On 8/17/2025 6:26 PM, Alan Grayson wrote:
On Sunday, August 17, 2025 at 2:00:28 PM UTC-6 Brent Meeker wrote:
On 8/16/2025 4:37 PM, Alan Grayson wrote:
On Saturday, August 16, 2025 at 12:56:53 PM UTC-6 Brent Meeker wrote:
On 8/16/2025 12:27 AM, Alan Grayson wrote:
On Monday, August 11, 2025 at 10:21:16 PM UTC-6 Alan Grayson
wrote:
On Sunday, August 10, 2025 at 8:23:53 PM UTC-6 Alan
Grayson wrote:
On Sunday, August 10, 2025 at 5:51:31 AM UTC-6 John
Clark wrote:
On Sun, Aug 10, 2025 at 6:01 AM Alan Grayson
<[email protected]> wrote:
On Saturday, August 9, 2025 at 5:45:01 AM
UTC-6 John Clark wrote:
*Until very recently the most distant
object our telescopes can see had a
redshift of about 14, but very recently
there are reports that the James Webb
telescope has seen point-like objects
that seem to have a redshift of 25!
Whatever these objects are they contain
little or no dust as you'd expect
because dust requires elements other
than hydrogen and helium which need to
be made in stars, but if we really are
looking at an object that has a red
shift of 25 then we're looking at
something that existed before stars did.
If confirmed that would be a pretty
profound discovery, and about the only
thing that could explain them are
Primordial Black Holes created during
the first nanosecond after the Big Bang.*
**
*JWST Found Objects at Insane New
Distances (Redshift of 25?!)*
<https://www.youtube.com/watch?v=saL_1R1WitA&t=797s>
*/> How is the red shift related to the
velocity of light? How large must it be to
equal c? TY, AG /*
*Because space is expanding and accelerating,
galaxies that have a redshift greater than about
1.7 are today moving away from us faster than
the speed of light, so we can never reach them
or even send a message to them, they are beyond
our causal horizon; however today we can still
see them because at the time the light from them
was emitted the galaxy was closer to us than it
is now, and back then it was receding away from
us slower than it is now, slower than the speed
of light. For the same reason today we can even
detect the Cosmic Microwave Background even
though ithas a redshift of about 1100, but we
could never send a message or influence anything
that happens that far away.*
*John K Clark See what's on my new list at
Extropolis <https://groups.google.com/g/extropolis>*
TY. If it's not too much trouble, can you show me
how you do that calculation? AG
What is the physical interpretation of the huge red
shift of the CMB? It can't mean extreme recessional
velocity since it's here, everywhere, in every
direction. AG
Since the CMB isn't receding, what is the physical
interpretation of its huge red shift? AG
It's all relative. We're receding, if you insist on
"somebody is receding". The bit of the CMB we see is a
further away bit every day. Its photons have traveled to us
thru space that has been expanding as they traveled.
Brent
Since I am free to choose any observer is receding, I did. But
more important is your model of the photon. Since the wave
property of light is an ensemble property, what allows you to
claim they lose energy as the universe expands? AG
Suppose you and a pro-baseball pitcher are standing alongside a
road playing catch. When you catch his fastball it has an energy
of 70J and stings thru you glove. Now his throw is little off and
instead going to you, it is caught by a kid in a passing car going
the same direction as the throw. But when the kid catches it bare
handed it doesn't even hurt because it's only got an energy of
2J. How did the ball loose energy?
Brent
Good question. The ball caught by the observer in the moving car
didn't lose all of its kinetic energy, and kept moving with the car
after being caught, whereas all the kinetic energy of the ball was
disappated into recoil, sound waves, and heating of the material in
the glove, when the ball was fully stopped by the guy on the ground
catching the ball. Now that I've answered your question, tell me how a
point particle, the photon, can get it wave stretched by an expanding
universe. AG
You didn't answer it correctly. You overlooked the impetus the ball
adds to the car increasing the energy of the car/ball system.
That the photon gets its wavelength stretched during it's long travel
from the CMB is obvious in the inflating balloon model. As space
expands it stretches the photon traveling thru it.
Brent
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