Kind: captions
Language: en
[Applause]
One of the most amazing things about
atoms is that they are mainly empty
space. If an atom were as wide as your
arms, then the electrons would all be
whizzing about inside the volume
enclosed by your fingertips. Meanwhile,
the nucleus would be sitting in the
center, and its diameter would be
smaller than the width of a single human
hair. So all of the atoms that make up
you and me and all the seemingly solid
things in the universe are mostly empty
space. Now this is incredible. But what
is even more mind-boggling is that empty
space is not truly empty. I know because
I've seen it. This is a simulation by
Professor Derek Lineweber at the
University of Adelaide. It was made
using a supercomput to crunch the
calculations of quantum chromodnamics.
Now, that is the theory of fundamental
particles called quarks, the building
blocks of protons and neutrons, and how
they interact with each other through
gluons.
What you're looking at here is the
energy density of uh the gluon field
fluctuations where the little red spots
come out, the energy density is very
high and it fades down through the
colors. And the lowest energy field
fluctuations, I'm not rendering this
animation so that we can actually see
into it. And what we see is a bubbling
soup of quantum field fluctuations that
come and go incredibly quickly. The
frame rate of this simulation is 1
million billion billion frames per
second. Now that is truly high speed.
The dimensions of this box are
absolutely tiny. They are millionths of
a billionth of a meter. Roughly enough
space to stick two protons. But there
are no protons here. This is a
simulation of the vacuum on its own.
What we'd normally think of as empty
space.
Empty space is actually full of these
quark mulon field fluctuations.
And on average um it is possible to
annihilate a quark from empty space cuz
it's it's not empty.
That just sounds like the most
ridiculous idea that you you're meant to
have empty space and yet you can go and
get rid of stuff from it.
That's right. So it is an empty.
Now it seems counterintuitive that the
vacuum at its lowest energy state should
contain all of this stuff. But in fact
to clear out the fluctuations and create
a truly empty vacuum would require a lot
of energy.
The empty vacuum actually costs an
enormous amount of energy to create. And
if you were able to create it, you
discover that that is actually unstable.
that any sort of perturbation would push
that empty vacuum into something where
the vacuum is actually full of quantum
field fluctuations.
Well, this may not be as strange as it
first appears. I mean, consider a
permanent magnet. It has a magnetic
field around it at low energy at room
temperature. And that's because the
individual little magnetic moments of
all the atoms inside are lined up. But
if you were to heat it up, you would
give thermal energy to all those
particles. And at a certain point called
the cure temperature, they would be so
randomly aligned that there would no
longer be an overall magnetic field. So
it actually takes energy to get rid of
the permanent magnetic field. And this
is just like the quantum vacuum. And
understanding how the quantum vacuum
fluctuations work gives us a sense of
what the fundamental particles do. Like
where are you most likely to find a
quark? And it turns out that the quark
likes to sit on top of those lumps. Now,
those lumps come into and out of
existence fairly quickly. And so, we
like to think of the quarks as hopping
from one lump over to the next lump as
it appears and then onto another one. I
like to think of it as a hiker trying to
uh cross a stream that's uh running
around and every now and then a stone
pops up, you know, because the water's
swirling around it. So you put your foot
there and then you look for the next
spot and if you go quickly enough you
might not get your feet wet. Uh so I
think quirks are are very much doing
well we know quirs are very much doing
the same thing.
So while it is true that you and I and
all of the other atoms in the universe
are mostly empty space. It is also true
that empty space isn't truly empty. And
in fact it is these vacuum fluctuations
which are essential for our existence.
If you're not subscribed to Derek's
channel, Veritasium, I don't know what
you're doing with your life. It is
amazing.
I got a pretty fat lip from doing this,
but luckily all my teeth were intact.