since that time. My principle pride in my family is that I know of not one in over two centuries who was drafted; they all volunteered. But the draft is involuntary servitude, immoral, and unconstitutional no matter what the Supreme Court says.
-- Robert Anson Heinlein, Afterword of "Who Are the Heirs of Patrick Henry?" in Expanded Universe, Ace Books 1980
Additionally, in Starship Troopers, no civil servant, military or otherwise, can vote or hold office until he or she has fulfilled the term of service and become a civilian once more. Thus, in order to acquire the right to vote or hold government office--and therefore the right to make decisions about society--one must serve that society in some capacity for a set amount of time. You're not forced to serve, you have a choice of what capacity to serve in, and you may quit early with no penalty if you decide it's not the way to go, but you don't gain the privelege of voting.
And when was the last time you saw a 20-40 pound sword? Even a scottish claymore (think Braveheart if you need a mental image) doesn't weigh that much. Granted, I've never weighed one, but I've held a 1.5 meter long sword, and even the 20-pound low end of your estimate seems too high. Go to a museum; see what they have to say. I'm betting you'll find swords to be surprisingly light.
And why such hostility towards feminists? Does the idea of a woman in hand-to-hand combat so disrupt your fragile self-image that you have to mock it as ridiculous and prove yourself ignorant? I'm male too, but at least I don't feel a need to prove myself in a "me tarzan, you jane" fashion.
While I can agree with the three benefits you pointed out, i have to disagree with your labelling Napster a "bad penny". If it weren't for Napster, Gnutella and others wouldn't have had such motivation to exist. If it weren't for Napster, many people would have never heard of mp3s or, if they had, thought about using them, so they wouldn't be able to get upset now that the supply has been cut off.
Thus, perhaps Napster shouldn't be trashed as a bad penny, but as an important catalyst whose death was, sadly, inevitable.
Lets say Magneto got in the machine and sacrificed himself to turn the human leaders to mutants. The human leaders then all die horrible painful deaths. Why? Because of a genetic attack perpetrated by mutants. You can be sure future leaders will be not too anxious to welcome mutants. And Magneto, being dead, will be able to do absolutely nothing about this situation.
On the other hand, if Rogue runs the machine and turns all the humans into mutants, who then die, causing more mutant backlash, then Magneto is still around to craft a new plan.
In a more general sense, if Magneto has someone else be the sacrifice, then that sacrifice will *not* be the last act of the campaign. As another example, where would America be today if George Washington had taken on the British all by himself rather than getting an army to help? As cool as Mel Gibson is, one man can't throw off an oppressing nation all by himself.
Slashdot Mirror
In general, pilots tend to prefer old-school analog dials and needles to digital readouts. Especially in high-performance aircraft. It's a heck of a lot easier to look at a needle and say, "oooh, that one's getting close to the red part," than to look at an LCD and say, "73. what does 73 mean? is that close to too high, or close to too low, or just right?"
/. a year or two ago on this in the space shuttle. but i'm too lazy to bother even thinking about finding it.)
Thus, when they rip out the old dials to put in computer screens, the computer screens display digital versions of the same old dials, because that's the way the pilots like it. (there was an article on
And a CRT/LCD has a lot more that can go wrong than does a mechanical dial (considering that most of the data is gathered in a mechanical fashion anyways). Meaning that if you can have the exact same info displayed on a mechanical dial or on a picture of a mechanical dial on a digital display, replacing the dial with the digital makes no sense whatsoever.
It doesn't do any real damage when your computer crashes, so it's perfectly fine to "upgrade" to the latest whiz-bang, bleeding-edge, doesn't-actually-work technology. When an airplane travelling at super-sonic speeds crashes, it does a lot more damage, so it pays to consider your upgrades a little more carefully.
Well, mine was right; I just failed to define my terms adequately....Here:
V = volume, p = pressure, T = temperature, n = moles of substance, Ru = universal gas constant
p*V = n*Ru*T, as you said.
p*V = m*R*T, m = mass = n*molecular weight of substance, R = gas constant = Ru/molecular weight
p = rho*R*T, rho = density = m/V
p*v = R*T, v = specific volume = 1/rho
So, basically, the same thing. I'm just used to writing it a different way, as it's more useful in fluid dynamics courses.
It's been said correctly several times already, but I'll repeat it for your convenience:
The speed of sound a = (gamma * R * T)^.5
gamma and R are constant in the atmosphere.
T, the local temperature *decreases* as you ascend through the atmosphere.
Therefore, a, the speed of sound, decreases (as in, goes down, as in, sound travels more slowly) as you increase altitude.
As I said before, go find yourself a textbook if you don't believe me. I suggest "Modern Compressible Flow", by Anderson. Check Amazon.
Hey, there are plenty of engineers who *do* get off on those things. The problem is that the people with money get off more on things which go fast and blow up things, thus allowing them to keep other people from getting money.
As a more direct reason why this won't replace the shuttle, it's still an air-breathing engine. And there's no air to breath where the shuttle goes.
And now we *know* you're not one. Or, if you are, you're perhaps an EE. I know *I* don't want you designing airplanes. Get yourself a fluid dynamics text if you don't believe me.
Almost right...Speed of sound varies with temperature (see my post down a little ways). If you assume constant pressure, then yes, speed of sound varies with density (ideal gas law: pv = RT). But density decreases with altitude, and thus so does sound speed. Mach 5 is about 3700 mph at STP; as you go up, this would *decrease*, not increase.
Actually, the speed of sound varies with local conditions:
The speed of sound a is defined as (gamma * R * T)^.5, where gamma is the ratio of specific heats (1.4 for air at reasonable temperatures), R is the gas constant (universal gas constant divided by molecular weight; 287 J/kg-K for air), and T is the local temperature. At standard atmospheric temperature and pressure (STP), a = 346 m/s. Mach 5 = 5 * a, or roughly 3700 mph at STP.
One consequence of this is that you can travel at a higher mach number while going the same speed if the local temperature is lower. As you go up to higher altitudes, temperature decreases, so the sound of speed decreases. For air-breathing vehicles, though, this can cause a problem, because local pressure also decreases significantly with altitude...*trails off in an irrelevant tangent*
IANAL...but I am an aerospace engineer...
Never underestimate the bandwidth of a 747 filled with CD-ROMs.
Just as an off-the-cuff, I'm-avoiding-homework estimate:
Okay, back to work...
The 99.9998% figure doesn't really have to do with money being made (or not made), but is the portion of works out of print by the time the copyright expires. Money can still be made off of those works after copyright expires--it's just that it can be made by a lot more people.
Doesn't it depend on who is considered to be on which side? In many European countries, I believe, "conservatives" share many positions with America's "liberals" and vice versa. Which way does NZ define them?
Well, according to a presentation I saw by some NASA engineer at the University of Michigan earlier this year, the Space Shuttles are only 25% into their predicted lifespan. Meaning they think they can get decades more out of them. I don't particularly agree, but it looks like they'll have to at least try...
Tang. And freeze-dried ice-cream, though I have no clue why anyone would *want* to eat that...
They used maneuvering thrusters to keep the probe in orbit around Eros until they decided to land it...That's part of the life cycle estimate for an object in orbit around a body; how much fuel are you willing to devote to keeping it there? Even orbits around Earth decay over time; every satellite up there will reenter eventually.
Of course, this begs the question, "why's the moon still up there?" All right, so maybe there *are* stable orbits. But we don't have anything to put in orbit that we expect to use in 100 years, so we don't bother perfecting the process of putting stuff there.
Yep...When the Lunar Prospector finished its mission they crashed it into the Moon's south pole in an attempt to kick up water vapor that could be observed from earth...They didn't find any, but the chance of finding any was given at about 10%, assuming that there was some there to find. But it was a good try...
Well, this is true. By the time it got near enough that we could pluck it out of space easily, we would have already gone out, grabbed an asteroid, and towed it into low-earth orbit (what the space shuttle travels at) with a craft designed for such an activity (large-scale sample return...yum) for ease of study. Okay, maybe not. But, at any rate, by the time NEAR got back, the only thing it would be useful for is sticking in the Smithsonian.
There's no reason to bring it home. Better to just use and abuse it where it is. See how much we can do with it before the fuel runs out and the camera gets destroyed. Hmmm....Do we need all four solar panels to run the instrumentation? If we oriented it so that one of them was stuck in the dust, we could scoot along and dig little trenches; see if we kick up anything interesting to take pictures of. (and, in space, *everything* is interesting to take pictures of)
Mars Global Surveyor
Stardust comet sample-return mission
Mars Pathfinder (the rover)
They're also talking about a sample-return mission from Mars (in about ten years), missions to Europa, and setting up a sort of GPS/communications network around Mars to coordinate movements of and data return by various Mars rovers. They're not exactly lying down on the job.
Disclaimer: I don't work for JPL...But I want to.
Right now I think NASA is focusing on the unix method of "do one thing and do it well", with the added requirement of "do it cheaply". This mission was meant to go out to the asteroid and take pictures of it, run spectrographic analysis, etc. Your basic ranged sensing package.
I'm sure sending some sort of rover/sample return mission to an asteroid can be expected in the relatively near future. It wouldn't be too much different from the Stardust mission, which is currently on its way to collect material from the tail of the comet Wild-2 and return it to Earth (in 2006).
Right now, though, they're just playing with the last bit of functionality from a defunct piece of equipment. Recall the Lunar Prospector probe, which they crashed into the moon after its mission had been completed, on the off chance that the plume of debris it kicked up would show signs of water. It's a matter of, "we could leave this floating in space forever, or we could try this one last thing before we abandon it." I have to give them credit; they've done some pretty cool things with spacecraft that weren't meant to do them.
I imagine lack of fuel, for one thing...Spacecraft tend to not carry much more fuel than absolutely necessary; NEAR is probably running on fumes right now. The kind of maneuvering they're doing (setting it down and taking off again) take a negligible amount of fuel , compared to changing orbits to rendezvous with Earth again.
According to David Brin's The Uplift War, male dolphins have been trying to get frisky with female human researchers for as long as such have existed. We just couldn't understand them under we made them sentient...
okay, so it's not a real good source of info. so what?
Please tell me you're not calling him a criminal based on these two acts. Think of his actions as walking down the street, noting that the door to some random house was standing open, and continuing along his way. And then being brought in for questioning in relation to a burglary at that house which occurred hours before he passed by. Seeing that there is a vulnerability is not a crime. It is only using that vulnerability that is wrong.
please tell me why you need to...
Please tell me why you need to read Slashdot. Answer: you don't. /. doesn't provide you with food, oxygen, water, or shelter, and that's really about all you *need*. Lack of necessity is perhaps the worst reason I've ever heard to not do something. The guy is curious; there's no reason whatsoever to punish someone for harmless curiousity.
As far as I remember, it was only military service.
Actually, it was any civil service whatsoever. In the words of Heinlein himself:
Additionally, in Starship Troopers, no civil servant, military or otherwise, can vote or hold office until he or she has fulfilled the term of service and become a civilian once more. Thus, in order to acquire the right to vote or hold government office--and therefore the right to make decisions about society--one must serve that society in some capacity for a set amount of time. You're not forced to serve, you have a choice of what capacity to serve in, and you may quit early with no penalty if you decide it's not the way to go, but you don't gain the privelege of voting.
And when was the last time you saw a 20-40 pound sword? Even a scottish claymore (think Braveheart if you need a mental image) doesn't weigh that much. Granted, I've never weighed one, but I've held a 1.5 meter long sword, and even the 20-pound low end of your estimate seems too high. Go to a museum; see what they have to say. I'm betting you'll find swords to be surprisingly light.
And why such hostility towards feminists? Does the idea of a woman in hand-to-hand combat so disrupt your fragile self-image that you have to mock it as ridiculous and prove yourself ignorant? I'm male too, but at least I don't feel a need to prove myself in a "me tarzan, you jane" fashion.
While I can agree with the three benefits you pointed out, i have to disagree with your labelling Napster a "bad penny". If it weren't for Napster, Gnutella and others wouldn't have had such motivation to exist. If it weren't for Napster, many people would have never heard of mp3s or, if they had, thought about using them, so they wouldn't be able to get upset now that the supply has been cut off.
Thus, perhaps Napster shouldn't be trashed as a bad penny, but as an important catalyst whose death was, sadly, inevitable.
Lets say Magneto got in the machine and sacrificed himself to turn the human leaders to mutants. The human leaders then all die horrible painful deaths. Why? Because of a genetic attack perpetrated by mutants. You can be sure future leaders will be not too anxious to welcome mutants. And Magneto, being dead, will be able to do absolutely nothing about this situation.
On the other hand, if Rogue runs the machine and turns all the humans into mutants, who then die, causing more mutant backlash, then Magneto is still around to craft a new plan.
In a more general sense, if Magneto has someone else be the sacrifice, then that sacrifice will *not* be the last act of the campaign. As another example, where would America be today if George Washington had taken on the British all by himself rather than getting an army to help? As cool as Mel Gibson is, one man can't throw off an oppressing nation all by himself.