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Posted (edited)

This was debated as a possible model of the universe when I was young. Then the cosmic microwave background was discovered. There isn’t much else to say.

But I gather various attempts have been made to revive the corpse. 

Edit: your link explains the main reasons it was rejected. 

Edited by Strange
p.s.
Posted (edited)

It should not be necessary to go offsite to respond to your post; your reference is not even a theory by Sir Jayant Narlikar.

 

From your ref
Quote

In cosmology, the steady state model is an alternative to the Big Bang theory of the evolution of the universe. In the steady state model, the density of matter in the expanding universe remains unchanged due to a continuous creation of matter, thus adhering to the perfect cosmological principle, a principle that asserts that the observable universe is basically the same at any time as well as at any place.

This perpetuates errors:

Any steady state model has a beginning and (arguably) an end. The (refuted) steady state model does not adhere to the perfect cosmological principle.

I'll try to find the last time I referred to this.

From https://www.scienceforums.net/topic/112696-can-you-witness-the-birth-of-the-universe/?do=findComment&comment=1033673
 

Quote

 

Bondi and Gold posited a 'perfect' universe which had been expanding 'unchanged' for infinite time, which Hoyle knew was impossible for basic mathematical reasons - it was formally disproved long before discovery of the CMBR.

From Mach's Principle and the Creation of Matter

 

Quote

 

If the C-field is not present, it seems that the universe itself is simply a 'transient' and the observed regularity is just 'chance'.

If the C-field is  present ... , it seems that the universe attains the observed regularity irrespective of initial boundary conditions.

 

 

 

 

Edited by Carrock
added ref
Posted
4 hours ago, Carrock said:

It should not be necessary to go offsite to respond to your post; your reference is not even a theory by Sir Jayant Narlikar.

 

From your ref

This perpetuates errors:

Any steady state model has a beginning and (arguably) an end. The (refuted) steady state model does not adhere to the perfect cosmological principle.

I'll try to find the last time I referred to this.

From https://www.scienceforums.net/topic/112696-can-you-witness-the-birth-of-the-universe/?do=findComment&comment=1033673
 

 

 

The evidence is stacked against any and all Steady State models suggested so far, but I don't believe this is true. None of them describe a beginning. If they did. how are they Steady State models?

Posted
1 hour ago, J.C.MacSwell said:

The evidence is stacked against any and all Steady State models suggested so far, but I don't believe this is true. None of them describe a beginning. If they did. how are they Steady State models?

If there is no beginning, they are eternal state, not steady state.

From  https://en.wikipedia.org/wiki/Steady_state

Quote

In many systems, a steady state is not achieved until some time after the system is started or initiated. This initial situation is often identified as a transient state, start-up or warm-up period.

or...

Quote

In electronics, steady state is an equilibrium condition of a circuit or network that occurs as the effects of transients are no longer important.

Consider a series RC circuit with 1volt across it. The steady state voltage across C is 1volt. The initial voltage across C is any voltage you want. Steady state is loosely defined as the state after all startup transients have become negligible. If transients never become negligible it's not steady state. If it is steady state, information about startup transients has been lost due to noise etc but there was still a beginning. (A student could have noted the initial voltage; the steady state is compatible with that knowledge.)

Hoyle suggested one possible beginning to his Steady State model, but that was arguably a demonstration that his model was steady state, not an (impossible) eternal state expanding universe.

 

I find the widespread insistence in cosmology  that steady state means eternal state rather irritating; that idea has lasted far longer than any steady state cosmological theory.

A point that's obscured by this is a (pre CMBR) fatal objection to unending steady state universe expansion which is also a fatal objection to many current lambda-CDM models. Formal descriptions of  these often invoke a future singularity; I have never seen one which describes this as the same fatal mathematical flaw as unending expansion of a steady state universe.

Posted
31 minutes ago, Carrock said:

If there is no beginning, they are eternal state, not steady state.

From  https://en.wikipedia.org/wiki/Steady_state

or...

Consider a series RC circuit with 1volt across it. The steady state voltage across C is 1volt. The initial voltage across C is any voltage you want. Steady state is loosely defined as the state after all startup transients have become negligible. If transients never become negligible it's not steady state. If it is steady state, information about startup transients has been lost due to noise etc but there was still a beginning. (A student could have noted the initial voltage; the steady state is compatible with that knowledge.)

Hoyle suggested one possible beginning to his Steady State model, but that was arguably a demonstration that his model was steady state, not an (impossible) eternal state expanding universe.

In an RC circuit there is a reason why it settles in at that state. What would be the reason in cosmology?

Posted
18 minutes ago, Carrock said:

If there is no beginning, they are eternal state, not steady state.

From  https://en.wikipedia.org/wiki/Steady_state

or...

Consider a series RC circuit with 1volt across it. The steady state voltage across C is 1volt. The initial voltage across C is any voltage you want. Steady state is loosely defined as the state after all startup transients have become negligible. If transients never become negligible it's not steady state. If it is steady state, information about startup transients has been lost due to noise etc but there was still a beginning. (A student could have noted the initial voltage; the steady state is compatible with that knowledge.)

Hoyle suggested one possible beginning to his Steady State model, but that was arguably a demonstration that his model was steady state, not an (impossible) eternal state expanding universe.

 

I find the widespread insistence in cosmology  that steady state means eternal state rather irritating; that idea has lasted far longer than any steady state cosmological theory.

A point that's obscured by this is a (pre CMBR) fatal objection to unending steady state universe expansion which is also a fatal objection to many current lambda-CDM models. Formal descriptions of  these often invoke a future singularity; I have never seen one which describes this as the same fatal mathematical flaw as unending expansion of a steady state universe.

Steady state is a very common term in electrical systems, fluid systems etc etc. I am not suggesting they had no beginning.

I am assuming a cosmological Steady State model.

A circle has no beginning or end. The fact that it seems impossible that expansion could continue forever and has no beginning or end does not mean it has been proven impossible mathematically. The fact that we can make assumptions and from them measure that the 3 most apparent dimensions are expanding does not even guarantee the Universe is getting bigger. A billion years from now it could still look like the time from the BB is still at 14 billion years...this certainly would seem unlikely given our present knowledge...but you need to lean on a set of assumptions to rule it out. 

Posted
5 minutes ago, swansont said:

In an RC circuit there is a reason why it settles in at that state. What would be the reason in cosmology?

I'm not defending a defunct theory, just criticising attacks with no factual basis which deflect from the issues that theory has in common with many lambda-CDM theories.

 

13 minutes ago, J.C.MacSwell said:

....

The fact that it seems impossible that expansion could continue forever and has no beginning or end does not mean it has been proven impossible mathematically. The fact that we can make assumptions and from them measure that the 3 most apparent dimensions are expanding does not even guarantee the Universe is getting bigger.

....

The fact that it seems impossible that expansion could continue forever and has no beginning or end does not mean it has not been proven impossible mathematically.

There's no relevant issue with models which don't predict continuing expansion or the universe getting bigger.

 

"The Problem of Infinite Matter in Steady-State Cosmology" has a proof that expansion must have started and must end within finite time, which has survived much criticism. It is relevant to modern models which predict unending expansion.

Philosophy of Science Vol. 32, No. 1 (Jan., 1965), pp. 21-31

(A free registration is required to read the full article.)

 

Posted
14 minutes ago, Carrock said:

 

There's no relevant issue with models which don't predict continuing expansion or the universe getting bigger.

 

"The Problem of Infinite Matter in Steady-State Cosmology" has a proof that expansion must have started and must end within finite time, which has survived much criticism. It is relevant to modern models which predict unending expansion.

Philosophy of Science Vol. 32, No. 1 (Jan., 1965), pp. 21-31

(A free registration is required to read the full article.)

 

I'm not defending any SS models. I know of none that are competitive with theBB model/s.

I suggest, as an example of what could be considered in a SS model, a continuous expansion space, everywhere as we see it, but without the Universe getting bigger.

Obviously this would require a different set of assumptions from the ones that would logically prove this impossible.

Posted
41 minutes ago, Carrock said:

I'm not defending a defunct theory, just criticising attacks with no factual basis which deflect from the issues that theory has in common with many lambda-CDM theories.

My point is that if there’s no mechanism to get to steady-state, then it must be eternal, and there’s no issue with equating the two.

Posted
40 minutes ago, swansont said:

My point is that if there’s no mechanism to get to steady-state, then it must be eternal, and there’s no issue with equating the two.

There is an issue....

Hoyle steady-state = disproved by observation of CMBR.

Bondi and Gold eternal = disproved by transfinite mathematics( Philosophy of Science Vol. 32, No. 1 (Jan., 1965), pp. 21-31  ) before observation of CMBR.

 There was an earlier, similar paper by the same author (Schlegel) in Nature, which I can't find offhand, but from fallible memory I'm pretty sure Hoyle was aware of it when he cowrote Mach's Principle and the Creation of Matter  in 1963.

That paper is a speculative discussion of initial boundary conditions (i.e. the beginning of the universe) as applied to the steady state theory. Hoyle was aware of the impossibility of an eternally expanding universe and I doubt he'd ever have claimed such was possible afterwards.

This impossibility is relevant to modern models which predict unending expansion. Schlegel later updated his proof to cover lambda-CDM.

 

I can dredge up the references eventually if anyone's really interested.

 

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