Comment on Can energy be associated with/related to spacetime ?
AbouBenAdhem@lemmy.world 4 days ago
Energy bends spacetime, just like matter. Is that what you mean?
Hartley has a very simple way of viewing this, see photo from his textbook “Introduction to General Relativity” photo
One thing to remember is that GR is still just a theory with a substantial lack of experimental proof, but the maths does work out quite well with it
I’m not sure what your definition of experimental proof is. There have been many experiments to test General Relativity over the past 100 years. As far as I know none of those experiments have found significant disagreement with the theory.
Here’s a paper about testing einstein’s theory:
It is an older paper, but aftet a skim the only significant missing experiment is LIGO.
If we had tested everything that could be for GR or it had no contraditions we wouldn’t be creating modified theories of gravity or proposing new constants to try solve things, or trying to come up with some quantum theory of gravity.
In physics theory doesn’t mean some random guess. Theory means it has been experimentally validated.
OrangePumkin@piefed.nl 4 days ago
That’s an important link. How does that happen ?
AbouBenAdhem@lemmy.world 4 days ago
Through mass/energy equivalence, E=mc^2^. Energy distorts spacetime the same as its equivalent rest mass.
FuglyDuck@lemmy.world 4 days ago
To clarify, energy isn’t a “thing” that exists. It’s a property of matter, and so is mass.
So spacetime are only related in that matter exists in spacetime, and can influence it in ways we don’t (or at least I don’t,) really understand.
ignirtoq@feddit.online 4 days ago
Energy is not only a property of matter. Photons have energy, no mass, and are not matter but in fact force carrier particles.
OrangePumkin@piefed.nl 3 days ago
Anything that occupies space and has weight is matter. And yes, every matter exists in time.
MastKalandar@feddit.online 4 days ago
Thanks for that link.
RIotingPacifist@lemmy.world 4 days ago
I don’t think through is the right term.
Mass distorts spacetime because that’s a thing that mass does, we can’t explain it any better than we can explain WHY apples fall from trees, we just have very detailed models for. HOW it works, and anything that has energy bends spacetime in the same way that mass does.
OrangePumkin@piefed.nl 4 days ago
Don’t understand this bit.
arctanthrope@lemmy.world 4 days ago
the simple forms of conservation you probably learned in school are not entirely accurate. you probably learned that neither energy not matter can be created or destroyed; whatever you do, the mass you begin with will be the same as the mass you end with, and the same is true, separately, for energy. that’s not actually true; mass can be converted into energy, and vice versa. the correct form of conservation is that the combined mass-energy is constant. mass can be destroyed, but only if a proportional amount of energy is created. the coefficient of that proportionality is the square of the speed of light. that’s what E=mc² means. that’s how nuclear weapons work, and why they’re so powerful. c² is obviously a pretty big value, so when a small amount of matter is destroyed, it creates a large amount of energy
similarly, energy can be converted into mass, but doing so makes it much “smaller.” c² units of energy will become 1 unit of mass. and mass, of course, interacts with space-time
AbouBenAdhem@lemmy.world 4 days ago
In plain terms, energy has gravity.
Blue_Morpho@lemmy.world 4 days ago
What I never understood is why the electric field doesn’t distort spacetime more than gravity. The force between 2 electrons is like 4*10^42 times stronger than gravity. So a tiny electric field should cause the same spacetime bending as a massive object.
FrenziedFelidFanatic@pawb.social 4 days ago
It does. The energy density of the em field will contribute to the mass-energy tensor that changes the metric of spacetime.
Though the force itself is irrelevant