Home » Dominic Walliman: Quantum Physics for 7 Year Olds at TEDxEastVan (Transcript)

Dominic Walliman: Quantum Physics for 7 Year Olds at TEDxEastVan (Transcript)

Dominic Walliman

Here is the full transcript of physicist and science communicator Dominic Walliman’s TEDx Talk: Quantum Physics for 7 Year Olds at TEDxEastVan conference. 

Dominic Walliman – Physicist

So, have you ever had this experience? You’re having a chat with someone and they’re telling you something about a subject they’re very interested in or they know a lot about, and you’re following along. Then, at some stage you realize you kind of lost the thread of what they’re saying.

And then, you’re standing there and you realize you have absolutely no idea what they’re talking about. I had this recently with a friend who knows a lot about investing. And it’s something I don’t know a huge amount about, but it’s very important, very useful information. But he started talking about kind of diversified investment portfolio – blah –

And unfortunately, I went away with no useful information. So, I think it’s a situation we all are familiar with, and fortunately there’s things you can do to improve this situation, which is what I’m going to talk about today.

So, I’m a scientist. I work in the area of quantum physics. And so, I’ve been on both sides of this kind of interaction. I’ve both been the guy explaining very complicated material to someone, but I’ve also been on the receiving end of lots of very kind of intense scientific discussions with my colleagues. And, when this kind of breakdown of communication happens, I’ve noticed something interesting, which is that, as a person who’s stopped understanding, you feel kind of guilty about it.

But, if you think about it, this is completely wrong, it’s the wrong way around because at that point in time, there’s literally nothing you can do to understand better. But there is something that the other person can do to help you understand by finding a better way of explaining what they’re talking about.

And so – during my experience in science, I found that the only way to survive was to kind of have the courage to politely stop the person who is explaining, say, “I’m sorry, I don’t understand what you’re saying,” and then try and go back and start off from where I’d lost the thread. And it does take a bit of courage to do this because you’re kind of admitting that you don’t know the subject matter. But I think that’s OK, and in fact, my fears were completely unwarranted.

Generally people respect you if you care much about, knowing the right information or care about, like, understanding it properly. So, I think we should never ever feel bad about not knowing something and we should never feel bad about asking questions.

So, I do a lot of science communication, and science really has this communication issue with it because generally the subject matter is very complex. And you might know scientists are always complaining about how their research is being misrepresented by the media, like “Drinking wine cures cancer.” It totally doesn’t, by the way.

But on the other hand, you can kind of understand how journalists will maybe oversimplify things or get things wrong because, to explain cutting-edge research, you kind of need a PhD in the subject beforehand, and that’s not something we can expect the media, journalists to have in all the different scientific disciplines.

So, I think the world would be very well-served by a whole load of people who are really good at science communication, people who understand the science but can also explain it in a way that the general public can understand. And this is important for many reasons, but one reason is you might know that just about all the science research that goes on around the world is publicly funded. So, it’d be nice if the general public could actually understand the work that their money is going towards. But for me, the even more important reason that science communication is good is because it’s also interesting.

The research going on is so fascinating it’d be nice if people could access it. Take my field, for example, quantum physics. I find quantum physics to be a deeply interesting subject, but it’s one that gets this reputation of being incredibly difficult. And that’s fair, it gets complicated when you get down into the details, but it doesn’t mean you can’t talk about it at all. So, let me get a show of hands.

So, put your hand up if you don’t know what quantum physics is. And if you don’t, don’t feel bad about it. Raise your hand, you know. Own your ignorance. It’s totally fine.

Okay, okay, right. So, quantum physics is the description of the smallest things in our universe. So, if you zoom right down smaller than cells, down to the scale of molecules, atoms, and things atoms are made of, you know, subatomic particles, protons, neutrons, electrons, it just describes how they all work and also how they interact with light.

And the interesting thing about quantum physics is it’s like the fundamental rules of the universe, and yet, the things that happen there are so very strange. So, I’ll tell you a few of the phenomena that go on in quantum physics.

One you might have heard of is called particle wave duality. So, you can imagine all these subatomic particles, these protons, neutrons, electrons, like little bouncy balls, kind of bouncing around, bouncing off each other. But sometimes you have to treat them as like spread-out waves. And they kind of do both at the same time, which is hard for us to imagine. So, I’ll paint a picture.

Imagine dropping one of these bouncy balls into like a pond of water. The ball would disappear, and then you’d get these ripples going out over the surface. Now, imagine one of the ripples hits, say, a stick. All of the ripples on the surface disappear, and by that stick suddenly a bouncy ball pops out again. That’s kind of strange for us to think about, right? But this is the kind of behavior that goes on in the subatomic realm all the time.

Another phenomenon you might have heard is called quantum tunneling. So, imagine I’ve thrown one of these bouncy balls against a window. So, it would be like bounce – oh, sorry – throw, bounce, catch – throw, bounce, catch – throw – It’s gone completely through the window. It’s not smashed it. It’s not interacted with it at all.

It’s just suddenly on the other side of the window and you can see it flying away. If we saw that, we’d think it was crazy, right? But this goes on at the subatomic realm all the time. In fact, it’s the only reason we exist. So, you might know that, in the Sun, the way it generates energy is through nuclear fusion. And nuclear fusion is when two hydrogen atoms come together and the protons in their nucleus bounce off each other.

Now, if it wasn’t for quantum tunneling, they’d bounce off each other and nothing would happen. But what actually happens is they quantum-tunnel into each other, and that’s what lets them fuse and release the sunlight, and without that sunlight, we wouldn’t exist. So, we can thank quantum tunneling for our existence.

Another phenomenon is called superposition. And it’s a very fancy word, but all it means it something that can do opposite things at the same time. So, for example, I can spin around one way, I can spin around the other way, but what would it look like for me to spin around in both directions at the same time? We can’t do that, we can’t imagine that, but this is what these subatomic particles do all the time.

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