I believe I see now. I had been reading "June 11" as "July 11". An entire month for a patch does seem rather a long time, and certainly out of line with "standard practice".
Yes, actually, I believe you do need to elaborate. As far as I can tell the article's statement is accurate. In fact, I seem to recall a post on BUGTRAQ a week or two ago admonishing people to contact vendors privately and give them ten days or so to work up a patch before publishing a vulnerability. What is your beef with that?
And who, may I ask, determines ``what is good for us,'' if not us, the people? Surely you don't mean to suggest that we should turn over our lawmaking to the likes of the RIAA, because, I humbly submit, they are hardly an unbiased party when it comes to copyright law.
Your argument cuts both ways. Just as people who copy music do not take into account the needs of musicians when they make their copies, so, too, the record companies do not take into account the needs of the public. Some sort of a compromise is necessary. The compromise we've been using up until now has worked reasonably well, but changes in technology are beginning to necessitate a new compromise. As it gets ever easier to make and transmit copies of music, people are going to want to do so; people like sharing good things with their friends. Any attempt to `compromise' by forbidding people to share is doomed to fail; instead we have to find a way to compensate musicians for their work while still allowing people to copy and share music that they like.
Of course, it may turn out that the new compromise, whatever it turns out to be makes it possible to make money as a musician, but not possible to make money as a middle man standing between musicians and their fans. There are some established interests that aren't going to like that very much, but in the end it is the will of the public that matters. If record companies end up going the way of gaslight manufacturers and horse-buggy builders, well, that's progress for you.
The laws you discuss seem fair and equitable to me, and I suspect that most people would share that opinion. However, they also make a striking contrast to the laws we actually have. As of this writing it is illegal to circumvent copy protection, even if the use to which you put your copies is otherwise legal under copyright law. Moreover, we have an initiative through litigation to make it effectively illegal even to promulgate information on how to break copy protection schemes. These are disturbing laws, and they go far beyond the intended scope of copyright law.
Intellectual property law has always been a compromise between incentive to create on the one hand, and the rights of people to do whatever they want with their (physical) property on the other. Advances in technology have changed the balance between these two needs, and a new, sensible compromise needs to be reached. It is only natural for the record companies to put forward as strong a case as they can to protect their interests; we, the public, must similarly look out for our own interests because often they do not coincide with those of the established music industry.
The difference is that when I encrypt email to my friends to ensure that only they can read it, I am doing it with their complicity. They don't want someone else to read those messages any more than I do. Copy protection, on the other hand, is all about coercion. It's about forcibily limiting your ability to manipulate the data that you bought and paid for. There are two problems with that. First is that other, legitimate uses become collateral damage in the fight to prevent copying, and fair use becomes a thing of the past. Many (including me) believe that we all lose if we allow that to happen.
Second, and even more troubling, is that it is infeasible to enforce copyright through technological means. Any copy protection can be broken by someone sufficiently motivated to do so, and somewhere out there on the internet there is bound to be someone who is sufficiently motivated. All it takes is one person to break the protection scheme, and then the cat is out of the bag. Consequently, copyright enforcement turns to laws and the tools of law enforcement. That isn't necessarily a bad thing, but we have to ask ourselves, if a law is widely violated by a majority of the citizens, then is that law really an expression of the will of the people (the ultimate force from which the law's authority is derived)? And if not, then should we really be enforcing legal penalties on those who violate this law that does not derive from the will of the people?
These stereotypes arise more out of need to believe that people are created with some sort of rpg-esque "point balance". Geniuses must pay for their intellect with personal shortcomings; gifted athletes must pay for their skills with a lack of intelligence, and so on. With Einstein it's hard to separate the reality from the myth, but I wouldn't be surprised if his absentminded professor traits have been greatly exaggerated in the popular consciousness. In any case, scientific genius is not always accompanied by being a social misfit or an absent minded fool (e.g. Richard Feynman was neither), and excellence in computers and technology does not necessarily preclude one from living a "normal" life (however you care to define that.) In fact, I'd wager that computer geeks that aren't obsessed with striking it rich in an IPO in general lead lives that are every bit as normal as anyone else's (I know I do.)
Regarding the original quote that spawned this debate, it sounds like so much apologism to me. If you read between the lines what it's saying is, "Don't worry your pretty little head about all this trivia; it's just chimpanzee work. You have a `higher' intelligence." Feh.
George Lucas is, of course, free to make whatever sort of film he wants to, and if he wants to make a kids' film, far be it from me to tell him otherwise. I, however, am not a kid, and haven't been for quite some years. Most of what appeals to kids is quite banal, and I don't want to sit through two hours of it if there's nothing for the grownups in the audience. I went to Episode I to see tragedy: Anakin's fall, the Republic unable to stop its steady decline, and so on. If Lucas wants to make a kids' film he can at least have the courtesy to say so so that those of us in search of meatier fare know to look somewhere else.
Black holes do emit Hawking radiation, which over time will cause them to shrink; however, they have an effective temperature of 6x10^-8/M, where M is in solar masses. For a stellar mass black hole, that translates to roughly 10^-25 erg/s emitted from the black hole. At that rate it would take about 10^70 years for the black hole to radiate away its entire mass (discounting the fact that the temperature goes up as the mass increases, that is). So, the conclusion is that for astrophysical black holes Hawking radiation is an entirely negligible effect unless you are talking about time scales vastly longer than the present age of the universe.
-rpl
More on licensure versus sales
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DeCSS Update
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· Score: 2
You ask, "If a merchant wants to sell a license to information instead of the information itself, what's to stop them?" A merchant can, of course, sell whatever he wants, but the law may or may not choose to recoginze the terms and conditions of his license as valid. Whether it does or not is a decision that ultimately lies in the hands of the electorate. (In a fit of idealism I am ignoring the realities of our bought and paid for government in the US--maybe we should consider merely "licensing" our elected officials to corporate interests.) We should think carefully about that decision because without the ability to own and control our property we are little better than slaves.
I should remind you that as "radical" as it sounds, my view is in fact the status quo. Until recently there was no question that you owned your copy of a book or recording or any other sort of copyrighted material. Software, movie, and recording companies are trying to extend their rights under copyright law to levels that are completely unprecedented historically. The questions that we should be asking is why should we grant them these extra rights? In this time of soaring profits, do they really need more control in order to stay in business? Will these expanded rights be good or bad for us as citizens and consumers?
I do not advocate eliminating copyright, but recent advances in technology are forcing us to reexamine its role in society and in the marketplace. Old laws will have to be scrapped, and new ones written to replace them. When that happens, social justice, not profit margins, should be the primary concern.
-rpl
DeCSS is neither for Linux, nor for piracy
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DeCSS Update
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· Score: 5
The real importance of DeCSS is not that it could be used to make a Linux DVD player. The real importance of DeCSS is to make DVD an open format, which is important to make sure that we retain our right to use material that we have legally purchased however we see fit. That means watching it on Linux if we want. That means watching it irrespective of the DVD consortium's arbitrary region restrictions if we want. It means reselling our DVDs and editing them or making excerpts if we want. It means that when you buy something you own it, and you can use it however you please (provided, of course, you don't distribute copies or perform it publicly).
One of the basic principles of our society is that people have the right to use and dispose of their personal possessions however they see fit. The recent trend toward licensure of goods instead of sales threatens to undermine that principle by stripping the common man of his ability to own any possesions at all; instead he will license them and use them at the suffrance of the companies who retain ownership. As we saw with DIVX, that license can be revoked at any time, and for any reason. For movies on DVD, maybe that isn't such a big deal, but for truly important goods (say, your car, or your home, or the textbooks you need for your education), licensure keeps you under the thumb of the license holder for as long as you need to use "his" goods. DeCSS is about fighting this trend on every front. It's about not starting down the slippery slope that leads from unimportant stuff like movies and entertainment to the things that really are essential to modern life. Petty concerns like piracy, or even Linux, pale by comparison.
Bringing the subject back to DVD specifically, I think the DIVX fiasco has spooked a lot of people. People that thought they had bought a permanent copy of a movie on DVD suddenly found that they could lose that copy (or, more correctly, the right to watch that copy) at the whim of the company that had sold it to them. This has made a lot of people skittish about any scheme that separates them from the content that they have legally bought and paid for. Few people want to be dependent on the good graces of an organization like the MPAA for anything, not even something as trivial as one's movie collection. (Speaking of DIVX, does anyone know if DIVX discs use CSS? If so, then that might be another legitimate use of DeCSS; DIVX-silver owners could recover the movies that they are no longer allowed to watch owing to DIVX being discontinued.)
And if the first generation of these tools, with their crude pattern-matching, generates some false positives, that's no big deal. If you're going to prosecute someone for piracy, you're obviously going to have to manually confirm the offenses.
That's obvious to you and me, but is it obvious to judges and lawyers in the real world? As long as those people bear in mind that simple pattern matching in the title is at best meager evidence, then I've got no problem with this software. If, on the other hand, some of these false positives start getting hauled into court (and incurring attendant attorney fees and airfares), then I think that's a real problem. Does the justice system really understand what does or does not constitute evidence in digital crimes? Sadly, I don't have a whole lot of confidence that they do.
Nobody's suggesting that something like this should be used to automatically generate arrest warrants.
Aren't they? This was exactly the sort of evidence that was used to get people banned from Napster, wasn't it?
Uploading a song with a title like "My stuff (similar to Metallica)" would probably fall under fair use of the Metallica trademark. It would be much the same as Burger King saying its burgers taste better than Big Macs or Pepsi saying it beat Coke 2-1 in taste tests. A trademark prevents you from naming your band "Metallica"; it doesn't prevent you from using the word "Metallica" in ordinary speech, nor from comparing the relative merits of Metallica versus some other band.
Actually, last week there was an article in the C-ville weekly (Charlottesville, VA) reporting that a writer for the C-ville attempted to auction a used CD online, and the auction was pulled. It seems that software and recording companies have declared all out war on the doctrine of first sale.
Movies that insult the viewer's intelligence considered not fun.
Why is it that apologists for really bad movies always pull out the same tired cliche about ``intellectual stimulation?'' I may be pretty dense at times, but I assure you I wasn't thick enough to walk into MI2 expecting to see some sort of european art film or anything like that. Nevertheless, I don't think it is asking too much for the holes in the plot to be smaller than the helicopter our heroes were flying around in. I mean, the bad guy's master plan made no sense whatsoever, on any level (as if he's going to just walk in and take his seat on the board of directors after having released a super-flu on the world. Hello, McFly?). Add to that a love story between two characters that had no chemistry whatsoever, mix in some glaring continuity errors, add a dash of fight scenes that would make an anime director blush, stir, and simmer for two hours, and you have a recipe for a seriously mediocre film.
I'm not saying I hated it; it had its good points. Some of the stunts were cool, and the soundtrack was pretty good, but a film can get a hell of a lot better than this without venturing into ``deep flick'' territory. If you haven't seen it already, wait for it to come out in the $2 theatre.
If only it were that simple. Have you used any commercial software lately? If you have, then you know that a several page long "license agreement" laden with incomprehensible legalese has become de rigueur for even the most trivial piece of software. Moreover, the sum total of most of these agreements is something along the lines of "You are about to install a piece of software. Use at your own risk." As a result, clicking on "Agree" has become a meaningless ritual. Personal responsibility or not, it isn't reasonable to put critical information inside a body of text that is generally acknowledged as being content-free. Reality check: could you get away with selling a box of breakfast cereal laced with strychnine just because you listed it right after polysorbate 60 in the ingredients list? Hell, no.
Does this come as any surprise to Real? Quite the contrary, they know that people generally read at most the first page of those agreements; they were counting on it. They could have put the notice about the software's logging in big bold letters at the top of the agreement, but they didn't. Why? Because they knew many people wouldn't agree to it; that's why. You can scream "caveat emptor" until you're blue in the face, but the fact is that a merchant that cheats his customers is still a villain, even if the customers should have known better than to be taken in.
In a finite amount of whose time? The proper time taken for the surface of the star to collapse is most assuredly finite. It takes an infinite amount of coordinate time (or proper time for an observer 'at infinity'), but so what? None of those people are in a position to observe that the surface hasn't actually gone into the hole.
The salient points are:
For anyone sitting at a safe distance, the hole looks like a hole and acts like a hole. For all practical purposes it is a black hole.
There is an event horizon and a region of spacetime on the other side of it which cannot communicate with the outside spacetime.
The surface of the star does eventually pass into the region of spacetime beyond the event horizon in a finite amount of its proper time.
In other words, real holes have all of the important features of theoretical holes; they differ only in minor details.
That's true, but not all of those count as "gravitational fields produced solely by gravitational energy density". In particular, solutions with boundary conditions that force nonzero mass densities in regions outside of the region considered by the solution probably don't count because a reasonable person might object that the field is being caused by that mass "over there", outside the boundary.
Take the Schwarzschild black hole, for instance. The Schwarzschild solution exludes one point, the singularity, from the solution. Moreover the boundary condition is that far from the hole it "looks like" there is a pointlike mass at the singularity. Most would say that the gravitational field "comes from" the mass hidden away in the singularity. This intuitive view is bolstered by the fact a (spherical) compact object (say, a neutron star) will give you exactly the same field (outside the star, of course). Would we say that a neutron star's field is caused by "gravitational energy density creating a gravitational field"? I think not.
By contrast, I think a gravitational wave really does represent a gravitational field that gives rise to other gravitational fields without any implied mass, in much the same way as an electromagnetic wave represents E-M fields that give rise to other E-M fields without any implied charge.
This article contains several factual errors. Presumably this is a case of the 'telephone game', where the Analog columnist is incorrectly reporting the physicists' claims. However, some of them still trouble me.
Even the recent Type 1A supernova observations that are taken as indications that the vacuum itself contains energy (see my column in the May-99 Analog.) have not required a modification of GR. Einstein anticipated the possibility that space contained energy and introduced the "cosmological constant" in the theory to account for it.
Einstein included the cosmological constant to create a long-range force opposing gravity. He did this to make a static universe possible. In this respect, he just missed predicting the expanding universe long before it was observed. Also, it is not correct to say that the Type Ia SNe results have not resulted in a modification to GR. Hardly a week goes by that there isn't a paper on astro-ph describing a time-variable cosmological 'constant' of some sort. It is too early to tell what effect these proposals will ultimately have on our understanding of GR.
The exception to this rule is the gravitational field itself. While there is energy stored in the gravitational field, unlike all of the other known energy fields (the strong, weak, and electromagnetic interactions) the energy present in gravitation does not, in conventional GR theory, produce space curvature.
This statement is patently untrue. The gravitational energy does not appear explicitly in the stress-energy tensor, but it still contributes because Gmu nu is nonlinear in derivatives of gmu nu. Indeed, if memory serves, people have constructed solutions to the vacuum Einstein equations in asymptotically flat space that have a nontrivial metric. If so, that would be an example of a gravitational field produced solely by gravitational energy. In fact, gravitational waves in free space might qualify, but I'd have to ponder it for a while to be sure.
Another well-known problem with GR is that many of its solutions have space-time "singularities", places where the mathematics "blows up" to give infinities in certain physical quantities. An example of this problem is the event horizon of a black hole, where time "freezes" at a certain distance from a super-massive object.
The event horizon of a black hole is a "coordinate" singularity, which means that it can be gotten rid of by a change of coordinates. (The pole in a polar coordinate system is another example of a coordinate singularity; there is nothing special about the pole in cartesian coordinates.) In Penrose coordinates, for example, the event horizon is well behaved. It is because of this that we know that a particle can cross the event horizon in finite proper time. The center of a Schwarzschild black hole, on the other hand, is an "essential" singularity, which means it really does represent a point where the theory breaks down. Getting rid of "coordinate" singularities is no fantistic feat. I hope this is just something that the author bungled.
For stars of about the mass of our Sun, the collapse process is halted by nuclear forces, and after the supernova explosion a neutron star is left behind.
The sun will most likely neither have a supernova explosion, nor form a neutron star. The sun is expected to end life as a white dwarf.
In this context it is interesting that recent fast X-ray observations suggest a neutron star with about 2.3 times the mass of the Sun. This is a very large mass for a neutron star. It is at the very outer limits of what standard GR can accommodate and requires considerable tinkering with nuclear forces at high densities to make it possible. This is not definitive evidence, but it does tend to provide some support for the Yilmaz theory.
The nuclear equation of state is very poorly understood, so a little "tinkering" (or even a lot) is to be expected. To me, this evidence is better taken as a constraint on the nuclear EOS than as evidence against GR. If arbitrarily massive (non-black hole) compact objects are allowed, then where are the 5 or 10 solar mass neutron star--like ojbects? For that matter, what holds them up? Degenerate neutron pressure has to fail eventually because the pressure contribution to the stress-energy tensor outstrips the pressure forces' ability to resist gravity. Since their theory claims to include an explicit gravitational contribution to the stress-energy tensor, I would think that the tendency would be to make this problem worse instead of better.
it provides exact solutions for gravity waves of arbitrary field strength while GR does not.
This is not a statement about physics, so much as it is a statement about mathematics. We can't (usually) solve the GR equations in closed form. Big deal; the same is true of quantum field theory. Surely he doesn't mean to claim that solutions don't exist for strong gravitational waves in GR.
it implies Einstein's equivalence principle, while GR must take equivalence as a separate assumption.
I don't understand this claim at all. If this theory is a metric theory of gravity, then it builds the equivalence principle into the theory in the same way that Einstein GR does; viz., by making the equations of motion depend on the metric.
Several critics have published detailed criticisms of the new formalism and its interpretation.
I am beginning to see why; the more I read about this theory the more skeptical I get. It would be interesting to see what the criticisms were; pity the author didn't give them a few column inches. Maybe there are references in the original article.
You are correct, GR and QM are inconsistent with one another. This has been the great embarrassment of 20th century physics; the two great theoretical advances of the century, both backed by mountains of experimental evidence, cannot be reconciled. The usual assumption is that discovery of a quantum theory of gravity will reconcile the two theories.
It is true that a falling object takes an infinite amount of coordinate time to cross a (Swarzschild) event horizon. For an observer in the asymptotically flat regime (that is, an observer 'at infinity') coordinate time is basically identical to proper time, the infall would indeed take an infinite amount of time from such an observer's standpoint. That's not the whole story, however. Radiation emitted from an object falling into a black hole will be gravitationally redshifted, and the rate of emission will be slowed by time dilation. Beyond a certain point the object will be undetectable to the outside world, and at that point the object has, for all intents and purposes, fallen into the hole. I haven't done the calculation in several years, but if memory serves the 'vanishing time' for a collapsing neutron star is very short, on the order of a few seconds after the collapse starts.
The standard of "randomness" required by applications like Monte Carlo calculations is much less stringent than that required by cryptographic applications. Random numbers for MC calculations need only be "random" in the sense of uncorrelated. A well-constructed PRNG should be sufficient for these applications. (See, for instance, Numerical Recipes.)
Cryptographic applications, on the gripping hand, require random numbers that are "random" in the sense of unguessable. A PRNG won't do for this because the random output of a PRNG is entirely determined by the seed, and if you can produce a truly random seed, then the output of the PRNG is superfluous; you could just use the seed itself.
So, the situation is just the opposite of what you conclude. The random numbers you get from a PRNG are "random enough" for MC calculations, and you can generate them in sufficient quantity. For cryptography you need "more random" numbers, but you don't usually need as many (a 4096 bit key is usually plenty). It is this latter case that the radioactive device is meant to address.
I've been thinking about this since the RMS interview. As I understand it, copyrights allow the owner to restrict "public performance" of the copyrighted material. Wouldn't application service fall under the umbrella of "public performance"? And if so, wouldn't this provide a mechanism for upholding the spirit of the GPL in the face of asps?
Presumably there is something wrong with this line of reasoning, or the FSF folks would already have pursued it. So, can anyone explain why this wouldn't work?
I guess I don't understand why you beleive you know about all the forces, including those between particles that have never been observed except via their gravitational interactions. For example, before we observed subatomic particles, there was no need for the strong force. (You could argue weak was necessary to explain radioactivity.)
People have done all sorts of extensive tests for "fifth forces", and so far there has not been any convincing evidence for such a force. So, we would have to come up with a fifth force that for some reason affects only intergalactic matter, and not the stuff that stars, planets, and astronomers are made of. Doesn't that seem just a little contrived to you? The situation is not at all analogous to the discovery of the nuclear forces because evidence for those forces manifested as soon as we were able to make sufficiently precise measurements of plain-old everyday matter.
I haven't had a chance to look over the articles you posted earlier in the discussion. Do any of them even have workable models for a force that would make dark matter avoid clusters without producing dark clusters? Just coming up with such a beast seems a challenging mathematical problem in itself.
Anyhow, we could add a new force to describe every new particle, but then we wouldn't have very much confidence in our physical theories. We might just as well attribute physical phenomena to invisible faeries or something. The point is that whenever you discover a hitherto unknown phenomenon and you find that it is entirely explainable in terms of previously known physical laws, it's a big win for physics. Naturally, when theory and observation conflict, theory must give way, but the fantastic thing about this measurement is that it seems to indicate that that will not be necessary in this case. I guess what I can't understand is why you don't think this is a Good Thing.
The other points you make are well-taken, but I don't worry much about factor-of-order-unity discrepancies in a preliminary measurement. Remember that Hubble's original measurement of H0 made the universe to young to contain the earth's oldest rocks. It all got sorted out with time, and this will too. As I said earlier, I think the quintessence theories sound promising, since constant, nonzero lambda really doesn't make any sense theoretically.
You are wrong on several points. Taking your points in order:
"You have to step outside of space to measure the curvature of space". This is patently false. The curvature of a manifold can be defined entirely in terms of and measured solely by observing properties within the manifold. In other words, not only do you not have to step outside of a manifold to measure its curvature, there doesn't even have to be an "outside" for you to step into. For instance, you could compute the average curvature of the earth (i.e. the 2D manifold comprising the earth's surface) solely from a table of great-circle distances between cities, without any reference to the earth's 3-space properties like it's diameter.
The assmuption that the curvature of the universe is constant when averaged over large scales is derived from the observation that the matter density is constant when averaged over large scales. All curvature measurements will be averages over some length scale, but in this case the measurement extends far beyond the "immediate vicinity of our galaxy". In fact, CMBR measurements average over the electromagnetically observable universe, which is not much smaller than the entire observable universe. It is true that things may be different on length scales larger than the observable universe. This, in fact, is part and parcel of the inflation scenarios, which predict that the reason the observable universe is flat is because whatever the curvature of the universe before the inflation, inflation expands the universe so much that the curvature over any observable patch (i.e. (light crossing time) The effect on the curvature of the universe of observing the CMBR is so minute that it can safely be neglected.
Again, the CMBR curvature measurements are averages over the observable universe; local perturbations are insignificant. You do, however, have to control for distortions to the CMBR by nearby objects (either through lensing, or through noncosmic emissions), but the Boomerang researchers describe how they do this in their paper.
In other words, give the researchers a little credit for knowing their business. It's not like they haven't thought of these things and taken them into account to the best of their (or anyone else's) ability. The have gone to great lengths to give the best estimates possible given our current understanding of physics.
Sure, small amounts of hot dark matter are ok, but as you point out, the densities that people talk about for things like massive neutrinos are not enough to make up major portions of Omega. So, while the existence of hot dark matter is not ruled out, it doesn't provide a solution to the dark matter problem. In the context of my post, the point was that if cosmological measurements were to show that Omega(matter) were much greater than what we see in galaxy clusters, you couldn't invoke hot dark matter to make up the difference.
The reason I expect new particles to have short range interactions is that we (think we) know all the forces available to mediate the interactions between them. Of all of those forces only electromagnetism is a serious contender, and in practice it generally seems to be limited to modest-range magnetic interactions. I'm not saying it can't happen, but absent any evidence to the contrary it is generally wise to assume that new phenomena will resemble old phenomena. The significance of this measurement is that it fails to provide any "evidence to the contrary"; in fact, quite the opposite, it gives reasonably compelling evidence that dark matter, exotic though it may be, behaves much like the other forms of matter we are familiar with.
Finally, when I referred to the "predictive power of the standard model" I was thinking of particle physics, in the context of invoking some sort of "fifth force" to explain why dark matter is smoothly distributed without being hot. On giving it a little more thought, I don't doubt that one could come up with a way of making nonclustering dark matter while leaving the standard model largely intact, but I think my original conclusion remains valid; viz, that this result obviates the need for much of the physics gymnastics that would have been required to explain nonclustering dark mater. To the extent that our current physics, without substantial modification, explains the behavior of exotic matter as well as the behavior of the more familiar sort, I count that as a win for physics.
Slashdot Mirror
-rpl
-rpl
Your argument cuts both ways. Just as people who copy music do not take into account the needs of musicians when they make their copies, so, too, the record companies do not take into account the needs of the public. Some sort of a compromise is necessary. The compromise we've been using up until now has worked reasonably well, but changes in technology are beginning to necessitate a new compromise. As it gets ever easier to make and transmit copies of music, people are going to want to do so; people like sharing good things with their friends. Any attempt to `compromise' by forbidding people to share is doomed to fail; instead we have to find a way to compensate musicians for their work while still allowing people to copy and share music that they like.
Of course, it may turn out that the new compromise, whatever it turns out to be makes it possible to make money as a musician, but not possible to make money as a middle man standing between musicians and their fans. There are some established interests that aren't going to like that very much, but in the end it is the will of the public that matters. If record companies end up going the way of gaslight manufacturers and horse-buggy builders, well, that's progress for you.
-rpl
Intellectual property law has always been a compromise between incentive to create on the one hand, and the rights of people to do whatever they want with their (physical) property on the other. Advances in technology have changed the balance between these two needs, and a new, sensible compromise needs to be reached. It is only natural for the record companies to put forward as strong a case as they can to protect their interests; we, the public, must similarly look out for our own interests because often they do not coincide with those of the established music industry.
-rpl
Second, and even more troubling, is that it is infeasible to enforce copyright through technological means. Any copy protection can be broken by someone sufficiently motivated to do so, and somewhere out there on the internet there is bound to be someone who is sufficiently motivated. All it takes is one person to break the protection scheme, and then the cat is out of the bag. Consequently, copyright enforcement turns to laws and the tools of law enforcement. That isn't necessarily a bad thing, but we have to ask ourselves, if a law is widely violated by a majority of the citizens, then is that law really an expression of the will of the people (the ultimate force from which the law's authority is derived)? And if not, then should we really be enforcing legal penalties on those who violate this law that does not derive from the will of the people?
-rpl
Regarding the original quote that spawned this debate, it sounds like so much apologism to me. If you read between the lines what it's saying is, "Don't worry your pretty little head about all this trivia; it's just chimpanzee work. You have a `higher' intelligence." Feh.
-JACS (Just Another Chimpanzee Scientist)
-rpl
-rpl
I should remind you that as "radical" as it sounds, my view is in fact the status quo. Until recently there was no question that you owned your copy of a book or recording or any other sort of copyrighted material. Software, movie, and recording companies are trying to extend their rights under copyright law to levels that are completely unprecedented historically. The questions that we should be asking is why should we grant them these extra rights? In this time of soaring profits, do they really need more control in order to stay in business? Will these expanded rights be good or bad for us as citizens and consumers?
I do not advocate eliminating copyright, but recent advances in technology are forcing us to reexamine its role in society and in the marketplace. Old laws will have to be scrapped, and new ones written to replace them. When that happens, social justice, not profit margins, should be the primary concern.
-rpl
One of the basic principles of our society is that people have the right to use and dispose of their personal possessions however they see fit. The recent trend toward licensure of goods instead of sales threatens to undermine that principle by stripping the common man of his ability to own any possesions at all; instead he will license them and use them at the suffrance of the companies who retain ownership. As we saw with DIVX, that license can be revoked at any time, and for any reason. For movies on DVD, maybe that isn't such a big deal, but for truly important goods (say, your car, or your home, or the textbooks you need for your education), licensure keeps you under the thumb of the license holder for as long as you need to use "his" goods. DeCSS is about fighting this trend on every front. It's about not starting down the slippery slope that leads from unimportant stuff like movies and entertainment to the things that really are essential to modern life. Petty concerns like piracy, or even Linux, pale by comparison.
Bringing the subject back to DVD specifically, I think the DIVX fiasco has spooked a lot of people. People that thought they had bought a permanent copy of a movie on DVD suddenly found that they could lose that copy (or, more correctly, the right to watch that copy) at the whim of the company that had sold it to them. This has made a lot of people skittish about any scheme that separates them from the content that they have legally bought and paid for. Few people want to be dependent on the good graces of an organization like the MPAA for anything, not even something as trivial as one's movie collection. (Speaking of DIVX, does anyone know if DIVX discs use CSS? If so, then that might be another legitimate use of DeCSS; DIVX-silver owners could recover the movies that they are no longer allowed to watch owing to DIVX being discontinued.)
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That's obvious to you and me, but is it obvious to judges and lawyers in the real world? As long as those people bear in mind that simple pattern matching in the title is at best meager evidence, then I've got no problem with this software. If, on the other hand, some of these false positives start getting hauled into court (and incurring attendant attorney fees and airfares), then I think that's a real problem. Does the justice system really understand what does or does not constitute evidence in digital crimes? Sadly, I don't have a whole lot of confidence that they do.
Aren't they? This was exactly the sort of evidence that was used to get people banned from Napster, wasn't it?
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Why is it that apologists for really bad movies always pull out the same tired cliche about ``intellectual stimulation?'' I may be pretty dense at times, but I assure you I wasn't thick enough to walk into MI2 expecting to see some sort of european art film or anything like that. Nevertheless, I don't think it is asking too much for the holes in the plot to be smaller than the helicopter our heroes were flying around in. I mean, the bad guy's master plan made no sense whatsoever, on any level (as if he's going to just walk in and take his seat on the board of directors after having released a super-flu on the world. Hello, McFly?). Add to that a love story between two characters that had no chemistry whatsoever, mix in some glaring continuity errors, add a dash of fight scenes that would make an anime director blush, stir, and simmer for two hours, and you have a recipe for a seriously mediocre film.
I'm not saying I hated it; it had its good points. Some of the stunts were cool, and the soundtrack was pretty good, but a film can get a hell of a lot better than this without venturing into ``deep flick'' territory. If you haven't seen it already, wait for it to come out in the $2 theatre.
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Does this come as any surprise to Real? Quite the contrary, they know that people generally read at most the first page of those agreements; they were counting on it. They could have put the notice about the software's logging in big bold letters at the top of the agreement, but they didn't. Why? Because they knew many people wouldn't agree to it; that's why. You can scream "caveat emptor" until you're blue in the face, but the fact is that a merchant that cheats his customers is still a villain, even if the customers should have known better than to be taken in.
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The salient points are:
In other words, real holes have all of the important features of theoretical holes; they differ only in minor details.
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Take the Schwarzschild black hole, for instance. The Schwarzschild solution exludes one point, the singularity, from the solution. Moreover the boundary condition is that far from the hole it "looks like" there is a pointlike mass at the singularity. Most would say that the gravitational field "comes from" the mass hidden away in the singularity. This intuitive view is bolstered by the fact a (spherical) compact object (say, a neutron star) will give you exactly the same field (outside the star, of course). Would we say that a neutron star's field is caused by "gravitational energy density creating a gravitational field"? I think not.
By contrast, I think a gravitational wave really does represent a gravitational field that gives rise to other gravitational fields without any implied mass, in much the same way as an electromagnetic wave represents E-M fields that give rise to other E-M fields without any implied charge.
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Einstein included the cosmological constant to create a long-range force opposing gravity. He did this to make a static universe possible. In this respect, he just missed predicting the expanding universe long before it was observed. Also, it is not correct to say that the Type Ia SNe results have not resulted in a modification to GR. Hardly a week goes by that there isn't a paper on astro-ph describing a time-variable cosmological 'constant' of some sort. It is too early to tell what effect these proposals will ultimately have on our understanding of GR.
This statement is patently untrue. The gravitational energy does not appear explicitly in the stress-energy tensor, but it still contributes because Gmu nu is nonlinear in derivatives of gmu nu. Indeed, if memory serves, people have constructed solutions to the vacuum Einstein equations in asymptotically flat space that have a nontrivial metric. If so, that would be an example of a gravitational field produced solely by gravitational energy. In fact, gravitational waves in free space might qualify, but I'd have to ponder it for a while to be sure.
The event horizon of a black hole is a "coordinate" singularity, which means that it can be gotten rid of by a change of coordinates. (The pole in a polar coordinate system is another example of a coordinate singularity; there is nothing special about the pole in cartesian coordinates.) In Penrose coordinates, for example, the event horizon is well behaved. It is because of this that we know that a particle can cross the event horizon in finite proper time. The center of a Schwarzschild black hole, on the other hand, is an "essential" singularity, which means it really does represent a point where the theory breaks down. Getting rid of "coordinate" singularities is no fantistic feat. I hope this is just something that the author bungled.
The sun will most likely neither have a supernova explosion, nor form a neutron star. The sun is expected to end life as a white dwarf.
The nuclear equation of state is very poorly understood, so a little "tinkering" (or even a lot) is to be expected. To me, this evidence is better taken as a constraint on the nuclear EOS than as evidence against GR. If arbitrarily massive (non-black hole) compact objects are allowed, then where are the 5 or 10 solar mass neutron star--like ojbects? For that matter, what holds them up? Degenerate neutron pressure has to fail eventually because the pressure contribution to the stress-energy tensor outstrips the pressure forces' ability to resist gravity. Since their theory claims to include an explicit gravitational contribution to the stress-energy tensor, I would think that the tendency would be to make this problem worse instead of better.
This is not a statement about physics, so much as it is a statement about mathematics. We can't (usually) solve the GR equations in closed form. Big deal; the same is true of quantum field theory. Surely he doesn't mean to claim that solutions don't exist for strong gravitational waves in GR.
I don't understand this claim at all. If this theory is a metric theory of gravity, then it builds the equivalence principle into the theory in the same way that Einstein GR does; viz., by making the equations of motion depend on the metric.
I am beginning to see why; the more I read about this theory the more skeptical I get. It would be interesting to see what the criticisms were; pity the author didn't give them a few column inches. Maybe there are references in the original article.
Not holding my breath,
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Cryptographic applications, on the gripping hand, require random numbers that are "random" in the sense of unguessable. A PRNG won't do for this because the random output of a PRNG is entirely determined by the seed, and if you can produce a truly random seed, then the output of the PRNG is superfluous; you could just use the seed itself.
So, the situation is just the opposite of what you conclude. The random numbers you get from a PRNG are "random enough" for MC calculations, and you can generate them in sufficient quantity. For cryptography you need "more random" numbers, but you don't usually need as many (a 4096 bit key is usually plenty). It is this latter case that the radioactive device is meant to address.
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Presumably there is something wrong with this line of reasoning, or the FSF folks would already have pursued it. So, can anyone explain why this wouldn't work?
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People have done all sorts of extensive tests for "fifth forces", and so far there has not been any convincing evidence for such a force. So, we would have to come up with a fifth force that for some reason affects only intergalactic matter, and not the stuff that stars, planets, and astronomers are made of. Doesn't that seem just a little contrived to you? The situation is not at all analogous to the discovery of the nuclear forces because evidence for those forces manifested as soon as we were able to make sufficiently precise measurements of plain-old everyday matter.
I haven't had a chance to look over the articles you posted earlier in the discussion. Do any of them even have workable models for a force that would make dark matter avoid clusters without producing dark clusters? Just coming up with such a beast seems a challenging mathematical problem in itself.
Anyhow, we could add a new force to describe every new particle, but then we wouldn't have very much confidence in our physical theories. We might just as well attribute physical phenomena to invisible faeries or something. The point is that whenever you discover a hitherto unknown phenomenon and you find that it is entirely explainable in terms of previously known physical laws, it's a big win for physics. Naturally, when theory and observation conflict, theory must give way, but the fantastic thing about this measurement is that it seems to indicate that that will not be necessary in this case. I guess what I can't understand is why you don't think this is a Good Thing.
The other points you make are well-taken, but I don't worry much about factor-of-order-unity discrepancies in a preliminary measurement. Remember that Hubble's original measurement of H0 made the universe to young to contain the earth's oldest rocks. It all got sorted out with time, and this will too. As I said earlier, I think the quintessence theories sound promising, since constant, nonzero lambda really doesn't make any sense theoretically.
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In other words, give the researchers a little credit for knowing their business. It's not like they haven't thought of these things and taken them into account to the best of their (or anyone else's) ability. The have gone to great lengths to give the best estimates possible given our current understanding of physics.
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The reason I expect new particles to have short range interactions is that we (think we) know all the forces available to mediate the interactions between them. Of all of those forces only electromagnetism is a serious contender, and in practice it generally seems to be limited to modest-range magnetic interactions. I'm not saying it can't happen, but absent any evidence to the contrary it is generally wise to assume that new phenomena will resemble old phenomena. The significance of this measurement is that it fails to provide any "evidence to the contrary"; in fact, quite the opposite, it gives reasonably compelling evidence that dark matter, exotic though it may be, behaves much like the other forms of matter we are familiar with.
Finally, when I referred to the "predictive power of the standard model" I was thinking of particle physics, in the context of invoking some sort of "fifth force" to explain why dark matter is smoothly distributed without being hot. On giving it a little more thought, I don't doubt that one could come up with a way of making nonclustering dark matter while leaving the standard model largely intact, but I think my original conclusion remains valid; viz, that this result obviates the need for much of the physics gymnastics that would have been required to explain nonclustering dark mater. To the extent that our current physics, without substantial modification, explains the behavior of exotic matter as well as the behavior of the more familiar sort, I count that as a win for physics.
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