The special theory of relativity describes the motion and dynamics of objects moving at significant fractions of the speed of light.

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How is Einstein's arbitrary additive constant $C$ constant during the emission of light?

This is a follow up on this question. In his paper under the title:Does the inertia of a body depend upon its energy-content, Einstein considers two inertial frames $(x,y,z)$ and $(\xi,\eta,\zeta)$ ...
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Does Dark Energy change value when traveling near the speed of light?

To draw an analogy, we receive roughly the same amount of cosmic background radiation from all directions. However if we were to travel near the speed of light relative to the reference frame where ...
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Is potential energy frame dependent in special relativity?

In newtonian mechanics, As far as I'm aware, only kinetic energy is dependent on frames of reference, since kinetic energy is a function of velocity(squared) and velocity is dependent on frames of ...
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tensor products in special realitivity

Use the definition of a tensor as a linear function on vectors and 1-forms. For a one (2,1) tensor T, use a single vector as argument e.g. T(V) which converts it to a (1,1) tensor. However, if you ...
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What is disadvantageous about measuring time events using light signals sent from events?

In his paper: On the electrodynamics of moving bodies, under the section entitled I. KINEMATICAL PART: § 1. Definition of Simultaneity, Einstein discusses time and gives it an operational definition. ...
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Do relativistic electrons have more charge?

Gauss's law tells us that the total electric flux out of a closed surface is equal to the charge enclosed divided by the permittivity. When a charged particle is moving close to the speed of light ...
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Are relativistic spacecraft slowed down by oncoming gamma ray photons?

I recently read that a proton having an energy of ten billion GeV can travel across our galaxy in about 5 minutes from the frame of the proton. From the Earths frame we would see it take roughly ...
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1answer
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Derivation of relativistic mean free path

I am working through a short derivation found in Abramowicz 1991 regarding the mean free path of a photon. We have a fluid moving in a particular direction with velocity $v$ and in an inertial rest ...
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understanding twin paradox [on hold]

Is it really possible to observe such a phenomena in real life? I am confused. I have studied time dilation in relation to pion decay but am not sure if it will be true for us human being to observe ...
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The Twin Paradox using reference frame following the ship

The Twin Paradox is undoubtedly one of the most discussed things in special relativity and have a tendency to confuse most of us. Classically, it's resolved by either stick to one of the three ...
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Relativistic velocity in Special Theory of Relativity [closed]

Prove that, 0.5 m*v^2 , where m = M / (1- (v^2 / c^2))^0.5 ["M" is original mass, and "m" is mass with velocity] doesn't equal to the the Kinetic Energy of a particle moving at relativistic velocity. ...
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Time relativity

Lets say that I am on a spaceship moving with the speed of 0,90c and I am looking on my friend who stayed back on earth. My friend is looking on me. From my perspective, my friend is moving 7 times ...
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Is heavier object falls slower according to special theory of relativity?

I'm newbie in physics, but have some idea want to know whether it is correct! I saw some information about special theorey of relativity. It just like says "when objects go faster it becomes more ...
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Could gravitational source provide a fixed reference frame for the speed of light measurements?

I have wondered if a gravitational source could provide the fixed reference frame for the measurements of c? There is, at least one, experiment which could prove my hypothesis wrong, I mean an object ...
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27 views

How to Quantify the Relativity of Simultanuity [closed]

I cannot find an answer to this specifically on the internet. It would be of much help to many students studying SR and the twins paradox in particular. If someone could shed some light on the ...
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32 views

Gauge transformation and Special relativity

While explaining gauge theories, a book makes a comment that the U(1) transformation definition, $ U= e^{i q \lambda(x)}$ is analogous to a special relativity transformation in freely falling ...
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How does work function transform in Einstein's special theory of relativity?

A photon with energy greater than the work function hits the metal, and an electron is knocked off. Now, suppose we were in an inertial frame moving with a velocity $v$ with respect to the metal such ...
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1answer
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Humans on earth seen from traveling space ship

If I would stand on a space ship traveling with a speed of 0,99c I would be moving 7 times slower from Earth's perspective. But if I would look back on Earth I would see everything moving 7 times ...
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Higgs Boson mathematical elimination process [closed]

I heard that if the Higgs Boson could be mathematically eliminated, it would be easily accelerate the particles up to the speed of light. If so, how can the Higgs Boson be removed out from the ...
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17 views

Is there a standard of rest in the universe? [duplicate]

If you measure the cosmic background radiation you will find that in any direction it is roughly the same. However, if you were to travel near the speed of light relative to the Earth in a particular ...
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32 views

Transform coordinates to an other coordinate system and back using the Lorentz Transformation [closed]

So in order for special relativity to be self-consistent one should be able to transform some event coordinate to an other reference frame and then transform it back yielding the same as we started ...
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2answers
239 views

Why did Compton use X-rays in his experiment?

Why did Compton use X-rays in his famous experiment? Can it be done using other types of electromagnetic waves?
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48 views

Quantifying Simulaneity in the Twins Paradox [closed]

http://www.thescienceforum.com/physics/14881-special-relativity-primer-discussion.html After reading this explanation I made an attempt to calculate a full example of this. The key to solving the ...
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Why does gravity affect time?

So Special Relativity states that for all non-accelerating objects of matter the laws of physics are the same. I'm confused on why this law of physic applies to objects in acceleration and gravity ...
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Symmetrical twin paradox without changing direction

If I understood well, in the special relativity 1- A stationary observer sees other moving observer's clock works more slowly than the stationary clock. 2- Motion is relative, the moving observer ...
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2answers
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Shape and even connectedness of accelerating components in SR is frame dependent?

In some inertial frame consider a disk of radius 1 lightyear at rest. Then along the edge of the disk there are some people in spacesuits at rest hovering right above the disk (which has negligible ...
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5answers
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Euclidean geometry in non-inertial frame

Refer, "The classical theory of Fields" by Landau lifshitz (Chap 3). Consider a disk of radius R, then circumference is $2 \pi R$. Now, make this disk rotate at velocity of the order of c(speed of ...
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Derive the velocity-additon formula from the Lorentz transformation

In a Euclidian world the sum $s$ of two velocities $v$ and $u$ is so such that $s = v + u$. However, in the world of special relativity that's not the case. Instead, the velcity vector sum $s$ is ...
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Help with relativity simultaneity paradox

To begin I will explain briefly a classic thought experiment used to demonstrate simultaneity; There is a 100m long train rushing towards a 100m tunnel at a fraction of the speed of light, from an ...
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3answers
103 views

Special relativity: and Lorentz transformation [closed]

An astronaut travels in a spaceship from Earth to Mars, which is located $300LS$ (light seconds) from Earth. The spaceship's velocity is $0.4c$. Both Earth and the spaceship have synchronized clocks ...
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Special relativity paradox [closed]

Let's say a spaceship leaves Earth and is travelling at relativistic speeds. The spaceship's commander observes a supernova that took place somewhere ahead of the spaceship and then sends a signal to ...
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0answers
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Luminosity and entropy of a relativistic shell

I am looking to understand more about gamma ray bursts. The review I am reading through describes in equations (111), (112) the luminosity of a relativistic plasma shell, in an inertial frame at rest ...
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3answers
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If there is no definite speed in the universe, only relative speeds, how does energy increase when velocity approaches the speed of light?

Is the concept of energy increasing as it approaches the speed of light based on the fact that this is only true relative to the observer? Lets say, there's a scenario where a person in a rocket ...
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1answer
66 views

Time dilation and relativity paradox? [duplicate]

I've come across a weird paradox that I can't answer, I will explain it via the following thought experiment: There is a space-train and an observer 1 light year apart with synchronised clocks. The ...
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2answers
75 views

Transformation of four-velocity in special relativity

I am revising special relativity introducing more matrix form in the equation. Currently I am reading book in which transformation matrix is defined as $${\Lambda= \begin{bmatrix} \gamma & ...
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Is special relativity true? [closed]

Is the special theory of relativity true? http://www.npr.org/2014/03/20/291408248/einsteins-lost-theory-discovered-and-its-wrong
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How would the twins paradox be affected by wormholes?

The famous twins paradox where one twin travels to a distant star and returns to find an aged brother can be resolved with general relativity pretty easily, but I was wondering about this: If the ...
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Special Relativity - two beams of light in opposite direction

I just want to first say that I'm aware I am asking a question due to my own confusion and ignorance and not because of anything to do with special relativity. I hope that's alright. What I'm ...
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1answer
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How to calculate spacetime intervals on a spacetime diagram?

In SR, the spacetime interval is given by the metric: $ds^2=-dt^2+dx^2$ (where I set $c=1$). To calculate $ds^2$ of a worldline on a spacetime diagram, I measure $dt$ and $dx$ of the line of ...
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2answers
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Two sets of coordinates each in frames $O$ and $ O' $ (Lorentz transformation)

Suppose inertia frame $O'$ is moving at velocity $v$ relative to inertia frame $O$. Let the coordinate systems of $O$ be denoted by $(x,y,z)$ and the corresponding one on $O'$ be denoted by ...
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What would happen in this “close to the speed of light” scenario?

Say you had a really long pole made of a super strong material, and at the you turned it through an angle of (for example) 45 degrees. Turning the pole through a small angle at the bottom would ...
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angle between spacelike and timelike vector

What is the significance of the fact that the angle between a spacelike and a timelike vector has a real part of pi/2?
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60 views

Black Hole - Between event horizon and singularity

Dear Physics Board Users What is between the singularity and the event horizon? If the gravitation gets bigger and bigger coming nearer to a black hole, is then the gravition inside even bigger that ...
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1answer
67 views

Derivation of the Lorentz algebra explicity [closed]

I need the complete proof for commutation relation of the Lorentz group generators. The proof of Lorentz algebra using this commutation relation.
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1answer
75 views

Why is locality an important requirement in physics?

Why is locality insisted upon in physics? Is it simple because empirical evidence suggests it, and also taking relativity into account, required due to the upper limit of propagation limited by the ...
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Lorentz Transformations understanding

I am wondering whether or not I fully understood what the variables represent in the Lorentz time and distance transformations. What I understand is: t′ is the 'proper time', the time taken to move ...
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3answers
256 views

A question in Special Relativity

In books the equation for length contraction is derived by supposing that the velocity of the spacecraft is the same for both observers. So the question is that, is the velocity really the same for ...
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1answer
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Firing counter-propagating photons inside a moving train

This is sort of a follow-up to my other question, in which you have the following scenario: Have a photon gun firing two counter-propogating photons from the center of a moving train. The observer ...
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1answer
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What happens when breaking simultaneity leads to different outcomes?

Consider the classic example to show that simultaneity does not hold: Have a photon gun firing two counter-propogating photons from the center of a moving train. The observer inside the train sees ...
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invariant angles in Minkowski space

Invariant intervals are fundamental in relativity. But if you make a triangle in space-time from 3 invariant intervals, then it will also have 3 invariant angles, by the cosine law which can easily be ...