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MULTIREALISTS IN EINSTEINIANA
http://www.project-syndicate.org/com...utsch2/English
David Deutsch: "What these paradoxical interpretations have in common is that they abandon realism, the doctrine that a physical world, existing in reality, accounts for all of our experience. Anti-realism remains popular and appears in various guises in textbooks and popular accounts of quantum theory. But Einstein insisted that physical phenomena have explanations in terms of what he called "elements of reality." Fortunately, a minority of physicists, myself included, likewise side unequivocally with realism, by adopting Hugh Everett's multiple-universes interpretation of quantum theory. According to this view, no particles exist where they have insufficient energy to be; it is simply that in some universes they have more energy than average, and in others, less. All alleged "paradoxes" of quantum theory are similarly resolved." Bravo, David Deutsch! I think you are the greatest multirealist in Einsteiniana! Now there is a paradox that your brothers Einsteinians who are not multirealists cannot solve. According to Einstein's special relativity, arbitrarily long objects can be trapped inside arbitrarily short containers: http://math.ucr.edu/home/baez/physic...barn_pole.html "These are the props. You own a barn, 40m long, with automatic doors at either end, that can be opened and closed simultaneously by a switch. You also have a pole, 80m long, which of course won't fit in the barn. Now someone takes the pole and tries to run (at nearly the speed of light) through the barn with the pole horizontal. Special Relativity (SR) says that a moving object is contracted in the direction of motion: this is called the Lorentz Contraction. So, if the pole is set in motion lengthwise, then it will contract in the reference frame of a stationary observer.....So, as the pole passes through the barn, there is an instant when it is completely within the barn. At that instant, you close both doors simultaneously, with your switch. Of course, you open them again pretty quickly, but at least momentarily you had the contracted pole shut up in your barn. The runner emerges from the far door unscathed.....If the doors are kept shut the rod will obviously smash into the barn door at one end. If the door withstands this the leading end of the rod will come to rest in the frame of reference of the stationary observer. There can be no such thing as a rigid rod in relativity so the trailing end will not stop immediately and the rod will be compressed beyond the amount it was Lorentz contracted. If it does not explode under the strain and it is sufficiently elastic it will come to rest and start to spring back to its natural shape but since it is too big for the barn the other end is now going to crash into the back door and the rod will be trapped IN A COMPRESSED STATE inside the barn." http://www.quebecscience.qc.ca/Revolutions Stéphane Durand: "Pour mieux comprendre le phénomène de ralentissement du temps, il est préférable d'aborder un autre phénomène tout aussi paradoxal: la contraction des longueurs. Car la vitesse affecte non seulement l'écoulement du temps, mais aussi la longueur des objets. Ainsi, une fusée en mouvement apparaît plus courte que lorsqu'elle est au repos. Là aussi, plus la vitesse est grande, plus la contraction est importante. Et, comme pour le temps, les effets ne deviennent considérables qu'à des vitesses proches de celle de la lumière. Dans la vie de tous les jours, cette contraction est imperceptible. Cependant, si une fusée de 100 m passait devant nous à une vitesse proche de celle de la lumière, elle pourrait sembler ne mesurer que 50 m, ou même moins. Bien sûr, la question qui vient tout de suite à l'esprit est: «Cette contraction n'est-elle qu'une illusion?» Il semble tout à fait incroyable que le simple mouvement puisse comprimer un objet aussi rigide qu'une fusée. Et pourtant, la contraction est réelle... mais SANS COMPRESSION physique de l'objet! Ainsi, une fusée de 100 m passant à toute vitesse dans un tunnel de 60 m pourrait être entièrement contenue dans ce tunnel pendant une fraction de seconde, durant laquelle il serait possible de fermer des portes aux deux bouts! La fusée est donc réellement plus courte. Pourtant, il n'y a PAS DE COMPRESSION matérielle ou physique de l'engin." http://www.parabola.unsw.edu.au/vol3...ol35_no1_2.pdf Parabola Volume 35, Issue 1 (1999) LENGTH AND RELATIVITY by John Steele "The Pole in the Barn Paradox. Now we know about length contraction, we can invent some amusing uses of it. Suppose you want to fit a 20m pole into a 10m barn. If the pole were moving fast enough, then length contraction means it would be short enough. (...) Now comes the paradox. According to your friend who is going to slam the barn doors shut just as the end of the pole goes in, the pole is 10m long, and therefore it fits. However as far as you are concerned, the pole is still 20m long but the barn is now only 5m long: length contraction must work both ways by the first postulate. How can you fit this 20m pole into a 5m barn? This paradox is apparently due to Wolfgang Rindler of the University of Texas at Dallas. Of course the key to this is relativity of simultaneity. Your friend sees the front end of the pole hit the back wall of the barn at the same time as the doors are closed, but you (and the pole) do not see things this way. You are standing still and see a 5m long barn coming towards you at some shockingly high speed. When the back of the barn hits the front of the pole (and takes the front of the pole with it), the back end of the pole must still be at rest. It cannot 'know' about the crash at the front, because the shock wave travelling along the pole telling it about the crash travels at some finite speed. The front of the barn has only 15m to go to get to the back of the pole, but the shock wave has to travel the whole length of the pole, namely 20m. The speed of the barn is such that even if this shock wave travelled at the speed of light, it would not get to the back of the pole before the front of the barn did. Hence in both frames of reference, the pole fits inside the barn (and will presumably shatter when the doors are closed)." David Deutsch, Multirealists, could it be that in some universes the long object is safely trapped inside the short container but in other universes it cannot be trapped at all? This would be a glorious multirealist solution to the awful paradox - brothers Einsteinians would be grateful. Another paradox: According to Einstein's special relativity, the observer travelling with the rivet sees the bug squashed while the bug sees itself alive and kicking: http://hyperphysics.phy-astr.gsu.edu.../bugrivet.html "The bug-rivet paradox is a variation on the twin paradox and is similar to the pole-barn paradox.....The end of the rivet hits the bottom of the hole before the head of the rivet hits the wall. So it looks like the bug is squashed.....All this is nonsense from the bug's point of view. The rivet head hits the wall when the rivet end is just 0.35 cm down in the hole! The rivet doesn't get close to the bug....The paradox is not resolved." I think the multirealist solution to this paradox is easier: different observers live in different universes where different things happen. Am I right? Pentcho Valev |
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MULTIREALISTS IN EINSTEINIANA
In some universes the youthfulness of the travelling twin has nothing
to do with the accelerations she has suffered: http://www.damtp.cam.ac.uk/research/...tivity2010.pdf Gary W. Gibbons FRS: "In other words, by simply staying at home Jack has aged relative to Jill. There is no paradox because the lives of the twins are not strictly symmetrical. This might lead one to suspect that the accelerations suffered by Jill might be responsible for the effect. However this is simply not plausible because using identical accelerating phases of her trip, she could have travelled twice as far. This would give twice the amount of time gained." http://www.informaworld.com/smpp/con...ent=a909857880 Peter Hayes "The Ideology of Relativity: The Case of the Clock Paradox" : Social Epistemology, Volume 23, Issue 1 January 2009, pages 57-78 Albert Einstein wrote in 1911: "The [travelling] clock runs slower if it is in uniform motion, but if it undergoes a change of direction as a result of a jolt, then the theory of relativity does not tell us what happens. The sudden change of direction might produce a sudden change in the position of the hands of the clock. However, the longer the clock is moving rectilinearly and uniformly with a given speed in a forward motion, i.e., the larger the dimensions of the polygon, the smaller must be the effect of such a hypothetical sudden change." In other universes the youthfulness of the travelling twin is entirely caused by her turn-around acceleration: http://en.wikisource.org/wiki/Dialog...f_rela tivity Dialog about Objections against the Theory of Relativity (1918), by Albert Einstein "...according to the special theory of relativity the coordinate systems K and K' are by no means equivalent systems. Indeed this theory asserts only the equivalence of all Galilean (unaccelerated) coordinate systems, that is, coordinate systems relative to which sufficiently isolated, material points move in straight lines and uniformly. K is such a coordinate system, but not the system K', that is accelerated from time to time. Therefore, from the result that after the motion to and fro the clock U2 is running behind U1, no contradiction can be constructed against the principles of the theory. (...) During the partial processes 2 and 4 the clock U1, going at a velocity v, runs indeed at a slower pace than the resting clock U2. However, this is more than compensated by a faster pace of U1 during partial process 3. According to the general theory of relativity, a clock will go faster the higher the gravitational potential of the location where it is located, and during partial process 3 U2 happens to be located at a higher gravitational potential than U1. The calculation shows that this speeding ahead constitutes exactly twice as much as the lagging behind during the partial processes 2 and 4. This consideration completely clears up the paradox that you brought up." http://www.pitt.edu/~jdnorton/teachi...yon/index.html John Norton: "Now consider the judgments of simultaneity of the traveling twin, as shown in the spacetime diagram opposite. Since the traveling twin is moving very rapidly, the traveler's hypersurfaces of simultaneity are quite tilted. Two hypersurfaces of simultaneity are shown in the lower part of the diagram for the outward part of the traveler's journey. These are the hypersurfaces that pass through the event at which the clock reads 1 day and just before the turn-around at the traveler's clock time of 2 days. We read from these hypersurfaces that the traveling twin judges the stay-at-home twin's clock to be running at half the speed of the travelers. When the traveler's clock reads 1 day, the stay-at-home twin's reads 1/2 day; just before the turn around, when the traveler's clock is almost at 2 days, the stay-at-home twin's clock is almost at 1 day. Then, at the end of the outward leg, the traveler abruptly changes motion, accelerating sharply to adopt a new inertial motion directed back to earth. What comes now is the key part of the analysis. The effect of the change of motion is to alter completely the traveler's judgment of simultaneity. The traveler's hypersurfaces of simultaneity now flip up dramatically. Moments after the turn-around, when the travelers clock reads just after 2 days, the traveler will judge the stay-at-home twin's clock to read just after 7 days. That is, the traveler will judge the stay-at-home twin's clock to have jumped suddenly from reading 1 day to reading 7 days. This huge jump puts the stay-at-home twin's clock so far ahead of the traveler's that it is now possible for the stay-at-home twin's clock to be ahead of the travelers when they reunite." Pentcho Valev |
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MULTIREALISTS IN EINSTEINIANA
Seth Lloyd is not a multirealist but his discoveries seem more epoch-
making than David Deutsch's discoveries: http://www.physorg.com/news/2011-03-...r-paradox.html (PhysOrg.com) -- Among the many intriguing concepts in Einstein's relativity theories is the idea of closed timelike curves (CTCs), which are paths in spacetime that return to their starting points. As such, CTCs offer the possibility of traveling back in time. But, as many science fiction films have addressed, time travel is full of potential paradoxes. Perhaps the most notable of these is the grandfather paradox, in which a time traveler goes back in time and kills her grandfather, preventing her own birth. In a new study, a team of researchers has proposed a new theory of CTCs that can resolve the grandfather paradox, and they also perform an experiment showing how such a scheme works. The researchers, led by Seth Lloyd from MIT, along with scientists from the Scuola Normale Superiore in Pisa, Italy; the University of Pavia in Pavia, Italy; the Tokyo Institute of Technology; and the University of Toronto, have published their study in a recent issue of Physical Review Letters. The concepts in the study are similar to an earlier study by some of the same authors that was posted at arXiv.org last year. "Einstein's theory of general relativity supports closed timelike curves," Lloyd told PhysOrg.com. "For decades researchers have argued over how to treat such objects quantum mechanically. We believe that our theory is the correct theory of such objects. Moreover, our theory shows how time travel might be accomplished even in the absence of general relativistic closed timelike curves." In the new theory, CTCs are required to behave like ideal quantum channels of the sort involved in teleportation. In this theory, self-consistent CTCs (those that don't result in paradoxes) are postselected, and are called "P-CTCs." As the scientists explain, this theory differs from the widely accepted quantum theory of CTCs proposed by physicist David Deutsch, in which a time traveler maintains self-consistency by traveling back into a different past than the one she remembers. In the P-CTC formulation, time travelers must travel to the past they remember." David Deutsch, as the time traveler travels back into a different past, can she see, simultaneously, what is going on in the corresponding different future? If the answer is yes, you are undoubtedly the greatest Einsteinian; Seth Lloyd will go into deep depression. Pentcho Valev |
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MULTIREALISTS IN EINSTEINIANA
http://www.magazine.utoronto.ca/blog...ativity-works/
"Dick Bond, a U of T cosmologist and physics professor, raised the possibility that what we observe with our telescopes may be just one "bubble" in a vastly larger "landscape" of multiple universes. That idea, rooted in the "inflation" model of the big bang, has widespread support – yet the question of how "time" in one universe relates to "time" in another universe is far from clear. James R. Brown, a U of T philosophy professor, meanwhile, argued that past, present, and future – as fundamental as they may seem – do not make up part of our "objective reality." He says that past, present, and future must all be considered equally "real." This view is sometimes known as the "block universe," in which time is represented as just another dimension, analogous to the dimensions of space, and all parts of the block are equally real. Incredibly, this leaves the so-called "flow" of time as mere illusion, Brown says. The future is just as fixed and as impossible to change as the past. Lee Smolin, a physicist with the Perimeter Institute in Waterloo, Ontario, took issue with that argument: For him, the passage of time is real. He rejects both the block universe and the idea of multiple universes, preferring the idea of a single universe in which the passage of time is real. (...) As the event's moderator, I took the liberty of asking the panellists about time travel, a topic that seems to be a perpetual favourite among science fiction writers. While forward-directed time travel is a basic aspect of Einstein's theory, and loops through time are not specifically prohibited, all three panellists were skeptical of the idea of travelling backward through time." Here the multirealist and the illusionist are not very interesting but their opponent, Lee Smolin, presents himself as an extremely subtle and original thinker. He rejects the block universe but does not reject "forward-directed time travel", although both are consequences of Einstein's 1905 false constant-speed-of-light postulate. Bravo, Lee Smolin! http://www.liferesearchuniversal.com...html#seventeen George Orwell: "Doublethink means the power of holding two contradictory beliefs in one's mind simultaneously, and accepting both of them. The Party intellectual knows in which direction his memories must be altered; he therefore knows that he is playing tricks with reality; but by the exercise of doublethink he also satisfies himself that reality is not violated. The process has to be conscious, or it would not be carried out with sufficient precision, but it also has to be unconscious, or it would bring with it a feeling of falsity and hence of guilt. Doublethink lies at the very heart of Ingsoc, since the essential act of the Party is to use conscious deception while retaining the firmness of purpose that goes with complete honesty. To tell deliberate lies while genuinely believing in them, to forget any fact that has become inconvenient, and then, when it becomes necessary again, to draw it back from oblivion for just so long as it is needed, to deny the existence of objective reality and all the while to take account of the reality which one denies - all this is indispensably necessary. Even in using the word doublethink it is necessary to exercise doublethink. For by using the word one admits that one is tampering with reality; by a fresh act of doublethink one erases this knowledge ; and so on indefinitely, with the lie always one leap ahead of the truth. (...) It need hardly be said that the subtlest practitioners of doublethink are those who invented doublethink and know that it is a vast system of mental cheating. In our society, those who have the best knowledge of what is happening are also those who are furthest from seeing the world as it is. In general, the greater the understanding, the greater the delusion ; the more intelligent, the less sane." Pentcho Valev |
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MULTIREALISTS IN EINSTEINIANA
Einsteinians abandon "the dominant paradigm for cosmic time and
evolution - the Big Bang" and become buddhists: http://www.npr.org/blogs/13.7/2011/0...-an-older-time Adam Frank: "The punch line is that the dominant paradigm for cosmic time and evolution - the Big Bang - is on its way out. Since we will soon be replacing our version of cosmic time, it is likely that our culturally defined experience and organization of time is going to shift as well. A good way to start thinking about this topic might be to remember what other versions of time, very different from the one we experience daily now, have looked like in the past. Here is a passage from the famous buddhist writer Thich Nhat Hanh..." Pentcho Valev |
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MULTIREALISTS IN EINSTEINIANA
The Big Bang is dead and will be replaced by... Big Bang!
http://usairwaysmag.com/articles/the...the_beginning/ Adam Frank: "The Big Bang is all but dead, and we do not yet know what will replace it. There are those who will tell you that cosmology - the study of the Universe entire - has become an exact science. They will tell you that this grand and all-embracing field has, in the last 50 years, moved from the realms of philosophical speculation into the purest domains of science via exacting confrontations between theoretical models and high-resolution data. You should know that they are right. For the first time in the long march of human thinking we are now, finally, able to construct a detailed and verifiable account of cosmic history. So when I tell you that the Big Bang is dead I am not referring to the story that begins with a Universe far hotter and far denser than what we see today. I do not mean the story of a Universe expanding, of matter cooling and congealing over billions of years into stars and galaxies. That story, the scientific narrative of cosmic evolution over the last 13.7 billion years is, for all intents and purposes, secure." http://www.liferesearchuniversal.com/1984-17 George Orwell: "Doublethink means the power of holding two contradictory beliefs in one's mind simultaneously, and accepting both of them. The Party intellectual knows in which direction his memories must be altered; he therefore knows that he is playing tricks with reality; but by the exercise of doublethink he also satisfies himself that reality is not violated. The process has to be conscious, or it would not be carried out with sufficient precision, but it also has to be unconscious, or it would bring with it a feeling of falsity and hence of guilt. Doublethink lies at the very heart of Ingsoc, since the essential act of the Party is to use conscious deception while retaining the firmness of purpose that goes with complete honesty. To tell deliberate lies while genuinely believing in them, to forget any fact that has become inconvenient, and then, when it becomes necessary again, to draw it back from oblivion for just so long as it is needed, to deny the existence of objective reality and all the while to take account of the reality which one denies - all this is indispensably necessary. Even in using the word doublethink it is necessary to exercise doublethink. For by using the word one admits that one is tampering with reality; by a fresh act of doublethink one erases this knowledge ; and so on indefinitely, with the lie always one leap ahead of the truth. (...) It need hardly be said that the subtlest practitioners of doublethink are those who invented doublethink and know that it is a vast system of mental cheating. In our society, those who have the best knowledge of what is happening are also those who are furthest from seeing the world as it is. In general, the greater the understanding, the greater the delusion ; the more intelligent, the less sane." Pentcho Valev wrote: Einsteinians abandon "the dominant paradigm for cosmic time and evolution - the Big Bang" and become buddhists: http://www.npr.org/blogs/13.7/2011/0...-an-older-time Adam Frank: "The punch line is that the dominant paradigm for cosmic time and evolution - the Big Bang - is on its way out. Since we will soon be replacing our version of cosmic time, it is likely that our culturally defined experience and organization of time is going to shift as well. A good way to start thinking about this topic might be to remember what other versions of time, very different from the one we experience daily now, have looked like in the past. Here is a passage from the famous buddhist writer Thich Nhat Hanh..." Pentcho Valev |
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MULTIREALISTS IN EINSTEINIANA
In Einsteiniana's schizophrenic world signals regularly come from the
future and shape believers' minds. As a result, believers give money to Paul Davies: http://www.fqxi.org/community/articles/display/156 "The universe has a destiny - and this set fate could be reaching backwards in time and combining with influences from the past to shape the present. (...) Cosmologist Paul Davies, at Arizona State University in Tempe, is embarking on a project to investigate the future's reach into the present, with the help of a $70,000 grant from the Foundational Questions Institute. (...) "It's a very, very profound idea," says Davies. Aharonov's take on quantum mechanics can explain all the usual results that the conventional interpretations can, but with the added bonus that it also explains away nature's apparent indeterminism. What's more, a theory in which the future can influence the past may have huge - and much needed - repercussions for our understanding of the universe, says Davies." In 2003 Paul Davies believed for a while that toppling Divine Albert's Divine Theory would bring even more money but quickly realized his mistake: http://www.prospect-magazine.co.uk/a...ls.php?id=5538 Paul Davies 2003: "Was Einstein wrong? Einstein's famous equation E=mc2 is the only scientific formula known to just about everyone. The "c" here stands for the speed of light. It is one of the most fundamental of the basic constants of physics. Or is it? In recent years a few maverick scientists have claimed that the speed of light might not be constant at all. Shock, horror! Does this mean the next Great Revolution in Science is just around the corner?" Pentcho Valev |
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