I was in my second year as an undergraduate and staying with my down-to-earth Northern Nana. She’s a bright woman, but didn’t have much of a formal education. I was revising quantum mechanics. “What’s that?” Nana asked, peering over my shoulder. I did my best to explain but she looked puzzled and said, “And what can you do when you know that?” It’s the question that every mathematician and scientist should never forget. You can be brilliant at the theory. You may know everything there is to know about the concept or the equations, but the biggest challenge is to relate it to the real world. If I ever get around to writing a book, I think I’ll call it What Can You Do When You Know That? I face that test every time someone asks me what I do. If I say, I’m a physicist and oceanographer at Southampton University, the inevitable response is, “Oh, I hated physics at school.” But if instead I start telling them about my research work on ocean bubbles, or explosives – which was the subject of my PhD at Cambridge – or the weather and how the earth’s orbit affects it (which I’ve recently explored in a three-part series for the BBC), then I get a totally different reaction. They feel interested and involved. It becomes real to them. It is often about how we communicate what we know. So if you are teaching maths, you will turn people off straight away if you start talking about prime numbers. But if you begin instead by talking about egg boxes, then they don’t realise that the topic is maths. The very word seems to carry so many negative associations from their school days for so many people that sometimes it’s best to avoid it altogether. I was lucky in that respect. Maths came easily to me. I went to an all-girls grammar school in Altrincham, Cheshire, where I had superb maths and physics teachers. One of the best things about getting involved in television presenting is that those teachers have recently got back in touch. And maths was a part of life at home. My mother was good at it, and had started a physics degree, but she dropped out because – among other things – she felt oppressed by the all-male environment around the subject. Recently, though, she has started again, doing an Open University maths degree. I think she feels she wasn’t fulfilling the potential that she had, and that was bugging her. At home we used to have a blackboard, mostly for shopping lists, but sometimes for playing with maths. My mum and I would do square numbers or how to calculate the area of a circle using pi, but not because my parents were pushy. They weren’t. It was just that questions would crop up and they’d share what they knew and we’d think about how we could know more. Their main thing was that they didn’t want any part of the world to be closed off to me. It wasn’t about achievement, but what they thought I might find interesting. And anyway, I was a very independent-minded child, so was soon doing it for myself. Not everyone has that opportunity, or even that interest in maths, but it is surely desirable that everyone today has some level of competence in maths. However, there is a balance to be struck in schools between pushing the subject so hard that youngsters are completely turned off it and making sure that everyone who can it to a higher level is given the chance to do so. As ever, the problem is with those on the borderline between the two. Too much pressure to do well at maths and they will be pushed down, but too little and they will miss out on being pushed up. I did maths at A-level, and there was a lot of maths in my physics degree. The number of women in these areas reduces the higher up the academic ladder you go. I am the only female at my level on the academic staff in my group. But I don’t want to sound too gloomy. There are positive signs of change for the better in the way we regard maths and science. The public seems to be rediscovering an appetite for them. In Victorian England, an acceptable evening’s entertainment would have been going to the opera, a concert or attending a scientific lecture. We had lost some of that public interest in science until lately, but now I can see it coming back in events like Robin Ince’s annual Nine Lessons and Carols for Godless People or the Radio 4 series The Infinite Monkey Cage, which takes an irreverent approach to science. So that shift in the culture away from maths and science can and is beginning to be reversed.