The Last Of The Steady-State Trio Has Moved On

By cjohnson | September 12, 2005 11:17 pm

bondiHermann Bondi, a giant in the fields of astrophysics and cosmology, died on September 10th. He was best known as one of the co-authors (with Fred Hoyle and Tommy Gold, who passed away in 2001 and 2004, respectively) of the Steady-State model of the universe. Whatever you think of Steady State now, we must credit it (and its authors) for helping launch the modern era of precise cosmological debate – construction of models and confronting them with precise data. For a long while, it simply was not clear which model (Steady-State or Big Bang) better fit the data, and the arguments over this matter firmly matured cosmology as a field. The physics of this issue is truly exciting, and I recommend (as I have before on this blog) Simon Singh’s excellent book “Big Bang” for a great piece of writing on the subject.

For the Guardian’s obituary of Hermann Bondi, written by Andrew Tucker and appearing in print Tuesday, see either the digital edition, or the regular website version. There was an obituary today in the Independent, and it can be found here.


  • Brad Holden

    It is worth noting that Bondi and Hoyle also came up with an elegant solution for the problem of the accretion of matter in the form of a wind onto a sphere. Called Bondi-Hoyle accretion, people still use this solution as a basis for more sophisticated problems and solutions. It was not that Bondi or Hoyle were always wrong, they were very gifted, but they were wrong about steady state cosmology. I am guessing there is an important lesson for all of us in that.

  • Clifford

    Brad, see my comments on the thread of the Greatest Physics Paper! post on Hoyle’s brilliant work in nuclear processes in stars, and the “Hoyle resonance”. As far as I’m concerned, having done that amazing piece of work, he was alllowed to be as wrong as he liked about anything else.



  • Steve

    Bondi Mass, Bondi-Metzner-Sachs group…all very clever stuff. Who cares if they were wrong about Steady State—Hoyle, Gold and Bondi really were ‘The Guvners’!

  • Adam

    Bondi was a big fan of Karl Popper’s views on the nature of Science, I think. The strength of the ‘hot big bang’ vs steady state debate is a great example of what Popper was talking about; being on what turned out to be the ‘wrong’ side at a time when the evidence wasn’t strong enough to decide either way is no disgrace.

    How did the steady-state people address the Second Law, incidentally (ie, if the universe was immortal, why wasn’t it in a state of maximum entropy?). I guess that new matter arrived in a state of minimum entropy? Or, at least, the system wasn’t sealed, so the question wasn’t relevant?

  • MobyDikc

    Isn’t it a false dilema to assume that Steady State and Big Bang are the only possibilities?

    I’ve considered the idea that light doesn’t just get “tired” and lose energy, but it also loses velocity over huge intergalactic distances, so it takes more time to travel the same amount of space, rather than it taking more time to travel more space if the velocity of light was constant.

    Of course, this breaks the laws of relativity, which seems to irritate a bunch of people. But it doesn’t break the laws of QED, so maybe that speed of light postulate isn’t a good one.

  • Sean

    I don’t know anyone who would say that Steady State and the Big Bang are the only possibilities. If you mean “possibilities that fit the data,” you only have the Big Bang; if you mean all possibilities, there are an infinite number.

    Tired light models, with or without modified velocities, do indeed violate the laws of relativity, but that isn’t what bothers people. It’s the flagrant disagreement with observations — supernovae time dilation, the CMB blackbody spectrum, and the Tolman surface brightness test (not to mention all ground-based tests of electromagnetism, of which there is an impressive array) — that is kind of irritating. See Ned Wright’s Cosmology Tutorial.

  • Clifford

    And Ned Wright is coming to USC on Monday to do the departmental colloquium entitled “What’s New In Cosmology”. Do attend if you’re in the area; he’s a great speaker!


  • MobyDikc

    Sean, I had been looking for research on slowed light (velocity modified) models.

    You’re saying that these models exist and do not match what is observed.

    I haven’t seen them, and I was looking pretty hard. Can you point me in the right direction?

    By the way, from what I’ve read, Ned’s critiques of tired light have never included velocity modified theories.

  • Adam

    Joao Magueijo is a proponent of a varying speed of light theory, isn’t he? Although I don’t know what ‘tired light’ means; is that just a loss of energy merely as a function of time, or what?

  • Clifford

    Adam…click the link sean gives above. Explantion right there…. -cvj

  • Sean

    There’s a crucial distinction between “tired light” and “slowed light,” despite the connotational similarity. Tired-light models try to replace the cosmological redshift with a decay in photon frequency even while traveling through a non-expanding universe; those models are ruled out. Variable-speed-of-light theories have been pursued by Albrecht and Magueijo and Moffat and others, typically with an eye to the early universe. I don’t know of anyone who tries to use them to explain the cosmological redshift, since they would then be ruled out for the same reasons given above.

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  • MobyDikc

    Sean, can you cite a paper that supports your assertion that the same flaws of steady-state and tired-light models are unavoidable in a slowed-light model?

    I haven’t found any research that concludes what you assert.

    You’ve pointed me to Albrecht and Magueijo and Moffat, but they all seem to believe that the speed of light is going slower than it was at the beginning of time.

    That’s very different than what I’m asking to be considered. You realize that, right?

  • Fyodor

    Hawking and Ellis point out that the steady-state guys were using a spacetime that isn’t geodesically complete. Does anyone know whether the steady staters were aware of this? This may seem like a weird question but you have to bear in mind that this was at a time when people didn’t even understand the Schwarzschild solution properly……

  • Shantanu

    Brad and others, even though Bondi was the originator of steady -state
    theory I am not sure whether he still believed in it after the discovery
    of CMB. Many people who thought could be right turned skeptics after
    the discovery of CMB in 1965.
    See Hale Kragh’s book on “Cosmology and Controversy”
    which has a very good discussion on the history of the two theories
    of cosmology. This book actually makes a list of people who believed
    in steady state theory (before 1965)
    fydor, I am sure the steady state people would be aware of it, given
    that Hawking, Ellis, Hoyle, Narlikar, Burbidge etc. overlapped at Cambridge
    University during 60’s and 70s when most of this was worked out.
    anyhow one important lesson is that even though Hoyle and Narlikar
    may have been believers in steady stata theory, they were very supportive
    of young colleagues working on Big-Bang and other issues which maybe
    directly contradictory to their own research.

  • John Farrell

    I was saddened to see the post. While I was writing my book, Prof. Bondi was kind enough to send me some brief personal reminisinces of his acquaintance with Georges Lemaitre.

    Contrary to the hyped up rivalry one often reads about between the original proponents of the big bang and the steady state during the 1950s, I was surprised (and I really shouldn’t have been) by how well Bondi and Hoyle got along with Lemaitre. They obviously had a high respect for each other’s work and enjoyed dining out together. Hoyle and Lemaitre even spent two weeks on the road during a car tour of Italy.

  • Shantanu

    Sean since you have commented a lot on this blog as well as on on recent
    as well old astrophysical/cosmology controversies , one question which I have is that what are your thoughts on the speed of gravity controversy from two years ago?
    (For others I am am referring to
    do you think the speed of gravity has been measured to be “c” in a model-independent method as claimed by Kopeikin?
    if you have already discussed this somewhere , could you point to the url.
    note the same question is also open to other contributors as well as readers
    of this blog.


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