Do you have a solar system-sized television, Brian?

I don’t like massive TVs that dominate rooms. I have a relatively small one and watch it from a black and white comfy sofa made of different fabrics. It’s quite cool.

What are you watching on your relatively small sofa?

My son, George, is eight and into Harry Potter. I’m watching the new Twin Peaks. In anybody’s hands but David Lynch’s it would be absurd, but he’s a magician. I can’t explain that feeling you’re left with after you’ve watched it. 

Are you drawn to strange, magical things?

Definitely. Physics is quite abstract. The understanding of it can’t really be put into words. Good TV is the medium for things you can’t put into words. If I’m making a documentary about general relativity, that’s a fourth-year lecture course, so I’m not going to explain the theory but I can give an impression, a feeling that there’s something interesting and beautiful and elegant there.   

We look down at our phone screens a lot – should we look up at the sky more?

I do want to encourage people to look up because once you know what’s up there, you really want to look at it. It’s also good to look at the most common bits of life, like a blade of grass – the history of four billion years of evolution is written into it. In science, the more you know what you’re looking at, the more magical it becomes.

Are young people today less curious than they used to be?

I worry that we underestimate  young people. I found out from my live tour – when 150,000 people came to the shows and were all ages from seven up – that there was no age limit either way on curiosity. It might be that you have to engage younger people more. The responsibility we have is to make sure we give them things to be interested in.

That’s the point of public service broadcasting at its best. If there is a problem, it’s that audiences can be ghettoised by the choice. While you have a vast number of options, you can choose just to watch rubbish – we need to make sure people can be challenged.

Is your son mad about space?

We took him to Arles to see where Van Gogh painted a lot of his paintings and he got interested in him, so you can get an eight-year-old interested in anything. It’s up to you. What are you going to point them at? 

Do people come up to you and say that you’ve helped them understand space?

It’s usually people saying, “I didn’t know we knew this.” For instance, the concept of a universe in a time when all the stars have burnt away doesn’t really occur to people. The physical insignificance of us as individuals is something people don’t think about very often. The fact that the Earth is in one solar system among 200 billion stars and a trillion galaxies, which is a small patch of what’s out there. So it challenges you to go, “What is the point then? ” Our existence – it really is absurd.

Do you ever find the universe a bit overwhelming?

At the end of my live shows when I talk about how insignificant we are physically, I also point out how rare we might be, that we could be the only people alive in our galaxy. If that’s the case, we are valuable. We are part of the greatest of mysteries. 

Professor Cox co-presents The Infinite Monkey Cage on Mondays at 4.30pm on Radio 4