On 2/28/2025 10:42 PM, Alan Grayson wrote:
On Friday, February 28, 2025 at 1:22:43 PM UTC-7 Brent Meeker wrote:
On 2/27/2025 10:59 PM, Alan Grayson wrote:
On Thursday, February 27, 2025 at 4:17:13 PM UTC-7 Brent Meeker
wrote:
On 2/26/2025 11:39 PM, Alan Grayson wrote:
If we assume an infinite universe and run the clock
backward, is it reasonable to conclude that the singularity
we imagine forming in the observable region,
The singularity is not IN the observable region, it is the
limiting origin of the observable region.
is identically the same singularity for the entire universe?
Secondly, why do we imagine the hypothetical singularlty
indicates the GR fails in this situation? After all, if the
expanding universe is determined by measurements, and the
average distances between galaxies decreases as the clock
runs backward is also determined by measurements, what has
this to do with GR, since it's all measurement determined?
TY, AG
You can't be so dense as to not know the difference between a
measurement and an extrapolation.
Brent
I'm just saying that measurements suggest a singularity without
applying GR. The reason the unobservable region is unobservable
is because expansion in that region is faster than light speed.
So if we run the clock backward, won't that region collapse
faster than light speed, with the result that the entire universe
converges to a single singularity? AG
It depends I suppose on what "run the clock backwards" means.
It's unphysical to have spheres of outgoing radiation contract
backward to a point as in playing a video backwards. But if
that's what you mean then yes the entire universe becomes
infinitely dense, a singularity...but not a point, it's still
infinite.
Brent
So, as we go backward in time, the observable universe seems to
converge to a point, while the rate of expansion of the unobservable
universe increases since the rate of expansion in earlier times was
greater than it is at present? In this scenario, how could the
unobservable univese reach an ultra high temperature as we approach
the BB? AG
The matter in it becomes more dense. That's the opposite of expansion.
Brent
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