All Questions
18
questions
3
votes
2
answers
504
views
Is the mass of curved space, additional mass?
According to Einstein, mass, say in the form of matter, curves space. It is the curvature of space that gives rise to gravity. Now I have heard there is an energy associated with the curvature of ...
- 131
1
vote
1
answer
85
views
Does the intrinsic energy of an object vary, if measured at different heights in a gravity field?
The gravitational redshift has different interpretations. Several quantities vary with height (or seem to), by the same equation - time, energy, mass. I wondered if measurements can shed some light on ...
- 85
2
votes
4
answers
405
views
Mass-energy equivalence and gravitational potential energy
If mass and energy are equivalent, and if gravitational potential energy is energy, why doesn't an object have more mass when it is at a higher altitude? Does the mass-energy equivalence work for ...
- 181
15
votes
2
answers
3k
views
Has it been experimentally proven that energy causes gravity?
I know that under general relativity energy and mass are equivalent under $E=mc^2$. But has it been experimentally proven that energy alone causes gravity, for example, does a nuclear reaction ...
- 4,783
0
votes
1
answer
86
views
How is the fabric of space-time curved? It bends due to energy or mass, but what causes bending? [duplicate]
When we experiment with General Relativity on Earth, a tissue bends according to the experiment due to the placement of a mass, but of course there is a gravitational pull that causes bending. If we ...
- 49
0
votes
2
answers
57
views
Potential Energie equals Mass in GR. Does that mean we can choose mass abitrarily?
In GR, mass is equal to energy (and appearently, that means also potential Energy). But I can choose an abitrary value for the electromagnetic potential at a certain spot, because for potentials, it's ...
- 6,763
-1
votes
1
answer
54
views
Does the laws of gravitation apply to two energies as well? [duplicate]
Can the laws of gravitation be extended to two energies? Is there a a force of attraction similar to gravity among two energies? (Excluding things like magnetic or electric attraction).
- 1,423
3
votes
1
answer
528
views
How quickly does gravity extend from created mass? [duplicate]
I apologize in advance if this is a stupid or off-topic question. Since Energy can be converted into matter according to $E=mc^2$, how fast does it take for the gravity of that new matter to extend ...
- 133
0
votes
1
answer
583
views
Gravitational lensing of massless photons [duplicate]
I recently got a more complete proof of photons having no mass. (I knew it before, but now I really know it.) But now, I'm curious how gravitational lensing can occur without a mass to act on.
I have ...
- 1,340
4
votes
1
answer
775
views
The FRW universe is NOT asymptotically flat? Its mass?
The Friedman-Robertson-Walker (FRW) metric in the comoving coordinates $(t,r,\theta,\varphi)$ which describes a homogeneous and
isotropic universe is
$$
ds^2\,= -dt^2+\frac{a(t)^2}{1-kr^2}\,dr^2 + a(...
- 117
16
votes
9
answers
5k
views
How can gravity affect light?
I understand that a black hole bends the fabric of space time to a point that no object can escape.
I understand that light travels in a straight line along spacetime unless distorted by gravity. If ...
8
votes
2
answers
5k
views
Where is Strong Equivalence Principle stronger than Weak Equivalence Principle?
Where is Strong Equivalence Principle stronger than Weak Equivalence Principle? In my note, the two equivalence principles are stated as follows
Weak Equivalence Principle:
Gravitational and ...
- 777
6
votes
1
answer
718
views
Does relativistic mass exhibit gravitiational effects?
Groundhog Day Update, 2014
The simple and dumb way to ask my main question is this: If something like a neutron start goes sailing by at very close to the speed of light, say fast enough to double ...
- 22.1k
3
votes
1
answer
411
views
Gravitational interactions by energy or by mass?
The mass-energy equivalence, first established by Einstein is an important and highly discussed phenomenon in physics. Without claiming much knowledge about high-end discussions on this topic, I would ...
- 3,148
1
vote
3
answers
2k
views
Is light affected by gravity? Why? [duplicate]
I would like to know if light is affected by gravity, also, I would like to know what is the correct definition of gravity:
"A force that attracts bodies with mass" or "a force that attracts bodies ...
- 41