Thread: Gravity is awesome

Gravity isn't a force, it's a dip in space-time. If you experience the 'force' of gravity, you're just sliding in the dip. That's why Newton's formula F = m * a (Force equals mass multiplied by acceleration) works when you're calculating the force of gravity on an object. a = 9.81 m/s^2 here. You're just accelerating down the dip

This image uses a 2D raster to explain. Notice how the dip is down (in the 3rd dimension, while the raster is 2D) Real gravity works just like this, just in the 4th dimension, which is quite impossible to visualize.


I know I am confusing. Ask questions.

That's tautological, and basically wrong. This is something that they do teach to school children, but then when they get older, they ask, "what force other than gravity causes the ball to go down into the pit"? It's a good question.

As it turns out, I'm actually taking an advanced course on it right now, so I can explain. The actual force of gravity isn't a force at all. It's a fictitious force that only appears when you're in a 'weird' reference frame. Standing on the surface of the Earth is one such 'weird' frame. The proper frames for gravity are actually spacetime geodesics, and in these frames, ignoring tidal forces, you don't feel gravity at all. Now, because these are paths in space AND time, this involves movement, and hence this is why things fall. Or, in other words, in curved spacetime, being "at rest" is falling.

I've been thinking about that too, thank you for your reply

I still don't get it. How is your explanation different from mine, except in some tough words?

But then gravity is also hyptothesised to be due to gravitons, which would make them one of four basic force-causing particles.

I don't personally remotely understand how the ideas of particles and quanta can lead to General Relativity though. It seems quite contradictory to me.

That's because the ideas about gravity don't lead to General Relativity.

The relativity principle and constant speed of light lead to General Relativity

So why are gravitons needed?

Originally Posted by drewmandan

Or, in other words, in curved spacetime, being "at rest" is falling.

I don't understand. Do you mean being at rest "on Earth", for example, or being generally at rest somewhere in the middle of nowhere, where no other mass is attracting you. If the latter then I don't understand even further

Originally Posted by Bonsay

I don't understand. Do you mean being at rest "on Earth", for example, or being generally at rest somewhere in the middle of nowhere, where no other mass is attracting you. If the latter then I don't understand even further

At rest means that no real force is acting upon you. Near a gravitating body, the only way to be at rest is to orbit the the body in some way. Near the surface of the Earth, these orbits are almost perfect parabolas, which is why thrown objects follow parabolic trajectories. Note that during the entire flight, a thrown object never "feels" gravity, whereas a person standing on the ground does. In fact, the person not moving is in a sort of non-inertial reference frame, being accelerated by the normal force of the ground.

Gravity is very not awesome.

It's a pussy compared to electromagnetism.

Originally Posted by Elis D.

Gravity is very not awesome.

It's a pussy compared to electromagnetism.

+1

Originally Posted by drewmandan

That's tautological, and basically wrong. This is something that they do teach to school children, but then when they get older, they ask, "what force other than gravity causes the ball to go down into the pit"? It's a good question.

As it turns out, I'm actually taking an advanced course on it right now, so I can explain. The actual force of gravity isn't a force at all. It's a fictitious force that only appears when you're in a 'weird' reference frame. Standing on the surface of the Earth is one such 'weird' frame. The proper frames for gravity are actually spacetime geodesics, and in these frames, ignoring tidal forces, you don't feel gravity at all. Now, because these are paths in space AND time, this involves movement, and hence this is why things fall. Or, in other words, in curved spacetime, being "at rest" is falling.

You call that an explanation? A "weird" frame? How fucking scientific is that?

Originally Posted by drewmandan

The actual force of gravity isn't a force.

Then what is it, a no-force? A fictious force that only "suddenly" appears in a "weird" frame. How the hell is a fictious force supposed to appear anywhere at all to start with?

Originally Posted by drewmandan

The proper frames for gravity are actually spacetime geodesics, and in these frames, ignoring tidal forces, you don't feel gravity at all.

If you ignore tidal forces, you don't feel gravity at all. But if you don't ignore them, you will freel gravity? LOL.

Originally Posted by drewmandan

Because paths are in space AND time, this involves movement and hence that is why things fall.

Wtf? Is that even a correct english sentence? Because paths involve movement is why things fall! Sounds like something a kid with down syndrome would say.

Originally Posted by drewmandan

Being at rest, not falling, is falling.

Shit man, that's deep.

This is science, not writing a goddamn poem ffs. It's like you're trying to explain gravity by poetry. Are you sure you weren't taking advanced courses in linguistics by accident instead of physics? Or maybe the courses were a bit too advanced for you Next time pay a little bit more attention so you can give us a decent explanation which isn't full of contradictions and poetry.

Go away Chayba. Clearly anything posted here about general relativity is going to be extremely dumbed down. Unless you have a degree in theoretical physics (you don't) you aren't ever going to be able to understand.

There hasn't been a single argument on this forum so far, and unfortunately the people here aren't gullible enough to buy your blatant strawmen and baiting.

We all know what you're trying to do, and we don't care. Please just stop trying and leave.

Lol! You obviously don't understand yourself, or you would see how this is utter bullshit. Nobody understands as a matter of fact, thats why this theory is still accepted. Bashing my person won't explain gravity, nice try tho

The mere fact that we still lack a unified theory should be enough indication to you that current theories are incorrect, but for some reason you keep defending them like a fundamentalist christian defends the bible. Amazing how you call yourself a scientist when you leave no room for discussion at all.

Done?