Brother Jeff Posted May 26, 2014 Share Posted May 26, 2014 http://news.nationalgeographic.com/news/2014/03/140318-multiverse-inflation-big-bang-science-space/ Link to comment Share on other sites More sharing options...
Guest ninurta Posted May 26, 2014 Share Posted May 26, 2014 I like this. It's fascinating, and it explains well the "something from nothing" question Xians have. Link to comment Share on other sites More sharing options...
Thought2Much Posted May 26, 2014 Share Posted May 26, 2014 Thanks for sharing this. I've posted the article on my Facebook wall. Link to comment Share on other sites More sharing options...
Moderator Joshpantera Posted May 26, 2014 Moderator Share Posted May 26, 2014 BAA in 3, 2, 1..... Link to comment Share on other sites More sharing options...
Thought2Much Posted May 27, 2014 Share Posted May 27, 2014 BAA in 3, 2, 1..... This article was something of a layman's summary for things that BAA has posted before. A lot of it still goes over my head. Link to comment Share on other sites More sharing options...
miekko Posted May 27, 2014 Share Posted May 27, 2014 I find two problems that multiverses bring: 1) They are still unfalsifiable; we can't verify whether they actually exist. 2) It looks a little bit too much like the biggest ad hoc explanation since God. The latter is problematic in light of the former: We have a situation where "the numbers don't add up". So, we add things to this sentence: "the numbers don't add up because they describe an average universe, and ours is a statistical outlier". This is really a very cheap solution: if it's wrong, we currently don't have any methods of rejecting it, if it's right, we currently have no methods of being sure whether it's right. It would be much preferable if new, testable models were developed. Who knows, there may be elegant solutions to the problem, solutions that just haven't occurred to anyone yet and that don't require the biggest untestable proposition since god. Link to comment Share on other sites More sharing options...
bornagainathiest Posted May 27, 2014 Share Posted May 27, 2014 BAA in 3, 2, 1..... ...and BAA will sound a note of caution. . . . VERY IMPORTANT POINT TO REMEMBER! The BICEP2 result, which appears to indicate that we inhabit some kind of Inflation-driven multiverse is... . . . ... p - r - e - l - i - m - i - n - a - r - y . . . . Any bona fide detection MUST be reproduced and independently verified. This has not happened yet. There are about a dozen science teams currently sweeping the Cosmic Microwave Background (CMB) for these faint signals from the distant past. If they cannot duplicate the result from BICEP2, then the whole show is off. Sorry to rain on your parade boys and girls, but we don't have any valid evidence for a multiverse, yet. The BICEP2 data will become valid evidence when (and only when) it's independently reproduced. That's how science works and we shouldn't jump the gun... even if the popular press is inclined to do so. . . . Furthermore, there's some doubt about the validity of the BICEP2 data. Please check this out. http://profmattstrassler.com/2014/05/19/will-bicep2-lose-some-of-its-muscle/#more-7659 Point #2 is where it's at. The signal appears to be real, but where's it coming from? The CMB, which is the Background signal of microwaves or polarized dust in the Foreground, which is contaminating the signal and skewing the data? The jury's still out and may well stay there until the European Space Agency Planck satellite teams release their data. Whenever that is...? . . . So please maintain a holding pattern. You can be sure that as soon as I know something, I'll leap to bring the news here. Thanks, BAA. 2 Link to comment Share on other sites More sharing options...
bornagainathiest Posted May 27, 2014 Share Posted May 27, 2014 I find two problems that multiverses bring: 1) They are still unfalsifiable; we can't verify whether they actually exist. 2) It looks a little bit too much like the biggest ad hoc explanation since God. The latter is problematic in light of the former: We have a situation where "the numbers don't add up". So, we add things to this sentence: "the numbers don't add up because they describe an average universe, and ours is a statistical outlier". This is really a very cheap solution: if it's wrong, we currently don't have any methods of rejecting it, if it's right, we currently have no methods of being sure whether it's right. It would be much preferable if new, testable models were developed. Who knows, there may be elegant solutions to the problem, solutions that just haven't occurred to anyone yet and that don't require the biggest untestable proposition since god. Hello Miekko! In the light of your post, may I ask what your reaction is to these points? 1. "All theories in physics predict some things which are directly amenable to experiment and some which aren't. For example, our theories of the stars predict things one could measure, like how brightly they will shine, and when they're going to go supernova. But they also predict things like the temperature at the center of the star, which we cannot measure directly. We accept these ideas, including their unobservable predictions, because they are the simplest way of explaining the things we can see within a consistent physical theory." David Deutsch, 'The Ghost in the Atom' p.84. By P.C.W. Davies & J.R. Brown, Cambridge University Press. Here Deutsch is referring to the ramifications of the Everett Interpretation of Quantum Mechanics. http://en.wikipedia.org/wiki/Many-worlds_interpretation But the principle holds good for the unobservable regions of the multiverse, inferred to exist by Inflationary theory. 2. http://en.wikipedia.org/wiki/Modus_ponens 3. An example I've used in another forum to illustrate the underlying principle. I'm in a boat out at sea and I observe the following. A line of clouds passes over me, blown by the prevailing wind and appearing to emanate from a fixed point, over the horizon. Seabirds fly towards and away from this point. The ocean swell seems to be disrupted, with trains of waves emanating from this point. Floating debris (the branches of trees) drift across my path, apparently coming from where the clouds, the birds and waves originate from. The prevailing wind also carries with it the distinct odor of pine trees. On the basis of these various indicators, can I reasonably infer the existence of an island, even if I cannot see it? Thanks, BAA. Link to comment Share on other sites More sharing options...
miekko Posted May 27, 2014 Share Posted May 27, 2014 1. Are we sure this is the simplest possible theory? Are we sure no simpler possible theory exists that we have just failed to envision and formalize? From the point of view of computational complexity theory, it seems rather daring to go and say the theories we now have are the simplest possible ones. I would want to know how they went about measuring simplicity in this instance. It's hard to apply Occam's razor for some competing physical theories, and different ways of measuring simplicity may well favour different ones. 2. I know modus ponens. However, we don't know whether this kind of implication is certain to exist. It seems we're dealing with hypothetically likely implications, which is quite a different thing. In that case, we're basically off on some kind of fuzzy logic, in which case our conclusions are less certain. I would accept saying that it's highly likely that multiple universes exist. 3. As for the island, it would seem that most sailors have seen more than a few of these by their own eyes, and thus are aware and certain that such things indeed exist, and that they indeed aren't even a singular thing. As for universes, that's a somewhat different ballpark for obvious reasons. If you were created ex-nihilo as an empty slate on a raft in the middle of the sea, and saw these same things, positing that the thing of which you see the evidence is anything like an island is unjustified, as you have never seen such a thing and cannot infer it from zero. In that case, you would only be epistemologically justified in believing that it is the thing it indeed is once you've somehow witnessed enough evidence of such things to know what an island is. Link to comment Share on other sites More sharing options...
♦ ficino ♦ Posted May 27, 2014 Share Posted May 27, 2014 The multiverse, intermundia and all - Epicurus said it, I believe it, that settles it.Sorry, I'll go away now. 1 Link to comment Share on other sites More sharing options...
bornagainathiest Posted May 27, 2014 Share Posted May 27, 2014 1. Are we sure this is the simplest possible theory? Are we sure no simpler possible theory exists that we have just failed to envision and formalize? From the point of view of computational complexity theory, it seems rather daring to go and say the theories we now have are the simplest possible ones. I would want to know how they went about measuring simplicity in this instance. It's hard to apply Occam's razor for some competing physical theories, and different ways of measuring simplicity may well favour different ones. It's Deutsch's personal contention that it's the simplest. I retain an open mind on this one. 2. I know modus ponens. However, we don't know whether this kind of implication is certain to exist. It seems we're dealing with hypothetically likely implications, which is quite a different thing. In that case, we're basically off on some kind of fuzzy logic, in which case our conclusions are less certain. I would accept saying that it's highly likely that multiple universes exist. The appeal to modus ponens is, once again, not mine, but that of a certain scientist. This one, to be precise. http://space.mit.edu/home/tegmark/mathematical.html I agree with your last sentence, btw. 3. As for the island, it would seem that most sailors have seen more than a few of these by their own eyes, and thus are aware and certain that such things indeed exist, and that they indeed aren't even a singular thing. As for universes, that's a somewhat different ballpark for obvious reasons. Yes, I'm inferring from what I know and making the assumption that what I don't not know is similar to what I do know. This is how the Copernican and Cosmological principles work. They require us to make assumptions about what we do not know, based upon what we do know. If you were created ex-nihilo as an empty slate on a raft in the middle of the sea, and saw these same things, positing that the thing of which you see the evidence is anything like an island is unjustified, as you have never seen such a thing and cannot infer it from zero. In that case, you would only be epistemologically justified in believing that it is the thing it indeed is once you've somehow witnessed enough evidence of such things to know what an island is. Agreed. The inferences that I'm making about the unseen island (like the Copernican and Cosmological principles) are not inferences from zero. Thanks for the prompt reply, btw. Link to comment Share on other sites More sharing options...
DrNo Posted May 28, 2014 Share Posted May 28, 2014 Layman's article on the recent doubts about the data. An important takeaway is that this is all part of the scientific process! Challenges are to be expected and even welcomed here. Nothing has been proven yet, but there is still room for future studies to correct some of the problems and make a stronger case. Link to comment Share on other sites More sharing options...
Thought2Much Posted May 28, 2014 Share Posted May 28, 2014 Layman's article on the recent doubts about the data. An important takeaway is that this is all part of the scientific process! Challenges are to be expected and even welcomed here. Nothing has been proven yet, but there is still room for future studies to correct some of the problems and make a stronger case. Agreed. It's great to watch science move the way it should, with a good dose of skepticism and questioning. Link to comment Share on other sites More sharing options...
bornagainathiest Posted June 4, 2014 Share Posted June 4, 2014 As promised, more info on the BICEP2 controversy. http://profmattstrassler.com/2014/05/30/the-bicep2-dust-up-continues/#more-7706 Thanks, BAA Link to comment Share on other sites More sharing options...
bornagainathiest Posted June 6, 2014 Share Posted June 6, 2014 Big Bang Blunder Bursts Multiverse Bubble http://www.math.columbia.edu/~woit/wordpress/ Link to comment Share on other sites More sharing options...
Brother Jeff Posted June 6, 2014 Author Share Posted June 6, 2014 Big Bang Blunder Bursts Multiverse Bubble http://www.math.columbia.edu/~woit/wordpress/ So... what does this mean? No multiverse? Thanks. Link to comment Share on other sites More sharing options...
♦ ficino ♦ Posted June 8, 2014 Share Posted June 8, 2014 The same thing happens in archaeology: researchers race to get announcements into the media, and sometimes years later when they publish their reports, the announced find is quietly downsized as something less groundbreaking. Possibly similar thing with Gospel of Jesus' Wife papyrus fragment. But then, the media hype keeps interest perked up. It sounds as though Steinhart is in the minority by calling the multiverse theory unfalsifiable. I guess we just have to wait for more experimental results? I am excited that Vilenkin is lecturing tomorrow at the Nat. History Mus!! I hope I can get there to hear it - depends on whether tickets are still available and on getting home health aide to stay late with Mervin. Thanks for posting the link, BAA. What's your take on it? Link to comment Share on other sites More sharing options...
bornagainathiest Posted June 9, 2014 Share Posted June 9, 2014 Big Bang Blunder Bursts Multiverse Bubble http://www.math.columbia.edu/~woit/wordpress/ So... what does this mean? No multiverse? Thanks. No Jeff. It means that we wait until anyone else looking for b-mode polarization in the CMB can replicate BICEP2's results. Remember cold fusion? Remember faster-than-light neutrinos, just a little while back? Lots of hype, but nobody was able to replicate the results. That's how science works. A result is considered kosher and bona fide if it can be independently replicated by different scientists. If it can't... Thanks, BAA. Link to comment Share on other sites More sharing options...
bornagainathiest Posted June 9, 2014 Share Posted June 9, 2014 The same thing happens in archaeology: researchers race to get announcements into the media, and sometimes years later when they publish their reports, the announced find is quietly downsized as something less groundbreaking. Possibly similar thing with Gospel of Jesus' Wife papyrus fragment. But then, the media hype keeps interest perked up. It sounds as though Steinhart is in the minority by calling the multiverse theory unfalsifiable. I guess we just have to wait for more experimental results? I am excited that Vilenkin is lecturing tomorrow at the Nat. History Mus!! I hope I can get there to hear it - depends on whether tickets are still available and on getting home health aide to stay late with Mervin. Thanks for posting the link, BAA. What's your take on it? I'll get back to you asap, F. Please maintain a holding pattern. Thanks, BAA. Link to comment Share on other sites More sharing options...
bornagainathiest Posted June 10, 2014 Share Posted June 10, 2014 The same thing happens in archaeology: researchers race to get announcements into the media, and sometimes years later when they publish their reports, the announced find is quietly downsized as something less groundbreaking. Possibly similar thing with Gospel of Jesus' Wife papyrus fragment. But then, the media hype keeps interest perked up. It sounds as though Steinhart is in the minority by calling the multiverse theory unfalsifiable. I guess we just have to wait for more experimental results? I am excited that Vilenkin is lecturing tomorrow at the Nat. History Mus!! I hope I can get there to hear it - depends on whether tickets are still available and on getting home health aide to stay late with Mervin. Thanks for posting the link, BAA. What's your take on it? Well Ficino, The bottom line in science is the data. If the data to support an Inflationary multiverse doesn't come in (i.e., get replicated other CMB teams) then, attractive as the theory is, it'll still be speculative, rather than strongly-supported by evidence. But where do we go from there? String theory is also fabulously attractive - but where's the supporting data? One whisper I read in the Particle Physics blogsphere is that certain ardent String theorists are suggesting that if the upgraded LHC doesn't find any evidence of SuperSymmetry (SUSY) in the energy-range it can reach - then they'll simply adjust the parameters of the theory by hand, putting it out of the reach of that machine. THAT IS WRONG! THAT IS UNPROFESSIONAL! THAT IS NOT HOW SCIENCE IS DONE! Fyi, SUSY is a key prediction of String theory. In some String models, the LHC should have found evidence for it by now. If it isn't found soon, there's going to be one hell of a crisis in particle physics! Likewise, with Inflation. It looks great and seems to have some evidence going for it - but that critical smoking gun just hasn't been confirmed as yet. I hope that I've got the honesty and integrity to be realistic about Inflation, when it comes down to the crunch. I hope that I can let it go, if the need arises. Thanks, BAA Link to comment Share on other sites More sharing options...
♦ ficino ♦ Posted June 10, 2014 Share Posted June 10, 2014 Thanks, BAA. Once I check over my notes, I'll post a thread on Vilenkin's lecture last night on cosmic inflation and the multiverse. Not that what he said will be news to you or other aficionados, most likely. Link to comment Share on other sites More sharing options...
bornagainathiest Posted June 19, 2014 Share Posted June 19, 2014 BICEP2 latest! http://www.math.columbia.edu/~woit/wordpress/ Link to comment Share on other sites More sharing options...
♦ ficino ♦ Posted June 19, 2014 Share Posted June 19, 2014 Well, it's good to see the scientific process at work. Linde could have just said that the truth was revealed to him. Link to comment Share on other sites More sharing options...
bornagainathiest Posted June 23, 2014 Share Posted June 23, 2014 http://www.nature.com/news/gravitational-wave-team-admits-findings-could-amount-to-dust-1.15440 Link to comment Share on other sites More sharing options...
♦ ficino ♦ Posted June 23, 2014 Share Posted June 23, 2014 http://www.nature.com/news/gravitational-wave-team-admits-findings-could-amount-to-dust-1.15440 Why does Ron Cowen, author of the linked post, say that the theory of Cosmic Inflation is "popular but outlandish"? Link to comment Share on other sites More sharing options...
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