So until today, I think if you'd asked any well-informed astronomer, the answer would have been, "Why of course black holes have been proven to exist."
As Dr. Mitra points out in his paper, what's really been demonstrated is that there's something more dense than a standard-model neutron star -- which I believe is an accurate assessment. He explicitly addresses (and allows for) the existence of things more dense than that, however -- he just "forbids" them from forming event horizons and turning into black holes. If black holes are "allowed", present theory doesn't provide for anything between neutron-star density and black holes, though: a collapse past neutron-star density just "keeps going."
IIRC the paper in Science revealing the compact massive object in our own galaxy's center actually made the statement that it was more dense than a neutron star -- and therefore could only be a black hole. (Of course, after that they simply called it "the black hole"...).
One thing I'd wonder about is whether the spacetime outside an ECO is predicted to be any different than the spacetime outside a black hole... maybe his theory would make different, testable predictions about the x-ray spectra that have been observed for matter falling into black-hole candidates?
You've got me on that one. I'd doubt it -- basically what he's arguing is that the trapping surfaces never form, so there's no event horizon and such. The physics of black holes is different inside the event horizon (if that's a meaningful statement), not outside.
That said, he does predict some different physics: magnetic fields would probably dominate after a while (classic black holes don't have a magnetic field), and you'd see the continuing collapse and evolution of the massive body after a supernova, for example -- which becomes relevant with the present model of a gamma burster (he actually addresses some of this in the paper, making predictions about observations).
I'm also unclear on how you can have a permanent ("eternal") gravitational field pattern if all the mass is gone...???
The mass goes to zero as the radius goes to zero, and for sufficiently-massive starting bodies, this takes "forever" -- and he actually discusses the concept of a "zero-mass singularity" (although he calls it something different -- I don't have the paper up now) as the limiting case for unbounded t. I couldn't follow that one, though... For cases we're likely to encounter, I'd suspect that the rate of mass loss through radiation would be low enough that you'd not notice the slow change in mass within the measurement sphere -- and of course that mass (if it's spherically symmetric) is equivalent to a singularity of equal mass. I'd expect him to say that gravitational field strength does slowly decay with time -- but very slowly. For all I know, it'd be indistinguishable from Hawking radiation...
So the only country where the Imperial system is the standard is the US. Which is definitely not a good thing, one example being the NASA blunders.
Another way to look at it is that, of the whole aerospace industry in the US, NASA is the only entity which uses metric units -- everyone else uses what we refer to as "US" units (sometimes called the "English system"). The Lockheed thruster calibration was done with US units -- as always -- and NASA didn't bother to check (they also didn't bother to cross-check after several course corrections didn't give the desired results... there "wasn't enough time or money" to do that).
I've worked in this industry for a long time; the only time I've used metric units was on NASA projects, and then conversion to metric was the last thing done. NASA is the odd man out, when it comes to units. If you accept the argument that "everybody else does it this way," you have to decide which "everybody" you're talking about: the world vs. the US, or US aerospace industry vs. NASA. If the whole aerospace industry were to switch to metric today, I guarantee you there'd be many years worth of problems like the loss of the Mars Observer -- and some of 'em would involve people, not robotic spacecraft.
I've got the paper open in PDF format, and am trying to read it...
What he appears to claim is:
Within the formal General Theory of Relativity, a trapped surface (a surface formed by light moving radially outward, which is not expanding because of the gravitational field inside the surface) cannot exist. This appears to imply that the mass inside the surface goes to zero as the radius goes to zero...
The proper radial length goes to infinity as the radius goes to zero, so the collapse process continues indefinitely (he refers to Eternally Collapsing Objects -- ECOs)
Because there is no trapped surface and the collapse itself takes infinitely long, all the mass interior to the collapse is radiated away as electromagnetic energy (he refers to Eternally Collapsing Objects -- ECOs)
There can therefore be no "naked singularity" problem, because a finite-mass Schwartzschild black hole doesn't form: the mass "escapes" during the collapse.
He does allow for massive compact objects, however, even with densities larger than that of a static neutron star -- and claims that the infinitely-long accretion time prevents the gravitational radiation from being observed. He allows for exotic equation-of-state matter ("quark stars") and points out that extremely large magnetic fields are possible if black holes aren't allowed -- which might explain some of the more exotic species of high-energy objects, like gamma bursters and so on.
For the most part, what he's doing is beyond me -- my degree's in physics, but it's been a long time, and this is esoteric stuff. But the flavor of it is this: past work has made several incorrect simplifying assumptions, and when the physics and math are done correctly, black holes can't exist. It'd take me a year to check his math, though, so I'm going to stop right here.
Interesting stuff -- this will be very controversial, and we should know shortly whether or not he's made a trivial error. If not, the arguments will take years...
1. The Space Shuttle System was not designed to survive a failure of the Solid Rocket Boosters. There are no corrective actions that can be taken if the boosters do not operate properly after ignition, i.e., there is no ability to separate an Orbiter safely from thrusting boosters and no ability for the crew to escape the vehicle during first-stage ascent.
Neither the Mission Control Team not the 51-L crew had any warning
of impending disaster.
Even if there had been warning, there were no actions available to
the crew of the Mission Control Team to avert the disaster.
The original design of the Shuttle was quite different from what we finally ended up with; check this bibliography if you want more detail. The short story was that it went from a completely-reusable, general-purpose launch vehicle to one which was extremely compromized by two things: reusable space vehicle only (with partial reuse of the solid boosters) and the military-driven cross-range necessary for once-around abort returns to Vandenberg AFB. What had been liquid boosters were now solids, and there was no separation capability during solid burn -- the separation rockets had been removed to meet DOD spy-satellite launch requirements.
These changes were driven by Congress, admittedly with help from the Nixon administration.
The present vehicle bears little resemblance to the original proposals; not having seen those embodied and flown, I can't say whether they'd meet the design turnaround and costs. However, if you bother to talk to anyone who was significantly involved in the early Shuttle work, you'd find that I have told the simple truth. In a sense, they are technology problems -- but the technology is a forced, cutrate bastardization of the original designs.
They did count on multiple failures -- that's why they had two backups for the critical system. The guy's comment was just frustration, not a statement of design philosophy.
Spacecraft (especially manned spacecraft) tend to be designed with redundant systems, to remove single-point failure modes. When a system is particularly critical (like for breathing), they'll make it triple-redundant (yeah, I know -- but that's what they tend to call it, anyway). In this case, they simply provided three of the part, but it would appear that all the parts had similar failure rates. A better design philosophy might be to provide alternative methods for the redundancy, but this costs more -- a lot more -- and Congress was intent on reducing the cost of the ISS, if not killing it outright.
Come to think of it, they gutted the project pretty much the same way they did Shuttle -- did you know the original Shuttle designs had emergency systems which would have prevented the Challenger disaster?
Of course, the same thing could be done with a bunch of hydrometers
But you have to go there to read the hygrometer -- all you have to do with the faintly glowing green plants is look out the window (well, at night...).
Better yet: you need a plant that will radio you when it wants water. Oh, where is Kevin Warwick when you need him?
Thanks to you for reconsidering -- I halfway expected to get flamed...
...your original post made it sound like you were claiming there was a definite plan for a particular probe to be sent. From the pages you linked to, it sounds more like blue-sky speculation.
I think the impression you get will depend on whom you talk to -- Engelhardt and Carsey appear to be pretty gung-ho on drilling Europa with hot water (Lake Vostok is just the proving ground), while others are waiting on more results.
As always, you can't count on NASA's plans until the probe is actually built -- if even then. (The last project I worked on is sitting in a warehouse, and probably will never be launched -- although it is a perfectly good Mars lander.)
Can I quote you when I next talk to the folks planning this?;)
Some quick, publicly-available mentions of the plans (note the recurrent references to Lake Vostok, the Antarctic lake with miles-thick ice cover, which is our present best model for the Europa ocean):
From Wired; search for "Engelhardt", near the end. He's the CalTech glaciologist who invented the "hot water drill."
BBC's Online talks about this, too: the article is about the parallels between Antarctia's Lake Vostok and Europa. Search for "melt," it's the third occurance of the word. Frank Carsey, who's talking, is with the Polar Oceanography Group at JPL (and is mentioned in the Wired link, too).
JPL's website also mentions it; search for "hydrobots". Also check the Europa Orbiter Fact Sheet link (to a PDF) on that same page.
And finally, a Michigan State University honors course page which talks about the proposed Odysseus Mission, which is looking at an ice-melting "drill".
I'm not misinformed -- I think you haven't thought it through. Yeah, drilling that deep on Earth is incredibly hard, if not impossible. But Europa (and Lake Vostok, for that matter) are covered with miles of ice, not rock... a very different problem, with a very different solution.
Or something that's warm enough to be above freezing, and stay that way... the warmer it is, the faster it "bores."
AFAIK this is just what's being discussed for the Europa-ocean probe. It'll need a power supply for the instruments anyway, so you might as well just use that to keep it warm for the "drilling."
Not that these folks are necessarily right, but the topic has a long and detailed history with exobiologists, many of whom do consider it possible, if not likely.
Just because your imagination doesn't stretch that far, doesn't mean it's not possible. Maybe college will open your eyes a little, huh? (When you get there.)
When it gets cold enough, water ice is a bit different from what you're familiar with -- it behaves more like your "geologic crust" than something you can skate on. In the extremely cold conditions of the outer Solar System, water ice (and other volatile ices, too) are very much structural materials; they work just fine as the crust of a planet or a moon. There are even "geologic" processes akin to plate tectonics which can operate with volatile ices replacing the rock that Earth uses.
In this case, the ocean might be similar to Earth's mantle in function: the still-frozen crustal ice floats on it, much as the Earth's low-density continental and lithospheric rock "floats" on the denser, plastic mantle.
Just one more comment. It may be that some of the outer Solar System objects (Pluto and Charon, plus some of the outer-System moons) have no "geologic crust" in the sense of a separate rock component: they may be nothing more than large "dirty" snowballs which never differentiated. They would still have a "surface", however...
Well, except for the fact that granite is not a metamorphic rock...
The big change is that it may not have taken millions of years for the initial granite crust to form. But since granite is the primary constituent of the crust, and the crust had to form before anything was done with it (like plate tectonics shoving it around), this just pushes the "start" line back a bit; it's not changing what the crust is made of, just how quickly it was emplaced. And considering that the oldest rocks are around 4 billion years old, this will turn out to be a change in maybe the fifth decimal place... not too serious, I think.
Eventually the geology books will change; dunno 'bout the geography texts, though.
Even if desirable, it would be prohibitively expensive. The stations are in different orbital planes, and it's expensive (in terms of fuel) to change orbital planes. They're also at different altitudes, but that's much less of a problem.
For what it would take to change planes and do a rendezvous with Alpha, the Russians could reboost Mir to prevent its reentry many, many times over. And they're unwilling to do that even once more.
Nukes have already been used on a small scale here. Remember?
Your statement that nuclear war "won't happen" is faith-based, maybe -- certainly there's nothing objective to assure us that it won't happen. Ever notice the willingness of some people to kill themselves in suicide-bomb attacks? To me, the possibility of a "doomsday" response by the losing side in a major war is very real. YMMV -- but reality is independent of either of our beliefs, isn't it?
The other question that comes up for me is: Did earth start as a gas giant? I'm thinking that what we're living on could easily be the evaporation residue of something the size and composition of Jupiter.
Very doubtful. The huge gravitational field associated with a giant planet such as Jupiter means that "evaporation" of the gases which make up the bulk of the planet is impossible. For smaller bodies, the more-volatile substances can escape, which is why the small moons and planets tend to be airless.
The escape mechanism is basically this: at a given temperature, molecules of a gas have a roughly-Gaussian distribution of momentum -- and the high-speed upper "tail" of that distribution may be above escape velocity, if the planet is small enough and the gas molecule light enough. Of course, there are plenty of things which add to the molecule's momentum, in the upper regions of the atmosphere, and I won't go into those...
But the bottom line is that the gas giants are too big to lose much of their tremendous atmospheres -- which is precisely why they're "gas" giants. I suppose a collision with a large-enough object could strip gas away, but I doubt that this is what you're looking for.
"Infrared catastrophe?" What are you talking about?
The Rayleigh-Jeans spectral distribution of blackbody radiation has the form required by Wein's law: the energy density varies with the inverse fifth power of the wavelength. This leads to an exponential increase in energy density with decreasing wavelength, which is referred to as the "ultraviolet catastrophe," just as the previous poster said (what's catastrophic is the complete failure of the Rayleigh-Jeans spectrum, which is a necessary consequence of classical physics).
Pick up any introductory modern physics text -- it will say precisely what I (and dmatos) just did.
You have an excellent point there -- I installed QT4 on this box a couple of days ago, and went through the same process. It's almost enough to persuade me to stop using the app. I suspect Netscape 6 works similarly, although I haven't tried to install it to a second machine, given its wretched performance on the first.
I understand your point: in the end it may not really be up to the user. But the choice of which software to use is up to me, expecially when I pay hard cash for it. QuickTime and Netscape are both free, so it's not like I have a lot of clout there. However, if "paying customers" are subjected to this same abuse, I'd expect them to protest loudly to the vendor; I know I certainly will.
While I sometimes purchase downloaded software, whenever I can I also get an installable CD as part of the deal -- even if I have to pay a few dollars for it. And if I can't get that, I make a backup copy before I do the installation. I haven't seen a EULA yet that forbids me to make a backup copy for my own use. But you're right about QT4 -- it doesn't give you any of those options...
When people get used to just downloading their apps in an instant, they won't want to take the trouble to actually install software they'd posses themselves, even if that would ultimately benefit them.
Huh... you must know a different crowd of people than I do. I don't know anybody who'd rely on downloaded software instead of their own copy. Hell, I even download my antivirus updates, so I can apply 'em to several machines, instead of using the builtin "smart updates."
Not to mention the fact that an app's startup time is a whole lot shorter if it's installed locally -- drive and bus transfer rates are still growing faster than broadband transfer rates, and I see no reason why that won't continue.
I think it says something if 6 out of the top 10 recommended displays are Trinitron... If one can get equivalent or better display out of the invar style displays, great.
I think the Trinitron displays are prettier than equivalent Invar-mask displays: they tend to be brighter and more saturated. That said, I went from a Trinitron to my Invar-mask ViewSonic, and I've never regretted it. Especially when I do a marathon 16-hour day at CAD (fortunately, this isn't every day!).
I think your guess is correct -- the high-contrast lines are the critical part, and there's often little in the way of fill (unless you're doing 3D modeling).
I wasn't clear, I guess -- resolution per se isn't a problem with Trinitrons; antialiasing at high resolutions is more difficult, though.
For an example of what I was talking about, check out this article in CADalyst, where they review their "Top 10" 21-inch monitors; 4 of them (and not the least expensive 4) are Invar-mask CRTs. My point is this: if Trinitron were the best, all 10 would be Trinitrons... but they're not.
I did a quick search, trying to find the article I was specifically thinking of (I read it when I bought my ViewSonic 21-inch monitor, about 3 years ago), but I can't find it now. It highly recommended Invar-mask CRTs for professional CAD use.
All that said, it's clearly possible to do CAD on a Trinitron (or Diamondtron -- there are some of those around, too). YMMV... as always.
Ummmm... it appears that they had to use the first-generation drivers, because that's all 3dfx ever developed. It makes sense not to invest a lot of time in drivers for something you're not sure you're going to release -- but it makes the card look worse than it actually is.
How good do you think the original GeForce was with its first-gen drivers?
Yep, Trinitrons are nice, and they're often preferred by the graphics types -- unless they're doing CAD.
Serious CAD needs high resolution and good antialiasing, which is more difficult to get with the Trinitron's vertical phosphor stripes than it is with discrete dots. That's why some of the top-line Invar-mask monitors are more expensive than even the Trinitrons.
Slashdot Mirror
As Dr. Mitra points out in his paper, what's really been demonstrated is that there's something more dense than a standard-model neutron star -- which I believe is an accurate assessment. He explicitly addresses (and allows for) the existence of things more dense than that, however -- he just "forbids" them from forming event horizons and turning into black holes. If black holes are "allowed", present theory doesn't provide for anything between neutron-star density and black holes, though: a collapse past neutron-star density just "keeps going."
IIRC the paper in Science revealing the compact massive object in our own galaxy's center actually made the statement that it was more dense than a neutron star -- and therefore could only be a black hole. (Of course, after that they simply called it "the black hole"...).
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You've got me on that one. I'd doubt it -- basically what he's arguing is that the trapping surfaces never form, so there's no event horizon and such. The physics of black holes is different inside the event horizon (if that's a meaningful statement), not outside.
That said, he does predict some different physics: magnetic fields would probably dominate after a while (classic black holes don't have a magnetic field), and you'd see the continuing collapse and evolution of the massive body after a supernova, for example -- which becomes relevant with the present model of a gamma burster (he actually addresses some of this in the paper, making predictions about observations).
The mass goes to zero as the radius goes to zero, and for sufficiently-massive starting bodies, this takes "forever" -- and he actually discusses the concept of a "zero-mass singularity" (although he calls it something different -- I don't have the paper up now) as the limiting case for unbounded t. I couldn't follow that one, though... For cases we're likely to encounter, I'd suspect that the rate of mass loss through radiation would be low enough that you'd not notice the slow change in mass within the measurement sphere -- and of course that mass (if it's spherically symmetric) is equivalent to a singularity of equal mass. I'd expect him to say that gravitational field strength does slowly decay with time -- but very slowly. For all I know, it'd be indistinguishable from Hawking radiation...
---
Another way to look at it is that, of the whole aerospace industry in the US, NASA is the only entity which uses metric units -- everyone else uses what we refer to as "US" units (sometimes called the "English system"). The Lockheed thruster calibration was done with US units -- as always -- and NASA didn't bother to check (they also didn't bother to cross-check after several course corrections didn't give the desired results... there "wasn't enough time or money" to do that).
I've worked in this industry for a long time; the only time I've used metric units was on NASA projects, and then conversion to metric was the last thing done. NASA is the odd man out, when it comes to units. If you accept the argument that "everybody else does it this way," you have to decide which "everybody" you're talking about: the world vs. the US, or US aerospace industry vs. NASA. If the whole aerospace industry were to switch to metric today, I guarantee you there'd be many years worth of problems like the loss of the Mars Observer -- and some of 'em would involve people, not robotic spacecraft.
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What he appears to claim is:
- Within the formal General Theory of Relativity, a trapped surface (a surface formed by light moving radially outward, which is not expanding because of the gravitational field inside the surface) cannot exist. This appears to imply that the mass inside the surface goes to zero as the radius goes to zero...
- The proper radial length goes to infinity as the radius goes to zero, so the collapse process continues indefinitely (he refers to Eternally Collapsing Objects -- ECOs)
- Because there is no trapped surface and the collapse itself takes infinitely long, all the mass interior to the collapse is radiated away as electromagnetic energy (he refers to Eternally Collapsing Objects -- ECOs)
- There can therefore be no "naked singularity" problem, because a finite-mass Schwartzschild black hole doesn't form: the mass "escapes" during the collapse.
He does allow for massive compact objects, however, even with densities larger than that of a static neutron star -- and claims that the infinitely-long accretion time prevents the gravitational radiation from being observed. He allows for exotic equation-of-state matter ("quark stars") and points out that extremely large magnetic fields are possible if black holes aren't allowed -- which might explain some of the more exotic species of high-energy objects, like gamma bursters and so on.For the most part, what he's doing is beyond me -- my degree's in physics, but it's been a long time, and this is esoteric stuff. But the flavor of it is this: past work has made several incorrect simplifying assumptions, and when the physics and math are done correctly, black holes can't exist. It'd take me a year to check his math, though, so I'm going to stop right here.
Interesting stuff -- this will be very controversial, and we should know shortly whether or not he's made a trivial error. If not, the arguments will take years...
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In a word, bullshit.
From the STS 51-L Mission Overview and Preface to Presidential Commission Report on the Challenger Accident:
The original design of the Shuttle was quite different from what we finally ended up with; check this bibliography if you want more detail. The short story was that it went from a completely-reusable, general-purpose launch vehicle to one which was extremely compromized by two things: reusable space vehicle only (with partial reuse of the solid boosters) and the military-driven cross-range necessary for once-around abort returns to Vandenberg AFB. What had been liquid boosters were now solids, and there was no separation capability during solid burn -- the separation rockets had been removed to meet DOD spy-satellite launch requirements.
These changes were driven by Congress, admittedly with help from the Nixon administration.
The present vehicle bears little resemblance to the original proposals; not having seen those embodied and flown, I can't say whether they'd meet the design turnaround and costs. However, if you bother to talk to anyone who was significantly involved in the early Shuttle work, you'd find that I have told the simple truth. In a sense, they are technology problems -- but the technology is a forced, cutrate bastardization of the original designs.
---
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Spacecraft (especially manned spacecraft) tend to be designed with redundant systems, to remove single-point failure modes. When a system is particularly critical (like for breathing), they'll make it triple-redundant (yeah, I know -- but that's what they tend to call it, anyway). In this case, they simply provided three of the part, but it would appear that all the parts had similar failure rates. A better design philosophy might be to provide alternative methods for the redundancy, but this costs more -- a lot more -- and Congress was intent on reducing the cost of the ISS, if not killing it outright.
Come to think of it, they gutted the project pretty much the same way they did Shuttle -- did you know the original Shuttle designs had emergency systems which would have prevented the Challenger disaster?
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But you have to go there to read the hygrometer -- all you have to do with the faintly glowing green plants is look out the window (well, at night...).
Better yet: you need a plant that will radio you when it wants water. Oh, where is Kevin Warwick when you need him?
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I think the impression you get will depend on whom you talk to -- Engelhardt and Carsey appear to be pretty gung-ho on drilling Europa with hot water (Lake Vostok is just the proving ground), while others are waiting on more results.
As always, you can't count on NASA's plans until the probe is actually built -- if even then. (The last project I worked on is sitting in a warehouse, and probably will never be launched -- although it is a perfectly good Mars lander.)
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Can I quote you when I next talk to the folks planning this? ;)
Some quick, publicly-available mentions of the plans (note the recurrent references to Lake Vostok, the Antarctic lake with miles-thick ice cover, which is our present best model for the Europa ocean):
From Wired ; search for "Engelhardt", near the end. He's the CalTech glaciologist who invented the "hot water drill."
BBC's Online talks about this, too: the article is about the parallels between Antarctia's Lake Vostok and Europa. Search for "melt," it's the third occurance of the word. Frank Carsey, who's talking, is with the Polar Oceanography Group at JPL (and is mentioned in the Wired link, too).
A website on Europa's oceans, which mentions the "melting" plan. Papers are cited, and the bibliography's here.
JPL's website also mentions it; search for "hydrobots". Also check the Europa Orbiter Fact Sheet link (to a PDF) on that same page.
And finally, a Michigan State University honors course page which talks about the proposed Odysseus Mission, which is looking at an ice-melting "drill".
I'm not misinformed -- I think you haven't thought it through. Yeah, drilling that deep on Earth is incredibly hard, if not impossible. But Europa (and Lake Vostok, for that matter) are covered with miles of ice, not rock... a very different problem, with a very different solution.
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AFAIK this is just what's being discussed for the Europa-ocean probe. It'll need a power supply for the instruments anyway, so you might as well just use that to keep it warm for the "drilling."
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Not that these folks are necessarily right, but the topic has a long and detailed history with exobiologists, many of whom do consider it possible, if not likely.
Just because your imagination doesn't stretch that far, doesn't mean it's not possible. Maybe college will open your eyes a little, huh? (When you get there.)
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In this case, the ocean might be similar to Earth's mantle in function: the still-frozen crustal ice floats on it, much as the Earth's low-density continental and lithospheric rock "floats" on the denser, plastic mantle.
Just one more comment. It may be that some of the outer Solar System objects (Pluto and Charon, plus some of the outer-System moons) have no "geologic crust" in the sense of a separate rock component: they may be nothing more than large "dirty" snowballs which never differentiated. They would still have a "surface", however...
---
The big change is that it may not have taken millions of years for the initial granite crust to form. But since granite is the primary constituent of the crust, and the crust had to form before anything was done with it (like plate tectonics shoving it around), this just pushes the "start" line back a bit; it's not changing what the crust is made of, just how quickly it was emplaced. And considering that the oldest rocks are around 4 billion years old, this will turn out to be a change in maybe the fifth decimal place... not too serious, I think.
Eventually the geology books will change; dunno 'bout the geography texts, though.
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For what it would take to change planes and do a rendezvous with Alpha, the Russians could reboost Mir to prevent its reentry many, many times over. And they're unwilling to do that even once more.
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Your statement that nuclear war "won't happen" is faith-based, maybe -- certainly there's nothing objective to assure us that it won't happen. Ever notice the willingness of some people to kill themselves in suicide-bomb attacks? To me, the possibility of a "doomsday" response by the losing side in a major war is very real. YMMV -- but reality is independent of either of our beliefs, isn't it?
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Geez, you didn't even bother to edit out the line break in the final paragraph...
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Very doubtful. The huge gravitational field associated with a giant planet such as Jupiter means that "evaporation" of the gases which make up the bulk of the planet is impossible. For smaller bodies, the more-volatile substances can escape, which is why the small moons and planets tend to be airless.
The escape mechanism is basically this: at a given temperature, molecules of a gas have a roughly-Gaussian distribution of momentum -- and the high-speed upper "tail" of that distribution may be above escape velocity, if the planet is small enough and the gas molecule light enough. Of course, there are plenty of things which add to the molecule's momentum, in the upper regions of the atmosphere, and I won't go into those...
But the bottom line is that the gas giants are too big to lose much of their tremendous atmospheres -- which is precisely why they're "gas" giants. I suppose a collision with a large-enough object could strip gas away, but I doubt that this is what you're looking for.
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The Rayleigh-Jeans spectral distribution of blackbody radiation has the form required by Wein's law: the energy density varies with the inverse fifth power of the wavelength. This leads to an exponential increase in energy density with decreasing wavelength, which is referred to as the "ultraviolet catastrophe," just as the previous poster said (what's catastrophic is the complete failure of the Rayleigh-Jeans spectrum, which is a necessary consequence of classical physics).
Pick up any introductory modern physics text -- it will say precisely what I (and dmatos) just did.
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I understand your point: in the end it may not really be up to the user. But the choice of which software to use is up to me, expecially when I pay hard cash for it. QuickTime and Netscape are both free, so it's not like I have a lot of clout there. However, if "paying customers" are subjected to this same abuse, I'd expect them to protest loudly to the vendor; I know I certainly will.
While I sometimes purchase downloaded software, whenever I can I also get an installable CD as part of the deal -- even if I have to pay a few dollars for it. And if I can't get that, I make a backup copy before I do the installation. I haven't seen a EULA yet that forbids me to make a backup copy for my own use. But you're right about QT4 -- it doesn't give you any of those options...
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Huh... you must know a different crowd of people than I do. I don't know anybody who'd rely on downloaded software instead of their own copy. Hell, I even download my antivirus updates, so I can apply 'em to several machines, instead of using the builtin "smart updates."
Not to mention the fact that an app's startup time is a whole lot shorter if it's installed locally -- drive and bus transfer rates are still growing faster than broadband transfer rates, and I see no reason why that won't continue.
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I think the Trinitron displays are prettier than equivalent Invar-mask displays: they tend to be brighter and more saturated. That said, I went from a Trinitron to my Invar-mask ViewSonic, and I've never regretted it. Especially when I do a marathon 16-hour day at CAD (fortunately, this isn't every day!).
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I wasn't clear, I guess -- resolution per se isn't a problem with Trinitrons; antialiasing at high resolutions is more difficult, though.
For an example of what I was talking about, check out this article in CADalyst , where they review their "Top 10" 21-inch monitors; 4 of them (and not the least expensive 4) are Invar-mask CRTs. My point is this: if Trinitron were the best, all 10 would be Trinitrons... but they're not.
I did a quick search, trying to find the article I was specifically thinking of (I read it when I bought my ViewSonic 21-inch monitor, about 3 years ago), but I can't find it now. It highly recommended Invar-mask CRTs for professional CAD use. All that said, it's clearly possible to do CAD on a Trinitron (or Diamondtron -- there are some of those around, too). YMMV... as always.
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How good do you think the original GeForce was with its first-gen drivers?
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Serious CAD needs high resolution and good antialiasing, which is more difficult to get with the Trinitron's vertical phosphor stripes than it is with discrete dots. That's why some of the top-line Invar-mask monitors are more expensive than even the Trinitrons.
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