All Questions
Tagged with gravity reference-frames
103
questions
2
votes
3
answers
462
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Einstein's principle of equivalence; Standing on earth vs sitting in accelerated car
When I am seated in a car that is accelerating in a particular direction I could, for example, throw a ball and it would appear to be flying the opposite way. With the windows covered etc. An ...
- 123
0
votes
2
answers
100
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Falling into the sun, a thought experiment for trying to understand reference frames
If someone were transported out into empty space, idk like hundred of thousands of miles straight "up," would they fall into the sun?
It would depend on their velocity right? If they were moving at an ...
- 2,613
2
votes
2
answers
2k
views
Why do we feel resistance to gravity rather than the acceleration of gravity?
What's the reason it behaves differently from all other forces? What I mean is, if you're in orbit you're accelerating toward the earth at almost 9.8m/s^2, but you feel nothing. If you are riding a ...
- 360
1
vote
0
answers
52
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Measuring Hawking radiation after the coordinate transformation
If an observer can measure the Hawking radiation or surface gravity in his co-moving/rest frame, what happens when we make a coordinate transformation to a moving frame of reference? Can we make such ...
- 844
2
votes
0
answers
636
views
Geodetic effect and Frame dragging
Two gyroscopes pointing perpendicular to each other were housed inside Gravity Probe B which performed polar orbit around Earth to test Einstein's theory of relativity.
As the probe is orbiting ...
- 13k
-1
votes
1
answer
343
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Relativity of simultaneity in Galileo's Leaning Tower of Pisa experiment
Galileo's conclusion can be roughly summed up as: objects of different masses, when dropped from the same height, descend in the same time interval, independent on their masses (neglecting friction). ...
- 317
5
votes
2
answers
5k
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When objects fall along geodesic paths of curved space-time, why is there no force acting on them?
On cseligman.com, it is written that
So, we see things falling with an acceleration which we call the acceleration of gravity,and thinking that we live in a straight line , uniformly moving or ...
user36790
5
votes
1
answer
365
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Explanation for "if all accelerated systems are equivalent, then Euclidean geometry cannot hold in all of them"
I'm doing an EPQ (mini college research paper) on gravity, and I found a site that explained things in simple terms. I am having trouble understanding how Einstein came to his revelation space-time ...
5
votes
1
answer
3k
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How to explain centripetal force in terms or relativity
At the end of a video of dropping a ball and feathers in a vacuum, Brian Cox explains that the Ball and Feathers, as understood in terms of General Relativity, aren't falling. (apologies I can only ...
- 153
1
vote
2
answers
431
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Perceived acceleration in an artificially modulated gravitational field
It's intuitive that while accelerating in a locally constant gravitational field, there is no perception of acceleration, since the body accelerates uniformly.
What if a body were in a rapidly ...
- 19
1
vote
2
answers
112
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Gravity mitigated by velocity regardless of mass?
We know that a small object moving fast enough can pass by a planet and escape its gravity. Would this be (theoretically) true in reverse? Meaning a planet moving fast enough past a stationary smaller ...
- 71
32
votes
4
answers
22k
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Does gravity slow the speed that light travels?
Does gravity slow the speed that light travels? Can we actual measure the time it takes light from the sun to reach us? Is that light delayed as it climbs out of the sun's gravity well?
- 1,011
5
votes
1
answer
3k
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Curvature of spacetime in only required to explain tidal forces?
I'm a bit confused about the equivalence principle in GR.
I'm quoting from Wikipedia:
An observer in an accelerated reference frame must introduce what
physicists call fictitious forces to ...
- 1,075