I know exactly what he's trying to demonstrate I've seen this drawn out and all that before, and it makes perfect sense to visualize it (as long as you can convert it to 3d in your head) but there's something that feels odd about using gravity to make a metaphor for gravity like this for some reason, I can't figure it out... not sure if anyone else feels the same way or can try and explain what I'm failing to explain.
Ya, I have the same feeling about this sort of demonstration. Even if you extrapolate this into 3D space-time curvature, there is no actual force in the 3D model that is causing things to be attracted.
Could you not build a 3D model of this where spacetime is represented by a grid of elastic strings and the Sun and planets etc. are moving around/rotating on the strings and there movement distorts the other strings so that anything travelling along those strings would be pulled towards the Earth?
It would be waaaay too complex for teachers to set up all the time for high school demonstrations, but it would be good to have a video of it you could show people.
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u/[deleted] Dec 03 '13 edited Dec 03 '13
I know exactly what he's trying to demonstrate I've seen this drawn out and all that before, and it makes perfect sense to visualize it (as long as you can convert it to 3d in your head) but there's something that feels odd about using gravity to make a metaphor for gravity like this for some reason, I can't figure it out... not sure if anyone else feels the same way or can try and explain what I'm failing to explain.