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Re:Neutron stars may be bigger than expected, measurement of... by gus_massa on Tuesday April 27, 2021 @05:05PM (#26961541)
All the stuff around a black hole and in a black hole is under a lot of tidal forces and will be crushed and crumbled.

Imagine a blender. According to quantum mechanics, using a blender for an hour is an unitary transformation, so it will not destroy the information, and it's an invertible operation, you can reconstruct the original items. [And even a classic blender is invertible at the molecular level. It's only not invertible if you consider the friction and other average macroscopically properties.] Anyway, after an hour of blending, you will get a horrible homogeneous mix.

But (if the current models are correct) a Neutron star is very different in the crust that is a few km near the surface. It has many levels with different properties that are called "nuclear pasta" https://en.wikipedia.org/wiki/Nuclear_pasta and one with graphics that explain the names https://astrobites.org/2017/10/05/nuclear-pasta-in-neutron-s...

Going again to the blender example, it's like a bad blended mix, that has foam at the surface, a liquid in the middle and solids at the bottom.

Re:Neutron stars may be bigger than expected, measurement of... by btilly on Tuesday April 27, 2021 @05:15PM (#26961662)
It depends on the size of the black hole. One with the mass of the Sun would rip your head from our feet under a tidal force of thousands of gravities. One the size of the monster at the heart of our galaxy has tidal forces so gentle that you wouldn't even notice them until after you were inside the event horizon.

If this seems non-intuitive, remember that the Schwarzschild radius varies linearly with mass, and tidal forces scale like mass / radius^3. So tidal forces at the event horizon scale like 1/mass^2. A black hole that is 100 million times heavier will have tidal forces that are 10 quadrillion times smaller at its event horizon.

Re:Neutron stars may be bigger than expected, measurement of... by gus_massa on Tuesday April 27, 2021 @07:23PM (#26963335)
You are correct.

But the "no-hair theorem" that says that a black hole can be characterized using only 3 properties does not apply instantly, but only after some time of isolation.

For a small black hole the time is very short, but for a huge black hole that will not tear you apart it takes a long time. So even a classic huge black hole has more internal state that should be measurable from outside.

Re:Neutron stars may be bigger than expected, measurement of... by a1369209993 on Tuesday April 27, 2021 @08:01PM (#26963722)
> using a blender for an hour is an unitary transformation, so it will not destroy the information

> Anyway, after an hour of blending, you will get a horrible homogeneous mix.

This (plus hawking radiation being that horrible homogeneous mix) sums up the solution to the black hole information paradox really well, thank you.