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Questions tagged [speed-of-light]

The speed of light is a fundamental universal constant that marks the maximum speed at which energy and information can propagate. Its value is $299792458\frac{\mathrm{m}}{\mathrm{s}}$.

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0 answers
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Plausible explanation for anomalous plasma antenna time difference of arrival?

Consider the below-pictured time difference of arrival system consisting of two plasma antennas* with opposing DC bias. Samples of time difference of a 100MHz signal are taken as the TDOA system is ...
James Bowery's user avatar
  • 1,357
4 votes
3 answers
1k views

Is the meter relative to time?

Is the meter relative when we are near the speed of light? I was reading a physics book and I found that the meter is the length that light travels for an amount of time, so since time is relative ...
Angel Echavarria's user avatar
1 vote
1 answer
104 views

Understanding the math of the Michelson-Morley experiment

I'm having some conceptual misunderstandings of the Michelson-Morley experiment. The time for the beam going perpendicular ($t_{across}$) of the aether wind I am getting: $$(ct)^{2}=d^{2}+(vt)^{2}\\ (...
Qubit's user avatar
  • 431
2 votes
3 answers
193 views

Why is the speed limit of special relativity $C$ equal to the speed of light $c$ and why must there be only one?

DISCLAIMER: this question is different from other questions posted here previously despite accidentally similar titles. This question is not a duplicate of the one linked bc the linked question is ...
ConformalSymmetry's user avatar
2 votes
3 answers
127 views

Is a Lorentz transformation allowing an infinite value $c$ still a proper Lorentz transformation?

Is it correct to say that inertial systems are related by Lorentz transformations even if we do not know if the "invariant speed" is finite or infinite? To me, this is incorrect because $c$ ...
Real Pattern's user avatar
1 vote
3 answers
138 views

What are relativistic particles? [duplicate]

What are relativistic particles? I got it in a question of mechanics. So, what is it about a particle that makes it "relativistic"?
Nishkarsh Singh's user avatar
0 votes
1 answer
108 views

Can the velocity of an image produced by a plane mirror be greater than that of light?

We are currently studying ray optics in school and it made me wonder if the velocity of an image produced by a plane mirror can theoretically be greater than that of light. Using the relation $v_i = 2 ...
Milkprisonersvostok1's user avatar
0 votes
1 answer
57 views

Non-homogenous Helmholtz equation in 3+1D: Green's function and solution

I've been reading Jackson's Chapter 8.10 and trying to find the Green's function for a non-homogenous Helmholtz equation. The problem is in cylindrical coordinates. I first made a Fourier transform to ...
Rosabella M's user avatar
7 votes
2 answers
1k views

Fermat principle: how did they know the speed of light in different mediums?

Pierre de Fermat derived his principle of least time by considering the path that light would take when traveling between two points. He postulated that light would follow the path that minimized the ...
Andy Chow's user avatar
0 votes
1 answer
54 views

Proof of the invariance of $c$ using the Lorentz group

Apologies if this question was already asked a few times but i could only find proofs of the invariance of $ ds^2 $. Is there any way of proving the 2nd postulate (that $c$ is invariant in all ...
Tomás's user avatar
  • 309
1 vote
2 answers
59 views

Speed of light along $y$ and $z$ axes when there is relative motion

There are two coordinate systems. One is stationary and the other moves in the positive $x$-direction with a speed of $v$. I don't know how to interpret the $\sqrt{V^2 - v^2}$ term since light always ...
Christina Daniel's user avatar
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0 answers
26 views

Why the photons are deflected during the refraction? [duplicate]

From what I learnt, when photons are passing throw a denser environnement with an positive angle (from the atmosphere to water for exemple), they are slow down. But I can't understand how this ...
Jay Labarsurlakantik 's user avatar
0 votes
0 answers
32 views

What is the speed of light during reflection? [duplicate]

What is the speed of light in a vacuum when the light reflects off of a mirror?
Christina Daniel's user avatar
0 votes
2 answers
177 views

Rindler coordinates and objects possibly exceeding the speed of light

Assume $c=1$ So I've been on a bit of a journey trying to derive special relativity by myself and in doing so was analyzing the viewpoint of a uniformly accelerating observer. I was particularly ...
NaiDoeShacks's user avatar
-8 votes
3 answers
217 views

How Taylor series is compatible with special relativity?

In mathematics, an analytic function is defined by its possession of a Taylor series with a positive radius of convergence ($R_c​>0$). Notably, certain analytic functions—such as holomorphic ...
Omid's user avatar
  • 342

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