A birch planet is a theoretical far future Giga-structure where a shell world is built around a supermassive blackhole. I have been playing around with different astrophysical calculators to find out the gravitational force, time dilation and escape velocity for different radius structures around ultra massive blackholes but I am having trouble understanding how a low gravity surface with a very high escape velocity can be survivable for humans.
As the black holes mass increases so does its event horizon radius which means the gravitational force lowers, so when its mass is 1.5 trillion solar masses its gravitational force becomes 1g, which sounds perfect for human life but the escape velocity is near the speed of light and time dilation is very high but how would this high escape velocity effect conditions there? could things lift off the ground with the same ease as on Earth, could planes fly in the sky or people jump off the ground?
I have not decided on the mass or radius of the Birch planet so its escape velocity may not be as extreme as the earlier example but it will still have a similar issue of a very high escape velocity but low gravity, other than the increased amount of energy needed for spacecrafts to escape the gravity of the Birch planet and black hole, what will be the other effects of a high escape velocity on structure which contains current earth-like life and features?