4 ms·

This felt somewhat wrong to me (as I’m sure it did many people that have take a Physics class) and ended up finding a Reddit discussion about this[1]. Seems lik

• deltasixeight 5y ago
  Reddit proves it. Case closed. Just kidding. No seriously that thread is long and there's no singular point, it's a debate. Take a look at this (not the same link above I target a single comment): https://www.reddit.com/r/Physics/comments/mn11r/the_dome_a_simple_violation_of_determinism_in/c33in7z/?utm_source=reddit&utm_medium=web2x&context=3 https://www.reddit.com/r/Physics/comments/mn11r/the_dome_a_s... I'll have you know you're debating with higher powers here. Some people here are not your typical people who just took a physics class. Either way intuition without the math is enough to break your brain. Imagine the opposite scenario you flick a ball up the dome with just the right amount of force that it comes to rest right at the apex. One property of Newtonian mechanics is that motion is time reversible. Meaning that the opposite motion here should be valid. And the opposite motion of the scenario I described is indeed what occurs. The particle is at rest on the dome and arbitrarily just rolls off randomly. Note that this is caveated on the site with the fact that this intuition doesn't work with hemispheres. Apparently with a hemisphere you can flick the ball with a certain amount of force and it takes infinite time to reach the apex of the dome. So if you time reverse that it means any ball resting on a hemispherical dome can roll off of the apex arbitrarily but it takes an infinite amount of time. The un-determinism only works for the special dome here called "Nortons Dome."