Comment on Can energy be associated with/related to spacetime ?
AbouBenAdhem@lemmy.world 4 days agoThrough mass/energy equivalence, E=mc^2^. Energy distorts spacetime the same as its equivalent rest mass.
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.
Don’t understand this bit.
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
You explain beautifully the reason why Shakti (energy) is the Divine Consort of Shiva (the overseer of destruction) according to Vedic philosophy.
This is a very interesting theory.
You’re on the right track.
Mass is a property of matter, they’re not the same thing.
A water molecule is the same matter as two hydrogen atoms and an oxygen, yet the molecule has less mass. The difference comes from the energy released when the molecule is formed. Fusion is the same, forcing two atoms together releases a neutron with lots of energy. Same matter, less mass.
It’s the opposite with fission. One atom splits into two and two really fast neutrons, and the total mass is less than the original atom. The matter isn’t destroyed, but some of its mass is converted into energy.
Matter can be destroyed by annihilating it with antimatter, but that hardly counts because we have to make the antimatter by turning energy back into mass and that also creates an equal amount of matter.
In plain terms, energy has gravity.
Energy has gravity ??
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.
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
Though the force itself is irrelevant
But force is a measure of the rate at which energy is transferred over a distance.
So if one force is greater than another and the distance is the same, then the energy is greater in the case of the greater force.
Not really that simple. Is EM curving space time? Yes. But it does it in a very different way. EM is a force which couples to charges, magnetism, transferred by light. Gravity is a completely different beast. Super weak, but couples to everything. Mass? Yeah. Massless particles (light)? Yeah. The interraction strength itself is not an indication on how it affects the curvature of space (well, EM as a gauge theory is a curvature of a mathematical space, but gravity is one of physical space).
As far as I know, none of the observed black holes (like in LIGO) have ever observed something that would be a charged black hole, but there is the theoretical formulation of one called a Reissner Nordström black hole. In that formulation you can see how adding charge and mass acts differently. For one thing, EM charge can be negative and positive, but either sign affects the spacetime the same, in a very simple way: the square of the charge appears in the expression. But mass only appears linear. Just as an example of how they play a very different role when it comes to curvature.
True. The em field is significantly more energetic, meaning that it contributes more to the stress energy tensor than the force of gravity
But recall that the force of gravity is the momentum change “due to” the curvature of spacetime. The fact that the force of gravity can bend spacetime at all is a really weird second-order perturbative effect.
These perturbative effects are typically described with a quantum field theory, but gravity has been thus far notably difficult to quantize.
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.
FuglyDuck@lemmy.world 4 days ago
Yeah, that sort of depends on the level of physics you’re talking about. regardless, it’s still a property of stuff even if that stuff is not always matter. if you want to go off on the weeds on that, go for it.
even so, energy is not something that exists, but a quantified attribute of things that do exist.
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.