Linked Questions

17
votes
3answers
4k views

Why must the speed of light be the universal speed limit for all the fundamental forces of nature? [duplicate]

Einstein discovered from studying the electrodynamics of moving bodies, that the speed of light $c_{em}$ is the same for observers, which move relative to each other with a constant velocity. But why ...
0
votes
1answer
172 views

Could gravitational waves and electromagnetic waves/light be the same thing? [duplicate]

They travel at the same speed, why? Maybe they are the same thing, but seen from different perspectives.
1
vote
1answer
117 views

Why is the speed of gravity the same as that of photons? [duplicate]

Why is it that the speed of massless particles in space is the same as propagating disturbances of space? We can´t send human information (with photons) faster than the speed of light. But we can ...
3
votes
0answers
75 views

What is the derivation of the speed of light $c$ that is not based on electromagnetism? [duplicate]

The "speed of light" is not just the speed of electromagnetic radiation, but of any massless particle. Therefore must not there be an expression for $c$ that is not in terms of $\mu_0$ and $\epsilon_0$...
1
vote
0answers
41 views

Will any massless particle/object in the vacuum of space always travel at the speed of light? [duplicate]

The question as stated above, is "Will any massless particle/object in the vacuum of space always travel at the speed of light?"
104
votes
16answers
13k views

Is it possible for information to be transmitted faster than light by using a rigid pole?

Is it possible for information (like 1 and 0s) to be transmitted faster than light? For instance, take a rigid pole of several AU in length. Now say you have a person on each end, and one of them ...
15
votes
3answers
2k views

The reference frame of $c$

I don't have a lot of knowledge of special relativity and associated topics; some of the few things I know are that "all motion is relative" (that is, there is no 'stationary reference frame'), and ...
21
votes
4answers
2k views

“Speed” of Gravity and Speed of Light

Some threads here touching speed of gravity made me think about that. This lead to some questions. The speed of gravity was not measured until today (at least there are no undebated papers to that ...
1
vote
3answers
9k views

What are good examples to demonstrate Einstein's mass-energy relation [duplicate]

According to Einstein's mass-energy relation mass and energy are interchangeable. Can you provide some examples where: Mass gets converted into energy. Energy gets converted into mass.
5
votes
3answers
457 views

Propagation speed of photons when taking higher-order QFT corrections into account

In our group of experimental physicist who have nothing to do with and know very little about quantum field theory, we recently had a question concerning the propagation speed of photons in vacuum: ...
9
votes
4answers
337 views

Why should gluons move at a speed determined by $\mu_0$ and $\varepsilon_0$?

I understand that the speed of light can be derived from Maxwell's equations, giving $c=\frac{1}{\sqrt{\mu_0\varepsilon_0}}$ I furthermore understand how the principle of invariance of laws w.r.t. ...
0
votes
2answers
2k views

Reason why only massless particles can travel at speed of light?

I have read this question: Do all massless particles (e.g. photon, graviton, gluon) necessarily have the same speed $c$? And the answer by WetSavannaAnimal aka Rod Vance: "Incidentally, if we ...
-1
votes
1answer
1k views

What do gravitons interact with?

The other three forces' mediating particles (photons etc.) are absorbed by their appropriate charge-carrying particles, but I can't seem to find a clear answer that applies to the gravitational force ...
0
votes
4answers
833 views

How did we disprove aether wind?

We know that the universe is not vacuum. The average temperature of the universe is 3° above absolute zero. So some "aether" really exists, but that is not some gas with very low density, but stardust....
6
votes
1answer
196 views

How soon that a force affect another object?

Imagine this scenario: I have 2 objects in vacuum without any force exerted upon them not even a possible gravitational force between them. Now if one of them gets a gravitational or magnetic force, ...

15 30 50 per page