Antimatter is Bananas!

Jeffrey Hangst (0:01)

I like to think of them as kind of the evil twin of normal matter.

Becky Smethurst (0:05)

Bananas.

Izzie Clarke (0:06)

It always comes back to Bananas. Every time. Cheetos came back to Bananas, and Cheetos will be back to Bananas.

Jeffrey Hangst (0:12)

They're asking the question that completely ruins my life.

Izzie Clarke (0:21)

Welcome to The Supermassive Podcast from the Royal Astronomical Society with me, science journalist Izzie Clarke and astrophysicist Dr. Becky Smethurst.

Becky Smethurst (0:30)

Are you ready for some particle-induced headaches, Izzie?

Izzie Clarke (0:35)

Yeah.

Becky Smethurst (0:35)

It's like monthly dose, you know?

Izzie Clarke (0:37)

I just like, this is my kind of existential session where I just go, okay, what am I confused about? Who can I ask? You know, let's go to all these experts.

Becky Smethurst (0:47)

Thank you. Because this month, we're getting to grips with antimatter. What is it? And crucially, where is it?

Izzie Clarke (0:56)

Now, this is absolutely one of those topics that falls into those things of like, but why? Kind of like our new True Nose episode where I, and probably everyone listening, just has to accept, okay, this is what the science says, and I just have to say, yes, okay, and not pick at that and pull at that thread too much.

Becky Smethurst (1:19)

To be honest, I think that's what physicists have to do as well. I think there's so much about antimatter that it's like, that's what we know, but we still don't know why. And the people picking at the threads are the people who are working in research right now. So it makes sense, Izzie. You're just training to become a physicist, that's all.

Izzie Clarke (1:36)

Yes, and I hope you're ready for me to just constantly ask you, but why?

And please can we have a drum roll? Because we are back with Dr. Robert Massey, the Deputy Director of the Royal Astronomical Society. Welcome back, Robert.

Jeffrey Hangst (1:55)

How are you feeling?

Robert Massey (1:57)

Oh, I'm all right. You know, definitely, I can't say that I'd recommend surgery as the way to spend a summer, but you know, but no, no, it went pretty well. Eight weeks of wrong recovery, getting my energy levels back. You know, I've put stuff on Instagram about it if anybody's interested in the details, but Crohn's disease is a bit of a bugger, but it's, yeah, but it's under control and possibly more surgery later this year, but I'm definitely feeling a lot better for it. I have to say, I have to say, actually, when I was looking at the top there, I thought, yep, looking at the script, I thought, oh good, particle-induced headaches, which is just what I need for my convalescence room, to think about incredibly difficult topics in antimatter.

Izzie Clarke (2:31)

Yes, welcome back. Let's talk about antimatter.

Jeffrey Hangst (2:34)

Okay.

Izzie Clarke (2:37)

So let's just start with, I think the big question, what is antimatter?

Jeffrey Hangst (2:43)

Yeah.

Robert Massey (2:44)

So antimatter is basically particles matter that has the same mass as, if you like, normal familiar matter. You could think of it as ordinary as well, depending on what kind of cosmologist you are, but the opposite properties. So, for example, electric charge being the most obvious ones, you have like an electron and a positron, which is the antimatter equivalent, and the internal composition can change too.

And if a particle and antiparticle collide, this is the crucial thing people tend to think about, they annihilate each other and they convert their mass to energy, mass and energy are equivalent anyway. And we do actually see in pure vacuums, particularly in the space around, say, black holes, for example, is the classic example. You see pairs of particles and antiparticles emerging and then annihilating each other. But it does get used in everyday life as well. And I was thinking about this when we said medical stuff, I haven't had a PET scan, but there is something called positron emission tomography. And you get a radioactive isotope that decays and emits anti-electrons. They annihilate with electrons and the location of those helps clinicians basically identify things in your body. So, you know, so they do have this very positive use as well.

But the big mystery is why, and I'm sure we'll come on to that in much more detail, is why the universe is made of almost entirely matter, and there's virtually no anti-matter sticking around. You know, that's one of the big things. It's very helpful because otherwise we might just not exist. But, you know, this is the big question.

Izzie Clarke (4:05)