All Questions
Tagged with newtonian-gravity general-relativity
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Negative Energy and Gravity
Why do many science communicators say that negative masses fall upwards? Is it the same in the physics literature that they say that negative masses fall upwards?
In general relativity, things don't ...
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How does a curvature in time equate to Newtonian gravity? [duplicate]
I often read that a curvature in time (the rate at which clocks tick) near a massive object, is considered to be the source of Newtonian gravity.
This got me wondering, does General Relativity use the ...
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Newtonian approximation for the tidal forces at the event horizon of a black hole
I'm currently working on a problem where I have to calculate the tidal forces a person experiences if their feet touches the Schwartzschild radius and their head is $1.8m$ elevated above the ...
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Can the gravitational singularities of black holes be solved by potential or self-energy?
In Newtonian Mechanics, the energy density of gravitational field is negative in comparison with the positive energy density assigned to mass density, meaning that that the total positive energy of ...
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Does gravity actually have a ‘reaction force’? [duplicate]
By (my limited knowledge of) Einstein’s theory of General Relativity, as gravity is not a force but rather the effect of an object’s inertial path following a geodesic through curved spacetime due to ...
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Equivalence Principle in Newtonian Physics vs GR: A Thought Experiment
I have a question regarding the equivalence principle as it applies in Newtonian Physics and General Relativity. Consider a thought experiment involving a free-falling elevator.
Inside the elevator, ...
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Contradiction in negative mass interactions according to GR
I quote Sabine Hossenfelder:
Gravitation is a spin-2 interaction. It is straightforward to see that this means that like charges attract and unlike charges repel. The charge of gravity is the mass. ...
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What is the difference between GPE and gravitational self energy in GR?
What is the difference between gravitational potential energy and gravitational self energy in General Relativity? Are they both the same in Newtonian gravity?
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Interpretation of gravitational waves
A wave has peaks and valleys. I can think of a sine wave as a wave with peaks and valleys.
Now, if gravity is a wave, can we say that gravity would have peaks and valleys, with the valley becoming ...
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How is when an object moves gravity not effect it ? As Einstein sais?
Experiment:
*a water bottle with a hole . Water is falling from the hole when the bottle is in rest . When the bottle is released and falls , water stops falling as gravity is not doing effect on it . ...
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Is there an equation that is quick to use that calculates gravity around black holes?
Is there an equation the can calculate gravity around black holes but is less time consuming than EFE? I want to find an equation that is simpler/faster than Einstein's Field Equations but can still ...
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Since when did inertial mass and gravitional mass became equal?
If we think about inertial mass and gravitational mass as independent concepts and develop physics then we would know after a while they are only propotional (by precision we have by now). but it seem ...
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How does Einstein's theory of relativity prove Newton's laws of gravitation (or is it incorrect)?
I have heard that at the speed of light the Newton's laws of gravitation stop working. Why does that happen or does that even happen? Is there any proof to it? From what I have heard It's related to ...
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How was the $n$-body problem solved before computers?
Explaining the anomalous progression of Mercurys orbit was one of the first successes of general relativity. Given that a $n$-body problem is not solvable analytically even in the Newtonian picture (I'...
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General relativity when can we approximate to Newtonian gravity?
Lets consider this scenario in deep void of space where other curvatures of large objects are negligible in this case and we bring 2 objects lets say $A$ and $B$.
We give it a force slightly lower ...
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