The two dimensions instead of three represented by the square part of the inverse square law is due to the fact that the surface of a sphere is 2 dimensional, n

The two dimensions instead of three represented by the square part of the inverse square law is due to the fact that the surface of a sphere is 2 dimensional, not three dimensional. I don’t know physics well enough to dispute anything else you said but as I understand it only gravity interacts with the extra curled up dimensions, not magnetism or the strong and weak nuclear forces. How do physicists “know” this? No clue but as the article says, gravity behaves differently than the other three forces so there should be an experiment that can show the difference by measuring one thing for gravity and another for the other three forces. I understand that the experiment would have to be conducted over currently impossibly small distances to actually see the graviton disappear as it leaves our three extended dimensions and reappear as it comes back. I don’t understand why the effect wouldn’t be clear to see over cosmological distances but that most likely stems from my ignorance more than theirs.