All Questions
23
questions
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
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
0
answers
36
views
What is the gravitational pull of a photon? [duplicate]
I know it may seem like a stupid question, but I recently found out that because a photon has energy (obviously) then it must have a gravitational pull. I was wondering exactly what this gravitational ...
- 1
0
votes
2
answers
69
views
Does an object with kinetic energy have increased mass? If so, how is this reconciled in relativity?
Let's imagine that you are standing in a field. You have a ball that weighs 10 grams. You throw this ball at 40 kph. If I understand things correctly, this ball now has kinetic energy relative to your ...
- 357
0
votes
0
answers
12
views
If incoming photons increase the mass and gravity of a black hole are they then some kind of source of gravity? [duplicate]
If incoming photons increase the mass and gravity of a black hole are they then some kind of source of gravity?I can not understand why equivalence of mass and energy lead as to say mass and energy ...
- 1,815
1
vote
2
answers
191
views
As the universe expands, how does it affect the mass of objects and therefore the gravity?
I think the mass of object would proportionately decrease as the universe expands, as the amount of matter is constant in accordance to the law of conservation of energy. If I am correct in this, ...
- 13
0
votes
1
answer
141
views
If you could bottle a photon would it have mass? [duplicate]
Ok. A photon has no rest mass for the good reason that it has no rest energy. But what about a standing wave? There is fair belief that particles are standing waves, so perhaps nothing rests.
So. ...
Blame
1
vote
1
answer
39
views
Does a field gain energy or does the mass/charge?
My textbook reads that when a mass/ charge is moved into the influence of a gravitational/ electric field the field gains/ loses energy rather than the mass/ charge. How can this be explained?
- 1,043
-3
votes
1
answer
567
views
Light absorbed by black holes why? [duplicate]
Why is light absorbed by black holes while it is massless as theory of gravitation works only for masses?
- 89
-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
5
votes
1
answer
1k
views
How did gravity exist before mass?
I'm brushing up on my Big Bang, and I noticed that, apparently, although gravity is the first force to split from the original "superforce", mass does not appear on the scene until after the second ...
- 415
4
votes
1
answer
1k
views
Why does the Gravitational Potential energy formula indicate that heavier masses in the same point in the field have lower potentials?
$$ U = -\frac{Gmm_E}{r} $$
Intuitively, it'd appear that the further away two objects are, the greater their gravitational potential, and this is confirmed by the gravitational potential formula. The ...
- 63
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
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 ...
