How long has the universe existed according to the steady state theory?

Question

how long has the universe existed according to the steady state theory?

Answer 1

infinite. no one can tell either. oh! wait, i'm gonna do some research!

Answer 2

Forever.

The steady state theory held that the universe expanded and new matter somehow was created to fill up the expanding void.  This process would have been unspecified.  Fred Hoyle was the proponent (& Biondi & Gold).   It was at least a plausible theory in 1948 but the business of new matter creation caused strong doubts and kept it at the margins.

After a while other evidence such as the cosmic microwave background radiation began to validate theories of a "Big Bang" which in fact was at first used as a put-down by Hoyle in 1950, but like so many put-downs, was adopted by the people who were derided.  And it is succinct!  

You basically have two choices in cosmology.  You can choose the always-is always-was, which means, that there is this huge effect (the universe) with no explainable cause.  That's the steady state theory.

You can choose the once-upon-a-time there-was-a-beginning.  That gives us a Big Giant Cause, with a visible effect, but we don't know how the Big Giant Cause came to occur.   That's the Big Bang Theory.   It is strongly backed by theory and observation, but one never knows, maybe some day some other theory will come along.   Theological explanations ("let there be light") don't get around the what-made-it-happen problem.  They shift the causation to God but leave us without recourse as to explaining the cause of God.   It gets around to: there's something happened and it defies description.   There are certain things one can say, such as a condition of no-time no-space is inherently unstable but that's just saying that we're here so therefore this happened because otherwise we wouldn't be here.

It is well to remember that in these theories we are always talking about the beginning of time as well as of space and stuff in space (like galaxies and us).  If you try to imagine a big black empty box, and then something happened in it leading to stuff, like galaxies, you're not there, you're not at what the theories are talking about.  Because the big black box you're thinking about is space, and that is the thing whose beginning is under discussion; and the thing that we imagine as happening in that big black box, the big explosion, has a moment of before:  we think in our heads there is this space, and this explosion happens, the creation, so there's a moment before, and a moment after.  That's not what this is all about.  When they say NOTHING they mean NOTHING as in no time no space no matter.   It is safe to say that the condition of no-space no-time is unimaginable to the human mind, which is a point made (of all people) by the philospher Kant.   But you can get there (actually there is no there there)  with some fine mathematics.  

Now, however, there is a new category of explanations that posit multiple dimensions and collisions of branes that make for the creation of universes and all that.   This theory amounts to saying well there is this big bang that happened, so Gamow and Hawking and all those guys are right about a Big Bang, BUT behind that big bang is all this other stuff which theories can't specify but anyhow if two things that we've never seen and cannot prove were to collide we'd get a universe with our physical laws.  In short, these are pre-Big-Bang speculations move us back to the  always-is always-was category.  Now we get the spontaneous and on-going (in other universes) creation of matter but instead of explaining it by waving the arms around, like Hoyle, we explain matter via the Big Bang as a one-time event in *our* universe even though *our* universe is only one dimension out of many.    So in these theories your answer would also be "forever" but one would qualify it by saying that time as it runs in *our* universe has only been ticking for about 13.5 billion years.  As for the pre-big bang we can't specify because we're not sure things like time would work there....but all considered, in the pre-big-bang brane way of looking at things, "forever" is probably as reasonable a word as any.

That's pretty much it.  

hope that helps,

GN

Answer 3

The steady-state theory holds that the universe looks, on the whole, the same at all times and places. The Austrian-British astronomer Hermann Bondi and the Austrian-American astronomer Thomas Gold formulated the theory in 1948.