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Questions tagged [relativity]

The union of special (SR) and general (GR) relativity. Use this tag if both SR and GR apply.

When to Use this Tag

This tag should only be used if both and apply. For Lorentz transformations or the speed of light, use (and possibly ). For classical black holes, use .

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How are accelerated reference frames non-symmetrical?

As in, if I'm accelerating away from the Earth, then does the Earth also appear to be accelerating away from me at the same rate? Or is there something to "break" this type of symmetry? My question is inspired by the below…
InquilineKea
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Alice and Bob moving in a circular ring of radius $R$

Alice and Bob are moving in opposite direction around a circular ring of Radius $R$, which is at rest in an inertial frame. Both move with constant speed $V$ as measured in that frame. Each carries a clock, which they synchronize to zero time at a…
Lembris
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Is space curvature relative?

If I have an object that is of some length $l$ moving at a relativistic velocity $v$ for some reference frame in a 1D universe, then length contraction states that $l=\gamma\times l'$. But at the frame of reference, there is no length contraction,…
VF1
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Time Dilation - what happens when you bring the observers back together?

I'm having trouble getting my head around the time dilation paradox. Observer A and B are at the same "depth" in a gravity well. Observer B then descends into the well. A will observe B's time as going slower than their own. B will observe A's time…
Andrew Bullock
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Relativity conclusions from Michelson-Morley Experiment

This is what my textbook says about the Michelson-Morley experiment: "This invariance of the speed of light between inertial reference frames means that there must be some relativity principle that applies to electromagnetism as well as to…
DWade64
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Would a star be observed to burn brighter traveling at relativistic speeds?

Would a star, similar to our own, be observed to "burn" differently at relativistic speeds? I am only thinking this because the observed relativistic mass would change.
Joe
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relativity and aberration of light

I am dealing with math and physics only at amateur level and I am writing regarding my question on relativistic aberration of light. Reading "Realtivity and Common Sense" by Hermann Bondi and some other texts I discovered that the following…
kostis
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Why can't we accelerate objects past the speed of light?

Is there any intuitive reasoning behind why there would be this universal speed limit? It just seems so arbitrary. I know that there must be things that are unknown, but what reasoning is there behind the existence of some limiting speed? Edit: I…
user24082
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Why is magnetism a consequence of special theory of relativity

Why is magnetism a consequence of special theory of relativity. Refrain from using mathematics as much as possible and try using physical arguments.
Amritanshu Tripathy
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Why does time pass slow in an orbiting satellite relative to an observer on the ground?

I know that according special relativity, if an object travels at a very high constant velocity relative to an observer, the observer will see the object's clock running slow. I also know that according to general relativity, gravity affects the…
Salar Khan
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Relativity of simultaneity

I was attempting explain to a co-worker my novice understanding of relativity, I'm was explaining how speed/time/events/etc is relative. My question was could this also lead to a paradoxical/multi-universal(excluding string theory) when two events…
person
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Is gravitational attraction increased by relativistic mass as well as rest mass?

Is gravitational attraction increased by relativistic mass as well as rest mass? If so what would happen if an observer travelled at relativistic speeds? Would it appear to him that the whole universe had acquired a greater mass as it was moving at…
Nigel Letheren
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Is simultaneity testable?

I was reading about Andromeda paradox, and I started wondering. How can we know that the situation in the Andromeda paradox is real ? How can you know that simultaneity is real ? How can you say that you are simultaneous with a star fleet coming…
Abc2000ro
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Relativity and predictability

My old theoretical physics professor used to say that (already) (special?) relativity shows that "the future is not predictable". Any ideas how this should be interpreted?
corto
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Relativity: stationary vs moving

In the book The Elegant Universe, Greene describes a situation in which there are two space travelers, George and Gracie, moving in relationship towards each other at a constant velocity with no other available vantage points. Both George and Gracie…
Bernadette
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