On Tuesday, June 10, 2025 at 9:27:11 PM UTC-6 Brent Meeker wrote:



On 6/10/2025 7:58 PM, Alan Grayson wrote:



On Saturday, June 7, 2025 at 6:28:41 AM UTC-6 John Clark wrote:

On Sat, Jun 7, 2025 at 8:05 AM Alan Grayson <[email protected]> wrote:

*>> The James Webb telescope recently found a galaxy that had a red shift 
of 14.44, from that number astronomers calculate that it took light 13.5 
billion years to reach us, so we're observing how that galaxy looked 13.5 
billion years ago. However during that 13.5 billion years the universe has 
not only been expanding it's been accelerating, so back then the universe 
was expanding slower not faster than it is now. Today that galaxy is not 
13.5 billion light years from us, it is 34.7 billion light years from us. 
Even if we could travel at the speed of light we could never reach that 
galaxy in a finite number of years, and any galaxy that has a red shift 
greater than 1.8 is forever out of our reach.*



*> You say we're observing how that galaxy looked 13.5 billion years ago,*


*Yes.*

 

*> but that the redshift being observed today, gives us the recessional 
velocity today?*


*Not exactly. Velocity is about objects moving through space, but the 
redshift tells us how much space itself has been expanding.*


*The redshift gives us a combination of expansion of space and the 
recessional velocity through space. *



*That's assumed to be zero. *

*But since we're observing the galaxy as it was, about 10 billion years 
ago, how can we deny that it's now receding at near light speed if that's 
what our measurements plainly r**eveal? *


*No one denies that.  The galaxy is further away now and receding faster 
now and hence still obeying Hubble's law.*


*How can it be receding near light speed NOW, if we're measuring the red 
shift in the PAST? AG *

*I am having difficulty resolving the rapid recessional velocity implied by 
Hubble's law, whether it's now or in the past. AG* 

*The movement through space can never be faster than the speed of light** 
nor can we communicate faster than the speed of light, but space itself is 
free to expand at any speed.*  

*> Seems contradictory. AG *


*It's not. 13.5 billion years ago when that light was emitted it was in the 
ultraviolet, but during its journey space has been expanding, so the 
wavelength of the light has been expanding, so now the light is in the 
infrared not the ultraviolet. *


*If photons have no measured extent, which I think Brent concedes, th*
*e model of their "waves" being stretched as the universe expands, does not 
explain their loss of energy. AG *


*They have extent in the direction of travel.*


*Has that been measured? AG *


* Brent* 

-- 
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 visit 
https://groups.google.com/d/msgid/everything-list/65940582-bc29-424d-b06b-16c075b5b9dcn%40googlegroups.com.

Reply via email to