Meet the Panel: From galaxies to calories

Who have we got this week
04 February 2020

Interview with 

Matt Bothwell, Camilla Nord and Sam Virtue, University of Cambridge, Lorna Nisbett, Anglia Ruskin University


Artists impression of a black hole at the centre of a galaxy


We kick things off by seeing what astronomer Matt Bothwell, forensic toxicologist Lorna Nisbet, neuroscientist Camilla Nord, and physiologist Sam Virtue want to get off their chests and tell us about this week...

Matt - Over the last couple of weeks I've got very into 3D printing actually. So we have a 3D printer now in the department. I've been busy 3D printing these nice models of galaxies.

Chris - How on Earth do you 3D print a galaxy?

Matt - You take an image, right? And then you just convert the brightness of the image to the height of the 3D model. You end up with something that looks a bit like a relief map of a galaxy, basically.

Chris - You've given me here, it looks a bit like a bathroom tile, but it's got lumps and bumps on it. So what's this all about? It's effectively a flat galaxy? We say the Milky Way is a disc. This is a basically a bathroom tile with a galaxy printed on it in lumps and bumps.

Matt - It's a very nice way of communicating astronomical ideas to people with visual impairments. Astronomy is a very visual field, lots of pretty pictures and stuff like that. If you're not a sighted person, then you're cut off from all of that. And so being able to make 3D models of things is a really nice way of reaching people that might not otherwise be able to appreciate space.

Chris - So you've got astronomical braille here.

Matt - Exactly. It's very cool, isn't it?

Chris - So I suppose that this means for a blind person instead of actually trying to envisage what a solar system like ours - and then even bigger than that, a galaxy - looks like by running your fingers over it, you get some sense of scale and shape and structure.

Matt - Exactly. Yeah, if you never got to see a picture of these things and you just had someone describe it to you, you'd be missing a lot of the richness of what one really was. But yeah, being able to kind of feel it in a tactile way, you know, gives just as much information as seeing it really.

Chris - And what do blind people say about it if you'd show it to them?

Matt - I think generally it's very, very well appreciated. The University of Portsmouth has had a version of this called the tactile universe going on for a long time and yet it's very successful.

Chris - Matt, thanks very much for showing it to me. I had some inkling that people were going to do something like that, but I've not seen them and I can see why that'd be very effective. So thanks very much for introducing me. Sitting next to Matt is forensic toxicologist Lorna Nisbet. Hello Lorna. What are you going to tell us about?

Lorna - I work at Anglia Ruskin University and so we have been really kind of trying to look at cause of death and the increase in poisons that have been happening with regards to drugs. Sadly, last year was the highest year for deaths relating to drugs and overdoses. And so we are trying to look at reasons behind this and what we can try and do to help within the community.

Chris - You can tell us later on how you're going about detecting those. Thanks very much Lorna. Also here is Camilla Nord who's a neuroscientist, psychologist, you know how the brain works. Welcome! What would you like to talk to us about this week?

Camilla - Well, I suppose I've brought a myth and it isn't actually what I work on in my research, but what I work on is I'm a neuroscientist who's interested in psychiatric disorders. And one of the main themes that comes out when you're trying to understand brain differences that manifest in different mental health disorders, is that the group is not the same as the individual. And sometimes differences that look really important at the level of two groups, don't allow us to identify an individual in any way whatsoever. So the myth that I've brought runs along those lines entirely. It's the myth that there's a male brain and a female brain. Much like looking at different sorts of psychiatric disorders, if you collapse across every female brain in a very large sample for a specific region of the brain, and every male brain in a large sample for a specific region of the brain, there's a handful of regions that look systematically different between male and female brains. But the problem at the level of the individual, is that if you look at each of these regions and you say, "Oh, there's a male size and a female size", almost every brain shows more of a mosaic of male versions and female versions of these different bits of the brain. So in fact, there is no true male brain or female brain.

Chris - Also, is it not reasonable to say, "well look, there's probably 100 billion nerve cells in the brain and they're all interconnected with each other. And some of these areas might be a different shape or size in a person who's male compared to a person who's female. But at the same time, all these other regions of the brain might be different in a different way. So the degrees of freedom, the number of variations, is enormous. So although it might be smaller in one particular area on average in say women in that bit of the brain, there might be another region of the brain that actually is bigger to compensate or is doing something else and vice versa. So it's a very different problem, isn't it? It's not a simple thing to say, it's this structure in men, it's this structure in women?

Camilla - Yes. That's a very good point about the difference between structure and function, which I think you're getting at there. But even just in structure, I think the, the argument is quite compelling that most brains are a sort of mix of male bits and female bits.

Chris - And you can tell us more about how the brain works later in the program. Thanks very much. That's Camilla Nord. And also here is physiologist Sam Virtue, and you're going to lay down the gauntlet before us Sam!

Sam - So yeah, so I was thinking about this as January came round, because over Christmas we all eat, well most of us eat a lot more food than we should and we put on weight and I think we all can think about putting on weight as putting on fat. And then in January we kick in with our New Year's resolutions and we start to try and lose weight. I was thinking about this, I wonder if people here can tell me where they think the weight that they're losing goes?

Chris - What you mean as in when you, when you become less heavy on the scales, where has the weight that that has gone off your hips, gone to?

Sam - Exactly. Where does it go to?

Chris - Anyone like to speculate?

Lorna - I'm going to do a QI buzzer moment I imagine here, but surely it's your body using all of your fat and you're using it as energy and you're burning it off in terms of movement and reduced calorie intake.

Sam - So the reduce in calorie intake will make you lose weight, but to lose the weight, the physical fat, if you lose a kilo of fat, it's got to go somewhere.

Matt - I think I remember hearing this somewhere. You breathe it out. Is that right?

Sam - So yeah, so basically fat is made of three things, carbon, hydrogen, oxygen. And so we can get rid of the hydrogen and oxygen in two ways. We turn it into water and we can lose the water in our urine, or we can also lose the water in our breath. However the carbon, we can only lose it from our bodies as carbon dioxide. So when you go on a diet, you lose all your weight by breathing out.

Chris - You literally breathe your weight into the atmosphere. Someone said to me once, "I don't really get this whole point about how can, how can you have a mass of carbon dioxide? When we're talking about emissions and they talk about tons of carbon dioxide, your carbon footprint is four to 12 tons. How can a gas weigh anything?" And you say, "well the fuel that you put in your car, for example, that tank of fuel weighed as much as one of your passengers and when the tank is empty, the car has lost mass. Where has the mass gone? Well it's gone out of the exhaust pipe. Therefore, that mass of carbon, which was in that fuel has turned into a mass of gas which has gone out of the exhaust pipe. It still weighs something. It's still atoms. It's just that when it's in the atmosphere it's floating on the rest of the atmosphere, so it doesn't appear to weigh anything but it certainly has mass". So it's an interesting question. Camilla?

Camilla - Does that mean your carbon footprint increases if you lose weight? And perhaps we should all have a couple more slices of cake in January?

Sam - I mean you are technically correct and I'm not going to go into any further details!


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