Know any theoretical physicists?

So, I tend to think about a lot of stuff. Some of which I'm not qualified to even think about thinking about. One of the things I keep coming back to is theoretical physics. I don't know a lot of maths, which does tend to hinder any deeper understanding, but I like reading and thinking about it nonetheless. It's like a puzzle the size of the universe.

There's an idea in physical cosmology that I've been thinking about for a while now. It works in my head, the puzzle piece seems to fit with all the adjacent pieces that I'm aware of, but... I'm still not qualified to tell whether it's anything except utter nonsense. Neither is anyone I know. I've tried emailing a couple of different physicists, but never got a reply. I suppose either they shook their heads in tired disbelief and erased the mail, or it ran afoul of their spam filters.

I'd still like to ask someone about it, though, so I'm posting this here on the off chance that one of you might know a physicist in the right branch of the field, who might be willing to take the time to tell a complete layman what's wrong with his idea. Any clue to finding such an individual would be much appreciated.

As it happens.....
I married a former physicist and know a few more....do you want to tell us more about your idea, so I can see if one of them may be able to give a view?

That would be wonderful. Thank you!

Briefly, the idea is a cyclic cosmology model based on a Big Rip-like scenario, that is, the acceleration of the expansion of the universe is fast enough to push the cosmological event horizon ever closer to the observer. From what I've understood, this scenario hasn't been ruled out, and some things I've read suggest there's some data pointing in that direction.

Now, if I've understood this correctly, the cosmological event horizon is believed to be similar to the event horizon around a black hole. Crucially, it's thought to have its own equivalent of Hawking radiation. The radiation temperature of the Hawking radiation is inversely proportional to the mass of the black hole, i.e. a very small black hole radiates at a very high temperature and quickly evaporates. Since the radius of the event horizon depends on the mass of the black hole, and the surface area of the event horizon depends on the radius, it follows that the smaller the apparent surface area of the event horizon, the higher the radiation temperature.

If the same is true for the cosmological event horizon, and if we assume that it gets closer to the observer with time, the radiation temperature, which is at present extremely low, should increase over time. There should be a point, when the observable universe (and thus the surface area of the event horizon) is sufficiently small, where the radiation temperature gets high enough to emit massive particles. Increasing numbers of massive particles emitted into a shrinking volume of space means increasing density. Eventually, the gravitational influence of this mass would be sufficient to slow the expansion, the cosmological event horizon would recede to a vastly greater distance, and its radiation temperature would drop nearly to zero.

This model would seem to avoid the singularity and the issues associated with it, since the expansion is continuously ongoing, albeit at a variable rate. It's widely accepted that the expansion was much more rapid very early in the history of the universe (cosmic inflation), which follows naturally from this model. It would also solve the horizon problem, just as cosmic inflation does, since the initial temperature in the early universe would be determined by the point where enough massive particles were emitted to slow the expansion, which would presumably be the same everywhere.

There are some more implications I've thought of, and probably a lot that I missed, but this might be enough to outline the idea. I'd be very grateful if someone knowledgeable in the field would take a look at it and let me know what they think. (It's very likely to be nonsense, but then I'd still like to know where I went wrong.)

I'm sure that is well explained, but beyond my feeble brain at present (I'll have to read it a few times).
I've sent a query into the ether and we'll see if we get a responce.

Nancy Reading wrote:I'm sure that is well explained, but beyond my feeble brain at present (I'll have to read it a few times).
I've sent a query into the ether and we'll see if we get a responce.

Understandable. I probably didn't explain as clearly as I could have, either (my head is full of flu at the moment), and again, maybe it's just a huge load of rubbish. But thank you so much for passing it on!

Good evening.  Although I only did observational astrophysics, and how it helps constrain cosmology, I do have an observational cosmologist to hand.

Our first note is, we are observing from within the system when it comes to the Universe.

So that's fundamentally different from when we observe a black hole, as in that case we're outside the system, and the event horizon.

With the Universe, there is no "outside" from which to observe it.  By definition, the Universe contains everything within itself.

I hope you feel better soon: no rush to reply!

Ac Baker wrote:Good evening.  Although I only did observational astrophysics, and how it helps constrain cosmology, I do have an observational cosmologist to hand.

Our first note is, we are observing from within the system when it comes to the Universe.

So that's fundamentally different from when we observe a black hole, as in that case we're outside the system, and the event horizon.

With the Universe, there is no "outside" from which to observe it.  By definition, the Universe contains everything within itself.

I hope you feel better soon: no rush to reply!

Hello Ac, and thanks for the reply!

As far as I can tell, we can't really observe the "inside" of a black hole from the outside, all we see (or would see if we actually spotted one close enough to observe it directly) is the event horizon. My understanding is that the regions outside the observable universe are an almost exact equivalent of the inside of a black hole. Both are separated from the observer by an event horizon, and so everything that goes on in these regions is completely unobservable. The only difference I can see is the curvature of the event horizon going different ways (the cosmological event horizon is essentially "inside out" compared to that of a black hole) and the somewhat related fact that in the cosmological case, what gives rise to the horizon is expansion due to dark energy, rather than gravity.

I gather that both types of event horizon are theorized to behave the same way regarding Hawking radiation (although there aren't any direct observations of either to back this up) which makes sense, since Hawking radiation is related to the Unruh effect. An observer just outside the event horizon of a black hole has to accelerate in order to avoid passing through the horizon, and due to the Unruh effect will then see a "glow" in space that appears empty and dark to a non-accelerated observer. Likewise, if you had two observers standing half the diameter of the observable universe apart, they would need to accelerate toward one another in order to not be separated by their respective cosmological horizons, and the same phenomenon would occur. I'll confess that I don't understand the details of how the Unruh effect and Hawking radiation are related to one another (like I said, I don't have a lot of maths, and this stuff is beyond me) but from what I've read, it's like that.

(Also, I feel more or less okay at the moment, but this virus is extremely back-and-forth. I feel fine, then I do something that's apparently just a bit too much physical effort, and I'm back to feeling lousy. It's frustrating. Thinking about this stuff is just fun, but maybe the clarity of my explanations suffers a bit. Anyway, thank you for helping to distract me from feeling bad!)