Dear PF Forum, What happens inside Event Horizon? 1. Will clock stop inside EH? An object crosses the EH of a black hole around 1 billions solar mass which its Schwarzschild Radius is 3 billions km. It takes light to cross that distance (in 'normal' space) 30 thousands seconds. The time for an object travels at, say, 99.99% the speed of light to travel that distance (in 'normal' space) according to a rest observer, after adjusting to time dilation is not 30 thousands second, but around 428 seconds. Faster than that it could take just 1 second. So what happen if a clock crosses the EH of a black hole, will it hit the singularity instantneusly? Or it will hit the singularity in 30 thousands seconds? 2. What is the speed of an object that crosses the EH? It's in a speed of light or it's an irrelevant question? @tiny-tim said in https://www.physicsforums.com/threads/acceleration-inside-an-event-horizon.402258/#post-2711192, I can't quote it because the thread was closed. But an object with mass can't travel at the speed of light Or the law of physics break down inside EH? Thank you very much.