Comment on When somebody backs up their argument with a 90-minute video
sukhmel@programming.dev 1 month agoGood point but why “no bowling ball on a trampoline nonsense”? That’s not a correct analogy, since it deforms “space” different from how gravity transforms space, but it’s good enough to understand how that works, I think
chonglibloodsport@lemmy.world 1 month ago
Oh because that incorrect analogy is the most common “lay person” analogy for describing gravitational curvature of spacetime. The most common reply from children is that it’s the earth’s gravity pulling down on the bowling ball so that the trampoline demonstration wouldn’t work in space.
Also the trampoline analogy doesn’t show us how gravitational lensing works, nor does it even touch how different gravitational reference frames affect the passage of time (GR generalizes special relativity, after all).
sukhmel@programming.dev 1 month ago
Affecting passage of time looks like a difficult idea to come up with an analogy.
For the better gravity analogy, I think a rubber sheet that has something pulling together at a “gravity well” and lines drawn on it may work better, but I’m not sure 😅
chonglibloodsport@lemmy.world 1 month ago
The harder thing to convey is the full dimensionality of it. With the rubber sheet (or trampoline) you can show a small ball orbiting around a larger one but only in a single plane (around the “equator” of the large ball). However in reality you can orbit in any direction you like and many satellites actually orbit over the poles. Trying to show that with a small model seems extremely difficult!
sukhmel@programming.dev 1 month ago
Not in Australia, though