All Questions
Tagged with spacetime reference-frames
197
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Acceleration and reference frames in General Relativity
A person walks on Earth in a straight line, he says he is walking with uniform velocity. But I (from space) see him walking on a curved surface and say that he must be accelerating since he is ...
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"Different reality" inside a black hole
why does our perception of space and time entirely change inside a black hole? And why does time not stop inside it from the perspective of the inside observer, however, extremely slows down for the ...
- 27
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Is the earth's version of time dictated by the earth's speed? [closed]
Is time on earth, relative to everywhere else, dependent on the earth's speed? Earth rotates at a speed, it moves around the sun, the sun moves around the galaxy and the galaxy is also moving - is it ...
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How to tell who is experiencing time slower and who faster when travelling at different speed?
I am trying to understand time dilation w.r.t velocity. Its said that when a satellite travels around earth (at speed more than a synchronized clock on earth which is stationary w.r.t earth), it ...
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Acceleration/gravitation vs velocity and the Twin Paradox
I see in Professor Pogge’s explanation
http://www.astronomy.ohio-state.edu/~pogge/Ast162/Unit5/gps.html dec. 2020.
that
“Because an observer on the ground sees the satellites in motion relative to ...
- 351
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4
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264
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Does changing direction change the frame?
In looking at explanations of the twin paradox, two examples are given to show that acceleration is not a factor:
First, where one rocket flies out past the star and a second rocket flies back to ...
- 4,783
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334
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Logic of general relativity
I’m a beginner in general relativity, I start with reading Field Theory written by Landau. There are some confusions arose when I tried to understand the physic logic of general relativity. Let me ...
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How does brain perceive time dilation due to gravity?
Einstein's General Relativity says gravity warps spacetime. Consider a hypothetical scenario:
A person travels into space from Earth.
He landed on a different planet in some far off galaxy where time ...
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6
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Can there be a theoretical synchronised ‘now’ moment at all points across the universe?
Einstein’s relativity rejects the notion of a universal ‘now’ moment. It underlines how the concept of ‘now’ is compromised due to time passing at differing rates in differing frames of reference, ...
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Why don't we assume a vector space structure for spacetime?
At the outset I'll state that I understand completely why, physically speaking, there's no preferred frame - that's not what I'm asking in the question.
I'm not sure why we don't give spacetime a ...
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Is spacetime curved in a near-earth-free-falling-object's frame of reference?
If I float motionless in outer space, I will measure spacetime to be approximately flat.
By the equivalence principle, I will get flat spacetime if I am free falling near earth.
Is this right? ...
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Properties of timelike congruences in flat spacetime
I'd like to learn about (or confirm) certain properties of congruences, concerning some presumably rather simple cases, namely of timelike congruences in the setting of flat spacetimes $\mathcal S$. ...
- 4,296
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215
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Space-Time Diagram in Special Relativity (for S and S')
So, this is how it is typically done. We have a reference frame $S$ and the coordinates $(x,t)$ of an event, $E$ (or collection of events which we call world-lines) are mapped onto a 2-dimensional ...
- 472
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Can traveling at relativistic speeds change your shape in your resting reference frame?
Let's say I start off standing on Earth, and I then accelerate up to half the speed of light. Let E be Earth's resting reference frame and V be the reference frame where I'm stationary at the end. Do ...
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Conflicting definitions of reference frames in general relativity
I'm having trouble understanding what constitutes a reference frame in general relativity as there seem to be several contradictory definitions.
It is my understanding that, in special relativity, ...
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