Red shift, gravity, and dark energy.

AI Thread Summary
The discussion centers on the relationship between redshift, gravity, and dark energy. It argues that as matter in stars transforms into light energy, the associated gravity does not diminish with the light's energy dilution due to space expansion. Participants clarify that dark energy is not a result of weaker gravity but rather an antigravity effect. The energy emitted from stars is linked to nuclear reactions and does not affect the gravitational stability of stars. The conversation concludes with a participant expressing the intention to explore the topic further in a new thread.
Sci1
Messages
6
Reaction score
0
When matter is transformed into light energy within a star, the gravity associated with the matter is now associated with the light's energy. As space expands, the redshift is dilluting the light's energy and reducing the gravity associated with that energy. Would the energy dillution further weaken the gravitational bonds between galaxies in addition to the expansion itself, giving the appearence of dark energy acceleration?
 
Space news on Phys.org
Would the energy dillution further weaken the gravitational bonds between galaxies in addition to the expansion itself, giving the appearence of dark energy acceleration?
No. Dark Energy acceleration is not weaker gravity, it's antigravity. Have a look at https://www.physicsforums.com/showthread.php?t=415607".
 
Last edited by a moderator:
Sci1 said:
When matter is transformed into light energy within a star, the gravity associated with the matter is now associated with the light's energy.
Nope, doesn't work this way. The energy emitted as light from a star stems directly from the nuclear reaction at its core. Except for brown dwarfs, stars are stable objects which do not collapse under gravity for the majority of their life cycle. The gravity of a star is entirely separate.

Sci1 said:
As space expands, the redshift is dilluting the light's energy and reducing the gravity associated with that energy. Would the energy dillution further weaken the gravitational bonds between galaxies in addition to the expansion itself, giving the appearence of dark energy acceleration?
Nope.
 
This is a result of frame-dependence in the measurement which leads to the appearance of energy attenuation, right?
 
Chalnoth said:
Nope, doesn't work this way. The energy emitted as light from a star stems directly from the nuclear reaction at its core. Except for brown dwarfs, stars are stable objects which do not collapse under gravity for the majority of their life cycle. The gravity of a star is entirely separate.

Chal, I am going to post another topic on this to better understand.
 

Thread 'Matter density right after the decoupling'

https://en.wikipedia.org/wiki/Recombination_(cosmology) Was a matter density right after the decoupling low enough to consider the vacuum as the actual vacuum, and not the medium through which the light propagates with the speed lower than ##({\epsilon_0\mu_0})^{-1/2}##? I'm asking this in context of the calculation of the observable universe radius, where the time integral of the inverse of the scale factor is multiplied by the constant speed of light ##c##.
View full post »

Thread 'Rutgers finds a transparent Einstein Cross - apparently a dark matter "halo".'

The formal paper is here. The Rutgers University news has published a story about an image being closely examined at their New Brunswick campus. Here is an excerpt: Computer modeling of the gravitational lens by Keeton and Eid showed that the four visible foreground galaxies causing the gravitational bending couldn’t explain the details of the five-image pattern. Only with the addition of a large, invisible mass, in this case, a dark matter halo, could the model match the observations...
View full post »

Thread 'Hubble Constant, Dark Energy and the Expanding Universe'

Why was the Hubble constant assumed to be decreasing and slowing down (decelerating) the expansion rate of the Universe, while at the same time Dark Energy is presumably accelerating the expansion? And to thicken the plot. recent news from NASA indicates that the Hubble constant is now increasing. Can you clarify this enigma? Also., if the Hubble constant eventually decreases, why is there a lower limit to its value?
View full post »

Similar threads

I Does dark-energy require a source of energy?
Replies
2
Views
2K
I More extended equilibrium configurations due to dark energy?
Replies
19
Views
2K
I How do you get to the conclusion that there is accelerating expansion?
Replies
23
Views
2K
B Dark energy might not be constant after all
Replies
6
Views
4K
I Avoiding structure collapse due to dark energy?
Replies
3
Views
2K
I Tidal effects of galaxies orbiting one another with dark energy?
Replies
2
Views
2K
I Sachs-Wolfe effect in a Dark Energy universe?
Replies
1
Views
2K
I Can dark matter explain dark energy?
Replies
6
Views
2K
A Models without dark energy
Replies
29
Views
2K
I Brian Cox and the end of the Universe?
Replies
13
Views
5K

Hot Threads

Recent Insights

Back
Top