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"gravity is a universal constant" contradicts Newtonian mechanics, special and general relativity.
by bigbacaloa 4y ago
"gravity is a universal constant" contradicts Newtonian mechanics, special and general relativity.
- nanidin 4y agoIn these "it's like taking a video of throwing a ball in the air and allowing it to land on the ground, then playing it in reverse" examples, I can't help but think of Newton's first law. If an object at rest stays at rest, how does the ball leap from the ground? Where does the impulse come from? Reverse time seems too far fetched for me, or at least the simplified naïve version of it does.
- bnralt 4y agoIt also seems a bit misleading, since in that scenario a ball is intentionally thrown so that it comes down the same way. Let's consider something else - imagine an accretion disk of space dust slowly pulling itself together to form a planet. Play that in reverse, and you have the a planet slowly coming apart piece by piece. Imagine reversing the impact that created the moon. The moon comes apart piece by piece, creating an accretion disk around the earth, which then all moves and hits one area of the earth, and there several parts of it (and part of the earth itself) move together to form a separate planet, which then launches itself from the earths surface into space, flies around the sun a few times, and then slowly breaks apart piece by piece into another accretion disk.