Kind: captions
Language: en
can you say what is entanglement it
seems one of the most fundamental ideas
of quantum again well let's temporarily
buy into the textbook interpretation of
quantum mechanics and what that says is
that this wave function so it's very
small
outside the atom very big in the atom
basically the wave function you take it
and you square it you squared the number
that gives you the probability of
observing the system at that location so
if you say that for two electrons
there's only one wave function and that
wave function gives you the probability
of observing both electrons at once
doing something okay so maybe the
electron can be here or here here here
and the other electron can also be there
but we have a wave function setup where
we don't know where either electron is
going to be seen but we know they'll
both be seen in the same place okay so
we don't know exactly what we're gonna
see for either electron but there's
entanglement between the two of them
there's the sort of conditional
statement if we see one in one location
then we know the other one's going to be
doing a certain thing so that's a
feature of quantum mechanics that is
nowhere to be found in classical
mechanics and classical mechanics
there's no way I can say well I don't
know where either one of these particles
is but if I know if I find out where
this one is then I know where the other
one is that just never happens they're
truly separate and in general it feels
like if you think of a wave function
like as a dance floor it seems like
entanglement is strongest between things
that are dancing together closest so
there's a there's a closeness that's
important well that's not that's another
step we have to be careful here it
should cause in principle if you if
you're talking my feet hang them into
two electrons for example
they can be totally entangled or totally
unentangled no matter where they are in
the universe there's no relationship
between the amount of entanglement and
the distance between two electrons but
we now know that you know the reality of
our best way of understanding the world
is through quantum fields not through
particles so even the electron not just
gravity and electromagnetism but even
the electron and the quarks and so forth
are really vibrations in quantum fields
so even empty space is full of vibrating
quantum fields and those quantum fields
in empty space are entangled with each
other in exactly the way you just said
if they're nearby if you have like two
vibrating quantum fields that are nearby
then they will be highly entangled if
they're far away they will not be
entangled so what do quantum fields in a
vacuum look like empty space just so
like empty space it's as empty as it can
be but they're still a field it's just
yeah it uh what is nothing just over
here or this location in space there's a
gravitational field which I can detach
by dropping something yes
I don't see it but there did
you