2 ms·

>The only way I've been able to reconcile this in my mind is to think that this is a visualization of gravity warping spacetime in a 2D universe, and that is wh

>The only way I've been able to reconcile this in my mind is to think that this is a visualization of gravity warping spacetime in a 2D universe, and that is why the masses are stuck to the surface Yes, that is correct. The sheet models a 2D universe, so objects are not allowed to "leave" the sheet, just like the Earth can't leave the three spatial dimensions it inhabits in the real universe. For the same reason, an object on the sheet universe can't see (or even imagine) the concept that its sheet is bending. After all, the sheet is bending in a dimension that it cannot know about. The analogy breaks down when you try to think where the force pulling the object down the bent spandex comes from. The objects on the sheet get pulled down a bend because of the Earth's gravity, but in the actual universe there's no 4D Earth that's pulling objects down a 3D slope.

jonsen 12y ago
... there's no 4D Earth that's pulling objects down a 3D slope. What is pulling it then?
- Rapzid 12y ago
  I suppose it's possible that mass interacting with the higgs field could give rise to motion in the way an object will be pushed from a high density area of liquid to a low density area as mentioned in another comment here..
  - coldtea 12y ago
    Those answers are so vague and abstract and far from a conceptual understanding from most people that have them told to me, that one comes to wonder how much they resemble the mystic explanations of the universe by priests and samans of yore in functionality. E.g. a lot of big words that many repeat but few are supposed to understand (and even those, not that good).
- Arnavion 12y ago
  There is no answer to this question. Relativity simply allows one to calculate how much curvature is created in a particular mass configuration, and what the resulting gravitational forces are. It doesn't try to explain why the curvature occurs. This link explains it better than I did: http://www.thenakedscientists.com/forum/index.php?topic=38879.0 http://www.thenakedscientists.com/forum/index.php?topic=3887...
  - amelius 12y ago
    Just wondering, if acceleration == gravity (equivalence principle), how would this be visualized in this model?

jonsen 12y ago

... there's no 4D Earth that's pulling objects down a 3D slope. What is pulling it then?

Rapzid 12y ago
I suppose it's possible that mass interacting with the higgs field could give rise to motion in the way an object will be pushed from a high density area of liquid to a low density area as mentioned in another comment here..
- coldtea 12y ago
  Those answers are so vague and abstract and far from a conceptual understanding from most people that have them told to me, that one comes to wonder how much they resemble the mystic explanations of the universe by priests and samans of yore in functionality. E.g. a lot of big words that many repeat but few are supposed to understand (and even those, not that good).
Arnavion 12y ago
There is no answer to this question. Relativity simply allows one to calculate how much curvature is created in a particular mass configuration, and what the resulting gravitational forces are. It doesn't try to explain why the curvature occurs. This link explains it better than I did: http://www.thenakedscientists.com/forum/index.php?topic=38879.0 http://www.thenakedscientists.com/forum/index.php?topic=3887...
- amelius 12y ago
  Just wondering, if acceleration == gravity (equivalence principle), how would this be visualized in this model?