The Art of Science

Last year, astronomers came across a planetary system called TRAPPIST-1, in the constellation Aquarius. It’s 40 light-years away; that’s about 370 trillion kilometres. The star at the centre of the system is only about 10% the size our sun, which makes it much easier for astronomers to view the 7 planets in orbit around it. These planets, at first glance, are very similar to Earth so over the last year astronomers have been scrutinising them in detail. Izzie Clarke heard how from Physicist Amaury Triaud from the University of Birmingham.

Amaury - Our uncertainties were pretty large. What we did not know then was exactly what mass or what radius the planets were. We had an idea which allowed us to call the Earth-like but those properties are some of the most fundamental properties of a planet. The mass and the radius combined tell us about the density, and the density of a planet tells us about what it’s made of. For instance, a planet like the Earth has a certain density and it’s telling us that it has at the centre something made of iron and nickel, and on top is a big layer of rocks. So by comparing our planets to the Earth we can deduce what’s inside of them, how they were built, how different or similar they are to what we know.

Izzie - But one thing was certain, the TRAPPIST-1 system was bright, allowing scientists to study it’s planetary atmospheres. But, before they could start exploring, it was important to turn their attention to the star at the centre of the system…

Amaury - What we measure always in relation to the star, we always measure the mass of a planet compared to the mass of the star; the radius of a planet compared to the radius of a star. If we get the star wrong, we get the planet wrong so we started by the most obvious - what is the star? Then we observed more as the planet passed in front of the star casting a shadow, and from how deep the shadow was we could measure more and more precisely how big the planets where.

Then we tried to measure the mass, and we did that by measuring how early or late they came in front of this star which was a reflection of the forces that are acting between the planets themselves.

最后,我们做了一个侦察观察试着g to find out if any of the planets had an atmosphere made of hydrogen or helium, something that would be similar to Uranus and Neptune. Mind you, we did not know whether those planets were really Earth-like or more like Neptune, but now we can say, with a fair amount of certainly, that they must be rocky.

Izzie - Our own home, planet Earth, is also a rocky planet, so are Mercury, Venus and Mars. But how similar is this system compared to our own?

Amaury - They're remarkably similar. When we had large uncertainties it meant that the planets could have any mass or radius within those uncertainties and it could have fallen anywhere. But we find out that TRAPPIST-1c is almost a copy of Venus. We find that TRAPPIST-1d looks really much like the Moon, and TRAPPIST-1e is by far the most interesting. It’s the most Earth-like planet we’ve identified so far with an inner composition that seems to match our planet.

Izzie - So things are looking up with this fourth planet. It’s density is almost the same as Earth’s meaning that the inner cores must be similar. But what about those all important signs of water?

Amaury - TRAPPIST-1e, at the moment, we still do not know. The amount of water that is on Earth is minute - 0.02% of the mass of the Earth is made of water. With this little amount it’s hard to measure it on TRAPPIST-1e. However, we do know that there is a lot of water around. TRAPPIST-1b, the planet closest to the star seems to have a vast amount of volatiles. A volatile is something that is something that is not solid. If it is water then it would have 250 times more than the Earth has. Having a lot of water in a system bodes well for water on TRAPPIST-1e.

Izzie - And, given ten years, Amaury suspects that we’ll even know what TRAPPIST-1e’s atmosphere will be like. So, could we humans ever set foot there?

Amaury - With imagination only I think. They’re really close astronomically speaking, sadly, astronomical distances are astronomical in nature; they’re enormous, extremely vast. The system is 40 light years away and that may sound far to travel there, but it’s among the 300 closest stars to the Sun, so it’s close in astronomical terms. But, despite this proximity, I doubt that humanity will look at this world anytime soon. Although I do hope our discoveries inspire the next generation of physicists to find a way to bring us there.

电子烟:英国公共卫生建议他们should be available on prescription; some people are taking them up for fun, while others are using it to help them quit smoking. In all cases there’s a strong belief that vaping is the healthier alternative to cigarettes. But a study out this week suggests that the inhaled vapour from e-cigarettes can make the cells that line our airways much stickier and increase the odds that bacteria like the pneumococcus - that can cause chest and other infections - can gain a foothold. Chris Smith spoke to Jonathan Grigg, a respiratory consultant at Queen Mary University of London.

Jonathan - Vaping is increasingly popular as a smoking cessation aid, and youngsters are taking up vaping itself, so it’s important that we understand the effects on the lung. What we’re looking at is the risk of developing a serious infection, that’s with a bug called the pneumococcus, and that causes pneumonia. We know that if you smoke cigarettes, you’re at a significantly increased risk of pneumonia, and the mechanism is that bugs just stick more to the airways and they can get a little niche and they can get a foothold in the airway and cause infection.

What we did is we put vape onto the human airway cells. We sort of expected not to see very much but, in fact, the cigarette vapour significantly increased the stickiness of the bugs to the cells in the same way as cigarette smoke.

Chris - Do you know how it makes them stickier?

Jonathan - The mechanism is really interesting. What the bug does is it hijacks a normal substance that’s expressed on the cells as a receptor so it uses it a trojan horse. It sort of sticks to that receptor and then as the receptor normally gets into the cell, the bug just moves across into the cells, so it’s like a hijack literally. What we saw was that vaping increased the amount of receptor on the cell and more bugs stuck to that receptor.

Chris - That’s in cells in a dish. But how confident are you that that represents what’s going on in one of your patients?

Jonathan - To address that, what we took was a group of vapers. We took little scrapes of the cells from their nose before they vaped during their normal vaping session and one hour after that. We looked for the expression of this receptor that the bugs can hijack and we found that the receptor was significantly increased at least a two or threefold increase after vaping.

Chris - Does that end up reflecting an increased risk of infection? Obviously you can’t do that with human patients, it would be unethical. Because, at the moment, all you can say is that it appears the cells get stickier, it appears that this is secondary to the vaping, but can you put the whole puzzle together and say vaping causes more infections?

Jonathan - You’re quite right. We haven’t translated that into a risk. It really needs large scale what we call epidemiological surveys to be able to do that in the same way as smoking. But what we did do is, in an animal model, we exposed animals to vape and infected them with the pneumococcus, and we found increased amounts of pneumococcus in the nose of vape exposed animals. So, at least in that situation, we saw an effect.

克里斯-怎么样,我听说经典if you go and wander round in London you may as well have smoked a packet of cigarettes if you walk down some streets because the traffic pollution is so significant, how do you quantify, qualify and standardise what you call vaping and the infection risk arising from it, and compare it to say just occupational exposure or day to day exposure to pollution?

乔纳森-我认为这是一个非常非常重要的int. We’ve looked at various other exposures in our model which are known to be increased risk of pneumococcal infection and, as you say, diesel exhaust particles increase the risk, especially in young children, of bacterial pneumonia. Welding is an occupational exposure that increases that and in our model we see those effects. I think yes, just walking around a polluted environment is increasing your risk, as we know, but that doesn’t of course mean that vaping can be dismissed. This would be an additional risk to what is an unacceptable level of pollution we have in our cities.

Chris - Do you think it makes a difference what the composition of the vape fluid is because they come in lots of different flavours don’t they?

乔纳森-它可能。和我们能做什么now with our model is to play around, if you like, with the vape composition. We can make our own vape, we can look at the effect of just a major component which is propylene glycol, which is like a food additive on its own. We can add in the flavourings and, as you say, there are many hundreds of thousands of flavourings. So we can start doing these sort of experiments to scale and really nail down what are the components which are causing it. As yet, we think nicotine isn’t the major player although it has some effect, but what it is in the nicotine-free vape is unclear.

They say a picture paints a thousand words, right? Well, sometimes it can tell us even more. Paintings on rocks have helped scientists solve the mystery of when the first modern humans settled in an area, how they diversified over time and even if they had different accents. Chris Smith spoke to Jo McDonald, Director for the Centre of Rock Art and Management at the University of Western Australia.

Jo - We’re involved in a project at the moment on the dampier archipelago - that’s known as Murujuga Aboriginal people that live there. It’s in the coastal Pilborough, so that’s about 1500 kilometres north of Perth. Since 7,000 years ago it’s been an archipelago but before that it was an inland range.

Chris - How long do we think modern humans have lived in Australia?

Jo - We are pretty sure that modern humans got here about 50,000 years ago. We’ve got archaeological sites all the way across the top of Australia which are increasingly coming up with that date range between 45 and 50,000. We’ve also got caves with similar aged occupation in Tasmania so people got there and moved around pretty quickly and occupied almost the entire landscape.

Chris - They sure did. And they left a lot of very impressive paintings and those paintings have been added to over many years, so tell us how you study them?

Jo - We record what’s there and in different parts of the country we can obviously see different signs of what people have done through time. We, at the moment, suspect that when modern humans got here they did settle fairly quickly across the majority of the continent. But because they were basically moving into a naive continent, one that was not used to dealing with humans that they had a pretty open signaling system and they had a homogeneous set of art styles which we find across most of Australia.

Chris - Is that just founder effect that they probably brought in some artistic styles as the first incomers to Australia but then, as the population diversified, because this place is huge there wouldn’t have been the same communication on the same timescales that we have today obviously? Then it would in the same way accents evolve - you have a different accent to me - that would have led to different art styles?

乔-是的,完全正确。现在遗传学ing, and we’ve suggested before in our modeling that regionalisation probably occurred in the pleistocene because you have some of these earlier engrave styles which show diversification. The genetics is now coming out as wel. By 25,000 years ago Aboriginal populations in Queensland had different accents to people in Western Australia.

Chris - Can you date the pictures to work out what’s in the art and how those styles relate to different time zones in that migration process?

Jo - We are getting much better at dating the pictures. We still have quite a lot of difficulties with engravings because they are, of course, they don’t have anything organic in them. But pigment art and art that occurs on surfaces that forms geochemical crusts we are getting really good at getting very small amounts of the pigment out and dating that. Or using uranium, thorium and various other techniques to actually mine in and find layers of systems that can be dated in these crusts.

Chris - So when the pigments are put on the rocks, chemical changes over time begin to happen and you know what rate that sort of happens at so you can trace back to when we think the art was first put on the rock?

Jo - We are beginning to understand that. There’s a team from Melbourne University who’s working on that in The Kimberley at the moment and they are beginning to be able to demonstrate that these are closed systems. That you can in fact get isolated uranium threads, if you like, in the crusts and they can go in an mine those and get individual dates and see how much of the crust was there before the pigment, where the pigment is, and then what has happened subsequently. So you can actually date a sequential lot of actions on the rocks on the rock surface, yeah.

Chris - What story’s emerging when you look at this?

Jo - I think what we’re beginning to see is that people have seen the landscape very differently through time. They’ve obviously always marked it in a way. I think humans are inveterate doodlers, if you like, and we have writing now that Aboriginal people had used rock art as a way of, in fact, telling information about themselves. Telling information which would distinguish them from others, and I think people have always liked producing beautiful things. And I think Australian rock art is a really good example of this extraordinary aesthetic which is incredibly full of information and can tell us all sorts of things about the people who made it.

Chris - But critically, talking to modern day Aborigines because, obviously, what they have is a rich history which they pass on through generations, can you tie what they tell you to what’s written in those pictures?

乔-嗯,是的,你可以。我们一直使用the Martu in the western desert who only made their first contact with white people in the 60s and 70s. They, therefore, still have a connection and a whole set of narratives about that landscape which sometimes engage with rock art, sometimes don’t. But certainly, where you can see these dreaming mythologies going across the landscape, and you can see the rock art, you can see patterns archaeologically which engage with that set of narratives and allows you to see how people have, in fact, changed that focus on the landscape through time and have marked those places differently through time and that rock art is recursive. People will come to a location, an important water hole for instance in the desert, there will be all this rock out there for them. It won’t necessarily be part of their current marking system but the Martu say that the engravings have been there and been left by their ancestors. So these things which are there and which are pictures of people or animals and various different things or tracks, they say have been left by the ancestors. They recognise that they were done by people other than them but they’re part of their narrative. It allows them to understand how different people have moved across that landscape and have engaged with them.

Chris - One big question that we just don’t know the answer to yet is when these individuals, the early ancestors, first came to Australia they did so 50,000 years ago or so, but then no-one came since - or did they? Because the genetics and other archaeology seems to suggest that one bunch of people came and they were the founders, and no-one came afterwards. Do we know why only one group of people came?

Jo - I don’t think we do know that. I think certainly the genetics is suggesting that that’s exactly right that we don’t have multiple waves, and that was certainly the original hypothesis about how Aboriginal people look very different in Northern Queensland to Southern Tasmania that there were obviously different waves of people through time. It’s been disproved by the most recent genetics. Obviously there is contact between Southeast Asia and Northern Australia. We’ve got indications that Macassans came to harvest Trepang - the sea cucumber - that’s the last 6 or 700 years; it’s not very long. But there is that contact so people could have come between once boat travel was the way to do things.

Chris - Dogs turned up, and we know dogs came after people.

Jo - That’s right. And that’s about 4,000 years ago so there seems to be some sort of introduction by people at that stage, but there doesn’t seem to be any major influx of new genes at that time.

Chris - Until us lot turned up?

Jo - Till us lot. That’s right. Came and messed things up. Yeah, that’s right.

Videogames are an artform that also links closely with science. An obvious link is that with advanced technology comes advanced graphics, but one group from the University of Cambridge are actually using video games to measure how we learn. Georgia Mills was joined by Seb Wride from the Adaptive Brain Lab at Cambridge University

Seb - Previously, in the lab we’ve looked at the ways that people learn and in particular we’re looking at how people predict what’s coming up in the environment that they’re in. Particularly in uncertain environments, this is a particularly important function of the brain. We have discovered that there seem to be these two strategies that people use to predict the incoming situation and we are interested in what it is that makes a person pick one of those two strategies.

Georgia - Okay. Just thinking about this way of learning; for example, I’m in a new situation. Let’s say I’m playing American football for the first time and the ball is coming towards me and I need to adapt to the situation, what are the two strategies I might use?

Seb——也许更好的看待它的方式be rules of American football itself. You might try to memorise all of the rules of American football and get them down so that you make no mistakes whatsoever. Alternatively, what you could do is just memorise the most important rules such as I need to run the ball to that end of the pitch. These would effectively be the two strategies: are you just taking in the most important information to save processing power perhaps, or are you taking in all the information to save on accuracy. We are interested, in particular, as to what would make you pick which of those strategies.

Georgia - I see. How does your video game do this?

Seb - In the video game we submerse people in a new environment in which they are trying to communicate with aliens who are speaking a language that you can’t understand because it doesn’t exist. You are presented with a string of symbols and you have to pick the next one in sequence, and you pick either according to whether you’ve memorised all of the symbols up to that point or what you think is most likely to come next all the time.

Georgia - So how well a player does basically tell which strategy they’re using?

Seb - Yeah.

Georgia - I actually had a go at your game and it’s quite fun. You’re in this little rocket and you meet these aliens and then they fire a load of symbols at you. Then you’re rather confused and just have to hit one of them and hope they give you some fuel. So looking at people’s responses, this is giving you actual data to do your science?

Seb - Yeah, absolutely. And we’re combining this with some survey information that we get from everyone who takes part which will tell us a little bit about their backgrounds, their personality perhaps, and some other psychological tasks which will tell us more cognitive traits such as working memory, risk taking, and other things like that.

Georgia - Who is the study aimed at?

Seb——我们的目标是尽可能多的教养le as we can possibly, but we’re also looking, in particular, at an adolescent group so people aged 13 to 17 because this is a vastly understudied group in the literature. We’re wondering if perhaps there are different strategies that adolescents would use to learn something than adults.

Georgi - Right. Is this new method of collecting data, I suppose, letting you reach this target demographic more easy?

Seb - Sure, That’s the intention. Getting it out there, particularly seeing as everyone these days has access to some kind of mobile device or the internet at least. They should be able to take part in this study and that will get us far broader than just the people who can make it into the lab for a day of testing.

Georgia - What’s that statistic? More people have access to a smartphone than to a toilet or something like that.

Seb - Exactly.

Georgia - This is designed to get data and it’s helping you do your science but are there any benefits to playing video games in general?

Seb - This is a very interesting area of research there’s a lot of people looking into right now. Video games, partly because of the way that they’re such an immersive environment that you get involved in and because you are interested in getting reward from these environments, you want to win the game, you want to do better, this leads the brain to develop. As a result we seem to find that people who play a lot of action video games, in particular, where there’s a lot of fast-paced interaction between the person and the machine. People tend to be able to track things visually. Where most of the population would be able to track four visual objects, gamers can track up to seven, maybe in excess of. It also seems to show that there’s this level of plasticity or flexibility in the brain which only really occurs in this immersive environment, which they’re using to treat stroke patients where, perhaps, part of the brain has been damaged and the only way to overcome that is to change the connections in that area.

Georgia - So would you say art has helped science and was it, when you were designing this video game were you like “oh, as a scientist I’m finding this a different kind of skill set now”?

Seb - Yeah. I think art is definitely helping science in this circumstance. It allows us to reach more people. It definitely makes it a little bit more fun to take part in psychological experiments. And it allows for this generation of entirely new environments which wouldn’t be possible without it.

Georgia - I’ve got to say some science studies can have you looking at the clock. But make it a video game and people are only too happy to play.

Seb - Exactly.

Georgia - Sam Aaron from Sonic Pi, would you agree then? Would you say science and art make good bedfellows?

Sam - Absolutely. I could almost argue that they don’t have that much difference at all - they’re both founded in creativity. Science is an approach which is fundamentally principled on having a hypothesis which is a guess, which is creative itself. I think they’re both tools we use to explore the society around us and ask questions that we don’t necessarily have answers to. They’re very different tools and they allow us to explore different questions but, ultimately, they’re about communicating whether or not we’ve found those answers or whether the questions are worth exploring further and I think to put so much force behind one and not the other is actually detrimental to humankind.

Georgia - Maybe we shouldn’t really be pigeonholing these two separate ideas of art and science and just squidge them together in one big brilliant thing.

Sam - I think if you look throughout history there are large periods of time where we didn’t have a separation at all.