An event horizon is a conceptual sphere surrounding a singularity, the
whole structure being a black hole. My question deals with why things
cannot exit the event horizon.
Let's say we have a Dyson sphere surrounding a black hole and its
singularity. Let's assume the Dyson sphere is kept in position by
fleets of thrusters that stabilize it. From the Dyson sphere we
dangle an incredibly strong string (nanotube or something) with a ball
attached to the end.
We lower the ball to just outside the singularity, then stop it there.
The force on the ball from gravity is equal to that of the string --
the ball is in equilibrium.
We now lower the ball to just inside the event horizon, then stop it.
Question: Why can't we pull the ball back out of the event horizon?
Things to consider: if the force on the ball is finite, then we
should be able to match that force with an equal force on the rope.
if the force is infinite, we should be able to convert the pull on the
rope to an infinite amount of mechanical work. How is this dilemma
resolved within physics?
I would prefer an answer more detailed than "physics breaks down".
Also, an answer such as "no rope can be strong enough" is not good
enough -- why can't a rope be that strong? What if our ball is
instead a rocket with some hypothetical extremely strong engine? What
proves that the engine can't output enough force to match gravity?
Assume we have a supermassive black hole with a shallow gravity well.
Please answer with a level of detail that can be understood by someone
with a AP Physics C understanding, combined with coffee-table physics
reading at _A Brief History Of Time_ and _The Elegant Universe_.
Equations are OK if they can be explained well. |
