Questions tagged [gravity]
Gravity is an attractive force that affects and is affected by all mass and - in general relativity - energy, pressure, and stress. Prefer newtonian-gravity or general-relativity if sensible.
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Is it possible to know if you're moving or standing still due to the definition of Einsteins equivalence principle?
I have a question regarding Einstein's theory of relativity.
Einstein's equivalence principle states that locally it's not possible to tell if you're accelerating or being stationary in a ...
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How is Gravity, assuming only General Relativity, *not* like Centrifugal Force?
It is common to state that "Gravity is not a force" due to its interpretation as a curvature effect in general relativity. By this, is it right to say that gravity is a fictitious force due ...
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Can there be structures made from neutrinos that can have angular momentum?
Would it be possible to eventually have structures made from neutrinos somewhere in the universe, as it is indicated in this question (Are neutrino stars theoretically possible?), like halos of ...
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Does dark energy work on the principle of anti-gravity, i.e. repulsive gravity?
Our universe is made up of 95% dark energy+ dark matter (of which most is dark energy), and this dark energy is considered to be the main reason for the expansion of our universe. But, anything that ...
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Gravitational potential due to arbitrary shape
Outside the uniform sphere, the potential is expressed as if all the masses are concentrated in the center of the sphere.
Is it also true for arbitrary shape?
That is, outside any body, is potential ...
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Contribution of gravitational energy to mass of spherical shell
Suppose we have a spherical shell of mass M. Suppose we are able to variate it's radius while maintaining the same mass.
When two masses are subjected to attraction and are approached we may extract ...
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Suppose a shell of a sphere formed by matter and with large radius, start afterwards to diminish the radius, give $E=mc^2$ the system stops
Thinking in classical mechanics terms but with the knowledge that $E=mc^2$ let's make the below thought:
Suppose you have a shell of a sphere formed by a mass uniformly distributed over the surface of ...
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Do two bodies with the same mass but different volumes, exert the same gravitational pull?
Asking this strictly from GR, not Newtonian gravity. I am not well versed with GR, so let me know if my question fundamentally misunderstood the concepts of GR, but if there are two independent bodies,...
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So just because gravity "merely" bends space and isn't "really" a force at a distance - isn't it still a thing at a distance? [closed]
As a preamble, just for clarity as far as I can remember (I was awfully drunk) I have a degree in physics, math and comp sci: my point is "here's a probably stupid question at the level of person ...
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If gravity is not a force, what makes massive objects spheroid?
For most of my life, the explanation given for why celestial bodies like stars, planets, etc. are round is due to gravitational force. Simply put, if an object has enough mass, it will, in turn, have ...
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Ideal Gas law and Universal gravitational constant
In a hypothetical universe with a different Universal gravitational constant $G$, will the nature of ideal gas change by any means?
i.e, will $PV = nRT$ be no longer applicable in that case?
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Energy created by gravity
So just a thought experiment: I take my rocket and fly through space. Meanwhile I pick up some piece of debris that experiences no (big) gravitational pull. I attach it with an infinitely long rope to ...
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Is it possible to change the amount of gravity applied to an object? [duplicate]
The question might be silly. I'm not a physics student either my question might be asked incorrectly. I would love to learn from you.
Is it possible to change the gravitational force applied to an ...
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How does gravity act and propagate in a 2+1D universe?—Newtonian versus general relativity
In a hypothetical 2+1D universe:
if we apply the Newtonian concept of gravity, we might expect that the gravitational force between two mass points with a distance of $r$ would diminish linearly with ...
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How is Wald deriving this Gauge condition: $\partial^b\, \overline{\gamma}_{ab} = 0$?
R. Wald in Section#4.4 of his book General Relativity derives the EFE in the case of a weak gravitational field by taking the curved spacetime metric $g_{ab}$ to be a "small" perturbation $\...
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