Witness Life of Universe from Black Hole Event Horizon

Ping
Messages
1
Reaction score
0
I know there are many threads about falling into black holes and I'm sorry for posting another one. I have a specific question and couldn't find the answer in prior threads, although it's possible that it's there somewhere. If A is outside the supermassive black hole and B falls into it, I know that A will never see B cross the event horizon. The image of B will get dimmer and dimmer from A's perspective as A's coordinate time ticks off to infinite. I know that the proper time for B to reach the singularity is finite. I know that if B is looking back at A, B will only see a finite number of photons from A, and B will not witness the progression of the entire life of the rest of the universe.
Now imagine that B is falling in a spaceship with his rocket boosters pointed towards the black hole.​
B can look out the front window of his ship at A. If B turns on his rocket boosters just before passing into the singularity or being ripped apart by tidal forces, and B expends an infinite amount of energy, then can B hold himself in position or slow himself and witness the entirety of the progression of events in the rest of the universe? If this is impossible after crossing the event horizon, then can B hold himself at the event horizon using this energy and witness the same thing?
I apologize if I've assumed anything wrongly. I realize its impossible for B to have an infinite energy​
source on his ship.
 
Physics news on Phys.org
Ping said:
If B turns on his rocket boosters just before passing into the singularity or being ripped apart by tidal forces, and B expends an infinite amount of energy, then can B hold himself in position or slow himself and witness the entirety of the progression of events in the rest of the universe?

No.

Ping said:
If this is impossible after crossing the event horizon, then can B hold himself at the event horizon using this energy and witness the same thing?

No. It is not possible to "hover" at or inside the horizon, only outside it.
 
Although hovering at the event horizon is impossible, hovering just outside the horizon is allowed. If one were to hover close enough, one could see as much of the future of the rest of the universe as one pleased. (And get cooked by the blue-shifted radiation).
 
jbriggs444 said:
(And get cooked by the blue-shifted radiation).

If you weren't crushed by the severe acceleration. :eek:
 
  • Like
Likes jbriggs444
Thread 'Can this experiment break Lorentz symmetry?'
1. The Big Idea: According to Einstein’s relativity, all motion is relative. You can’t tell if you’re moving at a constant velocity without looking outside. But what if there is a universal “rest frame” (like the old idea of the “ether”)? This experiment tries to find out by looking for tiny, directional differences in how objects move inside a sealed box. 2. How It Works: The Two-Stage Process Imagine a perfectly isolated spacecraft (our lab) moving through space at some unknown speed V...
Does the speed of light change in a gravitational field depending on whether the direction of travel is parallel to the field, or perpendicular to the field? And is it the same in both directions at each orientation? This question could be answered experimentally to some degree of accuracy. Experiment design: Place two identical clocks A and B on the circumference of a wheel at opposite ends of the diameter of length L. The wheel is positioned upright, i.e., perpendicular to the ground...
In Philippe G. Ciarlet's book 'An introduction to differential geometry', He gives the integrability conditions of the differential equations like this: $$ \partial_{i} F_{lj}=L^p_{ij} F_{lp},\,\,\,F_{ij}(x_0)=F^0_{ij}. $$ The integrability conditions for the existence of a global solution ##F_{lj}## is: $$ R^i_{jkl}\equiv\partial_k L^i_{jl}-\partial_l L^i_{jk}+L^h_{jl} L^i_{hk}-L^h_{jk} L^i_{hl}=0 $$ Then from the equation: $$\nabla_b e_a= \Gamma^c_{ab} e_c$$ Using cartesian basis ## e_I...

Similar threads

Replies
46
Views
7K
Replies
40
Views
3K
Replies
43
Views
3K
Replies
7
Views
2K
Replies
22
Views
1K
Back
Top