Joining us this time...

Joining Chris Smith to tackle your questions this week: Lewis Dartnell, who's an astrobiologist interested in the search for microbial life on Mars and elsewhere. He's also the author of a number of books, including a new one he's just bringing out, called 'Being Human: How Our Biology Shaped World History.' What's that all about?

Lewis - For this new book, I am looking at all different aspects of us as an animal, as a species - our human-ness. Things like our genetics or our anatomy and our physiology or our psychology (things like cognitive biases) and how they've had a huge influential effect through the course of human history. How did a particular mutation in Queen Victoria end up indirectly leading to the Russian Revolution a hundred years later, for example?

Chris - Is that haemophilia?

Lewis - It is haemophilia, exactly. A single point mutation that appeared to have arisen spontaneously when she was fertilised.

Chris - And so the point you're making is that because we make the world, things that change us change the world we make?

Lewis - Yeah, exactly. So humans today, living in our glittering skyscrapers, are basically the same as our ancestors living a hundred thousand years ago in Africa. Our humanness is the same and we have been a constant throughout history. So what I'm doing through the chapters of this book is unpicking the thread of these stories of how different aspects of our biology have had these long term effects on the course of history: its themes and its trends or particular events, particular outcomes.

Chris - And what's the relation between that and the fact that you are looking for life on Mars?

Lewis - Oh, very little, to be honest. My first book, 'Life in the Universe', a Beginner's Guide, was all about astrobiology and how we're looking for aliens, how we're looking for life on other planets. But as a research field, astrobiology is very interdisciplinary. It's biology overlapping with planetary science and space science and astronomy and geology. So I've kept that sort of interdisciplinary hat on through all the books I've written. 'Being Human' will be my fifth book now, looking at science and how it overlaps with other things: science and history in this particular case.

Chris - It's great to have you with us, Lewis. Thanks for popping in. Also, here is Ems Lord who is the director of NRICH. That's Cambridge University's maths outreach programme. I should just tell everybody at home, GCSE maths starts tomorrow so I have brought in a GCSE maths question, and the reason I brought it in is because my daughter gave it to me and she said, "this is a really hard question, can you do it?" And I thought, "Oh, this is easy." And I had a go at it and thought, "no, actually, I can't, but I know a woman who can!" You've been having a go so we'll impart and share with the listeners what that question is later on. I don't know if you're making progress, but the last time you were on and the reason for that long spiel is it was the day that Sunak said, "I want to see people studying maths through to 18 and I want to increase mathematical literacy in the general population and numeracy." There's been a bit more detail added to the formula and the equation since then. Your views?

Ems - You are right there has been more background provided and that's been incredibly important because I think when we all first heard it, everyone was throwing their hands in the air going, "how are we gonna manage this? Where are we going to get the teachers? How's everyone going to manage to take A-level maths?" And I think we've got some really interesting conversations going on. How does that look for apprentices? What does it look like for A-level students right now? It's actually a really exciting time to be involved in Maths ed and be part of those conversations.

Chris - Your role in NRICH, is that really an ambassadorial role to kind of explain and show people that maths is not as scary as they might think it is?

Ems - I would never think of maths being scary!

Chris - That's because you're a mathematician! I find it a bit intimidating,

Ems - But we're all mathematicians. You are using mathematics every day. People sitting on either side of me here in the studio are using maths every day.

Chris - Well they are at the moment because we gave them the same question! They've got a page of notes as well.

Ems - But the thing is, we're all using it so we're all mathematicians just like we are all readers and we're all looking at text every day. So I think it would be good to get away from this idea that mathematics is just what you do in the classroom and look at it more as something that we do every day. It's a really useful tool and let's us do some fantastic things. Mathematics is part of our everyday lives.

Chris - Thanks Ems. Anna Ploszajski is also here this week. She's been on the programme a couple of years ago. You are a materials scientist. You're very interested in how things are made, what they're made of, and therefore the properties that what they're made of endows them with and how to give them additional properties.

Anna - Exactly right. But the difference I guess with what Lewis looks at, you know, he's looking at how biological materials and beings are made, I'm talking very much about human made stuff.

Chris - Well give us some examples of the kinds of things that, uh, float your boat?

Anna - Back in my days as a researcher, I was looking at new materials that can store hydrogen. This was with a view to being able to contribute to the vast range of materials that help us to hopefully try and mitigate climate change and create a more sustainable future. So these hydrogen storage materials, which people might be familiar with from the movie, the Glass Onion, which came out just before Christmas, these materials store hydrogen, which is normally a gas, a very lightweight gas as a solid. The benefit of that is that solids are much more dense and it means that we can carry around a lot more hydrogen with us in a smaller and more lightweight way. The reason that we'd want to do that is that hydrogen contains a lot of available energy, so we can also make hydrogen from plain water. So it represents a really exciting potential new energy source for a really sustainable future if we can crack a few of the material science conundrums.

Chris - It sounds like we need breakthroughs like that because I saw an alarming headline this week that we are predicted to breach the Paris agreements 1.5 degree temperature target by 2027. I mean this is just a handful of years away.

Anna - It's a very, very scary statistic. Time really is of the essence for us all to pull together in order to do what we can to help mitigate the damage from climate change.

Chris - That's Anna Ploszajski, she's a materials scientist. We'll be talking to her about the materials that we use and the materials that we don't yet use or don't even yet know exist that we could put to useful uses out there in the wider world. Also with is Xander Byrne who is an astronomer. He's from the Institute of Astronomy at the University of Cambridge. What do you work on?

Xander - I'm just about to start my PhD, actually. I'll probably be doing something to do with modelling planets around other stars, perhaps looking at the atmospheres and getting an idea of what they're made of, perhaps with a view as well to assess how habitable these planets might be.

Chris - There was a report in the paper this week about a massive explosion that astronomers dubbed the biggest explosion they had ever seen. What was that?

Xander - It's called Scary Barbie.

Chris - Who names that?

Xander - Well, the acronym for the way that it was catalogued was ZTF20ABRBEIE.

Chris - Trips off the tongue doesn't it. I can see why they may have wanted to rename it.

Xander - Exactly. Astronomers are really, really bad at naming things.

Chris - Where did it happen?

Xander - It happened in a very distant galaxy. Astronomers always have a bit of trouble working out how far away things are because if you see something bright, it could just be something really, really bright very far away. Or it could just be really close by.

Chris - So what blew up?

Xander - It's not exactly known. There's two major competing theories about what it was, but the best theory that we seem to have at the moment is that it was a cloud of gas falling onto a super massive black hole. This would probably be something about a hundred million times the mass of the sun - the black hole, that is - and then the gas fell onto it, heated up, got to incredibly high temperatures, burst into this big explosion a hundred times the size of the solar system.

Chris - How did they spot this? Are there telescopes scanning the sky for these sudden emergences of bright lights and things all the time then?

Xander - It was discovered by a facility called the Zwicky Transit Facility.

Chris - Well that's brilliant. So if you have any space science questions or any questions on maths, any questions on materials science, or astrobiology - life on Mars, then now's your chance to have them answered by our dream team.