I love learning but I'm also really time poor so I've gotten a bunch of
experts to try and explain to me something about their field in the time
it takes for an elevator to go from the bottom of the building up to the top
and then all the way back down and this time I'm going to ask someone about
string theory. Now I have my own string theory which is along the lines of how
long is a piece of it? But I've heard that string theory is actually the
theory of everything and I don't know how you can fit that into an elevator
ride but that sounds like a them problem not a me problem so let's go see whether
they get tied up in knots or not.
So have you heard the saying if you can't explain something to a
six-year-old that means you don't understand it yourself?
Yes I heard that saying. I'm your six-year-old let's do this.
Ready? What is string theory? So string theory
is the idea that at the smallest level all of the stuff in the universe
everything we can see all the atoms etc are made of these tiny vibrating strings.
Okay so why is this important? It's important because physicists are lazy at
the moment we have two fundamental theories quantum mechanics on one hand
and we have general relativity on the other hand which prescribes gravity. They
don't work together string theory's this idea - one of the ideas - to bring these
two together. So we'd have one theory to work with. So do we know if string theory
is true? Is there evidence? There's no observational experimental evidence at
the moment. The problem is is that we need to build a Large Hadron Collider the size
of our galaxy just actually test the energies. It's a theoretical idea.
People love the theory of love the mathematics but... Why do they love the
maths? Because the maths is beautiful yes so physicists love beautiful maths and
string theory is built on this very beautiful idea that... We're halfway. Are
you halfway? Halfway through a point. Let's go back down and I want to know what
makes maths beautiful? Well physicists are attracted to beautiful ideas and
beautiful mathematics. Mathematics you can write down relatively simply but has
lots of consequences so you can explain lots of things with it. So string theory
is grown building up these mathematical ideas to sort of encompass gravity and
everything else. So it ties everything together. Absolutely and that's what's why they're
made of strings right? Aha yes. What is a string? So you know it's a tricky
question... In our mathematics the strings are these one-dimensional loops that
vibrate and how they vibrate tells you what they are as an electron or quark or
something else. So they're all the same but they're vibrations is what makes
them different. Yes that's right. And they vibrated in multiple dimensions maybe twelve, fifteen or
twenty four dimensions. But you can't answer the question of what is the
string itself. It's not a thing it's just a fundamental piece of the universe. It's
just a nothing that vibrates. It's a nothing that vibrates but makes up everything.
So I'm made up of vibrating strings that are made up of nothing? Vibrating strings
in nothingness. In nothingness! Absolutely. Great I'm gonna go have an existential
crisis now. Thank you. Bye.
Wait what do you mean in nothingness?
So to recap string theory is a theory that if we could prove it could link
together a bunch of other theories about the way that the world works. It's not
the only theory that exists but it is a really interesting one and it says that
the most fundamental thing that makes up the universe is basically a string that
exists in one dimension yet vibrates in multiple dimensions - how I don't know - and
the vibrations tell us what that string is creating. So everything in the world
is made up of these vibrating loops and if we can learn to understand them
better then we could probably influence them right and we could make
technologies and apparently influence gravity and maybe even time in ways that
my mind cannot even fathom at this point. Strings.
Well that ties that up with a nice little bow of string theory string. The
expert, Geraint, also has a video about the end of the universe that
you can see in the link in the description below. It's a little bit
longer than an elevator ride but I highly recommend it just make a cup of
tea before you go watch it. If you want to see more videos from us then you can
hit that subscribe button to get an alert when something is ready. You can
expect something from us next week as well and if there's some big idea that
you want explained in a claustrophobic space then put that in the comments
below and I'll see if I can find an expert who can explain it to me so that
I can explain it to you. See you next time.