You might as well talk about "The heart of TV"...
on
Heart of the Net
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· Score: 2
... or "the heart of books" for that matter. What's the most important thing on TV? News? Sports? Sitcoms? The Cartoon Network? It's a meaningless question - there's just far too much material there, being used by so many people in different ways, that it's pointless to try to find a center to it all.
The Internet has grown up. It's through its childhood (ARPAnet, with its heart in academics and defense) and just recently got through its crazy teenage years (the dot-com boom!). It's not
-done- growing up yet, by any means, but it's a heck of a lot more mature than it used to be, and it's got a heck of a lot more diversified in the process. You might as well ask "What's the heart of the Library of Congress?" With everything from
amateur webzines to CNN, from personal homepages to vast realms of technical scientific data, from spam and porn to rational, well-argued intellectual discussions, there's a little bit of everything on the net these days.
Tides aren't a substantial argument. The sun's gravity produces tides on the Earth as well. The amplitude of solar tides is about half that of lunar tides, so even the complete absence of the moon doesn't imply there would be no tides. They'd just be somewhat smaller.
Beyond that, there's an increasing body of evidence that early life was highly extremophilic and more likely formed deep underground or near a deep-sea hydrothermal vent. I don't know of -any- hard evidence that tidal pools played a large role in biogenesis; it's all speculation as far as I know, though I'm admittedly only an astronomer, not an astrobiologist.
Just as a flame-worthy side note, there is a lot of antagonism in New Zealand towards the US because of Bush's decision to boycott the Kyoto(sp?) Protocol.
Yes well. There's a fair amount of antagonism to Bush about it up here, too, especially from those of us who (a) didn't vote for him, and (b) don't think he actually won the election. I personally make a great effort to "live green" even if it involves some personal sacrifice (spending more $$ to buy environment-friendly products, etc) and I wish our semi-elected leadership was willing to do the same.
You're absolutely right, it's a damn shame Bush is telling everybody else to shove off about Kyoto. I only hope the rest of the world is strong enough to say "screw you!" right back at him and keep on implementing the treaty. I firmly believe you guys are doing the right thing, and I know many other Americans do too...
Au contraire. Compare the following two snippets of code, taken arbitrarily from one of the other raid header files in the kernel:
struct m {
int a;
int b;
kdev_t c;
int d;
/*
* State bits:
*/
int e;
int f;
int g;
int h;
};
And:
struct mirror_info {
int number;
int raid_disk;
kdev_t dev;
int head_position;
/*
* State bits:
*/
int operational;
int write_only;
int spare;
int used_slot;
};
Those are the same exact structure, no? Exact same data types and everything. I even left in the comments. Now, which of those would you rather have to program with? A structure is *not* just a structure; different source codes for the same structure can be of radically different usefulness. There's definitely intellectual property there.
Typical slashdot attitude. Any time new technology is mentioned (and it's not on store shelves right now, waiting to go into your computer), the
immediate reaction is to say, "Help! Help! I'm being oppressed!" In this instance, it means that every piece of new technology will be bad, because
(though the descriptions don't support it) everything with a way-nifty feature will automatically report to the government.
Everything in moderation, including paranoia. I agree with you that people shouldn't knee-jerk that new technology is necessarily oppressive, but at the same time I too found Martin's vision rather utopic. The important thing is thinking ahread of time about all the ways in which things can go wrong, so as to try to steer around them.
I can guarantee that every possible abuse of Smart ID cards, every possible invasion of privacy via computer surveillance, every possible way to make a buck off of somebody else when they weren't paying attention, will happen unless steps are taken to prevent it. That's just the way human nature is; all it takes is one jerk to mess things up for everybody. And so it's good to have nay-sayers around - not to prevent progress, but to make sure it's done carefully. Think of safeguards for your universal ID. Think of watchdogs for the megacompanies. Think of ways to keep your data in the TV and not in the FBI.
Yes, bitch and moan over things that don't exist yet. But don't live in general terror - take action. I agree with you that we, today, need to guide these changes, and do it logically and rationally. But a healthy helping of paranoia - no, call it cautious and proactive worrying;-) - never hurts, as long as you don't let it get out of hand.
every object in the universe has an infinitely large magnetic field
Not actually true. Yes, a magnetic dipole in isolated free space will have a magnetic field that should go to infinity, assuming there's nothing else there. Except the real world isn't as simplified as E&M textbook problems would have you think - there are other objects and other fields out there, with the effect that a magnetic dipole (like the Earth or Jupiter) doesn't have a field which extends to infinity. Rather, it goes out to some finite distance at which point it is stopped by the Sun's much stronger field. The shock between the two is known as the magnetopause, and the finite-sized region inside of it is called the magnetosphere.
As others have said, excellent post.:-) But it only takes us up to the step of finding out the *average* density inside a planet. The next step is, how do you extend that to get detailed information on the interior structure? Turns out that's not too hard to understand, either.
Item 5 above is "measure the gravity of the planet." For Earth that's easy to do - drop something. For Jupiter, we can do it by measuring the orbit of something going around Jupiter. It's got a whole mess of moons which are nice and visible, so this is relatively straightforward. But you can get *much* better data if you send a spacecraft there. As the spacecraft flys by or orbits the planet, its course will be deflected by Jupiter's gravity. Carefully measuring the spacecraft's course (which you do anyway for navigation purposes) lets you measure the gravity of Jupiter, and more importantly, how it differs from place to place
Turns out Jupiter is not a sphere. None of the planets are - they all spin, so they're all flattened by rotation. (Take a look at pictures of Jupiter - it's *visibly* about 10% wider than it is tall. Spinning a planet 320 times larger than the Earth around once every 10 hours will do that to ya.) Now maybe you've heard of a physics theorem that if you have a spherical object, its gravity is the same as that of a point source at the center. You couldn't figure out the internal structure of a sphere based on its gravity because it's so symmetric. But Jupiter's not a sphere, and so the gravitational potential varies from place to place in such a way that you can calculate backwards from it and get the densities at different places inside of the planet. Voila, we know it's mostly atmosphere, turns to metallic hydrogen a few thousand km down, and probably has a rocky core about 6-10 times larger than the Earth.
I don't think the US is without fault. I agree that all of the above are problems we should look into seriously. However, I think there's one strong argument that the US is a far better country than China:
You and I, right now, can have this conversation. We could stand in front of the White House and point out all of these flaws to everyone that comes by, we can publish articles and books exposing them, and we can work with our elected representatives to try and change the system. In short, we can openly criticize the hell out of the system, as much as we want. Try that in China.
The US is not perfect by a long shot. But since we can talk about and admit our mistakes, we can change them. We had slavery once, but no longer, even though it took a damn long time. I certainly hope that the War on Some Drugs and the ridiculous incarceration route go that way too. But can you imagine the US trying to do, _today_, the sorts of things it did to American Indians in the past, or even to Asian americans in WWII? It would be unthinkable; the public outcry would be tremendous. We're not perfect, but we're learning.
There's a simple explanation for this: The policy is more recent than the.edu domain. Back when the domain name system was first getting set up, there were so few high schools on the internet that it was entirely reasonable to give all four or five of them.edu domains. As time went on and the number started to go up, someone made the decision to restrict new.edu's to 4 year colleges only. Existing high schools etc with.edu's were grandfathered in, but no new ones were granted. As far as I know this policy was enforced rigorously.
I'm speaking from personal experience here. We wired up my high school to the net in '95, when it was still pretty much bleeding edge for a high school to have a T1 and a server room of its very own. We wanted severn.edu but were refused due to not being a 4 year college, and thus went with severnschool.com. Not nearly as nice a domain, and believe me there's no way we would have gone with it if we had had any choice!
I agree with you that China's power is only likely to continue to grow. However, there's no way I can welcome them.
Go do a Google search on China and human rights abuses. Or go read the State Department's report on human rights violations.Go read about how they've jailed four university professors in the past three months, including three with US citizenship or residency, for no crime greater than spreading ideas against the state. They also jailed for a month the husband and 5 year old son of one of the academics, failing to inform the US that they had done so, even though both of these people are US Citizens! (This is a major violation of international law.)
Read about how they brutally suppress religions, including everything from Falun Gong to Christianity. Read about what they've done in Tibet.
Not expansionist? Read about how they backed the establishments of Communist governments in Korea and Vietnam, and how they want to take back Taiwan after 50 years of independence.
Read about the silencing of free speach in Hong Kong, the crushing of student demonstrators in Tienanmen square, the censorship of the Internet throughout China, the control and manipulation of public opinion through their state news agencies.
Go read all that, and then tell me that you welcome China.
The reason the US is not apologizing has nothing to do with some militaristic notion of masculine inability to apologize. The US military can and has in the past apologized for things for which it was at fault. The problem here is that we're not the ones at fault, at least not completely.
I think if China wanted to have an independent agency (Switzerland?) investigate the crash and determine whose fault it was, the US would agree to that. If that commission determined it was our fault, I bet we would apologize. But that's not what the Chinese are asking for. They're asking for us to claim total responsibility for what happened, without any investigation as to whether that's the truth. Bush and co. won't do that, and I think that's absolutely the right way to go.
Why? Because it sets one hell of a bad precedent, the "Yes, China, we will roll over and do whatever you ask us to in order to maintain peace." precedent. This sort of thing was tried before wrt Germany in the 1930s by a guy called Chamberlain, and look where that got us. As much as we would all like for there to be peace, we can't forget that China is a big, powerful, authoritarian state with major expansionist drives and a history of human rights violations a mile long. I sure as hell don't want us to go to war with them, but I also don't want to see us roll over and give them everything they want. Give in once, and they will learn the US's leadership is weak, and then they'll just start pressing for more, more more.
That will only lead to conflict further down the line. Better to take a stand now, show them we mean business, and try to keep things from getting out of hand.
These planets are detected indirectly, by noticing their effects on the stars they orbit. As the planet swings around the star, it makes the star move opposite it (to be precise, both the planet and star are moving around the center of mass of the system.) This stellar motion can be detected via extremely careful measurements of the Doppler shifting of the star's light.
Take a look at Geoff Marcy's website at exoplanets.org. Marcy is a professor here at Berkeley who leads one of the two teams which has done most of the planet finding thus far. This most recent announcement is by Michel Mayor, a Swiss astronomer who leads the other major extrasolar planet hunt. I think the two teams have a fairly friendly rivalry going on, and often both end up observing/discovering the same planets. One of Geoff's graduate students (who I think reads/.; Jason, you reading this?) told me that this latest batch was all discovered by using southern hemisphere telescopes, so none of these were discovered by Marcy et al's search, since that is conducted solely with Northern hemisphere telescopes.
Right now, we're finding Jupiter-sized planets around roughly 5% of the stars we've looked at - 60-ish planets around about a thousand stars. It's expected that the actual numbers of stars with planets is much higher than that, potentially as much as 50% or so, but smaller planets or ones further from their parent star are much harder to detect, so we have not yet identified any.
Tito's paid a heck of a lot more in taxes than you or I ever will. That's not a valid point, anyway. Have *you*, personally, put up $20M of your own money to fly in space?
astronauts and cosmonauts adjust and repair classified satellites,
and both space agencies shoot up spy satellites in unmanned missions on behalf of national security.
Actually, no, none of this happens. Most spy satellites are in orbits the shuttle can't reach, either polar orbits, which have too high an inclination, or geosynchronous orbits, which are far too high for the shuttle to reach. The Hubble is the only satellite which is serviced with any sort of regularity, and there's a substantial proportion of the community that regards that as a waste - it would quite possibly have been cheaper to plan on a series of telescopes, a new one every five years or so, since the costs of a shuttle mission to do repairs are, well, astronomical. The shuttle has been used to launch military satellites, but not repair them, and the launch market since Challenger has largely gone to unmanned lift vehicles like the Titan and Atlas.
There were plans originally for a shuttle launch facility in Vandenburg, CA, which would have allowed the shuttle to reach retrograde polar orbits for spy sat launches, but the air force was already losing its interest in the shuttle by '86 and used the Challenger disaster as an excuse to drop the whole program. It's a shame, too, because several major design decisions were made in the shuttle to allow it to meet the requirements for these military missions - the wing design in particular could have been simplified substantially without the cross-range requirement for once-around landings.
And as for shooting down spy sats, this only happens in James Bond movies. Oh, the US is working on developing the capabilities to do so, and we've done target practice on one of our *own* sats, but don't for a minute think that anyone could actually do this without starting a major international incident.
No, you can't say that it goes on our there anyway, just in secret and we don't know about it. This is all happening up in the sky, after all, and it's quite visible. Amateur satellite hunters have identified the orbital parameters for pretty much all the classified hardware up there. There's just no good way to hide something when it's sitting up in the sky glowing like a star.
Moreover, NASA has refused Tito admittance to the astronaut training facilities in Houston. They're making a big stink about it for no real reason other than an institutional desire to squash space tourism and keep the high frontier for themselves.
A few relevant facts:
When the shuttle-Mir dockings were going on in the mid 90s, shuttle astronauts did not receive any special training on visiting Mir. They got a briefing or two on the ground, and then when they got there in orbit, the cosmonauts gave them a 2 hour tour and safety lesson. And that's all that was needed.
The Russians have been flying non-professional cosmonauts to Mir for years, including various members of the media and government officials. They certainly have the experience to know how much training is necessary. Tito has taken all of their training and passed with flying colors.
One of NASA's big objections has been that Tito poses a danger to the crew in the event of an emergency. There was in fact a guest aboard Mir in '97 when one of the fires broke out. His duties in the event of an emergency were "put your oxygen mask on and stay out of the way of the cosmonauts fixing stuff." He succeeded in carrying out these orders quite well, thankyouverymuch. And NASA thinks that Tito, who is widely acknowledged to be an extremely smart and capable man, couldn't do likewise?
$20 million bucks is approximately 10% of the Russian Space Agency's entire annual budget. Tito's flight is going to have a major effect on their bottom line, and in their ability to continue developing their half of the space station.
One of NASA's biggest problems is their desire to be the space agency, rather than just a space agency. They're control freaks, and this has hurt the private launch market, and now it's hurting the start of the space tourism market. Trying to block Tito's flight is one of the dumbest things they've done lately. (Well, except for Dan Goldin's mad quest to eradicate all the old worm-style logos...) The ability for private citizens to fly into space would, I think, get people a lot more excited about space travel in general, would generate public support for NASA and ISS, and would pump a lot of money into the system.
Two passengers a year, on the every-six-month Soyuz changeout missions which are scheduled anyway, would bring in $40M/year to the Russian Space Agency, which desperately needs the cash, at practically no cost to NASA or any of the other international partners. It's a win-win-win situation, and it's a damn shame that NASA's being so stubborn about it. If there really was a substantial risk to the station, then they'd have a point, but the Russians have proven before that they can safely fly non-professionals, and they can do it again.
I recall reading a study on this very topic, which was done a while ago by I think one of the major online news sources - WashPost or NYTimes or somebody, but I forget precisely who.
Their research showed that people who get their news online frequent *more*, not fewer, sources of news than their offline counterparts, and are exposed to a broader range of topics as a result. Furthermore, nearly everyone checks one or two "general news" sites like NYTimes or CNN, and sees all of the "front page" headlines there. The most common scenario is someone who checks a major site like CNN regularly plus a variety of sites on more specialized topics. Furthermore, the net allows much greater coverage of those specialized topics than would be possible in a print media. So the long and the short of it is, no, there is statistical evidence out there that people don't put blinders on their eyes and only read narrow slices of the news; the vast majority of people in practice chose to combine the narrow and the broad.
And I dare say the average person who gets their news online is better informed than the people who only watch the 6 o'clock news! TV news is all sound bites and no substance; text on the net has more details, more bite to it.
I really wish I could remember the name/source of this study. Anyone help me out here?
- Marshall (Reads WashingtonPost, spacedaily.com, slashdot, bottomquark, and fifteen different AP newsfeeds from ClariNet. Yes I'm a news junkie.;-)
Latin, not Italian. Luna has been the name of our satellite for a couple of millenia longer than the word "Moon" has been around. I agree it's somewhat surprising that the GPN lists just "Earth's Moon" as its official name. However, I think it's also worth noting that "Moon", being an English word, is certainly not what most people on this planet call our satellite. Most Romance languages use some form of Luna or Lune, and I don't know the word in Hindi or Chinese, but it's certainly not "Moon".
IMO, Latin is a good compromise language for an official name, and certainly it has the benefit that the majority of planet and major moon names are already in Latin, so it would at least be consistent. Furthermore, "lunar" is the accepted adjective form, even in English.
Well, you're oversimplifying a bit. Yes, there's a major problem with HRC. But the instrument isn't totally useless - they've done a number of clever things to salvage as much science from it as possible, as indicated if you read a bit further in the manual. Yes, it's nowhere near what it was supposed to be, but to say "We are very sorry, but that is all we can do about it." just isn't accurate.
Actually, the HST *has* been used to image the moon, very carefully and using very short exposures. See photos here.
As for actually imaging things on the moon, you're correct, even the Hubble does not have the resolution to pick out the Apollo landers. Some actual numbers to back this up:
Angular resolution of a telescope goes roughly as wavelength/diameter. For visible light at 5000 Angstroms, this means the 2.4 m HST can resolve down to about 0.04 arcsecond (= 1x10^-5 degrees), and the 10m Keck, largest telescope on Earth, could get down to 0.01 arcsec in theory, but in reality atmospheric effects limit it to about ten times that. At a distance of 384400 km, these resolutions correspond to 80 m and 20m per pixel, which is not *quite* good enough to make out anything man-made on the surface. The proposed 30m California Extremely Large Telescope could maybe barely do it, but that's probably 30 years off.
Any college admissions system worth it's salt has a multiple regression model that predicts the likely success of a
student based on a variety of parameters - including the results of a standardized test like the SAT, the GPA, what
school that GPA was attained at, what courses and track the student was enrolled in, and the extracurricular activities
the student participated in, etc.
Yes, this is how it should be, I agree. However, for truly tremendous state school systems like the UC, which admits on the order of two hundred thousand students a year, they tend to decrease the complexity of the model. From what I've heard, the undergrad admissions process at UC really is a big equation into which they plug your test scores and GPA and about three other factors, and out pops a "yes" or "no". The current policy relies on standardized test scores *way* more than it should, and that's what they're looking to fix. Whether they need to completely drop it in order to stop over-relying on it is a seperate question, but I do think it's good that they recognize there's a problem.
The people who study and work hard to perform better on the SATs will tend to get better scores on the SATs than
those who slacked off.
OR, is it the kids whose parents pay for $900 Kaplan courses who will do better? There's a huge industry around preparing people for these tests, and it's not at all fair to poorer students who just can't afford that sort of resources.
No, I'm not saying that smart kids can't do well without such courses - that's how I was myself. But the existence of high-priced prep courses definitely does bias things towards people who can afford them.
There is no easy magic bullet when you come to testing. Every test is going to be unfair to some group or other, and you will have to take that into account. That said, there can come a time when it becomes clear that a certain test's flaws outweigh its utility, and you should ditch it.
I think what you're missing here is that this drive is targeted at mobile applications. That seems pretty clear to me from the sturdyness + reduced size. Sure, typical HDs work fine and don't fail all too often when you have them sitting on a desk all day. But put one in your MP3 player in your SUV's stereo and watch the head crashes commence when you go off-road. Or think about a laptop for the extreme-sports set, which gets jounced around all day in a backpack dangling off of someone hanging onto a cliff with three fingers.
Last year I had to select storage media for a NASA scientific balloon project. We needed something to hold a couple GBs of data that would handle the stresses of a parachute crash landing. I ended up going with a standard IBM laptop HD, since that was the most ruggedized drive I could find on short notice, but had this drive been available then, you can bet I would have gone with it instead. The head-park feature is *really* nice when you start thinking about the drive hitting the ground at five meters/second.
My guess is that no higher a percentage of computer scientists are gay than is true for the general population, but rather, there's simply a higher percentage who are *openly* gay. The culture of high-tech is one of openness, one where people question authority rather than just accepting "X is bad", where individial merit as a hacker matters more than who you sleep with. Geeks are more willing to go their own route rather than blindly follow the path they're "supposed" to.
If you look deeper, you'll probably find similar correlations between tech centers and BDSm and polyamory. Not because theres's some innate relation between high tech and alternative sexuality, just because the same sort of open mindset can lead someone to each.
And for what it's worth, I'm in a long-term monogamous hetero relationship. I have no interest in guys whatsoever. But I many friends who are, and I'm totally supportive of them. One of the best things about living in CA is the open environment for people of *all* walks of life.:-)
If you do, you'll note that it says
"could lead to computer-controlled overrides as a standard fitting within
five years." could being the operative word. Nowhere does it say that this is going to happen for sure or that it's been approved or anything like that.
Beyond that: I agree, this would probably be a bad idea if implemented stupidly. However, as was said very elegantly by another poster in response to the NASA brain control of a aircraft discussion,
why does everyone always automatically assume that the people developing the systems mentioned here are completely incapable of thinking of all the problems that everyone here comes up with in 30 seconds. I would bet you any reasonable sum of money that the people behind this system have already thought about emergency passing, gradually handling speed limit changes between zones, weather overrides, and all of that. If they haven't, you can bet someone will before they get around to implementing it in large scale five or ten years from now. Please, recognize that slashdot readers do not have a monopoly on common sense.;-)
Slashdot Mirror
The Internet has grown up. It's through its childhood (ARPAnet, with its heart in academics and defense) and just recently got through its crazy teenage years (the dot-com boom!). It's not -done- growing up yet, by any means, but it's a heck of a lot more mature than it used to be, and it's got a heck of a lot more diversified in the process. You might as well ask "What's the heart of the Library of Congress?" With everything from amateur webzines to CNN, from personal homepages to vast realms of technical scientific data, from spam and porn to rational, well-argued intellectual discussions, there's a little bit of everything on the net these days.
And that's the way it should be.
Tides aren't a substantial argument. The sun's gravity produces tides on the Earth as well. The amplitude of solar tides is about half that of lunar tides, so even the complete absence of the moon doesn't imply there would be no tides. They'd just be somewhat smaller.
Beyond that, there's an increasing body of evidence that early life was highly extremophilic and more likely formed deep underground or near a deep-sea hydrothermal vent. I don't know of -any- hard evidence that tidal pools played a large role in biogenesis; it's all speculation as far as I know, though I'm admittedly only an astronomer, not an astrobiologist.
Yes well. There's a fair amount of antagonism to Bush about it up here, too, especially from those of us who (a) didn't vote for him, and (b) don't think he actually won the election. I personally make a great effort to "live green" even if it involves some personal sacrifice (spending more $$ to buy environment-friendly products, etc) and I wish our semi-elected leadership was willing to do the same.
You're absolutely right, it's a damn shame Bush is telling everybody else to shove off about Kyoto. I only hope the rest of the world is strong enough to say "screw you!" right back at him and keep on implementing the treaty. I firmly believe you guys are doing the right thing, and I know many other Americans do too...
Au contraire. Compare the following two snippets of code, taken arbitrarily from one of the other raid header files in the kernel:
struct m {
int a;
int b;
kdev_t c;
int d;
* State bits:
*/
int e;
int f;
int g;
int h;
};
And:
struct mirror_info {
int number;
int raid_disk;
kdev_t dev;
int head_position;
* State bits:
*/
int operational;
int write_only;
int spare;
int used_slot;
};
Those are the same exact structure, no? Exact same data types and everything. I even left in the comments. Now, which of those would you rather have to program with? A structure is *not* just a structure; different source codes for the same structure can be of radically different usefulness. There's definitely intellectual property there.
Everything in moderation, including paranoia. I agree with you that people shouldn't knee-jerk that new technology is necessarily oppressive, but at the same time I too found Martin's vision rather utopic. The important thing is thinking ahread of time about all the ways in which things can go wrong, so as to try to steer around them.
I can guarantee that every possible abuse of Smart ID cards, every possible invasion of privacy via computer surveillance, every possible way to make a buck off of somebody else when they weren't paying attention, will happen unless steps are taken to prevent it. That's just the way human nature is; all it takes is one jerk to mess things up for everybody. And so it's good to have nay-sayers around - not to prevent progress, but to make sure it's done carefully. Think of safeguards for your universal ID. Think of watchdogs for the megacompanies. Think of ways to keep your data in the TV and not in the FBI.
Yes, bitch and moan over things that don't exist yet. But don't live in general terror - take action. I agree with you that we, today, need to guide these changes, and do it logically and rationally. But a healthy helping of paranoia - no, call it cautious and proactive worrying ;-) - never hurts, as long as you don't let it get out of hand.
every object in the universe has an infinitely large magnetic field Not actually true. Yes, a magnetic dipole in isolated free space will have a magnetic field that should go to infinity, assuming there's nothing else there. Except the real world isn't as simplified as E&M textbook problems would have you think - there are other objects and other fields out there, with the effect that a magnetic dipole (like the Earth or Jupiter) doesn't have a field which extends to infinity. Rather, it goes out to some finite distance at which point it is stopped by the Sun's much stronger field. The shock between the two is known as the magnetopause, and the finite-sized region inside of it is called the magnetosphere.
Item 5 above is "measure the gravity of the planet." For Earth that's easy to do - drop something. For Jupiter, we can do it by measuring the orbit of something going around Jupiter. It's got a whole mess of moons which are nice and visible, so this is relatively straightforward. But you can get *much* better data if you send a spacecraft there. As the spacecraft flys by or orbits the planet, its course will be deflected by Jupiter's gravity. Carefully measuring the spacecraft's course (which you do anyway for navigation purposes) lets you measure the gravity of Jupiter, and more importantly, how it differs from place to place
Turns out Jupiter is not a sphere. None of the planets are - they all spin, so they're all flattened by rotation. (Take a look at pictures of Jupiter - it's *visibly* about 10% wider than it is tall. Spinning a planet 320 times larger than the Earth around once every 10 hours will do that to ya.) Now maybe you've heard of a physics theorem that if you have a spherical object, its gravity is the same as that of a point source at the center. You couldn't figure out the internal structure of a sphere based on its gravity because it's so symmetric. But Jupiter's not a sphere, and so the gravitational potential varies from place to place in such a way that you can calculate backwards from it and get the densities at different places inside of the planet. Voila, we know it's mostly atmosphere, turns to metallic hydrogen a few thousand km down, and probably has a rocky core about 6-10 times larger than the Earth.
You and I, right now, can have this conversation. We could stand in front of the White House and point out all of these flaws to everyone that comes by, we can publish articles and books exposing them, and we can work with our elected representatives to try and change the system. In short, we can openly criticize the hell out of the system, as much as we want. Try that in China.
The US is not perfect by a long shot. But since we can talk about and admit our mistakes, we can change them. We had slavery once, but no longer, even though it took a damn long time. I certainly hope that the War on Some Drugs and the ridiculous incarceration route go that way too. But can you imagine the US trying to do, _today_, the sorts of things it did to American Indians in the past, or even to Asian americans in WWII? It would be unthinkable; the public outcry would be tremendous. We're not perfect, but we're learning.
I'm speaking from personal experience here. We wired up my high school to the net in '95, when it was still pretty much bleeding edge for a high school to have a T1 and a server room of its very own. We wanted severn.edu but were refused due to not being a 4 year college, and thus went with severnschool.com. Not nearly as nice a domain, and believe me there's no way we would have gone with it if we had had any choice!
Go do a Google search on China and human rights abuses. Or go read the State Department's report on human rights violations.Go read about how they've jailed four university professors in the past three months, including three with US citizenship or residency, for no crime greater than spreading ideas against the state. They also jailed for a month the husband and 5 year old son of one of the academics, failing to inform the US that they had done so, even though both of these people are US Citizens! (This is a major violation of international law.)
Read about how they brutally suppress religions, including everything from Falun Gong to Christianity. Read about what they've done in Tibet. Not expansionist? Read about how they backed the establishments of Communist governments in Korea and Vietnam, and how they want to take back Taiwan after 50 years of independence.
Read about the silencing of free speach in Hong Kong, the crushing of student demonstrators in Tienanmen square, the censorship of the Internet throughout China, the control and manipulation of public opinion through their state news agencies.
Go read all that, and then tell me that you welcome China.
I think if China wanted to have an independent agency (Switzerland?) investigate the crash and determine whose fault it was, the US would agree to that. If that commission determined it was our fault, I bet we would apologize. But that's not what the Chinese are asking for. They're asking for us to claim total responsibility for what happened, without any investigation as to whether that's the truth. Bush and co. won't do that, and I think that's absolutely the right way to go.
Why? Because it sets one hell of a bad precedent, the "Yes, China, we will roll over and do whatever you ask us to in order to maintain peace." precedent. This sort of thing was tried before wrt Germany in the 1930s by a guy called Chamberlain, and look where that got us. As much as we would all like for there to be peace, we can't forget that China is a big, powerful, authoritarian state with major expansionist drives and a history of human rights violations a mile long. I sure as hell don't want us to go to war with them, but I also don't want to see us roll over and give them everything they want. Give in once, and they will learn the US's leadership is weak, and then they'll just start pressing for more, more more. That will only lead to conflict further down the line. Better to take a stand now, show them we mean business, and try to keep things from getting out of hand.
Take a look at Geoff Marcy's website at exoplanets.org. Marcy is a professor here at Berkeley who leads one of the two teams which has done most of the planet finding thus far. This most recent announcement is by Michel Mayor, a Swiss astronomer who leads the other major extrasolar planet hunt. I think the two teams have a fairly friendly rivalry going on, and often both end up observing/discovering the same planets. One of Geoff's graduate students (who I think reads /.; Jason, you reading this?) told me that this latest batch was all discovered by using southern hemisphere telescopes, so none of these were discovered by Marcy et al's search, since that is conducted solely with Northern hemisphere telescopes.
Right now, we're finding Jupiter-sized planets around roughly 5% of the stars we've looked at - 60-ish planets around about a thousand stars. It's expected that the actual numbers of stars with planets is much higher than that, potentially as much as 50% or so, but smaller planets or ones further from their parent star are much harder to detect, so we have not yet identified any.
I thought not.
Actually, no, none of this happens. Most spy satellites are in orbits the shuttle can't reach, either polar orbits, which have too high an inclination, or geosynchronous orbits, which are far too high for the shuttle to reach. The Hubble is the only satellite which is serviced with any sort of regularity, and there's a substantial proportion of the community that regards that as a waste - it would quite possibly have been cheaper to plan on a series of telescopes, a new one every five years or so, since the costs of a shuttle mission to do repairs are, well, astronomical. The shuttle has been used to launch military satellites, but not repair them, and the launch market since Challenger has largely gone to unmanned lift vehicles like the Titan and Atlas.
There were plans originally for a shuttle launch facility in Vandenburg, CA, which would have allowed the shuttle to reach retrograde polar orbits for spy sat launches, but the air force was already losing its interest in the shuttle by '86 and used the Challenger disaster as an excuse to drop the whole program. It's a shame, too, because several major design decisions were made in the shuttle to allow it to meet the requirements for these military missions - the wing design in particular could have been simplified substantially without the cross-range requirement for once-around landings.
And as for shooting down spy sats, this only happens in James Bond movies. Oh, the US is working on developing the capabilities to do so, and we've done target practice on one of our *own* sats, but don't for a minute think that anyone could actually do this without starting a major international incident.
No, you can't say that it goes on our there anyway, just in secret and we don't know about it. This is all happening up in the sky, after all, and it's quite visible. Amateur satellite hunters have identified the orbital parameters for pretty much all the classified hardware up there. There's just no good way to hide something when it's sitting up in the sky glowing like a star.
A few relevant facts:
- When the shuttle-Mir dockings were going on in the mid 90s, shuttle astronauts did not receive any special training on visiting Mir. They got a briefing or two on the ground, and then when they got there in orbit, the cosmonauts gave them a 2 hour tour and safety lesson. And that's all that was needed.
- The Russians have been flying non-professional cosmonauts to Mir for years, including various members of the media and government officials. They certainly have the experience to know how much training is necessary. Tito has taken all of their training and passed with flying colors.
- One of NASA's big objections has been that Tito poses a danger to the crew in the event of an emergency. There was in fact a guest aboard Mir in '97 when one of the fires broke out. His duties in the event of an emergency were "put your oxygen mask on and stay out of the way of the cosmonauts fixing stuff." He succeeded in carrying out these orders quite well, thankyouverymuch. And NASA thinks that Tito, who is widely acknowledged to be an extremely smart and capable man, couldn't do likewise?
- $20 million bucks is approximately 10% of the Russian Space Agency's entire annual budget. Tito's flight is going to have a major effect on their bottom line, and in their ability to continue developing their half of the space station.
One of NASA's biggest problems is their desire to be the space agency, rather than just a space agency. They're control freaks, and this has hurt the private launch market, and now it's hurting the start of the space tourism market. Trying to block Tito's flight is one of the dumbest things they've done lately. (Well, except for Dan Goldin's mad quest to eradicate all the old worm-style logos...) The ability for private citizens to fly into space would, I think, get people a lot more excited about space travel in general, would generate public support for NASA and ISS, and would pump a lot of money into the system.Two passengers a year, on the every-six-month Soyuz changeout missions which are scheduled anyway, would bring in $40M/year to the Russian Space Agency, which desperately needs the cash, at practically no cost to NASA or any of the other international partners. It's a win-win-win situation, and it's a damn shame that NASA's being so stubborn about it. If there really was a substantial risk to the station, then they'd have a point, but the Russians have proven before that they can safely fly non-professionals, and they can do it again.
Their research showed that people who get their news online frequent *more*, not fewer, sources of news than their offline counterparts, and are exposed to a broader range of topics as a result. Furthermore, nearly everyone checks one or two "general news" sites like NYTimes or CNN, and sees all of the "front page" headlines there. The most common scenario is someone who checks a major site like CNN regularly plus a variety of sites on more specialized topics. Furthermore, the net allows much greater coverage of those specialized topics than would be possible in a print media. So the long and the short of it is, no, there is statistical evidence out there that people don't put blinders on their eyes and only read narrow slices of the news; the vast majority of people in practice chose to combine the narrow and the broad.
And I dare say the average person who gets their news online is better informed than the people who only watch the 6 o'clock news! TV news is all sound bites and no substance; text on the net has more details, more bite to it.
I really wish I could remember the name/source of this study. Anyone help me out here?
- Marshall (Reads WashingtonPost, spacedaily.com, slashdot, bottomquark, and fifteen different AP newsfeeds from ClariNet. Yes I'm a news junkie. ;-)
IMO, Latin is a good compromise language for an official name, and certainly it has the benefit that the majority of planet and major moon names are already in Latin, so it would at least be consistent. Furthermore, "lunar" is the accepted adjective form, even in English.
Well, you're oversimplifying a bit. Yes, there's a major problem with HRC. But the instrument isn't totally useless - they've done a number of clever things to salvage as much science from it as possible, as indicated if you read a bit further in the manual. Yes, it's nowhere near what it was supposed to be, but to say "We are very sorry, but that is all we can do about it." just isn't accurate.
So you can write email to your friends from the top of Mt. Everest via your Iridium satellite modem, of course. :-)
As for actually imaging things on the moon, you're correct, even the Hubble does not have the resolution to pick out the Apollo landers. Some actual numbers to back this up:
Angular resolution of a telescope goes roughly as wavelength/diameter. For visible light at 5000 Angstroms, this means the 2.4 m HST can resolve down to about 0.04 arcsecond (= 1x10^-5 degrees), and the 10m Keck, largest telescope on Earth, could get down to 0.01 arcsec in theory, but in reality atmospheric effects limit it to about ten times that. At a distance of 384400 km, these resolutions correspond to 80 m and 20m per pixel, which is not *quite* good enough to make out anything man-made on the surface. The proposed 30m California Extremely Large Telescope could maybe barely do it, but that's probably 30 years off.
Yes, this is how it should be, I agree. However, for truly tremendous state school systems like the UC, which admits on the order of two hundred thousand students a year, they tend to decrease the complexity of the model. From what I've heard, the undergrad admissions process at UC really is a big equation into which they plug your test scores and GPA and about three other factors, and out pops a "yes" or "no". The current policy relies on standardized test scores *way* more than it should, and that's what they're looking to fix. Whether they need to completely drop it in order to stop over-relying on it is a seperate question, but I do think it's good that they recognize there's a problem.
OR, is it the kids whose parents pay for $900 Kaplan courses who will do better? There's a huge industry around preparing people for these tests, and it's not at all fair to poorer students who just can't afford that sort of resources.
No, I'm not saying that smart kids can't do well without such courses - that's how I was myself. But the existence of high-priced prep courses definitely does bias things towards people who can afford them.
There is no easy magic bullet when you come to testing. Every test is going to be unfair to some group or other, and you will have to take that into account. That said, there can come a time when it becomes clear that a certain test's flaws outweigh its utility, and you should ditch it.
Last year I had to select storage media for a NASA scientific balloon project. We needed something to hold a couple GBs of data that would handle the stresses of a parachute crash landing. I ended up going with a standard IBM laptop HD, since that was the most ruggedized drive I could find on short notice, but had this drive been available then, you can bet I would have gone with it instead. The head-park feature is *really* nice when you start thinking about the drive hitting the ground at five meters/second.
If you look deeper, you'll probably find similar correlations between tech centers and BDSm and polyamory. Not because theres's some innate relation between high tech and alternative sexuality, just because the same sort of open mindset can lead someone to each.
And for what it's worth, I'm in a long-term monogamous hetero relationship. I have no interest in guys whatsoever. But I many friends who are, and I'm totally supportive of them. One of the best things about living in CA is the open environment for people of *all* walks of life. :-)
Beyond that: I agree, this would probably be a bad idea if implemented stupidly. However, as was said very elegantly by another poster in response to the NASA brain control of a aircraft discussion, why does everyone always automatically assume that the people developing the systems mentioned here are completely incapable of thinking of all the problems that everyone here comes up with in 30 seconds. I would bet you any reasonable sum of money that the people behind this system have already thought about emergency passing, gradually handling speed limit changes between zones, weather overrides, and all of that. If they haven't, you can bet someone will before they get around to implementing it in large scale five or ten years from now. Please, recognize that slashdot readers do not have a monopoly on common sense. ;-)