167 reputation
9
bio website thought.persianblog.ir
location Tehran, Iran
age
visits member for 2 years, 11 months
seen Apr 3 at 7:30

Favorites: Studying Religion, Philosophy, Mathematics, Physics and …

Islam means to submit to God ... I have intellectual and/or natural reasons for whatever belief that I have, from believing in the unique God to believing in the whole set of beliefs of the Shi'ite Muslims (in details sometimes I have my own views based on philosophical and mathematical or physical arguments), so I chose to yield to Allah


Apr
2
comment Does big bang have really any justification while we are living within a huge chaos?
Actually, I still have doubt about the relevance of the evidences for the expansion of the universe and the accuracy of the distance ladder and, thus, how redshift would be understood, but aside from that I accepted your answer as it seems to be the best and the ultimate answer that the present community of physics would give. Thank you for the time and effort you put in your answer.
Apr
2
comment Does big bang have really any justification while we are living within a huge chaos?
Your answer is very good, indeed, but I am going to accept @Jimnosperm's answer, as your answer justifies why Big Bang can be a good idea, but it doesn't conclude that the present state of the universe has necessarily triggered by a Big Bang or a anything close to it. There might be several other ideas that can prove to be good as well.
Apr
2
awarded  Scholar
Apr
2
accepted Does big bang have really any justification while we are living within a huge chaos?
Apr
2
comment Does big bang have really any justification while we are living within a huge chaos?
@annav, that you say "The BB is accepted because of its economy in hypothesis to fit the data" seems to be a reasonable answer on its own, but my question was around the reliability of the evidences for such a conclusion.
Apr
2
comment Does big bang have really any justification while we are living within a huge chaos?
Sorry @annav, as far as I can say, humbly, you have not fully understood my question and, actually, I know what I mean by chaos! Predictability that you claim to be infinitely possible is not possible in the real world. You can always solve an equation by integrating it forward or backward, but if the system behaves chaotically then there would be a horizon time after which the result is not reliable. If you read my question I already talked about the positive Lyapunov exponent and I should add that the planetarium example is irrelevant. Meanwhile, thank you very much for trying to be helpful.
Apr
1
comment Does big bang have really any justification while we are living within a huge chaos?
In particular, once I was studying the distance measurement in astronomy and the distance ladder for some problems that I had with some remarks in it, a great share in the knowledge we have about the distances come from luminosity of the stars, the speed of light and that light travels a straight line far enough from the huge massive bodies, but what if the inter-stellar space has more matter that we usually consider, density gradients and etc.? (actually I had some personal reasons to doubt such, not a totally blind guess but not also an acceptable reasoning for the scientific community)
Apr
1
comment Does big bang have really any justification while we are living within a huge chaos?
Meanwhile, it's a very good idea that if when we look deep at the sky we are looking at the history of universe, then we can safely claim that the universe has had always expanded and this trend has not been chaotic, so that predictability is proved in this regard and the red shift alone is sufficient for the Big Bang theory or a theory close to it to be relevant. Good idea, indeed, and I guess you and all the other great physicists would easily accept it, however, I'm not an expert and things come to my sight rather messy.
Apr
1
comment Does big bang have really any justification while we are living within a huge chaos?
Many thanks for the time you spent on your answer. Actually, I was thinking of the Earth being captured in the gravity of sun as one probable scenario if we really have chaos here. I guess, the stability analysis of the trajectories of the planets would support your point, but I doubt whether this stability analysis considers also nonlinear instabilities as well or not. Considering other celestial bodies beside the solar system in calculations the occurring of a large instability seems not to be safely unbelievable. One may consider solar system alone and find trajectories that never existed?
Apr
1
comment Does big bang have really any justification while we are living within a huge chaos?
I think I can understand your point, please bear with me if I am wrong. You mean if there arise a preferred direction at the great blast, then this direction will be the source of a long-term order if we ignore the chaotic details, am I right? Meanwhile, I'm not an expert in this field, but read somewhere that the anisotropy was in the form of expansion (red shift) in two directions and contraction (blue shift) in the third one, and I guess the preferred direction has its root in quantum fluctuations, right?
Apr
1
comment Does big bang have really any justification while we are living within a huge chaos?
@annav, if I have hopefully understand your point correctly, then one should perhaps provide a thermodynamic study (and indeed a non-equilibrium thermodynamic analysis) of the problem. So far I have seen the footprint of only one non-equilibrium thermodynamicist in this survey, Prigogine, the Noble laureate. However, I read his name around this subject in the book "the big bang never happened" by Lerner. Although I'm not sure how much share Prigogine has in Lerner's ideas, but it looked to me that Lerner identified him as a supporter of his ideas and his ideas are largely refuted
Mar
31
comment Does big bang have really any justification while we are living within a huge chaos?
@annav, I guess you are talking about the very thermodynamic definition of temperature and pressure and entropy for the whole universe? Am I right? You mean because we define such concepts so the study of the Big Bang is thermodynamical and, hence, statistical, as "DirkBruere" has indicated in his answer, but not dynamical? I know that even for the present state of the universe we can define such concepts like temperature and entropy, but is postdiction (borrowing the term from "jimnosperm" below) of the whole trend really a thermodynamic predictability?
Mar
31
revised Does big bang have really any justification while we are living within a huge chaos?
added 47 characters in body
Mar
31
comment Does big bang have really any justification while we are living within a huge chaos?
Please check the update provided for the question, thanks
Mar
31
comment Does big bang have really any justification while we are living within a huge chaos?
@annav, I didn't try to say that the chaos theory invalidate thermodynamics, my concern was the predictability of the dynamics of the universe backward in time ... toward big bang if it will be required to exist ... Predictability is a concern of the chaos theory, isn't it?
Mar
31
comment Does big bang have really any justification while we are living within a huge chaos?
@RobJeffries, please check the update
Mar
31
revised Does big bang have really any justification while we are living within a huge chaos?
updated my answer in an attempt to better understand the matters introduced in comments and answer
Mar
25
comment What was Feynman's “much better way of presenting the electrodynamics” — which did **not** appear in the Feynman lectures?
According to an interview made by the American Spectator with Mead around his book, Mead's idea about the whole subject is somehow revolutionary, although apparently the formulation has nothing really new to the physics world. I guess Mead's idea is from himself, not from Feynman. (Meanwhile, personally, I like his view very much as we already knew it from Islamic philosophy)
Mar
23
comment Does big bang have really any justification while we are living within a huge chaos?
Well, before I read your answer I thought overall prediction in gas dynamics is possible but is not possible for turbulence because of the nonlinearity of the equations governing the latter, missing in the former ... this is what is commonly said ... but reading your answer I suspect and seek Internet for a better explanation and eventually it seems to have something found. Let me take a look at two books just found before to judge your answer.
Mar
23
comment Does big bang have really any justification while we are living within a huge chaos?
@KyleKanos, the idea was to ask if the whole universe as a dynamical system is not predictable for the long-term because it is chaotic, then the short-term experimental evidences cannot say anything special about the long-term behavior of the system, hence, about its probable origin or its probable end.