Re: That Black-Hole Space-time curvature thing

Keith (
Sun, 14 Sep 1997 12:34:34 -0700

Eliezer S. Yudkowsky wrote:
> Kennita Watson wrote:
> >
> >
> > A big hug to John K. Clark (assuming he wants one)!
> >
> > I spent all these years thinking that people who fell into a black
> > hole would be torn apart, when actually they would be crushed together!
> > This explanation is great!
> >
> > Kennita (still dazzled by the light bulb going on over her head :-) )
> Um, no. Actually, you would be simultaneously crushed and torn about. As you
> got close to the singularity, assuming you headed in feet first, the atoms in
> your feet would be torn away and crushed into an infinitely dense point. Then
> the atoms in your knees. And so on. You get torn apart from the feet up, but
> the loose parts get compacted again.
> Probably before that, your head and feet would get ripped off, heading in on
> their own time. Before you start disintegrating, that is. You're kind of
> being squeezed from one direction and torn apart from the other. Drop a bit
> of liquid into a black hole and it assumes an egg shape that rapidly becomes
> very long and thin, until it finally becomes a cone of atoms and quarks
> funneling into a point.
> I also seem to recall that the tidal forces wouldn't become strong enough
> until the last 4 seconds or so... so enjoy the view.
> Got it?

I wonder how, if at all, this result varies depending on the mass
of the black hole and its movement relative to the observer.
What if a particle, say a neutron, that was moving very fast -so
close to the speed of light that it's mass was equal to the
earth's mass -were to hit the earth dead center? Would the
particle just pass on through? Or would it hit other particles,
which in turn would hit more (other) particles, to such an extent
that the earth would be destroyed? Would there be an "entry
wound" and an "exit wound?" What if the particle were moving so
fast that its mass were 1 solar mass? 5 solar masses?