- What is the difference between proper acceleration and coordinate acceleration? What role does each concept play in relativity?
[Moderator's note: Spun off from previous thread due to topic change.]
Can you show me a situation where Newton says things accelerate and Einstein says they don't? Being in free fall doesn't mean things don't accelerate. I drop a ball towards the earth and it not only accelerates but it has a greater acceleration as it gets closer. If that case GR only slightly tweaks Newtonian gravity. Both say it accelerates at a greater rate as it gets closer regardless if you call it free fall along a geodesic. Right?Yes, the attraction changes and in Newtonian physics that means they are applying a gravitational force to each other? So what? This thread is about GR, not Newtonian physics. Things just naturally travel along geodesics (ie are in "free fall")