near a black hole space and time do some
very strange things because black holes
are probably the most violent places we
know of in the universe
this river provides a beautiful analogy
for what happens to space and time as
you get closer and closer to the black
hole
now upstream the water is flowing pretty
slowly let's imagine that it's flowing
at 3 km/h and I can swim at 4 so I can
swim faster than the flow and can easily
escape
but as you go further further downstream
towards the waterfall in the distance
the river flows faster and faster
imagine how is to decide to jump into
the river just there on the edge of the
falls the water is flowing far faster
than I could swim so no matter what I
did no matter how hard I tried I would
not be able to swim back upstream I will
be carried inexorably towards the edge
and I would vanish over the falls
well it's the same close to a black hole
because space flows faster faster and
faster towards the black hole literally
this still my space that I'm in flowing
over the edge into the black hole and at
the very special point called the event
horizon space is flowing at the speed of
light into the black hole
lies itself grabbing at 300,000
kilometers per second is not going fast
enough to escape the flow and lice
itself will plunge into the black hole
well as you fall into a black hole
across the event horizon then if you
were going feet first your feet will be
accelerating faster than your head so
you would be stretched and you will be
quite literally spaghettified
now as you get right to the center then
our understanding of the laws of physics
breaks down our best theory of space and
time
Einstein's theory of general relativity
says that space and time become
infinitely curved that the center of the
hole becomes infinitely dense that place
is called a singularity and it is the
place where our understanding of the
universe stops
you