Fig. 1: this illustration of how to derive the Hubble acceleration in terms of time since the big bang was inspired by a discussion at Dr Cormac O’Raifeartaigh’s blog. The original prediction of the acceleration of the universe (proof that a very small 6×10-10 ms-2 cosmological acceleration of the universe is implicitly present in the normal v = HR Hubble expansion law) was published via the October 1996 issue of Electronics World (after rejection by far more appropriate physics journals), and this size of cosmological acceleration was observationally confirmed a couple of years later by the discovery that distant supernovae are not decelerating due to gravity as predicted by the Friedmann-Robertson-Walker metric of general relativity. But the mainstream continued to ignore the prediction, and instead an ad hoc small positive cosmological constant was introduced into general relativity to overcome the failure of the original Friedmann-Robertson-Walker metric of cosmology. Cormac has very kindly made the following comment:
Hi Nigel, I think the solution you suggest is intriguing, and would certainly not dismiss it. My only caveat is that it is a little above the level intended for this blog, an introduction to the ideas of cosmology.
The purpose of the puzzle posed was
(i) was to illustrate what is meant by talk of the acceleration of the universe expansion
(ii)to illustrate the importance of discussing Hubble’s law in the context of general relativity.
I feel that teachers/communicators have a duty to present the mainstream view first (just as you and I would have encountered it) – after a while, one learns enough to question the accepted wisdom!
That said, I’m sure many of readers will have thoroughly enjoyed and learnt from the discussion on the Hubble post
Comment by cormac | September 8, 2008
I think that he is right, and that when I write a book on this subject the first half of each chapter will have to explain the existing theory in detail, before introducing new ideas. Otherwise there is automatic hostility. On a related note, I notice that Tony Smith has expressed regret about Professor Lee Smolin’s exclusion of non-PhD scientists from physics on the Not Even Wrong blog:
Tony Smith Says:
September 11th, 2008 at 12:34 am
Lee Smolin said (page 11 of 51 of the pdf of his talk):
“… without a Ph.D. from a reputable research department or group (or in very rare cases i.e. Freeman Dyson, the equivalent) someone cannot make useful contributions to a scientific community.
Scientific communities function well only because discussions among experts are restricted to those with a Ph.D. or at least those far along in a Ph.D. program … this is essential and not incidental …”.
Back in the 1980s when I was beginning to formulate my physics model, I asked Yuval Neeman to discuss it with me. He agreed to meet me in his office at U. Texas Austin, and we discussed what I was doing.
He pointed out some problems with my model as it was back then (since then I have worked through those problems) and I asked him about getting a Ph.D. working on the model.
He knew that I did not need a Ph.D. for a job (my law practice gave me both reasonable income and spare time in which to work on physics), and told me (a quote to the best of my recollection):
“If your model turns out to be right, then it is important enough that you do not need a Ph.D.
If your model turns out to be wrong, then no matter how many Ph.D.’s you have, it will still be wrong.”
Until recently, I have felt that Yuval Neeman’s advice would eventually be proven correct, and that my model would be evaluated on its merits.
Now, in light of the above statement of Lee Smolin, who seems to me to be the most liberal member of the physics community with respect to unconventional ideas, I see that Yuval Neeman’s advice will never be effective, as my model will never be evaluated by the physics community.
Tony Smith (no physics Ph.D. or “the equivalent”)
This possibly narcissistic-sounding attitude of Smolin’s towards the likes of non-PhD scientists, including in the past people like Isaac Newton, Michael Faraday, Charles Darwin, Thomas Edison, and others is probably inevitable in the ‘big science’ (financially motivated, obsessed with grants and expensive contracts) world today. Smolin has a footnote in his book The Trouble with Physics that dismisses any research done by people without a PhD.
What Smolin’s attitude will do is to tend to push all serious scientists into doing PhD’s, which as a professor with a vested interest in PhD programmes, Smolin is obviously interested in. I don’t think that Tony Smith’s deduction is completely correct, however. While an undergraduate, I had a paper peer-reviewed by Classical and Quantum Gravity, and it was rejected because it didn’t contribute to string theory, not for any other reason (the editor sent me a copy of the referee rejection report without the name of the referee).