Understanding Space Distortion in General Relativity

[MrNerd]

From what I understand, general relativity states that space itself is curved. Thus, gravity. What I don't understand is, why isn't motion necessary to follow the curve? What I mean by this is if in a two dimensional plane, with space in terms of arrows, they would curve into the object(I think). In order to get closer to the object, one would have to follow the arrows(representing the geodesics), therefore being in motion. If this is true, then shouldn't one be able to determine an absolute velocity, relative to space itself? It can't only be relative to the massive object, since standing on Earth still produces gravity, as well as those satellites that focus on a single spot on Earth by moving at the same angular speed.

Additionally, how does a black hole distort the space to prevent light from the singularity getting out? The light would be perpendicular to a sucking in of space, so how does it curve?

My only ideas to these questions are that space and time are actually rearranged(like cutting a piece of cloth, moving one, and then sewing it back together), or that space is kind of pushed out(it enters the distorted space at a position pushed away relative to it, but travels as if it were it's own. As in the space is already screwed up when sewn back together, but travels as if it were not screwed up. If pulled object A is at position 1,1, the space at 1,2 is pushed away so it's at 2,2, but the object continues as if the space was at 1,2. It's kind of hard to explain this idea without a picture)

My mathematical and physics skills are limited to about AP Calculus and AP Physics B(I got a 5 on both exams, so I'm pretty good with them), but I have a basic idea about tensors(essentially they're matrices, and you can do fancy stuff with them, and sometimes AB = -BA, and sometimes AB = BA, and you're not supposed to officially learn about them until about graduate school or senior year at undergraduate school(this sucks since I'm about to start my first year at college)).

 

[bcrowell]

Hi, MrNerd,

Welcome to PF!

The perfect book for you at this stage would be Exploring Black Holes by Taylor and Wheeler. IMO you're not going to be able to piece together a coherent understanding of this kind of thing just by posting online.

 

[MrNerd]

Thanks for the suggestion. It looks like an interesting book. Hopefully, I can get a job sometime soon and be able to afford it. I suppose you are probably right about the complete picture, too. I have some knowledge of relativity, but it's nowhere near complete.

 

[bcrowell]

Thanks for the suggestion. It looks like an interesting book. Hopefully, I can get a job sometime soon and be able to afford it. I suppose you are probably right about the complete picture, too. I have some knowledge of relativity, but it's nowhere near complete.

If you're about to start college, you should either be able to find it at the library or obtain it through inter-library loan.

 

[MrNerd]

It's not on the library(searched through the website, at least) at my college, although it is only a community college. I guess I'll see what what I can do about the inter-library loan when the semester starts, so I don't waste gas.

 

[bcrowell]

It's not on the library(searched through the website, at least) at my college, although it is only a community college. I guess I'll see what what I can do about the inter-library loan when the semester starts, so I don't waste gas.

Being a CC student may also give you borrowing privileges at nearby four-year state schools.

 

[pervect]

There's a pretty good chance you can get an interlibrary loan. I'm not sure if they'll charge a minimal fee, it depends on the library.

You can get the first few chapters online free, in any event, at the author's website:

http://www.eftaylor.com/general.html