- #1
Kekkuli
- 9
- 2
I find it interesting that the more massive the black hole, the weaker the fall acceleration at the distance of the Schwarzschild radius - that's why you wouldn't necessarily notice anything special in the event horizon.
##GM / R^2## is not "the fall acceleration" except in a very technical sense: it is the "redshifted" proper acceleration of an observer "hovering" at ##R##. So, for example, if an observer at infinity were holding up an object at ##R## using a very long rope, ##GM / R^2## is the force per unit mass that the observer at infinity would have to exert on the rope. But the object at ##R## would not experience that acceleration; the object's proper acceleration would be ##GM / (R^2 \sqrt{1 - 2GM / (c^2 R)})##.Kekkuli said:
No, it isn't. You wouldn't notice anything special falling through the horizon because spacetime is locally Lorentzian there just like it is everywhere else. It has nothing to do with "fall acceleration".Kekkuli said:
Saying "notice" you seem to think of tidal force or spaghettification. Yes, the larger the black hole the less you feel it, as already said in #4. The reason is tidal force goes with 1/M².Kekkuli said:
When falling into a massive black hole, the gravitational pull is relatively uniform across your body due to the large size of the black hole. This uniformity means that the tidal forces, which can stretch and squeeze objects in smaller black holes, are much weaker. Therefore, you might not feel extreme effects as you cross the event horizon, the boundary around the black hole.
Spaghettification is a process where objects are stretched into long, thin shapes by strong tidal forces as they approach a black hole. In massive black holes, these tidal forces are significantly weaker at the event horizon due to the larger radius and more gradual curvature of space-time. As a result, spaghettification might only occur much closer to the singularity, if at all, making it unnoticeable as you initially cross the event horizon.
You might not realize you've entered a black hole until you are well within the event horizon, especially if the black hole is supermassive. The initial crossing of the event horizon in such cases can be uneventful, and without any visual or physical cues, you may not notice any change. The realization might only come as you observe the distortion of light from the outside universe or potentially from increasing tidal forces as you approach the singularity.
No, once you've crossed the event horizon of a black hole, escape is not possible. The event horizon marks the boundary within which the escape velocity exceeds the speed of light. Since nothing can travel faster than light, not even light itself can escape from inside this boundary, making escape impossible for any object or information.
As you approach the singularity of a massive black hole, the tidal forces would increase dramatically. Eventually, these forces would become strong enough to cause spaghettification, where you would be stretched and compressed into an extremely thin strand of matter. The exact nature of the singularity and what happens at that point remains a topic of theoretical speculation and is beyond our current understanding of physics.