On Thursday, January 30, 2020 at 10:40:26 AM UTC-7, Lawrence Crowell wrote:
>
> On Thursday, January 30, 2020 at 11:21:25 AM UTC-6, Alan Grayson wrote:
>>
>>
>>
>> On Thursday, January 30, 2020 at 10:16:48 AM UTC-7, Lawrence Crowell
>> wrote:
>>>
>>> On Wednesday, January 29, 2020 at 2:57:25 AM UTC-6, Alan Grayson wrote:
>>>>
>>>> Considering the distant galaxies, they're receding at near light speed.
>>>> So according to SR, their clocks should be ticking at a much slower rates
>>>> than, say, a local clock in our galaxy. OTOH, there's a physical clock for
>>>> the entire universe; namely, the temperature of the CMBR. If we tell time
>>>> by this clock, all clock readings of all galaxies are identical. So which
>>>> is it? Are clocks in distant galaxies running slower than a local clock in
>>>> our galaxy, or are both clocks running at the same rate? TIA, AG
>>>>
>>>
>>> The physics with distant galaxies is general relativistic, not special
>>> relativity.
>>>
>>
>> *I know. Now, if you can, please answer my question. AG*
>>
>
> I did below
>
> LC
>
>
>>
>>
>>> The redshift factor v = Hd, in the near linear form, has the redshift
>>> factor v/c = z = Hd/c. In the FLRW metric this is a bit more general with z
>>> = e^{Ht} - 1, where for small HT << 1 then t = d/c and z =~ Ht. The reshift
>>> factor for the CMB is z = 1100, which means that anIR photon with
>>> wavelength 1000nm is expanded to 1100 microns, or a millimeter. The peak of
>>> the CMB blackbody radiation is 160 GHz and this was produced by radiation
>>> peaked at 17.6x10^{4}GHz. This is in the IR region with a wavelength of
>>> 5,87x10^{-5}cm, in the IR, The z multiplicative factor is the same as a
>>> time dilation, where we can think of these red shifted photons are
>>> representing the slowdown of clocks (clocks being the quantum oscillations
>>> of atoms etc) in this surface of last opaque scatter.
>>>
>>> LC
>>>
>>
Maybe I was making the wrong assumption; namely, that the CMBR "clock"
reads the same "time" for the far galaxy as compared to its reading in our
galaxy. But this is probably wrong since CMBR as viewed from the far galaxy
is from a much earlier epoch, so the reading cannot be identical. Do you
agree? AG
--
You received this message because you are subscribed to the Google Groups
"Everything List" group.
To unsubscribe from this group and stop receiving emails from it, send an email
to [email protected].
To view this discussion on the web visit
https://groups.google.com/d/msgid/everything-list/79048b7d-bcba-4cb8-814c-57515239a104%40googlegroups.com.
