Questions tagged [special-relativity]
The special theory of relativity describes the motion and dynamics of objects moving at significant fractions of the speed of light.
34 questions from the last 30 days
-2votes
0answers
69views
How to calculate things that include uniform acceleration with special relativity? [closed]
I've seen people do that, but also know that special relativity applies only to inertial frames. So why this is even possible and how to do that?
3votes
2answers
123views
Why can you not take $u \cdot u = c^2$ in the relativistic free massive particle Lagrangian?
In my classical electrodynamics class, we use the Lagrangian of the relativistic free massive particle as $$L = - mc\sqrt{\dot{r}\cdot\dot{r}}.$$ Where $\dot{r}^\mu = u^\mu = \frac{dr^\mu}{d \tau}$; $...
- 1,205
-7votes
4answers
167views
The concept of speed in relativity [closed]
A point which is sometimes raised by people in the foundations of physics, is how to make sense of the concept of "velocity" in relativity, given that neither space nor time are coordinate-...
-10votes
1answer
146views
Does the One-Way Speed of Light Problem Disprove Einsteinian Relativity? [duplicate]
Until recently, I was under the impression that the invariance of light was an experimentally proven fact. But it turns out that all such experiments testing for this (e.g. the Michelson-Morley one) ...
-7votes
0answers
39views
Relativity question about velocity [closed]
Two rockets A B move from common point C according to C they move perpendicular but observer A see they move at angle BAC=30° what is u/c?
-4votes
1answer
101views
Twins Paradox Resolution [closed]
In what sense is the following explanation of the Twins Paradox faulty in logic: Each twin views the other as length contracted, but the twin on earth only sees the rocket in motion and thus shortened ...
- 61
0votes
1answer
81views
Unification of Electric and Magnetic Forces
I'm trying to re-learn special relativity -- PhD in physical chemistry 50 years ago. In "Special Relativity for Beginners" by Jurgen Freund,p. 29, it states: "A copper filament ...
-11votes
0answers
104views
Why is the measured speed of light assumed to be the same for all observers? [closed]
Is the speed of light always measured using a two way mirror device? I have not found any reports where the one way light speed has been measured directly. But for some reason this important ...
0votes
1answer
115views
About the relativistic Doppler redshift and Lorentz transformation
I'm learning the relativity with A First Course in General Relativity, Bernard Schutz. In the last section of Chapter 2, the author derived the relativistic redshift formula $$\dfrac{\bar{\nu}}{\nu} = ...
0votes
0answers
20views
A mathematical model for spacetime as a framework for deriving the Lorentz transformations by group-theoretical techniques [migrated]
Yesterday I had posted this question. I have been pretty unclear there and the question has been closed before I could try to make a proper edit. I have anyway edited and submitted for review, but ...
- 183
0votes
0answers
65views
Do lorentz transformed gamma matrices satisfy the anticommutation rule?
Notation $\gamma$ are gamma matrices [0]. Context I am working through the proof of relativistic invariance of the Dirac equation that is presented by Bethe and Jackiw [1]. They write that The most ...
- 734
1vote
1answer
148views
Transformation law of Lie algebra of Lorentz group $SO^+(1,3)$
I'd like to understand why the Lie algebra of Lorentz group is described as $(2,0)$ tensor. One can take a basis of the Lie algeba $\mathfrak{so}(1,3)$ as \begin{align} J^{(23)}=\begin{pmatrix} 0&...
-3votes
3answers
350views
About mathematical models for physical space in Special Relativity
Empty, static, flat physical space may be considered as an abstract Euclidean space. This works because setting an origin and a basis to get to coordinates is trivial. But think now about spacetime, ...
- 183
1vote
0answers
36views
Relativistic Propagator for multi-particle states
In non-relativistic quantum mechanics, the transition amplitude for a system of $N$ particles is given by: \begin{equation} A = \langle\vec{q}_{1}|e^{-\frac{i}{\hbar}\hat{H}t}|\vec{q}_{2}\rangle \end{...
-7votes
1answer
114views
Understanding the andromeda paradox [closed]
I am quite suspicious about the the andromeda paradox and I am sure I am just lacking a detail. So let us assume Andromeda sends out a for my friend Bob deadly emission (I will survive the emission). ...
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