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Narrowing Hubble's Constant - 8 year study concludes

  1. Jul 24, 2008 #1
    This is a nice little article on the history of the Hubble Constant and its refinement over time. There is also a summary of the 8 year Cepheid Variable study headed by Wendy Freedman of the Carnegie Observatory in it, in which they try to narrow down the limits of the Hubble Constant via 100s of Cepheid Variable observations. A nice little read.

    Last edited by a moderator: Apr 23, 2017
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  3. Jul 25, 2008 #2


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    Nice article, dated July 1, 1999. Just about exactly 9 years ago.
    Wendy Freedman's project (Hubble Key Project) ushered in an age of precision cosmology.
    It was a major part of the revolution in cosmology that occurred in 1998, with not only Freedman's group narrowing down the Hubble parameter but also the reports of accelerated expansion. Cosmology became an exact observational science, not guessing game.

    We are in the wake of those 1998 events.
  4. Jul 25, 2008 #3
    But is this "science" scientific in Popperian sense?

    If the "BB theory" predicted decelerating expansion of the universe (due to "Einstein's biggest blunder") and it has turned out that the expansion is accelerating and Einstein was right plugging the cosmological constant into his equations, how do we know that the universe is expanding at all and it is not just another false assumption of the "BB theory"? We don't see the expansion just the redshift and know that it is assumed by the astronomers to be caused by the expansion.

    But how do we know it is a right assumption? Only because the astronomers can't figure out nothing better as the reason for the redshift? But the "BB theory" already dismissed cosmological constant (that turned out to be needed) and with it the whole idea of "Einstein's (stationary) universe", which may turn out not to be a blunder neither. Someone may suddenly discover that in general realtivity there must be the observed amount of redshift in stationary space. Then what? It couldn't be even published because it would be "against the present consesus of astronomers" (who may happen not to believe in general relativity since they do quite well with the Newtonian gravitation and in the Newtonian gravitation it is the only way).
    Last edited: Jul 25, 2008
  5. Jul 25, 2008 #4
  6. Jul 25, 2008 #5
    Your reasoning being sound, your logic not flawed, your mathematical proofs being rigorous; you truly have nothing to fear. The problem arises when one is convinced of the above, yet can not see the flaws that others may point out.

    The peer-review process is one of the more noble systems in human society.
  7. Jul 25, 2008 #6
  8. Jul 25, 2008 #7
    But in the case of the BB, if all the peers believe the universe is expanding and only they can't prove it (because it's not possible to prove that the reason for the redshift is as the BB assumes, and a lot of evidence is still no proof) but you can falsify the expansion (which is rather easy, as it maby be done by just pointing to a necessary mechanism for the redshift and show that it produces the same redshift yet without the expansion)? Then you end up with no knowledge why you can't be published because peers (referees) don't see any flaws in your stuff but you still can't be published since your peers believe there must be an error "somewhere".
  9. Jul 26, 2008 #8


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    Fortunately, this is not the case.

    Goodness, some of the peers don't, it seems, even "believe" that GR is the last word concerning gravity!
    Fortunately, the peers are doing science, not mathematics (so "proof" is irrelevant).
    Thereby neatly proving (!) that proof is not possible in science (or at least astrophysics).
    Well, write up this "necessary mechanism" and submit it to PF's IR section.

    Oh, and be sure to be prepared for this alternative mechanism to be examined closely, to see that it 'works' everywhere and everywhen (and that there are no fatal inconsistencies more broadly).

    Until there is such a mechanism on the table ...
    Fortunately, modern cosmology is not a religion.

    But let's stick with your paradigm and see if we can falsify the idea expressed in the post of yours I am quoting.

    A powerful falsification would be a paper, published in one of these peer-reviewed journals, presenting a cosmology in which the universe is not expanding, right?

    Now if that's all that's required, your idea is so easily falsified that it's funny ...

    Who wants to go first, with a reference to such a paper?
  10. Jul 28, 2008 #9
    I do not think anyone is claiming the BB is an exact science. I think its fair to say that cosmologists haven't the the foggiest about what occured before the CMB's creation, 380,000 after the BB. But I think cosmology is a very serious science now that Hubble and COBE and the WMAP surveys brought us so much data that they can now form plausible theories based on real evidence. Can string theory make such a claim?
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