Re: Tipler Weighs In
Lee Corbin points to Tipler's March 2005 paper The Structure of the World From Pure Numbers: http://www.iop.org/EJ/abstract/0034-4885/68/4/R04 I tried to read this paper, but it was 60 pages long and extremely technical, mostly over my head. The gist of it was an updating of Tipler's Omega Point theory, advanced in his book, The Physics of Immortality. Basically the OP theory predicts, based on the assumption that the laws of physics we know today are roughly correct, that the universe must re-collapse in a special way that can't really happen naturally, hence Tipler deduces that intelligent life will survive through and guide the ultimate collapse, during which time the information content of the universe will go to infinity. The new paper proposes an updated cosmological model that includes a number of new ideas. One is that the fundamental laws of physics for the universe are infinitely complex. This is where his title comes from; he assumes that the universe is based on the mathematics of the continuum, i.e. the real numbers. In fact Tipler argues that the universe must have infinitely complex laws, basing this surprising conclusion on the Lowenheim-Skolem paradox, which says that any set of finite axioms can be fit to a mathematical object that is only countable in size. Hence technically we can't really describe the real numbers without an infinite number of axioms, and therefore if the universe is truly based on the reals, it must have laws of infinite complexity. (Otherwise the laws would equally well describe a universe based only on the integers.) Another idea Tipler proposes is that under the MWI, different universes in the multiverse will expand to different maximum sizes R before re-collapsing. The probability measure however works out to be higher with larger R, hence for any finite R the probability is 1 (i.e. certain) that our universe will be bigger than that. This is his solution to why the universe appears to be flat - it's finite in size but very very big. Although Tipler wants the laws to be infinitely complex, the physical information content of the universe should be zero, he argues, at the time of the Big Bang (this is due to the Beckenstein Bound). That means among other things there are no particles back then, and so he proposes a special field called an SU(2) gauge field which creates particles as the universe expands. He is able to sort of show that it would preferentially create matter instead of antimatter, and also that this field would be responsible for the cosmological constant which is being observed, aka negative energy. In order for the universe to re-collapse as Tipler insists it must, due to his Omega Point theory, the CC must reverse sign eventually. Tipler suggests that this will happen because life will choose to do so, and that somehow people will find a way to reverse the particle-creation effect, catalyzing the destruction of particles in such a way as to reverse the CC and cause the universe to begin to re-collapse. Yes, he's definitely full of wild ideas here. Another idea is that particle masses should not have specific, arbitrary values as most physicists believe, but rather they should take on a full range of values, from 0 to positive infinity, over the history of the universe. There is some slight observational evidence for a time-based change in the fine structure constant alpha, and Tipler points to that to buttress his theory - however the actual measured value is inconsistent with other aspects, so he has to assume that the measurements are mistaken! Another testable idea is that the cosmic microwave background radiation is not the cooled-down EM radiation from the big bang, but instead is the remnants of that SU(2) field which was responsible for particle creation. He shows that such a field would look superficially like cooled down photons, but it really is not. In particular, the photons in this special field would only interact with left handed electrons, not right handed ones. This would cause the photons to have less interaction with matter in a way which should be measurable. He uses this to solve the current puzzle of high energy cosmic rays: such rays should not exist due to interaction with microwave background photons. Tipler's alternative does not interact so well and so it would at least help to explain the problem. Overall it is quite a mixed bag of exotic ideas that I don't think physicists are going to find very convincing. The idea of infinitely complex natural laws is going to be particularly off-putting, I would imagine. However the idea that the cosmic microwave background interacts differently with matter than ordinary photons is an interesting one and might be worth investigating. It doesn't have that much connection to the rest of his theory, though. Hal Finney
Re: Tipler Weighs In
Hal, Thanks for an illuminating explanation of Tipler's paper. I wonder if you and/or any other members on this list have an opinion about the validity of an article at http://www.hedweb.com/nihilism/nihilfil.htm This is a discussion of WHY DOES ANYTHING EXIST? (The author is apparently a David Pearce. There are many with that name and I am unable to determine which one.) His conclusion is that . . . the summed membership of the uncountably large set of positive and negative numbers, and every more fancy and elaborate pair of positive and negative real and imaginary etc terms, trivially and exactly cancels out to/adds up to 0. . . . Net energy etc of Multiverse = 0 = all possible outcomes. . . if, in all, there is 0, i.e no (net) properties whatsoever, then there just isn't anything substantive which needs explaining. (Please go to the URL to avoid misinterpretations which I may have introduced by my editing.) Norman Samish - Original Message - From: Hal Finney [EMAIL PROTECTED] To: everything-list@eskimo.com; [EMAIL PROTECTED] Sent: Monday, May 16, 2005 5:16 PM Subject: Re: Tipler Weighs In Lee Corbin points to Tipler's March 2005 paper The Structure of the World From Pure Numbers: http://www.iop.org/EJ/abstract/0034-4885/68/4/R04 I tried to read this paper, but it was 60 pages long and extremely technical, mostly over my head. The gist of it was an updating of Tipler's Omega Point theory, advanced in his book, The Physics of Immortality. Basically the OP theory predicts, based on the assumption that the laws of physics we know today are roughly correct, that the universe must re-collapse in a special way that can't really happen naturally, hence Tipler deduces that intelligent life will survive through and guide the ultimate collapse, during which time the information content of the universe will go to infinity. The new paper proposes an updated cosmological model that includes a number of new ideas. One is that the fundamental laws of physics for the universe are infinitely complex. This is where his title comes from; he assumes that the universe is based on the mathematics of the continuum, i.e. the real numbers. In fact Tipler argues that the universe must have infinitely complex laws, basing this surprising conclusion on the Lowenheim-Skolem paradox, which says that any set of finite axioms can be fit to a mathematical object that is only countable in size. Hence technically we can't really describe the real numbers without an infinite number of axioms, and therefore if the universe is truly based on the reals, it must have laws of infinite complexity. (Otherwise the laws would equally well describe a universe based only on the integers.) Another idea Tipler proposes is that under the MWI, different universes in the multiverse will expand to different maximum sizes R before re-collapsing. The probability measure however works out to be higher with larger R, hence for any finite R the probability is 1 (i.e. certain) that our universe will be bigger than that. This is his solution to why the universe appears to be flat - it's finite in size but very very big. Although Tipler wants the laws to be infinitely complex, the physical information content of the universe should be zero, he argues, at the time of the Big Bang (this is due to the Beckenstein Bound). That means among other things there are no particles back then, and so he proposes a special field called an SU(2) gauge field which creates particles as the universe expands. He is able to sort of show that it would preferentially create matter instead of antimatter, and also that this field would be responsible for the cosmological constant (CC) which is being observed, aka negative energy. In order for the universe to re-collapse as Tipler insists it must, due to his Omega Point theory, the CC must reverse sign eventually. Tipler suggests that this will happen because life will choose to do so, and that somehow people will find a way to reverse the particle-creation effect, catalyzing the destruction of particles in such a way as to reverse the CC and cause the universe to begin to re-collapse. Yes, he's definitely full of wild ideas here. Another idea is that particle masses should not have specific, arbitrary values as most physicists believe, but rather they should take on a full range of values, from 0 to positive infinity, over the history of the universe. There is some slight observational evidence for a time-based change in the fine structure constant alpha, and Tipler points to that to buttress his theory - however the actual measured value is inconsistent with other aspects, so he has to assume that the measurements are mistaken! Another testable idea is that the cosmic microwave background radiation is not the cooled-down EM radiation from the big bang, but instead is the remnants of that SU(2) field which was responsible for particle creation. He shows that such a field would look
Re: Tipler Weighs In
Dear Stephen, Pearce spends considerable time in his thesis discussing the harm that Brave New World has done to Utopian causes. I rather suspect that Huxley would not have been disapproving, given his libertarian sympathies and fondness for hallucinogens in his later work. Orwell is completely different; there's nothing even superficially pleasant about his dystopian vision. The others I would have to look up; do you mean Frank Dune Herbert or another Frank Herbert? Pearce's thesis is freely available on his website, and it really is very well written, addressing just about every possible objection before you think of it. --Stathis Hi Stathis, Nice review! I wonder about Pierce, has he read Huxley or Orwell? He and all should read the advice of Eric Hoffer, Frank Herbert and others, warning us of the dangers of trying to push utopias. More modern treatments include Philip Ball's Critical Mass. Stephen - Original Message - From: Stathis Papaioannou [EMAIL PROTECTED] To: [EMAIL PROTECTED]; everything-list@eskimo.com Sent: Monday, May 16, 2005 10:57 PM Subject: Re: Tipler Weighs In David Pearce is a British philosopher with Utilitarian leanings, and his extensive HedWeb site has been around for many years. His main thesis is contained in a book-length article called The Hedonistic Imperative, in which he argues that the aim of civilization should be the ultimate elimination of all suffering in sentient life. He proposes that this be done not primarily through traditional methods, such as banning animal cruelty (although he has much to say about that as well), but by directly accessing and altering the neural mechanisms responsible for suffering, through pharmacological and neurological means initially, and eventually through genetic engineering so that no organism is physically capable of experiencing suffering. Pearce's thesis does not really address the next stage after neuroengineering often discussed on this list, namely living as uploaded minds on a computer network. The interesting question arises of how we would (or should) spend our time in this state. It would be a simple matter of programming to eliminate suffering and spend eternity (or however long it lasts) in a state of heavenly bliss. The obvious response to such a proposal is that perpetual bliss would be boring, and leave no room for motivation, curiosity, progress, etc. But boredom is just another adverse experience which could be simply eliminated if you have access to the source code. And if you think about it, even such tasks as participating in discussions such as the present one are only really motivated by anticipation of the complex pleasure gained from it; if you could get the same effect or better, directly, with no adverse consequences, why would you waste your time doing it the hard way? --Stathis Papaioannou _ SEEK: Over 80,000 jobs across all industries at Australia's #1 job site. http://ninemsn.seek.com.au?hotmail
Re: Tipler Weighs In
Dear Stathis, - Original Message - From: Stathis Papaioannou [EMAIL PROTECTED] To: [EMAIL PROTECTED]; everything-list@eskimo.com; [EMAIL PROTECTED] Sent: Tuesday, May 17, 2005 12:28 AM Subject: Re: Tipler Weighs In Dear Stephen, Pearce spends considerable time in his thesis discussing the harm that Brave New World has done to Utopian causes. I rather suspect that Huxley would not have been disapproving, given his libertarian sympathies and fondness for hallucinogens in his later work. Orwell is completely different; there's nothing even superficially pleasant about his dystopian vision. The others I would have to look up; do you mean Frank Dune Herbert or another Frank Herbert? Frank Dune Herbert, particularly, The Maker of Dune: http://www.amazon.com/exec/obidos/tg/detail/-/0425058344/qid=1116308591/sr=8-1/ref=sr_8_xs_ap_i1_xgl14/002-5151334-9004020?v=glances=booksn=507846 Pearce's thesis is freely available on his website, and it really is very well written, addressing just about every possible objection before you think of it. Excellent, I will look for it. Stephen --Stathis
Tipler Weighs In
From Tipler's March 2005 paper The Structure of the World From Pure Numbers: Can the structure of physical reality be inferred by a pure mathematician? As Einstein posed it, Did God have any choice when he created the universe? Or is mathematics a mere handmaiden to the Queen of the Sciences, physics? Many Greeks, for instance Plato, believed that the world we see around us was a mere shadow, a defective reflection of the true reality, geometry. But the medieval universitywas based on the primacy of the physics of Aristotle over mere mathematics. Galileo, a poor mathematician, had to live on a salary of 520 ducats at the University of Padua, while Cesare Cremonini, the university's natural philosopher (physicist), had a salary of 2000 ducats (Tipler 1994, pp 372.3). Recently, mathematics has regained some of its primacy as theoretical physicists and mathematicians have struggled to determine if there is a Brane theory picked out by mathematical consistency. I shall investigate the idea that physical reality is pure number in the second section of this paper. I shall point out that quantum mechanics.more precisely the Bekenstein Bound, a relativistic version of the Heisenberg uncertainty principle.implies that the complexity of the universe at the present time is finite, and hence the entire universe can be emulated down to the quantum state on a computer. Thus, it would seem that indeed the universe is a mere expression of mathematical reality, more specifically an expression of number theory, and of integers to boot. I shall challenge this conclusion in the third section of this paper. I shall point out that even though quantum mechanics yields integers in certain cases (e.g. discrete eigenstates), the underlying equations are nevertheless differential equations based on the continuum. Thus, if we consider the differential equations of physics as mirroring fundamental reality, we must take the continuum as basic, not the integers. I review the field of mathematical logic, and point out the implications for pure mathematics of taking the continuum as fundamental. But if we take the continuum as fundamental, we are faced with the infinities of quantum field theory, and the curvature singularities of general relativity. I shall argue in the fourth section of this paper that taking proper account of the latter allows us to avoid the former. In particular, I shall argue that the mathematical difficulties of the most successful quantum field theory, the Standard Model (SM) of particle physics, all experiments carried out to date confirm the SM, naturally disappear if one requires that the SM be consistent with quantum gravity. ... http://www.iop.org/EJ/abstract/0034-4885/68/4/R04 Lee
