Hi there.
So, the first thing you’ll notice is that
I’m not where you normally see me.
I miss my blackboard.
But, like most people, I’m working from
home these days, which means I can’t make
the videos you’re used to seeing me in.
So instead, I thought I would take the opportunity
to devise a series of short videos that will
help you understand why I do the science I
do and furthermore why it is that I am so
interested in the world of very tiny things.
And, over the course of several videos, I
will focus on individual pieces of that and,
by the end, it’ll be essentially a master
class in understanding particle physics and
cosmology, and you’ll know everything that
I do.
So, let’s get started.
The goal of physics, fundamental physics at
least, is to understand the ultimate rules
that govern our universe.
So, that means that I want to know the fundamental
building blocks that make up everything and
the rules that govern them.
So, let’s start with the familiar.
We live in a world, well like us, like me,
like you.
It’s a world of people, pizza, and poodles.
And, if you’re lucky, toilet paper, if you
can find any these days.
If you ask yourself how are these things made,
why do they work the way they do, you get
very quickly into the rules of chemistry.
But chemistry brings you into the rules of
molecules and atoms.
And if you ask why molecules and atoms do
what they do, that leads inevitably to the
building blocks of atoms, or protons, neutrons,
and electrons.
Protons and neutrons are built of even smaller
building blocks called quarks and that’s
where we are now.
These particles called quarks and another
series of particles called leptons are the
ultimate building blocks that we know of.
Combine that with four forces, then you can
take them, put them all together and you have
the universe.
Our understanding of the microcosm and the
smallest known building blocks is represented
very nicely by this lovely picture.
In the upper left hand corner are particles
called quarks.
Quarks are only found in nature in the center
of atoms, basically they make up protons and
neutrons.
Only two of the quarks can be found in matter.
The rest are unstable and can only be made
in particle accelerators.
They also experience all of the known forces.
Well, that makes them unique among the microcosm.
We’ll learn more about these fascinating
objects in the next video.
The next fascinating building block of matter
are the leptons, which we see in these cyan
boxes down in the lower left hand corner.
Leptons are pretty diverse, with the top row
having electrical charge, and the most familiar
subatomic particle is the electron.
In contrast, the bottom has no electrical
charge.
They also don’t experience as many forces
as the quarks do, which makes them easier
to study.
Leptons are so fascinating that I’ll make
two videos talking about them, one about the
first row and the other about the second.
Over here on the right hand side we have these
purple boxes.
These are the force carrying particles.
There are four known forces, or maybe three,
or maybe five.
Even counting the number of known forces is
a subtle business.
But all the known forces are transmitted by
the particles you see here jumping between
two matter particles, for example this particle
called the photon might jump between the two
electrons, which will make them move in different
directions.
They’ll get their own video.
And, of course, in the center, we find the
Higgs field and the associated Higgs boson,
which is the newest discovery to join the
standard model.
It was discovered less than a decade ago.
The Higgs field gives mass to the quarks and
leptons and some of the force carrying particles.
It was the last of the subatomic particles
to be discovered and we’re still trying
to verify all of its properties.
I’d like to remind you that I’ve made
a long video that talks about the Standard
Model and I put a link to it in the description
below.
It’s important to remember that the standard
model doesn’t say anything about the force
of gravity.
For that, you need Albert Einstein’s theory
of general relativity.
Relativity is the theory of gravity and it’s
what holds the entire cosmos together, what
holds the stars, the galaxies, and the big
things.
Together, Einstein’s theory of relativity
and the standard model governs everything.
So that’s what we’re going to do in these
series of lectures.
In my next lecture, I’m going to tell you
in detail a lot of fascinating things about
quarks and then I will move through a series
of other topics – the leptons, the force
carrying particles, the Higgs, and then things
that the standard model doesn’t explain.
And together, when we’re done with all that,
you’ll know what I know.
So, this is going to be fun.
I hope you enjoy it, and I’ll see you in
the next episode.
One of the things I’d like to do for every
video is end it with an answer section.
So, if, as you watch the videos, something
comes to your mind, you have a question, put
your question in the comments below and I
will pick a handful of them and answer them
in a subsequent episode.
If you like the idea of this series, please
like and subscribe.
Share it to all of your friends on social
media and this is going to be great fun.
I’m going to enjoy it.
I hope you’re going to enjoy it, because,
like me, I’m sure you’ll agree that, even
at home, physics is everything.
