Gravity Forces Us to Move: PF Forum

[Stephanus]

Dear PF Forum,
I just want to ask a simple question.

Even if we are at rest (ignoring that the Earth rotates, evolves around the sun, orbitting SMBH and Milky way orbitting what? Virgo Supercluster? And Virgo Supercluster to what?),
A. So even if we are at "rest" (blue line), are we always moving just like in ST diagram? We move trough time.
B. And gravity curves what? Space? Time? Space Time? And we are forced to move (green line), so that $t_{green}^2-x_{green}^2 = t_{blue}^2$?
If we see the ST diagram, I think gravity just bends time not space. But what I ask, if we are FORCED to move.

 

[A.T.]

I think gravity just bends time not space.

Both are distorted, but time is more important for what we perceive as attraction.

 

[Stephanus]

Both are distorted, but time is more important for what we perceive as attraction.

Wow, the respond is so fast. Thanks A.T. Btw, what about the ST diagram. Are we forced to move so that $t_{green}^2-x_{green}^2 = t_{blue}^2$

 

[mfb]

Even if we are at rest

Saying "we are at rest" is not well-defined. Motion is relative - there is always a frame where you are at rest in a particular moment, and frames where you are not.

 

[Stephanus]

Saying "we are at rest" is not well-defined. Motion is relative - there is always a frame where you are at rest in a particular moment, and frames where you are not.

Thanks for your reply MFB.
But I don't say:
Even if we are at rest
but
Even if we are at "rest".
Because like you said, Motion is relative and there is always a frame where you are at rest,...
Thanks anyway

 

[Mentz114]

Dear PF Forum,
I just want to ask a simple question.
View attachment 85756
A. So even if we are at "rest" (blue line), are we always moving just like in ST diagram? We move through time.

Yes. Blue is not moving through space but is 'moving through time' in the sense that the passage of time is experienced as always.

B. And gravity curves what? Space? Time? Space Time? And we are forced to move (green line), so that $t_{green}^2-x_{green}^2 = t_{blue}^2$?
If we see the ST diagram, I think gravity just bends time not space. But what I ask, if we are FORCED to move.

Gravity is curved spacetime.

No we are not forced to move so that $t_{green}^2-x_{green}^2 = t_{blue}^2$. If blue and green are interacting through gravity it becomes very complicated.

 

[Stephanus]

Thanks for the answers

 

[eurus]

We are never at rest