E=mc^2, Gravitational Potential & Energy Balance

CaptainSlog
Messages
2
Reaction score
0
If two masses that are separated by a distance are created from pure energy using the equation E=mc^2, where did the gravitational potential energy between them come from? Does this mean the speed of light isn't really constant, and must be changed very slightly to accommodate it? Could it be that gravity itself is necessary to balance energy?
 
Physics news on Phys.org
You are mixing two concepts that do not really go together, namely gravitational potential, which is a concept from classical mechanics, and mass energy equivalence, which is a concept from relativity.

In order to make sense of this, you need to apply general relativity. In GR, mass is not the source of gravitation. Instead, the energy-momentum tensor is and any type of energy is therefore a gravitational source. It is not that you can simply create a new gravitational source out of nothing.
 
  • Like
Likes CaptainSlog
OK, thanks. I had always assumed gravity was due to mass, but if mass and energy are equivalent then that makes sense.
 
Thread 'Can this experiment break Lorentz symmetry?'

Thread 'Can this experiment break Lorentz symmetry?'

1. The Big Idea: According to Einstein’s relativity, all motion is relative. You can’t tell if you’re moving at a constant velocity without looking outside. But what if there is a universal “rest frame” (like the old idea of the “ether”)? This experiment tries to find out by looking for tiny, directional differences in how objects move inside a sealed box. 2. How It Works: The Two-Stage Process Imagine a perfectly isolated spacecraft (our lab) moving through space at some unknown speed V...
View full post »

Thread '1-Way Speed of Light'

Does the speed of light change in a gravitational field depending on whether the direction of travel is parallel to the field, or perpendicular to the field? And is it the same in both directions at each orientation? This question could be answered experimentally to some degree of accuracy. Experiment design: Place two identical clocks A and B on the circumference of a wheel at opposite ends of the diameter of length L. The wheel is positioned upright, i.e., perpendicular to the ground...
View full post »

Thread 'How can a black hole absorb matter?'

According to the General Theory of Relativity, time does not pass on a black hole, which means that processes they don't work either. As the object becomes heavier, the speed of matter falling on it for an observer on Earth will first increase, and then slow down, due to the effect of time dilation. And then it will stop altogether. As a result, we will not get a black hole, since the critical mass will not be reached. Although the object will continue to attract matter, it will not be a...
View full post »

Similar threads

I Potential energy and the gravitational field of a collapsing cloud of gas
Replies
1
Views
1K
B Gravitational potential energy, a thought experiment
3
Replies
125
Views
6K
B Does E=mc^2 apply to gravitational potential energy?
2
Replies
62
Views
6K
B Energy loss of a photon
Replies
1
Views
940
I Conservation of Energy in GR: A-B System Analysis
Replies
5
Views
2K
B Gravitational Potential Energy & Mass Change: Andrew's Question
Replies
4
Views
2K
I Does gravity bend gravitational waves?
Replies
14
Views
1K
B Does gravitational force act on system or its components?
Replies
5
Views
1K
I E=mc^2 and acceleration
Replies
26
Views
2K
I Gravitational Potential Energy in GR
Replies
13
Views
2K

Hot Threads

Recent Insights

Back
Top