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Unit 7: Astrophysics Page 51

Earth’s gravity because we’re return). This is the place where if

closer to the center of the Earth. you cross over this line into the
black hole, there’s no coming back
If we continue to squeeze the Earth
out.
down to the size of a ping pong
ball, the gravitational pull is Time slows in regions of higher
becoming so great that now the gravitational forces. Black holes
required escape speed is have such huge gravitational forces
approaching the speed of light. that time slows to a standstill.

A black hole is an object whose Myths about Black Holes
escape speed exceeds the speed of
Black holes are not vacuum
light. General relativity predicts
cleaners with infinite sized bags.
black holes also!
They do not roam around the
For our sun to become a black universe sucking up everything
hole, we’d have to squeeze it into a they can find.
ball about 4 miles in diameter, so
They will grow gradually as stars
you’re safe – the sun will never
and matter falls into them, but
turn into a black hole. It’s not
they do not seek out prey like
small enough and does not have
predators.
nearly enough mass (it needs at
least three times its current mass

to do so).

Black holes are formed from
intense supernova explosions or by

large objects colliding together.

Black holes are also called ‘frozen
stars’ because time stops at the
event horizon (the point of no

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