The Speed of Light & Gravity: Varied Across the Universe?

In summary, some physicists and cosmologists have observed that the speed of light is not constant in different regions of the universe. However, according to Einstein's theory of relativity, gravity also moves at the speed of light. This raises the question of whether gravity would be stronger or weaker if it traveled faster in certain regions. It is believed that the strength of gravity would remain the same, as local measurements eliminate the effects of spacetime curvature. Reports of the speed of light changing are actually variations in the fine structure constant, which could also indicate changes in the properties of atoms. These effects are not predicted by relativity and their existence is still uncertain. It is also important to note that all massless particles, including photons and gravit
  • #1
lnsanity
34
0
According to some physicist and cosmologist observation the speed of light is not a constant depending on region of the universe they observe and according to Einstein theory gravity move at the speed of light now my question is if gravity move at speed of light than gravity should move faster or slower in some region of the universe than would gravity be stronger or weaker if it travel faster or would it be the same ?
 
Last edited by a moderator:
Physics news on Phys.org
  • #2


It would be the same, although it should be noted work saying that universal constants like c vary throughout the universe are tenuous.
 
  • #3


ok why it would be the same what is the mechanism of gravity that explain that it would remain the same ?
 
  • #4


locally, the speed of light and gravity is constant...when viewed from a distance, measurement speeds can be different than c when gravity is present as spacetime curvature affects the observed measurements. Local measurements eliminates the observational affects of curvature.
 
  • #5


Usually results that are reported about "the speed of light changing" are actually results about variations in the fine structure constant.

See for instance http://www.phys.unsw.edu.au/einsteinlight/jw/module6_constant.htm

This is reported in the popular press as "the speed of light changing over time", because news reporters seem to like that the lay audience will like that idea, and the editors think it makes a catchier title. The actual situation is rather less clear - physicists are more likely to interpret the resujlts in terms of atoms changing their properties than the speed of light varying.

Note that the two descriptions are experimentally indistinguishable, once the details of what you mean when you say "mesaure the speed of light" is worked out.

These effects are NOT predicted by relativity, and are not really confirmed either, so the best way to think about them (assuming they do actually exist) isn't especially clear.
 
  • #6


I should have included: all massless particles are believed to travel at the fixed speed 'c'..of course that includes photons [light = electromagnetic radiation] and gravitons [gravity].
 

Related to The Speed of Light & Gravity: Varied Across the Universe?

1. What is the speed of light?

The speed of light is defined as approximately 299,792,458 meters per second (or about 186,282 miles per second) in a vacuum. This is the fastest speed at which all matter and information can travel in the universe.

2. How does the speed of light vary across the universe?

The speed of light is a constant in a vacuum, but it can vary in different mediums. For example, light travels slower in water or air than it does in a vacuum. Additionally, the speed of light may be affected by gravity, which can warp the fabric of space-time.

3. What is the relationship between the speed of light and gravity?

The speed of light and gravity are closely related in that they both play a role in the fabric of space-time. According to Einstein's theory of relativity, the presence of mass or energy can cause space-time to curve, affecting the path of light and the strength of gravity in that area.

4. Is the speed of light the same everywhere in the universe?

While the speed of light is considered a constant in a vacuum, it may vary in different regions of the universe due to the effects of gravity and the density of space-time. This is known as the cosmological redshift, which is affected by the expansion of the universe.

5. How does the speed of light affect our understanding of the universe?

The speed of light is a fundamental constant in physics and plays a crucial role in our understanding of the universe. It allows us to measure the distances between objects in space, determine the age of the universe, and study the behavior of light and gravity in different environments.

Similar threads

  • Special and General Relativity
2
Replies
45
Views
3K
  • Special and General Relativity
Replies
25
Views
3K
  • Special and General Relativity
Replies
15
Views
1K
  • Special and General Relativity
Replies
33
Views
2K
Replies
10
Views
2K
  • Special and General Relativity
Replies
1
Views
707
  • Special and General Relativity
Replies
2
Views
1K
  • Special and General Relativity
Replies
22
Views
1K
  • Special and General Relativity
Replies
21
Views
550
  • Special and General Relativity
2
Replies
45
Views
3K
Back
Top