I haven't posted on/. for years (though I've been reading it...), but I simply wanted to share this.
I was recently at a conference (attending mostly by academics who have been funded/supported by Germany) where Schavan gave a speech. It was utterly horrible: pompous, pretentious and condescending, half the sentences were grammatically correct but devoid of information, the other half contained mostly bullshit, wild hyperbole designed to sound grand, and misinformation. I was literally writhing in my seat in agony. The speech was surely impossible to satirize. Even the late, great Loriot (http://en.wikipedia.org/wiki/Vicco_von_B%C3%BClow) couldn't beat this speech.
Anyway, now it looks like she, too, may have plagiarized her PhD. Call me vindictive, but I really hope this pans out...
Holger Müller: Is registered as an author of this paper.
This means that Holger Müller is the guy who logged onto arXiv and uploaded the paper. It has nothing to do with who actually contributed how much to the research.
I think the term "solar sail" is a bit of a misnomer here. If I understood correctly, almost all the thrust comes from the recoil of particles boiling off the surface, because the surface is heated by a microwave beam. This thrust is therefore perpendicular to the surface of the "sail", which is (largely) independent of the direction towards the microwave source. The exception is that, if the sail is parallel to the beam, then the microwaves don't hit the sail at all, and the system doesn't work.
But it would work perfectly well for travelling towards the microwave source (i.e. Earth), or, equivalently, for slowing down on the way to Mars: just have the paint on the other side of the sail, which gets heated from behind.
So one can imagine a craft which has two sails. The first is unfurled in Earth's orbit, with paint facing the Earth, which is used to kick it in a suitable direction to get it to Mars. After the microwave beam is turned off, the sail is discarded. Once the craft gets close to Mars, it unfurls a second sail, this time with paint on the other side, pointing towards Mars. Again a (extremely well focussed!) microwave beam from the Earth heats this sail from behind and the craft can slow down to safe speeds to land on Mars.
Of course, if your beam is so well focussed that you can use the sail near Mars, then you can use a much weaker beam for much longer to get up to the same (or greater) speed. This means you don't need a 60 megawatt beam at all - just use a 1 megawatt beam for 60 hours or whatever.
That's cute. Pity there's a little flaw with this theory: a global flood would surely have left even more noticable evidence in the ice cores and tree rings and other records, no? So how come they record the ice age, but not the flood?
Here in Germany some idiotic anti-piracy adverts have recently started showing in movie theatres, claiming that pirates (the emphasis being on movies/musics) would get 5 years in prison. The advert I saw before my movie last night implied that the pirates would be raped there. This strikes a cord with one line in Stallman's "Author's note": "A BSA terror campaign in Argentina in 2001 made veiled threats that people sharing software would be raped in prison."
Except this time the threat was not much veiled at all. Assholes.
what with all the radical earth-shattering changes that have been made to mathematics in the last few years.[/sarcasm]
Of course, there have been radical advances in mathematics in the last few years: We now know that all rational elliptic curves are modular, we finally know that the usual canon-ball stacking of spheres is the densest possible in 3-space, we now know that the Langlands conjecture is true both for local fields and for global function fields, it appears that the Poincare conjecture may finally have been proved... etc.
But I'll bet none of these things were mentioned in the new edition of your calculus book;)
after all, it only killed 34 people, right? Besides, it happened somewhere in the Evil Empire, so it doesn't matter.
Perhaps you have missed the fact that a large portion of the Ukraine (and parts of other countries) is now contaminated with radioactive waste to the extent that it is uninhabitable. For the next 5000 years. Besides that, the population in the region has been affected: cancer and birth deformity rates have gone up significantly since the accident.
You may argue whether such accidents are likely to happen again (NEVER underestimate human stupidity), but to claim that Chernobyl was a minor mishap, comparable to a fire in a coal power station, is complete bullshit. It's a whole other ballgame once your contaminants are radioactive.
Now that would be useful, as one of the major concerns about GM crops is that they pollinate neighboring fields. This leads to:
(a) The spread of whatever new genes the GM crop contains to other fields and possibly other species.
(b) The neighboring farmer will no longer be able to sell his crop as non-GM. (This is a big issue in Europe, where products with GM-labels are expected to sell badly, once they finally hit the markets. It is enough for the grain to contain the modified genes, not the plants themselves).
(c) The owner of the GM patent could theoretically sue the neighboring farmer for patent infringement and demand license fees. Sounds idiotic, but as far as I know (IANAL), this is legally possible. And don't tell me that the big companies are too ethical to do this.
Therefor I propose that GM crops should only be allowed if they produce no viable pollen. This should be technically feasible (but it probably takes some effort breeding plants that cannot pollenate...)
If we do send a one-way manned mission, we'd be playing for high stakes: If it succeeds, having a bunch of hungry people on Mars is an excellent motivation for the public to continue funding further Mars missions. If, however, these people die in some horrible way, the public will become rather cautious about future missions. This could set us (humanity) back by decades.
I think the fate of a bunch of individuals is not very relevant. More people die in road accidents every day than have ever died in (or getting into) space. But the publicity generated by their fate could well dictate the pace of future space exploration.
If there WEREN'T any people around, nobody would watch the movie, and we wouldn't be asking about people in it in the first place. Therefor, in any such movie, people will always be around. End of story.:)
I, too, have made a dumb mistake. In fact, the mistake we both made was to think of the manifold as embedded in some R^n, in which case "closed" means closed in the topology of R^n. However, manifolds should rather be regarded intrinsically, and in its own topology any topogical space is closed. This is a tautology. When people (e.g. at MathWorld) talk about "closed manifolds" they actually mean compact manifolds.
It's always nice to come across an enthusiastic maths undergrad, and I certainly don't want to dampen your enthusiasm. But please, be careful not to mislead less informed readers with unaccurate posts. Somebody else has pointed this out in a less polite way, but I don't think you deserve any flames. Just be a bit more careful, and good luck with your studies.
Sorry Marvin, this is not the first time you write more about maths than you actually know.
Firstly, the Poincare Conjecture states that every compact 3-dimensional manifold is homeomorphic to the 3-sphere. So we're dealing with manifolds, not just any 3-dimensional figures. This means that every point of the figure is completely surrounded by a small region which looks like 3-space. In particular, any manifold is open. We also want our manifold to be compact (not just closed, inaccurate claims on Mathworld notwithstanding), which here means closed and bounded. Note further that closed does not imply bounded.
The following 3-dimensional objects are simply connected, but not homeomorphic to the 3-sphere:
(a) A closed ball in 3-dimensions. This is what most laymen would consider a "sphere". It consists of all points in 3-space at a distance of less than or equal to 1 from the origin. It is simply connected, closed, bounded, but not open, hence not a minifold.
(b) 3-space itself. This is a closed manifold, but not bounded, hence not compact.
Marvin seems to have misunderstood what a 3-sphere is. By "sphere", mathematicians generally mean the surface, not the inside. So a 3-sphere is the set of points in 4-space at a distance of exactly 1 from the origin. It is not the same thing as a closed 3-dimensional ball.
Oh, and Smale and Freedman's proofs of the Poincare Conjectue in higher dimensions were not easy. In fact, they both won Fields Medals for their efforts.
Enter the contest. If you win, decline your prize money and refuse to disclose your design. You'll get the satisfaction of being the best, you'll get PLENTY of publicity, and you'll really piss off DARPA. Now wouldn't that be fun?
Postulating that other life could exist is not ridiculous. Postulating that it *does* exist would be.
I consider it a reasonable assumption that an "interesting" environment is necessary for life, but by no means do I claim it is sufficient.
And when we do find an interesting environment, it is worth exploring to best of our capabilities. Even if we find no life (carbon-based or otherwise), we might find other stuff of interest. And even if we don't, we can't know that until we try.
Okay, so mod me down for offtopic, but one thing that has always bothered me is, why don't people seriously (i.e. besides science fiction) consider the possibility of life of some form inside a gas giant? Sure, there is no liquid water, hence probably no "life as we know it", but if there are other forms of life as we don't (yet) know it, wouldn't this be an even greater discovery?
What is needed for life (of any reasonable definition) to evolve in an environment, is that arbitrarily complex structures can form in such an environment. Basically, the environment must be "interesting". Nothing ever happens on the surface of our moon, so we don't expect life to evolve there. On the other hand, all kinds of cool chemical reactions can occur in liquid water - as has happened here on Earth. But what about Jupiter's atmosphere? There certainly are interesting molecules floating about - in fact the "Great Dark Spot" is conjectured to be a cloud of hydrocarbon droplets. There is plenty of energy - kinetic (storms), electric, magnetic, some solar as well as plenty of radioactivity. What's more, the environment is HUGE. You have all ranges of pressure from near-vacuum to something ridiculously dense in the core, and everything in between. Is it possible for some region inside Jupiter to have what it takes for life to evolve? And, since there are other sources of energy besides solar, this might happen in the dark depth, where we will never find it. Maybe there's a whole civilization deep in there that we're not aware of.
Does this remind anybody else of the Slylandros in StarControl 2?
This would be a GREAT aid to teaching: Maths, physics, biology, art, architechture, engineering, chemistry...
In fact, here at the maths institute where I work a bunch of differential geometers are currently holding a workshop, mostly about surfaces (I do number theory, so don't actually attend). But I see that they regularly use 3D representations of surfaces, with red/blue glasses.
I am a fan of "hard" scifi, and have read most of your books (especially the earlier ones), and enjoyed them very much. I confess I have something of a fetish concerning hard science, i.e. I want all the science I read about in stories to be correct, or at least be plausible and not in contradiction with known science. I appreciate your efforts in putting the "hard" back into scifi, but I do have some (hopefully constructive) criticism, and it would be great to hear your answers to this.
While all the physics and cosmology in your stories seem largely unassailable, I find that your grasp of biology is more lacking.
Firstly, my pet bugbear is about plausible, or at least imaginatively realistic, aliens. While I think your puppeteers are great, I find the Kzin, and especially the Fithp, disappointing. It seems that one formula you use to design aliens is "take another animal on Earth, and suppose it evolves intelligence instead of the primates", thus giving you the Kzin (felines) and Fithp (elephants). I'm sorry, but I find this rather lame. Have you ever looked into a rock-pool at the sea? There you can see some truly bizarre creatures, which are nevertheless *much* more closely related to us than any real aliens that might be out there. And the argument of convergent evolution - that similar niches call for similar bodyplans, even in (relatively) unrelated species - only applies when the species are not too unrelated. For example, both mice and shrews look similar, although they are only distantly related (compare their teeth), because they live in very similar niches. However, the last common ancestor of mice and shrews was still a mammal. Now think of the niche "swimming in large schools in the open ocean". Most fish in this niche (tunas, mackerel) have similar builds. But squids also live in this niche, and their body plan is only as fish-like as their mollusc ancestry will allow. In short, the more unrelated the species, the less convergent evolution will be. For TOTAL unrelatedness (humans vs aliens) we should not expect much, if any, convergence.
Another problem I have is with the Pak protectors. The current (vast) scientific evidence shows that humans are related to ALL other life on Earth, not just other primates. So we have the same ancestry as primates, frogs, oak trees and bacteria. Your Pak stories contradict this, hence fail my (very stringent) definition of hard scifi. Of course, as literary, or "not so hard scifi" works, they are still very good books.
I also have my own bigoted views about ESP and such like, but I will not say more about that, as here I may very well be wrong. (But a gene for "luck" is going too far).
Lastly, after all this cricism, some compliments. I loved Lucifer's Hammer! What I like in particular is the insightful description of social developement after the impact, which makes it so much more interesting than this "Deep Impact" or "Armageddon" junk. I also loved the Moties. They are some of the best aliens I've ever seen in a novel. Not their anatomy, which I still find banal (they are still bipeds, damn it, despite being slightly asymmetrical, and so what if they don't have a human spine) - but their sociology is brilliant. I think that a good alien psychology and sociology is actually more important than an original anatomy, and that really made the book worth reading.
Slashdot Mirror
I guess their model starts with "assume a spherical person"...
I haven't posted on /. for years (though I've been reading it...), but I simply wanted to share this.
I was recently at a conference (attending mostly by academics who have been funded/supported by Germany) where Schavan gave a speech. It was utterly horrible: pompous, pretentious and condescending, half the sentences were grammatically correct but devoid of information, the other half contained mostly bullshit, wild hyperbole designed to sound grand, and misinformation. I was literally writhing in my seat in agony. The speech was surely impossible to satirize. Even the late, great Loriot (http://en.wikipedia.org/wiki/Vicco_von_B%C3%BClow) couldn't beat this speech.
Anyway, now it looks like she, too, may have plagiarized her PhD. Call me vindictive, but I really hope this pans out...
From http://arxiv.org/auth/show-endorsers/0901.1819 :
Holger Müller: Is registered as an author of this paper.
This means that Holger Müller is the guy who logged onto arXiv and uploaded the paper. It has nothing to do with who actually contributed how much to the research.
I can imagine that shopkeepers might oppose parks on the grounds that urbanly stressed people are more likely to buy stuff they don't need.
I think the term "solar sail" is a bit of a misnomer here. If I understood correctly, almost all the thrust comes from the recoil of particles boiling off the surface, because the surface is heated by a microwave beam. This thrust is therefore perpendicular to the surface of the "sail", which is (largely) independent of the direction towards the microwave source. The exception is that, if the sail is parallel to the beam, then the microwaves don't hit the sail at all, and the system doesn't work.
But it would work perfectly well for travelling towards the microwave source (i.e. Earth), or, equivalently, for slowing down on the way to Mars: just have the paint on the other side of the sail, which gets heated from behind.
So one can imagine a craft which has two sails. The first is unfurled in Earth's orbit, with paint facing the Earth, which is used to kick it in a suitable direction to get it to Mars. After the microwave beam is turned off, the sail is discarded. Once the craft gets close to Mars, it unfurls a second sail, this time with paint on the other side, pointing towards Mars. Again a (extremely well focussed!) microwave beam from the Earth heats this sail from behind and the craft can slow down to safe speeds to land on Mars.
Of course, if your beam is so well focussed that you can use the sail near Mars, then you can use a much weaker beam for much longer to get up to the same (or greater) speed. This means you don't need a 60 megawatt beam at all - just use a 1 megawatt beam for 60 hours or whatever.
That's cute. Pity there's a little flaw with this theory: a global flood would surely have left even more noticable evidence in the ice cores and tree rings and other records, no? So how come they record the ice age, but not the flood?
...having a million cans of baked beans is pretty useless when you forgot to bring a can-opener
And a good thing too - they were using candles as a light source.
the "Anonymous Coward" account sure seems to get spoofed a lot around here ;)
My slashdot name is based on the name "Weeboo" which is what Elmo named me for some reason.
And she's probably wondering why you called her "Elmo".
Here in Germany some idiotic anti-piracy adverts have recently started showing in movie theatres, claiming that pirates (the emphasis being on movies/musics) would get 5 years in prison. The advert I saw before my movie last night implied that the pirates would be raped there. This strikes a cord with one line in Stallman's "Author's note": "A BSA terror campaign in Argentina in 2001 made veiled threats that people sharing software would be raped in prison."
Except this time the threat was not much veiled at all. Assholes.
what with all the radical earth-shattering changes that have been made to mathematics in the last few years.[/sarcasm]
;)
Of course, there have been radical advances in mathematics in the last few years: We now know that all rational elliptic curves are modular, we finally know that the usual canon-ball stacking of spheres is the densest possible in 3-space, we now know that the Langlands conjecture is true both for local fields and for global function fields, it appears that the Poincare conjecture may finally have been proved... etc.
But I'll bet none of these things were mentioned in the new edition of your calculus book
But Spirit was only transmitting "pseudo-noise", a random series of zeroes and ones in binary code and not anything the scientists could decipher.
It probably means "Do not run! We come in peace", we just haven't built the right translator gimmick for it.
(With apologies to Tim Burton)
after all, it only killed 34 people, right? Besides, it happened somewhere in the Evil Empire, so it doesn't matter.
Perhaps you have missed the fact that a large portion of the Ukraine (and parts of other countries) is now contaminated with radioactive waste to the extent that it is uninhabitable. For the next 5000 years. Besides that, the population in the region has been affected: cancer and birth deformity rates have gone up significantly since the accident.
You may argue whether such accidents are likely to happen again (NEVER underestimate human stupidity), but to claim that Chernobyl was a minor mishap, comparable to a fire in a coal power station, is complete bullshit. It's a whole other ballgame once your contaminants are radioactive.
Now that would be useful, as one of the major concerns about GM crops is that they pollinate neighboring fields. This leads to:
(a) The spread of whatever new genes the GM crop contains to other fields and possibly other species.
(b) The neighboring farmer will no longer be able to sell his crop as non-GM. (This is a big issue in Europe, where products with GM-labels are expected to sell badly, once they finally hit the markets. It is enough for the grain to contain the modified genes, not the plants themselves).
(c) The owner of the GM patent could theoretically sue the neighboring farmer for patent infringement and demand license fees. Sounds idiotic, but as far as I know (IANAL), this is legally possible. And don't tell me that the big companies are too ethical to do this.
Therefor I propose that GM crops should only be allowed if they produce no viable pollen. This should be technically feasible (but it probably takes some effort breeding plants that cannot pollenate...)
If we do send a one-way manned mission, we'd be playing for high stakes: If it succeeds, having a bunch of hungry people on Mars is an excellent motivation for the public to continue funding further Mars missions. If, however, these people die in some horrible way, the public will become rather cautious about future missions. This could set us (humanity) back by decades.
I think the fate of a bunch of individuals is not very relevant. More people die in road accidents every day than have ever died in (or getting into) space. But the publicity generated by their fate could well dictate the pace of future space exploration.
It's the Movie Anthropic Principle, of course!
:)
If there WEREN'T any people around, nobody would watch the movie, and we wouldn't be asking about people in it in the first place. Therefor, in any such movie, people will always be around. End of story.
"Prepare to commence pre-mortal religious ceremonies, 10, 9, 8, ..."
I, too, have made a dumb mistake. In fact, the mistake we both made was to think of the manifold as embedded in some R^n, in which case "closed" means closed in the topology of R^n. However, manifolds should rather be regarded intrinsically, and in its own topology any topogical space is closed. This is a tautology. When people (e.g. at MathWorld) talk about "closed manifolds" they actually mean compact manifolds.
It's always nice to come across an enthusiastic maths undergrad, and I certainly don't want to dampen your enthusiasm. But please, be careful not to mislead less informed readers with unaccurate posts. Somebody else has pointed this out in a less polite way, but I don't think you deserve any flames. Just be a bit more careful, and good luck with your studies.
Sorry Marvin, this is not the first time you write more about maths than you actually know.
Firstly, the Poincare Conjecture states that every compact 3-dimensional manifold is homeomorphic to the 3-sphere. So we're dealing with manifolds, not just any 3-dimensional figures. This means that every point of the figure is completely surrounded by a small region which looks like 3-space. In particular, any manifold is open. We also want our manifold to be compact (not just closed, inaccurate claims on Mathworld notwithstanding), which here means closed and bounded. Note further that closed does not imply bounded.
The following 3-dimensional objects are simply connected, but not homeomorphic to the 3-sphere:
(a) A closed ball in 3-dimensions. This is what most laymen would consider a "sphere". It consists of all points in 3-space at a distance of less than or equal to 1 from the origin. It is simply connected, closed, bounded, but not open, hence not a minifold.
(b) 3-space itself. This is a closed manifold, but not bounded, hence not compact.
Marvin seems to have misunderstood what a 3-sphere is. By "sphere", mathematicians generally mean the surface, not the inside. So a 3-sphere is the set of points in 4-space at a distance of exactly 1 from the origin. It is not the same thing as a closed 3-dimensional ball.
Oh, and Smale and Freedman's proofs of the Poincare Conjectue in higher dimensions were not easy. In fact, they both won Fields Medals for their efforts.
Enter the contest. If you win, decline your prize money and refuse to disclose your design. You'll get the satisfaction of being the best, you'll get PLENTY of publicity, and you'll really piss off DARPA. Now wouldn't that be fun?
Postulating that other life could exist is not ridiculous. Postulating that it *does* exist would be.
I consider it a reasonable assumption that an "interesting" environment is necessary for life, but by no means do I claim it is sufficient.
And when we do find an interesting environment, it is worth exploring to best of our capabilities. Even if we find no life (carbon-based or otherwise), we might find other stuff of interest. And even if we don't, we can't know that until we try.
And yes, I know that StarCon2 is only a game.
Okay, so mod me down for offtopic, but one thing that has always bothered me is, why don't people seriously (i.e. besides science fiction) consider the possibility of life of some form inside a gas giant? Sure, there is no liquid water, hence probably no "life as we know it", but if there are other forms of life as we don't (yet) know it, wouldn't this be an even greater discovery?
What is needed for life (of any reasonable definition) to evolve in an environment, is that arbitrarily complex structures can form in such an environment. Basically, the environment must be "interesting". Nothing ever happens on the surface of our moon, so we don't expect life to evolve there. On the other hand, all kinds of cool chemical reactions can occur in liquid water - as has happened here on Earth. But what about Jupiter's atmosphere? There certainly are interesting molecules floating about - in fact the "Great Dark Spot" is conjectured to be a cloud of hydrocarbon droplets. There is plenty of energy - kinetic (storms), electric, magnetic, some solar as well as plenty of radioactivity. What's more, the environment is HUGE. You have all ranges of pressure from near-vacuum to something ridiculously dense in the core, and everything in between. Is it possible for some region inside Jupiter to have what it takes for life to evolve? And, since there are other sources of energy besides solar, this might happen in the dark depth, where we will never find it. Maybe there's a whole civilization deep in there that we're not aware of.
Does this remind anybody else of the Slylandros in StarControl 2?
This would be a GREAT aid to teaching: Maths, physics, biology, art, architechture, engineering, chemistry...
In fact, here at the maths institute where I work a bunch of differential geometers are currently holding a workshop, mostly about surfaces (I do number theory, so don't actually attend). But I see that they regularly use 3D representations of surfaces, with red/blue glasses.
Don't YOU want to see Clippie in 3D?
Dear Larry,
I am a fan of "hard" scifi, and have read most of your books (especially the earlier ones), and enjoyed them very much. I confess I have something of a fetish concerning hard science, i.e. I want all the science I read about in stories to be correct, or at least be plausible and not in contradiction with known science. I appreciate your efforts in putting the "hard" back into scifi, but I do have some (hopefully constructive) criticism, and it would be great to hear your answers to this.
While all the physics and cosmology in your stories seem largely unassailable, I find that your grasp of biology is more lacking.
Firstly, my pet bugbear is about plausible, or at least imaginatively realistic, aliens. While I think your puppeteers are great, I find the Kzin, and especially the Fithp, disappointing. It seems that one formula you use to design aliens is "take another animal on Earth, and suppose it evolves intelligence instead of the primates", thus giving you the Kzin (felines) and Fithp (elephants). I'm sorry, but I find this rather lame. Have you ever looked into a rock-pool at the sea? There you can see some truly bizarre creatures, which are nevertheless *much* more closely related to us than any real aliens that might be out there. And the argument of convergent evolution - that similar niches call for similar bodyplans, even in (relatively) unrelated species - only applies when the species are not too unrelated. For example, both mice and shrews look similar, although they are only distantly related (compare their teeth), because they live in very similar niches. However, the last common ancestor of mice and shrews was still a mammal. Now think of the niche "swimming in large schools in the open ocean". Most fish in this niche (tunas, mackerel) have similar builds. But squids also live in this niche, and their body plan is only as fish-like as their mollusc ancestry will allow. In short, the more unrelated the species, the less convergent evolution will be. For TOTAL unrelatedness (humans vs aliens) we should not expect much, if any, convergence.
Another problem I have is with the Pak protectors. The current (vast) scientific evidence shows that humans are related to ALL other life on Earth, not just other primates. So we have the same ancestry as primates, frogs, oak trees and bacteria. Your Pak stories contradict this, hence fail my (very stringent) definition of hard scifi. Of course, as literary, or "not so hard scifi" works, they are still very good books.
I also have my own bigoted views about ESP and such like, but I will not say more about that, as here I may very well be wrong. (But a gene for "luck" is going too far).
Lastly, after all this cricism, some compliments. I loved Lucifer's Hammer! What I like in particular is the insightful description of social developement after the impact, which makes it so much more interesting than this "Deep Impact" or "Armageddon" junk. I also loved the Moties. They are some of the best aliens I've ever seen in a novel. Not their anatomy, which I still find banal (they are still bipeds, damn it, despite being slightly asymmetrical, and so what if they don't have a human spine) - but their sociology is brilliant. I think that a good alien psychology and sociology is actually more important than an original anatomy, and that really made the book worth reading.
Thank you for your time.