Is the Speed of Light Decreasing Due to a New Interpretation of Ether?

  • Context: Graduate 
  • Thread starter Thread starter vin300
  • Start date Start date
  • Tags Tags
    Ether Interpretation
Click For Summary

Discussion Overview

The discussion centers around the claim that the speed of light may have decreased over the last couple of centuries, exploring this idea through a new interpretation of ether. Participants examine the implications of such a claim, including its theoretical foundations and the relationship to the fine structure constant, while addressing historical and experimental contexts.

Discussion Character

  • Debate/contested
  • Technical explanation
  • Conceptual clarification

Main Points Raised

  • Some participants propose that the speed of light's decrease could be explained by a new interpretation of ether, suggesting that as space expands, the polarizability of the ether decreases, leading to a reduced speed of light.
  • Others argue that the idea of a decreasing speed of light is primarily promoted by creationist perspectives, and that scientific speculation about changes in the speed of light typically relates to variations in the fine structure constant over billions of years, not centuries.
  • One participant states that the speed of light has not measurably decreased in recent centuries, noting that any potential change in the fine structure constant observed from distant galaxies is negligible and would not support a significant change over 200 years.
  • Another participant mentions that ether dragging was previously suggested to explain the null result of the Michelson-Morley experiment but was discarded due to inconsistencies with observed stellar aberration.
  • A further claim is made that discussing changes in dimensionful universal constants lacks physical sense, as their values are dependent on the units used, and only dimensionless constants hold physical significance.

Areas of Agreement / Disagreement

Participants express disagreement regarding the validity of the claim that the speed of light has decreased. While some explore the theoretical implications of ether, others challenge the premise and assert that there is no measurable evidence supporting such a change.

Contextual Notes

Limitations include the dependence on definitions of constants, the historical context of ether theories, and unresolved mathematical interpretations regarding the fine structure constant.

vin300
Messages
602
Reaction score
4
Here I try to explain what I read somewhere- that the speed of light has decreased over the last couple of centuries.
If it is reported that the speed of sound is decreasing in a solid, you may say thatdue to continued vibrations and deformations of the solid, its modulus of elasticity has decreased.
I think an explanation of the decreasing speed of light could be explained by a new interpretation of ether.
As space expands, it expands the ether along with it so the polarizability of the ether decreases thus decreasing the speed of light.
The rotating Earth drags the ether so the MM shows null result.
Completely crankish? Forgive
 
Physics news on Phys.org
vin300 said:
Here I try to explain what I read somewhere- that the speed of light has decreased over the last couple of centuries.
You probably read this in an article by a creationist, since they are the only ones pushing this idea as far as I know (this is one way they try to justify the fact that we can see stars that are much more than 6000 light years away despite the fact that they believe the universe was only created about 6000 years ago). You do see a few scientists speculating about the speed of light having changed over billions of years, but more technically they are talking about a change in the fine structure constant, since it really only makes sense to talk about a "change" in a dimensionless constant (see this article). And the evidence for this is definitely not widely-accepted.
 
The speed of light has not decreased measurably over the last couple of centuries. The fine structure constant depends on the speed of light. We can tell if the fine structure constant has changed by looking at the spectra of distant stars and galaxies. The light we get from a galaxy carries information about the galaxy at the time the light left. Since some of these galaxies are billions of light years away, we get information about the state of these galaxies as they were billions of years ago. The only hint of a possible change in the fine structure constant seen amounts to about change of 1 part in 100,000 over billions of years. If this were due to a change in the speed of light, the change over 200 years would be not measurable.

Ether dragging has already been suggested as a reason for the MM experiment's null result. It was discarded because it was not compatible with the observation of stellar aberration. With ether and no drag you would get stellar aberration but a positive result from the MM experiment. Ether drag would give you a null MM result, but not the observed stellar aberration. What we get it both a null result and stellar aberration.
 
Also, independent of dc/dt, if ether were dragged along with the earth, it was shown by Airy in the 19th century that the predictions for stellar aberration would be different than what was observed.
 
vin300 said:
Here I try to explain what I read somewhere- that the speed of light has decreased over the last couple of centuries.
It makes no physical sense to talk about the value of ANY dimensionful universal constant changing. The value of a dimensionful universal constant is simply an artifact of the units used to express it. The only universal constants with physical significance are the dimensionless ones.

If c were double today what it was yesterday without a change in any of the dimensionless fundamental constants then we would not even be able to measure the difference with our most sophisticated instruments. On the other hand, if c were kept constant but the fine structure constant were doubled we would measure c to have changed by a factor of 2.
 

Similar threads

  • · Replies 3 ·
Replies
3
Views
3K
  • · Replies 5 ·
Replies
5
Views
4K
  • · Replies 1 ·
Replies
1
Views
2K
  • · Replies 6 ·
Replies
6
Views
3K
  • · Replies 16 ·
Replies
16
Views
4K
  • · Replies 8 ·
Replies
8
Views
4K
  • · Replies 11 ·
Replies
11
Views
5K
  • · Replies 62 ·
3
Replies
62
Views
12K
  • · Replies 21 ·
Replies
21
Views
7K
  • · Replies 38 ·
2
Replies
38
Views
47K