These kinds of feats just don't have the glamor they used to. Especially since his gondola is all tricked out with hi-tech stuff. The balloon even flies itself so that he can sleep. I understand that this is a very tough feat, particularly since this is his 5th attempt at it, but it just doesn't have that extra dimension that makes it very exciting (it isn't a first circumnavigation, because that was done in the 16th century; it doesn't demonstrate the possibilites of future transport or a smaller world; it doesn't have great political implications; nor is it a demonstration of new technologies and engineering). I doubt that 100,000 people will storm the landing zone in celebration if he does make it around.
I used to watch those shows when I was a wee tyke, and I even used to harbor nostalgic thoughts about them. Then I saw reruns of the shows years later and actually paid attention to them. In my opinion, it is entirely appropriate that Fox is redoing the series because it is right up their alley along with 'Did we land on the moon?' I guess I never listened to how pseudoscientific all those stories were at the time.
Typical story: 20 minutes on "ancient astronauts" with 5 minutes "balanced" reporting by talking to scientist/palentologist, etc.:
Interviewer: "Do you think these civilizations were visited by ancient astronauts?"
Scientist: "No"
Interviewer: "How can anyone explain the level of technology these people attained?"
Scientist: "There really is no need to insist on an intervention with an alien species. You see, the progress of this civilization develops quite naturally from..."
Interviewer: "Yes, yes, but can you say with 100 percent certainty that there were no ancient astronauts?"
Scientist: "Well, no, but you see one cannot say with 100 percent certainty about anything..."
Interviewer: "So it cannot be ruled out then?"
Scientist: "Well, I suppose you can say that, but..."
(cut to shot of the night sky)
Nimoy: Were there visitors long ago from very far away? Even science is not in agreement. Join us next time when we go In Search Of the little dwarves that hide in our refrigerators and turn the light off when the door closes. I, am Leonard Nimoy."
Re:Dumb Question from a NON Physicist
on
Universe is Flat
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· Score: 2
You are asking a lot of very good questions, and you are correct that they have all been pretty much raised at one point or another. However, these questions really have not been answered. Basically we can only infer what we can from the universe by looking through telescopes, so the most you can ask of a certain cosmological model is that it be consistent with observation. These questions in particular are certainly not boring, and far from being resolved.
The perception of time is an interesting topic because the "arrow of time" comes from thermodynamics (the second law in particular), and so some believe that it is independent of the expansion of the univese. However, some have entertained the possibility that if the universe were to contract, then time would reverse itself.
In addition to the books I referenced previously, if you really want to exercise your brain, I highly recommend Barrow and Tipler's The Anthropic Cosmological Principle. You might not agree with all that is in it, but it has some very nice historical chapters and discussions on the nature and fate of the universe.
Re:Dumb Question from a NON Physicist
on
Universe is Flat
·
· Score: 2
The best visual explanation of this is the expanding balloon analogy. Take a balloon of a certain size and put a bunch of dots on it with a magic marker. If you constrain yourself to the surface of the balloon (i.e., let the balloon be a 2-dimensional universe) and let the dots represent galaxies, then as you inflate the balloon you'll see that this universe expands and all the galaxies fly apart from each other. Note that no matter where you are on the balloon surface, all the galaxies are expanding away from each other, so there is no one spot on the balloon suface that is the "center" of this expansion. For the case of our universe our 4-dimensional (3 spatial and one temporal) spacetime is similarly expanding.
There also is the issue of the shape of the universe, which is what this story addresses. The balloon analogy describes a closed and unbounded universe. There are also other types such as the closed and bounded (such as an expanding dinner plate) and an infinite universe.
This all leads to some interesting questions such as what is this all expanding into? Is this 4-D space hung in a higher dimensional space, or is this all that there is? Some cosmologists look at possibilities such as whether our universe is just a local bubble and that there are other universes that are right next to us (and perhaps connected via black holes/quasars). Also, note that if the universe is as it is described above, then you should be able to set off in one direction and travel all the way around the universe and get back to your starting position, much like sailing around the Earth. However, with the rate of expansion of the universe, you would have to travel awfully fast. If the universe were not expanding and was closed (as with the balloon analogy) then if it were optically transparent and you had a big enough telescope, then you would be able to look far out and eventually see yourself.
There are a number of good layman-targeted books on this subject. Two of the most popular have been Hawking's A Brief History of Time, and more recently Brian Greene's The Elegant Universe. A very good book on the Big Bang itself is Steven Weinberg's The First Three Minutes.
I'm confused about how this is a science experiment. Apart from the confusing statement in the press release about gauging its mass in space (I assume they mean that they measured the resonant frequencies of the toy), from what I can see from a picture of the toy it is not an object that one would expect to behave much differently in zero-G because it appears to only be capable of rotational motion. I'm sure there are far more interesting Lego stuff they could have used (building a scale model of a space structure such as a boom used on the ISS would have been far more useful and could have been passed off as a legit experiment). They might as well have put a Pokemon card on the "mass measurement device." At least the Shuttle Crew (STS-54) brought along much more interesting toys with them (Picture 1 and Picture 2) and probably had more fun playing with them.
Besides that fact that the materials involved here are "cheap and easy," another interesting aspect to this is that the superconductivity appears to occur through the good 'ol BCS mechanism, which is your grandma's physics (not that wacky stuff they need to explain the ceramic material transitions).
I am not saying that one should not question scientific authority. I am saying that it is not the museum's place to re-interpret scientific authority. My position is probably best summed up in the AC reply (#11) to my comment that the museum has sided with the minority view on this issue that the museum does a disservice to the public by not presenting Pluto's place as defined by the IAU. There are many scientists that view Jupiter as a star that didn't have enough mass to initiate fusion; does this mean that the museum should remove Jupiter from the Planet classification and put it under a separate title such as Protostar? You can find people that advocate this, but I doubt many would change their view of Jupiter.
Take another example: the face on Mars. There are people who are strong advocates of this, some who are technically-trained and have Ph.Ds. I don't think it is the place of the museum to make a whole extra exhibit on the Face within the context that the scientific community is undecided on this issue (on the other hand I think it would be in their place to present this in the context of mankind's romantic ideas of Mars, including such things as Percival Lowell's canal observations). It is the place of the scientists and citizens who advocate the Face to question the authority and make their case; it isn't the museum's place to do that for them.
I also do not advocate censoring museums, but I do think that museums have a responsibility to present information accurately and within historical context, especially the American Museum of Natural History. I think that by selectively removing Pluto as being listed as a planet when the IAU classifies it as a planet is being inaccurate. Because this was a deliberated decision of omission, it does make one wonder what other museum exhibits are subject to their reinterpretation/selected-omissions.
I think the museum is incorrect in their position by going against the stance of the international community. The museum seems to argue that the status of Pluto is a controversial open question and they are taking what they feel is the correct side of the "controversy" (they argure that they sidestep the controversy, but in doing so they are in fact taking the side opposite the predominant scientific opinion). However, as far as the international astronomical community is concerned, there is no controversy.
If the museum wants to take this approach, they may as well include other significant sections to the museum, such as a phrenology section when discussing current medical and psychological techniques. There are some people who still advocate phrenology, so therefore it must be a controversial subject and they should present all sides of this issue. This kind of handling of issues is just a reflection of what passes as journalism these days: no matter what issue is being presented, give equal time to an opposite opinion no matter how insignificant this opinion is considered because this is supposed to show "balanced" and "un-biased" reporting. What it does in many cases is promote very minor opinions and give them legimate status and create controversies that do not really exist.
To present something within historical context is one thing, but an exhibit on the current state of things should reflect the current majority opinion. It might turn out that down the road the international community changes its mind about Pluto, but until then the museum should list it as one of the planets.
It is not immediately clear to me how significant the implications of this are. Regardless of whether granite can form in such a quick manner, it still needs to be shown that the Earth's mantle did form in this manner. What do these results say about the isotopic dating calculated ages of the crust? Hopefully if one assumes that the continents formed in such a swift manner, this will point the field geologists in the right direction to look for further evidence. Any geologists care to comment?
I am also not sure what the implications of these experiments have on cosmology. From a cosmological standpoint anything heavier than helium is not that important (unless the "missing mass" consists of blobs of granite floating around between the stars!).:)
A little quibble with the subtitle
on
Longitude
·
· Score: 3
I believe that what was solved was the greatest engineering problem of the time, not scientific. Everyone knew that you needed an accurate timepiece, it was just that no one knew how to build one that worked on a ship.
Marcel Gagne has written a nice series of intro articles on this topic for The Linux Journal. You can find the articles, called Tweaking Tux at LJ under the System Administration section in the archives section, or listed on his personal page of his company's website.
I would disagree with the premise that politics is more important these days than in the past. This is the kind of thinking where the current populace puts more historical weight on the times which they live rather than bygone eras. The history of the world is full of political eras which have had major geopolitical ramifications. Are these current technological times more politically important than, say the effects of the television age on culture and politics in the 50s and 60s? How about the industrial revolution and the US Western expansion "Manifest Destiny" era of Polk? (Instead of running the risk of showing my ignorance of history, I will end my examples here).
Politics and politicians have been held in disdain for thousands of years. Just go back to the writings of the ancient Greeks, or read Plato's account of Socrates trial. I don't think our freedoms and liberties are under any more risk now than they always have been. Technological changes occur and the world eventually adjusts to them in spite of politicians.
Correct me if I am wrong, but isn't BMG one of the CD clubs that you purchase a dozen CDs for some price and you don't have any further financial commitments (as compared to some others where you have to purchase a certain number of full-price CDs within a certain time frame)? They might keep it free and load you up on ads or make money selling demographic information about you instead.
This books seems to be coming from the other side of the anthropic cosmological principle argument, which is explained very nicely in all its forms in the Barrow and Tipler book The Anthropic Cosmological Principle. In a nutshell Barrow and Tipler talk about how our very existence puts constraints on some of the fundamental constants, because if they were any different then we wouldn't be here. It is a very good book BTW.
The effect of apparent superluminal speeds, which has to do with propagation of waves through a medium with a large changing index of refraction, was well known for almost a century. Arnold Sommerfeld described the mathematics for it around 1917 as well as a nice discussion on the speed of information propagation (which was a hot topic at the time). A reprint of this paper is nicely given in Leon Brillouin's book Wave Propagation and Group Velocity, Academic Press, 1960.
The article itself mentions that the idea is several hundred years old. Besides the problems in getting a stable rotation source as well as getting rid of vibrations, if my fuzzy memory serves me, I recall another problem with the mercury mirrors has always been the danger of all that mercury vapor coming off of such a large surface area.
I can see it now, instead of "mad hatters" we'll be talking about "mad astronomers."
Suspending with string from above won't help you at all. There is nothing in a string that will absorb any energy. When the car hits a bump and goes up, the string will jerk the HD up, etc.
If you want to go with springs, suspend it from above and below with springs (and perhaps side to side and front to back). Just make sure they have the proper spring constants so that every little bump doesn't keep it bouncing for ever and ever (that's why you need something to damp out the energy, which is why you use shock absorbers in a car). With all the trouble that is, you might as well just get the proper foam rubber to do the job.
I agree, I'd like to see their proposal too. And perhaps once I did I would come around on it, but I am still very skeptical that it could be pulled off as easy as they (or at least the Fox reporters) say.
Perhaps they should be given money just to take the VLT mirror and make the primary. Then they can test it to get an idea if it should be tried. Or, if that is too expensive, maybe they could be given a spare smaller glass mirror and grind it to the correct proportional size to see if it would work.
The bottom line is that you cannot do the job with an arbitrarily thin piece of material because the disturbances will kill you. Remember, you have to maintain the shape to nanometer-scale. Shave off most of the glass and back it with any material you want, but now you're back to a heavy mirror because of all the backing material, or you have differential expansion problems between the mirror material and the backing material. Also, if you do manage to make the mirror thin and light, you still have the problem of de-coupling the satellite disturbances from the optics system (where all the extra mass in the mirror actually turns out to help you).
Gravity is not the limiting factor for ground-based mirrors, at least not for performance reasons. They didn't go to a segmented primary on Keck because of gravity effects, they went that way because you just cannot make a monolithic mirror that big with decent optical quality under any reasonable budget (not to mention that it would be about impossible to get it up the mountain if you did build one). And for some of the same reasons you can't just make an arbitrarily thin Keck-sized primary and back it with all the new composite materials because it will not hold the mirror shape down to nanometer levels. Believe me, it would have been done a long time ago for both ground and spaced-based telescopes.
My original point is that this is a very tough problem, which did not come through in the Fox News story. The story made it sound like you just shave down a mirror and stick it on Hubble with some shower curtain light shields. I don't think this idea will fly because not only of the technical challenges involved in grinding, mounting, and flying it, but also because NASA is already spending good money on thin-mirror research. I personally find the most exciting areas of research here to be flying individual telescopes and combining their signals the way radio astronomers do, or the ideas on very large thin metallic films that unfurl and are kept in shape using electrostatic forces (such as in the link I provided in my earlier comment).
(BTW, I appreciate the discussion on this. Mostly all I see on/. are postings of only one or two interesting comments (usually lost in the noise), lots of noise, or lots of "me too" comments.)
Temperature gradients can be huge! Remember that you are talking about a very thin piece of glass here. You had better hope that the coefficients of expansion is isotropic too because you can get some unpleasant occurances (e.g., cracks) in thin materials if they don't expand isotroptically.
Gyro vibration. You have to continually run the gyros to keep them pointed in particular directions, and these will cause vibrations. Thursters will shake the whole thing too. If your glass it too thin you'll start it vibrating like a drum head.
Also keep in mind that structures behave in completely different ways in zero-G. You might have characterized all your structures on the lab and have damped out most of the disturbances, but you will find that there are whole different modes of vibration in space. Something that wasn't a problem on the ground is now a problem in space.
Telescopes are not hard to build because they deform under their own weight; in fact, their deformation is easy to predict thanks to Mr. Newton. Large optical quality mirrors are ground to allow for their sag on the earth.
Remember, the Hubble mirror (and other mirrors in space) is as thick as it is because it has to be that thick. Believe me, the cost per pound to put somthing in orbit is so high, they made that mirror as thin as they could. You can't just artibrarily grind off most of the mass unless you can elsewhere compensate for all the problems you introduce. Maybe they have an idea on how to correct for all the aberrations that they'll have in the mirror (such as adding an active secondary, but here you start adding more and more R&D money), but they didn't mention that in the article. Or maybe the telescope isn't supposed to be optical quality and they want to use it in front of spectrographs.
There are many efforts all over the globe to come up with ultra-lightweight mirrors for space (see for instance some work at the U. of Kentucky). If you have a good idea on how to do it, you can make some nice bucks for yourself.:)
The array of visible telescopes is what the NGST is about (to some extent-it uses segmented mirrors acting as one). More directly, the Space Technology 3 mission is supposed to address this.
The article is long on details on what one can do with a big mirror, but it doesn't go into the major technical problems you'd run into. There is a reason that mirrors have the particular thicknesses they do, which has to do with stability. You can't just arbitrarily grind off the mass of a mirror without some major consequences. The article doesn't mention what they would do to handle the stresses and strains that the very thin mirror would undergo. A glass mirror that thin is going to flop all over the place unless you can control the mirror shape, and we're talking about controlling the shape down to nanometer length scales (assuming you want diffraction-limited quality, which is something like better than 1/14 of the wavelength averaged over the useable surface).
Keep in mind that this isn't a quick and easy retrofit for the Hubble. This is a major undertaking which would require a major budget. The article comes off sounding like it would be cheap and easy and silly not to do, whereas it would probably turn out that for the kind of money you'd be talking about, you might as well spend a little more and build a new, better telescope from scratch.
Hey, you can open a magnetic spa and make tons of money off of New Agers and other ignorant people. Haven't you heard about all the health benefits of magnetic fields? You can let people "re-charge" their bracelets and shoe inserts for a fee.
It is certainly true that the primary goal of a for-profit company is to make money, but this doesn't necessarily conflict with their involvement in education.
A company can perform alturistic deeds for a variety of reasons, such as good PR. MS contributes a lot to primary and secondary schools which result in nice press releases and commercials with sweater-wearing CEOs that give you the warm and fuzzies. This kind of educational contribution is relatively cheap for them, and it helps soften their image (particularly in MS's case when they are facing antitrust hearings). Westinghouse used to be well-known for their sponsorship of their world-famous annual highschool science competition (which they have recently dropped sponsorship after many decades, but has been picked up by Intel).
Another reason a company might become involved in education is to ensure a technically-literate workforce from which they can hire people. This issue has come up in the US (and I suppose other regions of the world) because the creation of new technical jobs is supposedly out-pacing the number of technically-trained graduates. This can take the form of multiple companies joining together to lobby the government for more educational $$ or higher educational standards, or companies might sponsor graduate student research.
The above are a couple of examples of the ways corporate involvement in education can take place. Another way, which I presume is the motivating factor behind the article's description of Metrowerks's CodeWarriorU, is product familiarity. Anyone who has been in a college or university bookstore knows the amazing discounts (I've seen 75% and higher) one can get on developmental tools such as the MS Office suite, MS Visual Studio, the old Boreland compilers, etc. Simply put, if you get college students using VisualC++ in college, what software developmental tool do you think they'll want to use in their post-graduation job if they are given a choice? Metrowerks is in the position where they can teach pure ANSI C++ and not even push their product if they wanted to, because just the fact that the students are using Code Warrior and are getting comfortable with it, that is all the selling they need to do. Sure the conceptual jump to VisualC++ probably isn't all that great once you know Code Warrior, but why bother if you already own CW and are comfortable with it?
Slashdot Mirror
See this link for examle.
These kinds of feats just don't have the glamor they used to. Especially since his gondola is all tricked out with hi-tech stuff. The balloon even flies itself so that he can sleep. I understand that this is a very tough feat, particularly since this is his 5th attempt at it, but it just doesn't have that extra dimension that makes it very exciting (it isn't a first circumnavigation, because that was done in the 16th century; it doesn't demonstrate the possibilites of future transport or a smaller world; it doesn't have great political implications; nor is it a demonstration of new technologies and engineering). I doubt that 100,000 people will storm the landing zone in celebration if he does make it around.
Typical story: 20 minutes on "ancient astronauts" with 5 minutes "balanced" reporting by talking to scientist/palentologist, etc.:
Interviewer: "Do you think these civilizations were visited by ancient astronauts?"
Scientist: "No"
Interviewer: "How can anyone explain the level of technology these people attained?"
Scientist: "There really is no need to insist on an intervention with an alien species. You see, the progress of this civilization develops quite naturally from ..."
Interviewer: "Yes, yes, but can you say with 100 percent certainty that there were no ancient astronauts?"
Scientist: "Well, no, but you see one cannot say with 100 percent certainty about anything..."
Interviewer: "So it cannot be ruled out then?"
Scientist: "Well, I suppose you can say that, but..."
(cut to shot of the night sky)
Nimoy: Were there visitors long ago from very far away? Even science is not in agreement. Join us next time when we go In Search Of the little dwarves that hide in our refrigerators and turn the light off when the door closes. I, am Leonard Nimoy."
The perception of time is an interesting topic because the "arrow of time" comes from thermodynamics (the second law in particular), and so some believe that it is independent of the expansion of the univese. However, some have entertained the possibility that if the universe were to contract, then time would reverse itself.
In addition to the books I referenced previously, if you really want to exercise your brain, I highly recommend Barrow and Tipler's The Anthropic Cosmological Principle. You might not agree with all that is in it, but it has some very nice historical chapters and discussions on the nature and fate of the universe.
There also is the issue of the shape of the universe, which is what this story addresses. The balloon analogy describes a closed and unbounded universe. There are also other types such as the closed and bounded (such as an expanding dinner plate) and an infinite universe.
This all leads to some interesting questions such as what is this all expanding into? Is this 4-D space hung in a higher dimensional space, or is this all that there is? Some cosmologists look at possibilities such as whether our universe is just a local bubble and that there are other universes that are right next to us (and perhaps connected via black holes/quasars). Also, note that if the universe is as it is described above, then you should be able to set off in one direction and travel all the way around the universe and get back to your starting position, much like sailing around the Earth. However, with the rate of expansion of the universe, you would have to travel awfully fast. If the universe were not expanding and was closed (as with the balloon analogy) then if it were optically transparent and you had a big enough telescope, then you would be able to look far out and eventually see yourself.
There are a number of good layman-targeted books on this subject. Two of the most popular have been Hawking's A Brief History of Time, and more recently Brian Greene's The Elegant Universe. A very good book on the Big Bang itself is Steven Weinberg's The First Three Minutes.
I'm confused about how this is a science experiment. Apart from the confusing statement in the press release about gauging its mass in space (I assume they mean that they measured the resonant frequencies of the toy), from what I can see from a picture of the toy it is not an object that one would expect to behave much differently in zero-G because it appears to only be capable of rotational motion. I'm sure there are far more interesting Lego stuff they could have used (building a scale model of a space structure such as a boom used on the ISS would have been far more useful and could have been passed off as a legit experiment). They might as well have put a Pokemon card on the "mass measurement device." At least the Shuttle Crew (STS-54) brought along much more interesting toys with them (Picture 1 and Picture 2) and probably had more fun playing with them.
Besides that fact that the materials involved here are "cheap and easy," another interesting aspect to this is that the superconductivity appears to occur through the good 'ol BCS mechanism, which is your grandma's physics (not that wacky stuff they need to explain the ceramic material transitions).
Take another example: the face on Mars. There are people who are strong advocates of this, some who are technically-trained and have Ph.Ds. I don't think it is the place of the museum to make a whole extra exhibit on the Face within the context that the scientific community is undecided on this issue (on the other hand I think it would be in their place to present this in the context of mankind's romantic ideas of Mars, including such things as Percival Lowell's canal observations). It is the place of the scientists and citizens who advocate the Face to question the authority and make their case; it isn't the museum's place to do that for them.
I also do not advocate censoring museums, but I do think that museums have a responsibility to present information accurately and within historical context, especially the American Museum of Natural History. I think that by selectively removing Pluto as being listed as a planet when the IAU classifies it as a planet is being inaccurate. Because this was a deliberated decision of omission, it does make one wonder what other museum exhibits are subject to their reinterpretation/selected-omissions.
If the museum wants to take this approach, they may as well include other significant sections to the museum, such as a phrenology section when discussing current medical and psychological techniques. There are some people who still advocate phrenology, so therefore it must be a controversial subject and they should present all sides of this issue. This kind of handling of issues is just a reflection of what passes as journalism these days: no matter what issue is being presented, give equal time to an opposite opinion no matter how insignificant this opinion is considered because this is supposed to show "balanced" and "un-biased" reporting. What it does in many cases is promote very minor opinions and give them legimate status and create controversies that do not really exist.
To present something within historical context is one thing, but an exhibit on the current state of things should reflect the current majority opinion. It might turn out that down the road the international community changes its mind about Pluto, but until then the museum should list it as one of the planets.
I am also not sure what the implications of these experiments have on cosmology. From a cosmological standpoint anything heavier than helium is not that important (unless the "missing mass" consists of blobs of granite floating around between the stars!). :)
I believe that what was solved was the greatest engineering problem of the time, not scientific. Everyone knew that you needed an accurate timepiece, it was just that no one knew how to build one that worked on a ship.
Marcel Gagne has written a nice series of intro articles on this topic for The Linux Journal. You can find the articles, called Tweaking Tux at LJ under the System Administration section in the archives section, or listed on his personal page of his company's website.
Politics and politicians have been held in disdain for thousands of years. Just go back to the writings of the ancient Greeks, or read Plato's account of Socrates trial. I don't think our freedoms and liberties are under any more risk now than they always have been. Technological changes occur and the world eventually adjusts to them in spite of politicians.
Correct me if I am wrong, but isn't BMG one of the CD clubs that you purchase a dozen CDs for some price and you don't have any further financial commitments (as compared to some others where you have to purchase a certain number of full-price CDs within a certain time frame)? They might keep it free and load you up on ads or make money selling demographic information about you instead.
This books seems to be coming from the other side of the anthropic cosmological principle argument, which is explained very nicely in all its forms in the Barrow and Tipler book The Anthropic Cosmological Principle . In a nutshell Barrow and Tipler talk about how our very existence puts constraints on some of the fundamental constants, because if they were any different then we wouldn't be here. It is a very good book BTW.
The effect of apparent superluminal speeds, which has to do with propagation of waves through a medium with a large changing index of refraction, was well known for almost a century. Arnold Sommerfeld described the mathematics for it around 1917 as well as a nice discussion on the speed of information propagation (which was a hot topic at the time). A reprint of this paper is nicely given in Leon Brillouin's book Wave Propagation and Group Velocity, Academic Press, 1960.
I can see it now, instead of "mad hatters" we'll be talking about "mad astronomers."
If you want to go with springs, suspend it from above and below with springs (and perhaps side to side and front to back). Just make sure they have the proper spring constants so that every little bump doesn't keep it bouncing for ever and ever (that's why you need something to damp out the energy, which is why you use shock absorbers in a car). With all the trouble that is, you might as well just get the proper foam rubber to do the job.
Perhaps they should be given money just to take the VLT mirror and make the primary. Then they can test it to get an idea if it should be tried. Or, if that is too expensive, maybe they could be given a spare smaller glass mirror and grind it to the correct proportional size to see if it would work.
Gravity is not the limiting factor for ground-based mirrors, at least not for performance reasons. They didn't go to a segmented primary on Keck because of gravity effects, they went that way because you just cannot make a monolithic mirror that big with decent optical quality under any reasonable budget (not to mention that it would be about impossible to get it up the mountain if you did build one). And for some of the same reasons you can't just make an arbitrarily thin Keck-sized primary and back it with all the new composite materials because it will not hold the mirror shape down to nanometer levels. Believe me, it would have been done a long time ago for both ground and spaced-based telescopes.
My original point is that this is a very tough problem, which did not come through in the Fox News story. The story made it sound like you just shave down a mirror and stick it on Hubble with some shower curtain light shields. I don't think this idea will fly because not only of the technical challenges involved in grinding, mounting, and flying it, but also because NASA is already spending good money on thin-mirror research. I personally find the most exciting areas of research here to be flying individual telescopes and combining their signals the way radio astronomers do, or the ideas on very large thin metallic films that unfurl and are kept in shape using electrostatic forces (such as in the link I provided in my earlier comment).
(BTW, I appreciate the discussion on this. Mostly all I see on /. are postings of only one or two interesting comments (usually lost in the noise), lots of noise, or lots of "me too" comments.)
Gyro vibration. You have to continually run the gyros to keep them pointed in particular directions, and these will cause vibrations. Thursters will shake the whole thing too. If your glass it too thin you'll start it vibrating like a drum head.
Also keep in mind that structures behave in completely different ways in zero-G. You might have characterized all your structures on the lab and have damped out most of the disturbances, but you will find that there are whole different modes of vibration in space. Something that wasn't a problem on the ground is now a problem in space.
Telescopes are not hard to build because they deform under their own weight; in fact, their deformation is easy to predict thanks to Mr. Newton. Large optical quality mirrors are ground to allow for their sag on the earth.
Remember, the Hubble mirror (and other mirrors in space) is as thick as it is because it has to be that thick. Believe me, the cost per pound to put somthing in orbit is so high, they made that mirror as thin as they could. You can't just artibrarily grind off most of the mass unless you can elsewhere compensate for all the problems you introduce. Maybe they have an idea on how to correct for all the aberrations that they'll have in the mirror (such as adding an active secondary, but here you start adding more and more R&D money), but they didn't mention that in the article. Or maybe the telescope isn't supposed to be optical quality and they want to use it in front of spectrographs.
There are many efforts all over the globe to come up with ultra-lightweight mirrors for space (see for instance some work at the U. of Kentucky). If you have a good idea on how to do it, you can make some nice bucks for yourself. :)
The array of visible telescopes is what the NGST is about (to some extent-it uses segmented mirrors acting as one). More directly, the Space Technology 3 mission is supposed to address this.
Keep in mind that this isn't a quick and easy retrofit for the Hubble. This is a major undertaking which would require a major budget. The article comes off sounding like it would be cheap and easy and silly not to do, whereas it would probably turn out that for the kind of money you'd be talking about, you might as well spend a little more and build a new, better telescope from scratch.
Hey, you can open a magnetic spa and make tons of money off of New Agers and other ignorant people. Haven't you heard about all the health benefits of magnetic fields? You can let people "re-charge" their bracelets and shoe inserts for a fee.
A company can perform alturistic deeds for a variety of reasons, such as good PR. MS contributes a lot to primary and secondary schools which result in nice press releases and commercials with sweater-wearing CEOs that give you the warm and fuzzies. This kind of educational contribution is relatively cheap for them, and it helps soften their image (particularly in MS's case when they are facing antitrust hearings). Westinghouse used to be well-known for their sponsorship of their world-famous annual highschool science competition (which they have recently dropped sponsorship after many decades, but has been picked up by Intel).
Another reason a company might become involved in education is to ensure a technically-literate workforce from which they can hire people. This issue has come up in the US (and I suppose other regions of the world) because the creation of new technical jobs is supposedly out-pacing the number of technically-trained graduates. This can take the form of multiple companies joining together to lobby the government for more educational $$ or higher educational standards, or companies might sponsor graduate student research.
The above are a couple of examples of the ways corporate involvement in education can take place. Another way, which I presume is the motivating factor behind the article's description of Metrowerks's CodeWarriorU, is product familiarity. Anyone who has been in a college or university bookstore knows the amazing discounts (I've seen 75% and higher) one can get on developmental tools such as the MS Office suite, MS Visual Studio, the old Boreland compilers, etc. Simply put, if you get college students using VisualC++ in college, what software developmental tool do you think they'll want to use in their post-graduation job if they are given a choice? Metrowerks is in the position where they can teach pure ANSI C++ and not even push their product if they wanted to, because just the fact that the students are using Code Warrior and are getting comfortable with it, that is all the selling they need to do. Sure the conceptual jump to VisualC++ probably isn't all that great once you know Code Warrior, but why bother if you already own CW and are comfortable with it?