Argument by analogy

[Helio]

I recall two mechanisms for the benefits of inflation.
1) Starting out smaller allows information to be moved brfore it gets too big.
2) Expanding more allows bumps to even out more.

1) Inflation theory itself occurs around t=1E-35 sec. so what I read is that it separates any two regions (points) so quickly that they don't have the ability to establish equilibrium (not that they would). If it were two hot rocks, then as you say, being close together would help even the temperature. But quantum fluctuations, apparently, are just the opposite. Putting a guy and a gal on Halmark closer together is how every show gets things right. But imagine two 2-year olds in a tantrum state; the farther apart the better. [Cat: Analogy rating...??? (1 to 10)[

2) Yes. If photons can stretch why not bumps, too, I guess.

 

[billslugg]

Inflation expanded so quickly the hot spots could not even out. Yet, we needed to invoke inflation to explain why the CMBR is now so even. I'm confused!

 

[Helio]

Inflation expanded so quickly the hot spots could not even out. Yet, we needed to invoke inflation to explain why the CMBR is now so even. I'm confused!

This paper may explain it a little, hopefully more with your background.

Prior to Inflation, as I see it, the distances were so close that a general thermal equilibrium would have existed. The exponential rate of expansion would hold that equilibrium, and perhaps smooth it even further since it would have on-going quantum fluctuations.

I'm guessing that if the expansion rate was weak, like today, the quantum fluctuation density would be greater than what is observed.

The paper does explain how the accelerated rate for expansion produced a flatter universe.

 

[billslugg]

So the accelerated rate of expansion, greater than c, "baked in" a certain amount of anisotropy so that what little was left after equilibration was able to satisfy what we see today.

Quantum fluctuations occurred
Thermal equilibration took them almost all away.
Inflation gave them back.

Now to read the paper. Takeaways:
1) Inflation solves the flatness, horizon and magnetic monopole problem.
2) It provides an explanation for the initial conditions that created galaxies.
3) The "Horizon Problem" is what we talked about where the different areas are not in communication with each other.

Magnetic monopoles confound me. In electricity school they told us you could have one of those. All magnetic field lines being continuous loops by definition.

 

[Gibsense]

The thread has been inactive for a while so maybe I can say a few things that have been discussed previously, some only briefly -

• Once an analogy successfully communicates and clarifies a concept, its primary purpose is fulfilled. Analogies help the listener grasp the intended argument by comparing complex or unfamiliar ideas to something familiar, making them easier to understand. They can also make explanations more relatable and memorable. If the analogy is properly understood, it can accurately convey the concept to the recipient. Although the main goal is achieved once communicated and agreed upon, an analogy can still highlight areas that might warrant further exploration.

• While Einstein's theory of relativity is demonstrably correct, the idea of spacetime as a homogeneous entity might be misleading. I prefer to consider 3D space and time as a process within a 4D embedding space. It is consistent with relativity and more revealing

• What limits the number of dimensions in reality? I see no reason to assume there's a limitation, though there might be something, of course, that I'm unaware of.

• What limits the number of processes that can be time-like? Anything (ignoring perception)?

• Why does science insist extra dimensions need to be curled up? Our perception is limited to 3 plus the time process; why then would we expect to perceive more (except by their effect if any)

• As the CMB can be perceived as an anchor why do we continue to state that there is no such thing as 'stationary'? (As Bill points out) and consequently, an absolute velocity which can still be consistent with relativity (but perhaps not so much with spacetime).

• As Cat points out words and their meaning are crucial to logical thought. I have been humbled by the effect of AI's use of more meaningful composition and better words. No wonder my staff sometimes got things wrong!