From an article in today’s Chicago Tribune on Hoyle:
“The steady state model, which Hoyle supported so strongly, really put the Big Bang to the test,” said Margaret Geller, a senior scientist at the Smithsonian Astrophysical Observatory in Cambridge, Mass. “I think the existence of an alternative spurred many tests both on the observational and the theoretical side.”
“The universe didn’t begin with a huge explosion, Hoyle and others believed, but rather was in a state of constant creation, with galaxies continually separating.”
Q:Can someone explain in layman’s terms for me, what is the “steady state model”?
The steady state model posits that the universe had no beginning in the past; that it had instead always existed more or less as it is today. Because redshift is observed, we know that galaxies are moving away from us. Therefore, the steady state model says that new galaxies are constantly being created and moving away from us.
Any physicist who wanders in can probably give a much better explanation.
Thanks for the link. I found very little when I did a search on google. This one is very to-the-point.
“A steady-state universe has no beginning or end in time; and from any point within it the view on the grand scale–i.e., the average density and arrangement of galaxies–is the same. Galaxies of all possible ages are intermingled.”
Is it possible that galaxies of all possible ages are intermingled?
Are any elements of Hoyle’s theories involving the “steady state model” generally accepted today?
The short answer is no. There are different types of galaxies and, historically, it was possible to believe that some types evolved from others. However as astronomers understood things like how the stars that make the galaxies evolve and so how galaxies themselves have changed in time, they no longer accept that the galaxies nearby can be ones at different stages in their lives. The fact that objects far away (and hence long ago), like quasars, are radically different and highly plausible candidates for being young galaxies indicates that the whole universe was different in the past.
Not as such. Where the essentials of the theory were different from the Big Bang, they aren’t accepted today. In some subsidiary aspects, the ideas were adopted by Big Bang theorists. The most famous example is Hoyle’s explanation of the elements. In both the SS and BB theories, everything is originally hydrogen, but BB theorists like Gamow were arguing that nuclear reactions in the very extreme conditions of the Bang could turn this into elements like oxygen and carbon. It looked as if the hydrogen in the SS theory would remain forever that, refuting the theory, until Hoyle developed the idea that nuclear reactions in stars can do the job. Since Gamow turned out to be overoptimistic about the BB doing the job, astronomers now see most of the elements being formed in the Hoyle manner, albeit with the basic building blocks coming from the BB.
Good ideas are good ideas, even when proposed in contexts that turn out to be wrong, and scientists have always credited Hoyle for this.
By the way, Hoyle’s model has not been disproven. It’s just the the Big Bang has more explanatory power than the Steady State Model, particulary when it comes to the background radiation.
I thought I read somewhere that scientists had calculated the radius of the four-sphere whose surface comprises our universe. This seems to hurt the steady-state model, but I’ve no idea where that came from, so I’ll take your word on it.
The Big Bang is certainly a much more “elegant” theory than Steady State. With BB you’ve just got a sudden, rare, possibly even unique creation of all the matter and energy in the universe. SS begs the question of, what mechanism exists to continuously create new hydrogen? Is it all supposed to be zero-point effects?