[Music]
RONALD MALLETT: In a way, a black hole can
act as a natural time machine.
[Music]
Now, a black hole is just simply a star, an
ordinary star, like our sun.
Our sun is just an average star and the way
which our sun works is the fact that it's
a ball of hydrogen gas and the gravity of
that gas is colliding hydrogen atoms together
as they collide together, they form helium
and there's little difference between the
mass of the helium which is a little less
than the mass of the hydrogen that came together.
That little difference in mass gives us the
huge energy and life from the sun that we
have.
But eventually what will happen is that that
internal furnace begins to get used up and
when that happens, the gravity that's trying
to collapse and push the star inward is not
gonna be balanced by the internal energy that's
pushing outward, so the star's gonna start
to collapse and if you have particularly large
stars, they still behave in the same way and
when they begin to collapse eventually what's
going to happen is that the gravity around
the star is going to become so great that
the very light that tries to get out of the
star is going to be pulled back to the star
by the gravity of the star.
That's what a black hole is.
A black hole is just simply a star that's
collapsed to such a point that the light that
tries to escape from it gets pulled back from
it so you see a black spherical object out
there.
It turns out that it does something else.
It doesn't just perfectly affect light.
It affects time.
If you take a clock and you were moving closer
and closer to a black hole, you would find
that time is actually beginning to slow down
so that if you got right to the edge of a
black hole, time would come nearly to a halt.
As a human being as you're getting closer,
you're metabolism, your heart rate will start
slowing down and you will age less than everyone
else.
You can just be near a black hole for a few
hours and decades could be passing for everyone
else and then when you move away from the
black hole you would find yourself in the
future, so I knew that by studying black holes
that would be a way that I could legitimately
talk about the real possibility of time travel.
