What do you feel when crossing the event horizon?

I have heard the claim over and over that you won't feel anything when crossing the event horizon as the curvature is not very large. But the fundamental fact remains that information cannot pass through the event horizon so you cannot feel your feet when they have passed it.

Is there a way to cross the even horizon at reasonable speed in radial direction (below say 0.01*c )? So what would it really be like?

• If you could include a reference to the recent "firewall" paper, it would make the question more topical. Sep 23, 2012 at 20:45
• Sep 23, 2012 at 20:52
• According to classical general relativity, one doesn't even notice when he crosses the event horizon: the space around it is mildly curved and indistinguishable from a patch of nearly-flat Minkowski space. There were very recent speculations that there is a firewall on the horizon of an old black hole, after all, due to some quantum-information issues black holes have to satisfy, see physics.stackexchange.com/questions/38005/… for the controversy. Sep 24, 2012 at 5:58

• No, if you're free falling than you hit the horizon at $c$ (relative to a shell observer) regardless of where you start from. This seems odd, but relative to a shell observer the acceleration at the horizon goes to infinity so it can always accelerate you to $c$ even if you start from rest a gnat's whisker from the horizon. But as discussed in the other question the meaning of the speed is ambiguous. Apr 3, 2022 at 8:57
With supermassive (a million solar masses) black holes the gravity gradient is very small and the tidal forces are so low that you won't feel anything until well after you have crossed the horizon. According to this site, the tidal force on your body at the horizon is $10^6$g for a 30 solar mass hole, but only 1g for a 30,000 solar mass hole.