Curved Space

[abygael]

I haven't written one of these for quite a while, so it's high time I did. In italic are lambdapi's questions, somewhat paraphrased for brevity.

Comments

[jeebuz_avt]

Lies to students! Space has as many spatial dimmensions as you want it to, and for thinking about gravitational lensing and spacetime distortions, it's best to think of it as having 4, but pretending there's really three and we're stuck in the first two (for visualisation purposes

[abygael]

I didn't say it was a model, I said it was a metaphor.

As for gravity acting in 4 dimensions, that's as yet speculation used to get rid of dark matter.

PS incidentally, someone invented anti-gravity by accident. Oops. See this week's New Scientist.

[jeebuz_avt]

The darkmatter thing IS what I was getting at, I just didn't think anyone would notice.

Also, there is a reason I don't read pop science magazines.

[jeebuz_avt]

You know, I just worked out that we can derive an elasticity of spacetime.. which means we can use it as a spring if we can somehow shift mass instantaneously.

[abygael]

Yeah, it wasn't acutally antigravity. I just thought that sounded cooler. It was like "oh shit, this shouldn't be happening but it still does after 200 goes. um... maybe it's 'cause gravitons also have mass inside superconductors... @.o"

[jeebuz_avt]

The superconductor 'antigravity' trick has been around for a long while now.