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.
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What exactly is different about the slice of space and lightcone concept in special relativity?
In Sean Carroll's book on GR, in the very first chapter about SR, he mentions how the difference between Newtonian concepts of space and time, and the view put forward in SR is how there is an "...
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The integral form of Faraday’s law seems nonlocal, what's wrong?
Consider this example I met in my physics class:
An infinitely long cylindrical region contains a uniform magnetic field
$B$ within it whose magnitude varies with time. Determine the induced electric ...
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Where is the increased mass reserved based on Einstein's mass-energy equation?
Assume a huge parallel-plate capacitor with plates located at an infinite distance away from each other. If we tend to move a positively charged object ($+q$) with a rest mass of $m$ against the ...
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In the Twin Paradox, can one twin travel backwards in time?
In the Twin Paradox, if the travelling twin, Betty, instead of returning to her brother Albert at home, continues her journey after a period of rest, why is causality not violated due to her brother, ...
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A question on the nonrelativistic limit of special relativity [closed]
In special relativity, one typically works in the spacetime manifold with the Minkowski metric:
$$ds^2=-c^2dt^2+d\vec x^2.$$
However, I find it intuitive that in the nonrelativistic limit, if one also ...
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Why can't only time dilation alone take place in special relativity, without length contraction? [closed]
In Einstein's special relativity, why can't just time dilation alone take place(without length contraction)? I mean if we slow down the time of the moving object/person, isn't it/or the person already ...
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Clock on a moving rocket
Let's say that there is a clock mounted outside a rocket that is moving at a constant velocity upwards as measured by an adjacent observer looking at the clock from a stationary platform. The clock's ...
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How does the relativistic action logically follow from the nonrelativistic action, and why is proper time involved? [closed]
In nonrelativistic mechanics, the action for a particle of mass $m$ moving in a potential $V(\mathbf{x})$ is
$$
S_{\text{classical}} = \int \left(\frac{1}{2} m \mathbf{v}^2 - V(\mathbf{x}) \right) dt.\...
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Dirac-Hartree-Fock [closed]
I am trying to work my way through Dirac-Hartree-Fock. I have reached a point where I am baffled. I will present the problem here, but will have to define a few things since nomenclature is so varied ...
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Positive values of Mandelstam variable $t$
Is it possible for the Mandelstam variable $t$ to reach positive values in the quasielastic charged current neutrino-neutron scattering?:
$$\nu_{\mu} + n \rightarrow \mu^- + p$$
(don't assume that ...
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Principle of relativity near a charged earth
If earth was electrically charged is it was possible for a person in a train to know that if it is standing still or it is moving by constant velocity?
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Could an extremely high velocity particle produce Cherenkov radiation in a near vacuum? [closed]
Could an extremely high velocity particle produce Cherenkov radiation in a near vacuum?
e.g. Interplanetary space?
What if the particle was Oh my God particle have produced Cherenkov radiation while ...
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Inertial frames, the speed of light and contraction and dilation of time
From the postulate that the speed of light is constant how it follows that if we have a static inertial frame and next moving inertial frame and we send the beam once in the direction of the movement ...
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Is there any formula for momentum which works for both particles with or without mass?
The formula
$$p=\gamma mv$$
can give us momentum for only the particles with mass. In case of massless particles(photons), it turns to $0/0$ indeterminate form. So it just tells that momentum can have ...
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Does the constant horizontal velocity of a projectile with relativistic velocity components reduce as it accelerates downward?
Assume an electron/proton is shot perpendicularly into a huge uniform electric field with a constant horizontal velocity of a considerable portion of the speed of light ($v_x=0.8c$). As it accelerates ...
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Why does the Lorentz transformation preserve the speed of light specifically under the Minkowski metric but not under alternative quadratic forms?
I know that Lorentz transformations are defined as the linear transformations preserving the Minkowski metric $s^2 = c^2t^2 - x^2 - y^2 - z^2$. But suppose we consider an alternate metric $s^{′2} = c^...
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Why does temperature increase mass?
We learn that $E_0=mc^2$, that is, internal energy is a form of mass. Also, kinetic energy does not relate to mass at all, and the complete relativistic energy momentum equation is
$$
E^2=(mc^2)^2+(pc)...
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Do higher-order virtual images between two mirrors move faster than light?
I was studying the case of an object placed between two plane mirrors. Whenever a object is placed between two parallel mirrors, the distances between the successive images is found using the criss-...
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Does the inertia of a body depend on its energy content?
The question title is taken from Einstein's 1905 paper which shows that the rest energy is $E_0 = mc^2$. In other words, an object's inertia -- the tendency to resist changes in motion -- is dictated ...
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Time dilation will not determine whether the speed of light is isotropic or anisotropic [duplicate]
It is well known that one can create an alternate form of special relativity where the speed of light is different in different directions and yet make all the same predictions of orthodox special ...
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A problem with a current-carrying sheet's magnetic field as viewed by an observer moving perpendicular to the current direction (Part I)
In my previous question, entitled a problem with a current-carrying wire's magnetic field as viewed by an observer moving perpendicular to it, @Dale answered that:
so indeed, as you mentioned, in ...
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Negative energy in special relativity
I am currently studying Quarks and Leptons by Halzen&Martin, and I have come across the typical presentation of the negative energy problem in QFT, introducing the free particle field in the Klein-...
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Is there a way to define a relativistic potential from Minkowski $4$-force in special relativity?
In classical mechanics, the potential energy is defined by
$$V({\bf x}) = -\int{{\bf F}({\bf x})}\cdot d{\bf x}$$
for a conservative 3-force.
Is there a similar way to do this in relativistic ...
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Is the magnetic field produced by a wire current $I$ on a moving train observer the same for a stationary observer?
Well, this question really doesn’t aim to be about relativity but the behavior of electromagnetic fields in a scenario. However, if the answer is due to relativity, please tell me.
Suppose there is an ...
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A problem with a current-carrying wire's magnetic field as viewed by an observer moving perpendicular to it
Resnick argued the motion of a charged test particle at rest relative to a current-carrying wire from the viewpoint of the electrons and protons inside the wire in his book, Introduction to Special ...
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