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Mathematical proof of the Big Bang Theory

  1. Jul 24, 2008 #1
    Can anyone tell where I can find the mathematical proof of the Big Bang theory and by whom, I'm interest in the calculation only.
    If you have a scientific paper available with you please send it to me(yousifhot@hotmail.com) I really need it.

    Thanks a lot,
     
  2. jcsd
  3. Jul 24, 2008 #2
    Hello and welcome to PF yousless!

    There is no one equation for the standard BB model of the universe. I am afraid you are going to have to do much more reading than you might have expected :smile:

    Just to get you started: http://arxiv.org/abs/0802.2005

    What exactly are looking for? How in depth? The theory is not one that can be written out in a single equation, it is based on many models and observations and equations. Think of it more as like evolution is a theory, but one could not write down the single mechanism of change over time.

    Just in case this is more of what you need: http://www.astro.ucla.edu/~wright/cosmolog.htm

    http://www.damtp.cam.ac.uk/user/gr/public/cos_home.html

    http://map.gsfc.nasa.gov/universe/

    These are all good general introductions to how we currently view the whole picture of cosmology, which natural follows from a big bang event. Good luck!
     
  4. Jul 24, 2008 #3

    marcus

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    EDIT: Looks like Robert already answered this. If I had known I wouldn't have posted. Thanks Robert. Good links!
    Anyway this is what I wrote earlier, attempting to respond.

    In the mathematical sciences like cosmology the way a theory is confirmed is by comparing a model with empirical data.

    I am not sure what you mean by Big Bang theory. that is a name that caught on in the popular media and I think it often is used to refer to the standard cosmology model, which is some math equations (Friedmann equations)

    What you do with the Friedmann equations model is you plug in some values of the parameters and see how it fits the data. The test is how well you can make a single choice of like 3 main numbers and then have it predict all the data in sight. All kinds of data----galaxy counts and redshifts, supernovas, the temperature map of the microwave background---all sorts of relatively old and relatively new stuff!

    The fit is amazing. so the 3 or so main numbers (the parameters) can be determined with remarkable precision and reliability.

    This is a big change since 1998. Before 1998 there were various competing guesses as to how to model the universe and what parameters to use. Now the data is a lot better. Better instruments helped.

    anyway the way the model is confirmed is by fitting to a huge body of observations.

    =================

    once you have the Friedmann model you can just look at it and it is obvious that, since it is always expanding for all our past history, if you follow it back in time you get to a condition of very high density and temperature

    I wouldn't call that a theory. It is more a little piece. It is just an automatic feature of the model that fits all the data over all time in the best way we know, so far. It's how the model that fits begins telling the whole story.

    someday when we get a better model (if we do) maybe it will have a slightly different beginning. To me, for what it's worth, the beginning is not the most important feature. What impresses me is how well it covers the whole story.

    Actually I think the details right around the beginning may change as the model is quantized, so people won't describe right at the start with the same words, probably won't say bang, may say bounce or something else. But that is just a little detail. We will still have a beautiful fit to the whole of the history that we can see.
    ==================

    I'm still sort of wondering what you mean by "the Big Bang theory" and what it is you would like a proof of. would you like to describe a bit more
    =================
     
    Last edited: Jul 24, 2008
  5. Jul 25, 2008 #4
    Sorry, but such a proof does not exist. That the Big Bang happened is an assumption based on another assumption, namely that the observed "cosmological redshift" is Doppler effect.
     
  6. Jul 25, 2008 #5

    marcus

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    actually in an introductory course in cosmology one of the first things you may learn is that the redshift is not doppler---there's a different formula for it because the mechanism that produces it over largescale distances is somewhat different

    doppler formula will work as an approximation at short distance though :smile: so you are part right.

    =======================

    Yousif,

    I think it is pretty clear that you are not in need of a mathematical proof. Math proofs are deductions from axioms. Science is different from mathematics. In science things are based on empirical evidence----observation, measurement, experiment.

    what you need is observational EVIDENCE that in very early universe there was a time of extreme high density and temperature.
     
  7. Jul 25, 2008 #6

    D H

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    You are looking for something that doesn't exist.
    Good start, as there is no such thing as a "mathematical proof" of any scientific theory. Mathematicians prove theorems using rules of logic. Scientific theories are based on observation. Observing 10,000 black crows does not mathematically prove the scientific conjecture that all crows are black.

    Good start, bad finish. Please do not bring your pyschoceramics to this forum.
     
  8. Jul 25, 2008 #7

    mgb_phys

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    Especially in astronomy!
    The famous joke about a bunch of scientists observing a cow from a train.
    Look says the astonomer - all cows in America are black
    No says the physicist - there are SOME black cows in America.
    Then the mathematician says - there exists at least one cow which is black on one side.

    (And finally the computer scientist says - look at the moo-moos !)
     
  9. Jul 25, 2008 #8
    Priceless! :rofl:
     
  10. Jul 25, 2008 #9
    I assume it was about Doppler effect translating into recession of galaxies? What is it then if not a Doppler?
     
  11. Jul 25, 2008 #10

    russ_watters

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    The problem is with your claim that the redshift-speed/distance corellation is purely an assumption. It isn't.

    edit: It may be better to put it another way: while it is true that when building a theory on another theory, the conclusion of the first theory must be taken as an axiom in the second, but that shouldn't mislead one to be believe that that first theory isn't still a testable scientific theory with evidence of its own to back it up. In addition, the success of the new theory provides evidence to back up the theories its axioms are built from.
     
    Last edited: Jul 25, 2008
  12. Jul 26, 2008 #11
    Thanks for clarifying the problem. I agree with most what you said. I even agree with redshift/distance correlation but I dont' agree that redshift/speed corelation is more than an assumption.

    My doubts are based on a fact that anything that moves in the universe, statistically, since there are exceptions called sling effect, loses its kinetic energy (the effect known as dynamical friction: see Pioneer 'anmaly' eqaul almost exactly the cosmolgical redshift) so since the laws of physics are universal it has to apply also to photons and if Pioneers can have such redshift why not the photons?

    Once, just for fun, I calculated, such dynamical friction for photons and I got almost the same results as there are for Pioneers. So in my opinion the redshift/speed corelation is just an assumption and also a false one. Unfortunately I'm not neither an astronomer nor a physics professor to whom people would listen so I'm doomed to keeping my opinions for myself (occasionally sharing them with interested people through the internet; though not many interested people are there).
     
    Last edited: Jul 26, 2008
  13. Jul 26, 2008 #12

    Nereid

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    But hey, you're making the same mistake that you accuse astrophysicists of making!

    "Pioneer 'anmaly' eqaul almost exactly the cosmolgical redshift"

    In this you assumed that what is reported as a residual unmodelled acceleration has no possible explanation other than {whatever your idea is}.

    What if, tomorrow, a new paper comes out which reports more detailed, more extensive modelling and reduces the Pioneer anomaly to only 10% of "the cosmolgical redshift"?

    What if, next week, a new paper comes out which reports an extensive study of other space probes and finds no "Pioneer anomaly" at all?

    You see the problem?
     
  14. Jul 26, 2008 #13
    This is the confirmation of the situation of physics walking on two legs: experimental/observational and theoretical :) And of course I know that theory can't be changed every time there are "new" observational data since the observations may be wrong. Even if they turn out finally to be right, only when a new theoretical support for them is found a new theory may be proposed (obviously). But there is already theoretical support for so called "Pioneer anomaly" called general relativity. More precisly the not often used properties of GR (surely not used by astronomers if they have problems with explanation of Pioneer "anomaly" or Arp's "local quasars").

    As I said above "I calculated, such dynamical friction for photons and I got almost the same results as there are for Pioneers". However I used GR and the friction turned out to be proportional only to the curvature of space. So it is surely "anomalous" in Newtonian gravitation where the space is flat.

    To reveal the way I did calculations is unfortunately against the rules of the forum and I don't want to be trown out from this forum for promoting "original research", so I rather wait until astronomers start using GR and find the same thing (I was told that I may use IR section of this forum for revealing such calculations but unfortunately any attempt to get there produces consistently Database error message and the address for reporting the problem comes out blank :)).
     
    Last edited: Jul 26, 2008
  15. Jul 26, 2008 #14

    marcus

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    Try again. I just this moment tried the link to Independent Research forum and it worked perfectly:

    https://www.physicsforums.com/forumdisplay.php?f=146

    I congratulate you for looking into the possibility of displaying your calculations in the IR forum. It seems like a good fit. Don't be put off by the "database error" message. I have encountered that dozens of time at PF, but never in IR. It normally goes away after an hour or so. System problems like that are not confined to IR, and they are infrequent. So I do encourage you to try IR forum again and I expect you will not encounter system problems.
    (if you do, let us know----I will try and see if I experience them also)
     
  16. Jul 28, 2008 #15
    I can see the posts (the forum works in this sense) just my posts can't be posted to it. I can't even preview the post. It accepts short posts though (up to about ten lines). I'm guessing there is a some kind of timeout problem since it comes with the messag "Database error" after almost exactly 20 sec.
     
  17. Jul 29, 2008 #16
    I do not know much about cosmology or even basic physics, so please pardon my ignorance. But don't the solutions to the Einstein field equations say that space must either by contracting or expanding? Although this is not proof of the big bang theory, it supports the empirical evidence that space is expanding, no?
     
  18. Jul 29, 2008 #17

    mgb_phys

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    Science works the other way around.
    Measurements that the universe is expanding supports the premise that Einstein's field equations are correct in being a good description of the universe.
     
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