Nature Podcast

This is a transcript of the 31st March 2016 edition of the weekly Nature Podcast. Audio files for the current show and archive episodes can be accessed from the Nature Podcast index page (, which also contains details on how to subscribe to the Nature Podcast for FREE, and has troubleshooting top-tips. Send us your feedback to

Kerri Smith: This week: making online gamers nicer to each other.

Brendan Maher: If they start taking ownership of the culture and saying that this kind of behaviour is not something that we want to live with and we know that there are ways to stop it, then that could have a pretty significant effect.

Adam Levy: And peering into the future of Antarctica's ice loss.

Tamsin Edwards: I would say it's the biggest unknown in future sea level rise.

Kerri Smith: Plus a bulky piece of kit for measuring gravity gets slimmed to the size of a postage stamp. This is the Nature Podcast for March the 31st 2016. I'm Kerri Smith.

Adam Levy: And I'm Adam Levy.


Adam Levy: Prediction is very difficult, especially about the future. This saying, attributed to physicist Niels Bohr, is often used to refer to quantum mechanics, but climate scientists know it a plays a role in their research too. After all how do you work out what the future holds for the climate when you've only got one planet? You're still learning how it works and you can't carry out carefully controlled studies. Well, the typical approach is to build computer models that simulate the relevant laws of physics and can be checked against the real world. But what if you only have limited data from the real world and how do you cope with processes that haven't even happened yet but might come into play in the future? These are questions that scientists looking at the Antarctica are grappling with. We only have satellite data of Antarctica from the last few decades, so scientists have to work hard to make the most of the information we have. But understanding what's going to happen to Antarctica's ice is vital to understanding how global warming will impact the world. Nature 531, 591–597 (31 March 2016); Nature 531, 562 (31 March 2016)

Robert DeConto: There's just so much potential sea level rise locked up in Antarctica. There's such a vast amount of ice.

Adam Levy: This is Rob DeConto from the University of Massachusetts, whose report is in this week's Nature. He's been trying to peer into the future by modelling how Antarctica contributes to sea level rise.

Robert DeConto: So even a small fraction of Antarctica being mobilized and going into the ocean is going to have global impact.

Adam Levy: Because it could have such a big influence, lots of different groups have tried simulating Antarctica's future and have come up with a broad range of results. Here's Tamsin Edwards of the Open University who published a study a few months ago on future ice loss in the Antarctic.

Tamsin Edwards: I would say it's the biggest unknown in future sea level rise.

Adam Levy: But why? What makes it so hard to pin down?

Tamsin Edwards: Pretty much everything about it. All of these different ways in which ice can flow, can crack, can be lost and gained, it makes quite a complicated picture.

Adam Levy: Both Tamsin Edwards and Robert DeConto have used models to try to get to grips with this problem, but they're somewhat divided about what their models should be based on. Here's Tamsin again.

Tamsin Edwards: So we kind of assumed that if the model is good at simulating the recent past, it's more likely to be good at predicting the future.

Adam Levy: But Rob thinks there's only so much that the last few decades can teach us.

Robert DeConto: In the very recent past, the climate and the oceans have been, you know, certainly not as warm as they're predicted to become in the next century, so we compared the results that we get with geologic records.

Adam Levy: Geologic records: that just means records of the climate from the distant past deduced from things like the erosion of now inland cliffs. Rob favours using data like these because there have been times in the Earth's past where the climate has looked pretty similar to today's situation.

Robert DeConto: 125,000 years ago, the world looks a lot like it does today, similar climate and yet sea level was between six and nine meters higher.

Adam Levy: So where Tamsin's model uses direct observations of Antarctica from the last few decades, Rob's uses understanding of sea levels from thousands of years ago; but whatever you're checking your model against, you can never be sure it'll apply to the future says Tamsin.

Tamsin Edwards: If you're calibrating with past data and that includes paleo climate data as well because you never find the perfect analogue of the future in paleo climate, there are always different things going on. So you have to bear that in mind when you're thinking about your predictions and be a bit cautious.

Adam Levy: And the same goes for models based on today's climate. It's not a done deal that tomorrow will behave like today. And what if Antarctica loses ice in different ways tomorrow than it does today? Rob's model includes certain processes that we haven't observed in Antarctica. For example, the possibility that melt water on top of ice could make ice cliffs unstable. This could cause ice to collapse into the sea much faster than we're seeing today. Rob says his model is only accurate if he includes these kinds of dramatic processes, but it's not easy to build these processes into the model.

Robert DeConto: I would say that these are just really the first baby steps to try to incorporate processes like these in the models.

Adam Levy: But Tamsin is not convinced that including processes like this that we've not really seen taking place yet is the best bet.

Tamsin Edwards: We haven't seen direct evidence of this, I would say that really says we have to put it in the models. Basically at the moment, it's an exciting time the jury is out.

Adam Levy: So where Tamsin's model is limited to the behaviour we know to have happened in Antarctica, Rob's includes processes that may or may not arise in the future. They're both trying to make the best use of limited information and so to the results. According to these different models, how much is the Antarctic going to contribute to sea level rise by 2100. We'll get to towards these numbers mean in a minute, but first here's Tamsin's estimate.

Tamsin Edwards: We came up with the most likely of about 10 centimetres – quite low – and we came up with the prediction that there is only a 1 in 20 chance it would be more than 30 centimetres by the end of the Century.

Adam Levy: How about Rob's model?

Robert DeConto: We're getting something between 64 centimetres and a little over a metre.

Adam Levy: It's a huge difference. Yes, the two models used slightly different scenarios of greenhouse gas emissions and yes there are plenty of other uncertainties but the difference is still striking and Rob's results could mean for example the low lying island nations could have to evacuate sooner than was previously anticipated.

Robert DeConto: You know, I hope we're wrong.

Adam Levy: Understandable when Rob's model also predicts over 10 metres of sea level rise 500 years from now. And remember Antarctica is just one piece of the sea level rise puzzle. Added to other sources of sea level rise like the Greenland ice sheet, even Tamsin's estimate could lead to sea level rises of about a metre by the end of the century: a huge challenge for coastal cities around the world. But such big uncertainties mean that it's hard for the world to know what to prepare itself for. Rob is hopeful that techniques like his and Tamsin's could be combined in the future to take advantage of both recent observations and geological records. Tamsin, on the other hand, thinks that for the time being it's good that we have a range of models tackling the problem in different ways.

Tamsin Edwards: We may come up with some super ice sheet model that captures everything perfectly, but it is a good idea to have different models with different approaches and that they'd be independent and you can compare their results.

Adam Levy: After all, if you can't compare lots of different Earths, at least you can compare lots of different models.

Kerri Smith: The details of both those model studies are available at You heard from Tamsin Edwards whose paper came out in Nature in December and Rob DeConto whose paper is out this week.


Kerri Smith: Coming up later in the show, turning poisonous rants into polite conversation in the online game League of Legends, but first here are the Research Highlights with Noah Baker.

Noah Baker: We know that rocks can be cracked and loosened by repeated freezing and thawing, precipitation and of course earthquakes but it turns out that gentle warm weather can cause rock falls too. Two researchers measured a crack in a 500 metre cliff in Yosemite National Park. The crack, between the main rock base and another large slab, widened each day as the rock expanded in the heat and closed up at night. Over several years, it gradually got wider, though the slab is still stuck to the cliff for now. This process could explain why some rocks crack and fall without an obvious trigger. The paper is in Nature GeoScience. Nature 531, 553 (31 March 2016)Scientists have genetically modified a Zebra fish so its skin glows with thousands of colours. Each outer skin cell glows with a random colour and the researchers can tell about 70 colours apart. This means that most cells are distinct from their neighbours. The cells can be tracked over time and that allows scientists to watch how they respond to an injury. They saw that when a fin was amputated, old cells migrated and grew and new cells appeared to keep the tissue covered. Check out the study in developmental cell and a very colourful video at Nature 531, 552 (31 March 2016)


Adam Levy: In the US a big study of transgender teens kicks off; that's all to come in the news chat but first that miniaturised metre for measuring gravity. Nature 531, 614–617 (31 March 2016); Nature 531, 585–586 (31 March 2016)

Kerri Smith: In her work as a volcanologist, Hazel Rymer often needs to look through the Earth at what lies beneath. For this, she uses an instrument called a gravimeter.

Hazel Rymer: My work is involved monitoring active volcanoes using gravity meters and also mapping subsurface structures of volcanoes using them. You end up with a map. It looks a bit like a contour map so instead of contours of height, which would tell you about the topography, you end up with contours of gravity.

Kerri Smith: And measuring gravity is an indirect way of measuring something's mass. So if you're standing over an underground lake, it has less mass than the surrounding rock and you can tell by measuring the differences by gravity where it begins and ends. The only trouble is…

Hazel Rymer: Standard gravity meters are quite temperamental and they're a bit bulky. You can put them into a back pack but they're the size of a small car battery. They're quite cumbersome.

Kerri Smith: Not to mention it's expensive. Some can run to a hundred thousand dollars and weigh up to a 150 kilograms.

Hazel Rymer: But something smaller would be of huge use.

Kerri Smith: Maybe the size of a mobile phone?

Giles Hammond: The device that we've been working on is based on a microelectricmechanical system, so a MEMS device.

Kerri Smith: This is researcher Giles Hammond and a MEMS device is a tiny little electronic circuit like you'd find in your smart phone or digital camera.

Giles Hammond: The actual MEMS device itself is a silicon wafer is about a centimetre squared and that has the benefit of being actually very sensitive but at the same time extremely small, compact, light weight, low power.

Kerri Smith: Gravimeters work in one of two ways. Absolutely gravimeters measure the acceleration of a mass falling in a vacuum inside them. Relative gravimeters are basically are a little weight on a spring and they measure the amount that the weight stretches the spring as a measure of gravity. Hammond and his team at Glasgow University have built a tiny version of the spring based relative gravimeter.

Giles Hammond: So you might imagine that mass on the end of the spring when it sits in the gravitational field of the Earth, the extension of the spring depends on the gravity and also how stiff the spring is. If the spring is really soft, the mass will deflect a lot more, so we need to make a spring that's actually quite soft. We utilise etching techniques which make our springs incredibly thin. So our spring's about half the thickness of a human hair and that allows us to make a little mass quite light, it's about 0.02 gram.

Kerri Smith: The team showed that their device works by measuring a well known tiny fluctuation in gravity. You know how the oceans are affected by the Moon pulling on them to make tides? Well the solid Earth has its own tide: the amount that the Earth's surface bulges due to the Sun and the Moon pulling on it. It's is a tiny force, two million times weaker than the Earth's gravity. But the device could pick up this micro-fluctuation. Now they're working to miniaturize the kit and the smaller it is, the cheaper it will get. Giles estimates that these mini gravimeters could go for around a thousand pounds a pop. This is great news for researchers like Hazel Rymer out measuring volcanoes.

Hazel Rymer: Instead of taking one instrument around and making lots and lots of measurements, you could potentially leave several of these things continuously recording in place, so that you would have not only an estimate of what the value of gravity was at a particular point, but how that changed through time. So for example, on an active volcano, if you had 10 or 20 of these things, located around areas of interest and see how gravity changes through time, you would have the sorts of measurements that are just completely impossible at the moment. You could almost chuck them into an active crater, not into the lava obviously, you know so that they were really close to the area of action in a way that there's just no way you could do it at the moment and you wouldn't want to sacrifice an instrument.

Kerri Smith: It might be a while until the new gravimeter can be dispatched into the gaping crater of a hot volcano. For one thing, it hasn't been out of the lab yet. Giles Hammond.

Giles Hammond: The thing with the lab based environment was the temperatures relatively stable, we stabilized it to about a milli Kelvin so about a thousandth of a degree Kelvin but you know our side of course the temperature fluctuations can be many, many degrees. So that's one thing we're working on, is actually making it robust in terms of its performance in the environmental conditions.

Kerri Smith: And then there's power supply to consider. Giles and his team planned to test their device on some nearby reservoirs, halfway at the side of a mountain near Glasgow.

Giles Hammond: There's not many 240 volt power sockets there unfortunately, so we're actually developing all the associated electronics to enable us to actually use the device running from a battery.

Kerri Smith: The mini gravimeter is something of a size contrast to Giles' other recent project. He spends half his team working on the LIGO gravitational wave detectors: sprawling kilometre long vacuum tubes and super polished suspended mirrors.

Giles Hammond: So really looking at the most energetic and violent events in the universe. That black hole system, it converted about three Solar masses of energy into gravitational waves in about a 100 milliseconds, yet as you say on the other side, you know, some of that spinoff technology, you know the ability to make suspension systems has really led to the development of this MEMS device.

Kerri Smith: Giles Hammond of Glasgow University and Hazel Rymer of the Open University based in Milton Keynes here in the UK.

Adam Levy: Find the gravimeter paper from Hammond's group and the News and Views article by Hazel Rymer at

Kerri Smith: Our next story is about people who are rude to others online and as such contains language which some listeners may find offensive. We've bleeped it, but just to let you know that's the tone. Noah Baker has the report. Nature 531, 568–571 (31 March 2016)


Noah Baker: This is the theme from a video game called League of Legends. In the game, millions of players from around the world form teams of digital champions who battle each other in an online fantasy arena – rousing stuff that is until you witness something like this.Holy , you , bronze I'm not even getting out kill yourself, write a note to your mum saying I killed myself because asked cuz I'm

Noah Baker: That's a real player in the midst of a game. For the record, most of the communication in League of Legends is done via typed chat boxes, but this is a recorded message and it's fairly representative of what you might read there. This kind of comment is so common that gamers had a name for it: toxic. And toxicity is a focus of this story – in particular what's being done to combat it but we'll get to that. First off I wanted to know how common toxicity actually is.(Phone ringing)

Gala: Hello.

Noah Baker: Hi Gala.

Noah Baker: My friend Gala is a gamer, so I figured she'd be a good person to ask. I'm calling to talk to you about League of Legends, is that a game that you play?

Gala: Not at the moment no but I have in the past.

Noah Baker: As it turns out, she stopped playing League of Legends because of toxicity.

Gala: It tends to happen with most online games I've tried to play. Yeah I've heard some really nasty homophobic and racial slurs just used quite freely on group chats with people who they don't really know anything about or have any type of grounding in anything real.

Noah Baker: Gala also mentioned aggressively sexual behaviour and misogynistic language but admitted that she quit the game pretty early. So I went to find some gamers who are more immersed in the world. At a video games bar in London, I met Nick, a gamer who has been playing League more or less since it was launched.

Nick: I'm Nick. I work as an artist in the film industry.

Noah Baker: Nick was no stranger to toxicity either.

Nick: Yeah I've experienced people calling me all kinds of things in various languages. The community is known for being toxic and awful, but if you have five good friends and you go in there and whether or not you win or lose you have a good time then it's a fantastic game for that.

Noah Baker: Clearly, toxicity doesn't put everyone off the game, but it's such a well known issue that Riot Games, the company that makes League of Legends, decided to tackle the problem head on. Here's Nature reporter, Brendan Maher, who has been writing a feature about Riot Games and their approach to toxicity.

Brendan Maher: The Riot founders have this very player centric view of what they want to do. They met with this fellow Jeffrey Lin who's a cognitive neuroscientist. He was working for another video game company at the time and they said to him, you know if we kind of gave you the keys to the kingdom what would you do?

Noah Baker: What Lin did was turned to science.

Brendan Maher: Well, he rooted a lot of his ideas in, sort of, basic behavioural psychology.

Noah Baker: He tried a whole host of things. The first was simple.

Brendan Maher: The one sort of tool that all video games can sort of have in their bag to combat toxic behaviours to punish other players and it doesn't really work well. So Lin developed these sort of really rich report cards that showed players exactly what it was that they had done that resulted in a ban and that tended to improve their behaviour pretty dramatically.

Noah Baker: Then there's the question of who determines what behaviour is deemed toxic and what isn't.

Brendan Maher: That's where the tribunal comes in. The tribunal is this way that players themselves would volunteer to rate different activities by their other players. An accused player will have this long chat log that sort of shows what he or she does in a game and the other players sort of have this chance to weigh in and say yeah, you know this guy's behaviour is pretty unacceptable.

Player: I got really into the tribune actually. I had arguments on forums about tribunal cases. I felt like I was, sort of, doing some kind of minor justice to my past self who'd had to experience all of that toxicity prior to the tribunal testing.

Brendan Maher: But the problem was that this process took a long time, sometimes two to three weeks, even a month or more. So Lin knew that he needed to give this feedback really immediately.

Noah Baker: Enter artificial intelligence.

Brendan Maher: They fed these thousands and thousands and thousands of reports into an algorithm. They basically, as Lin says, they unleashed machine learning and they used this to automatically and instantaneously render judgments and send people detailed feedback.

Noah Baker: So there's community involvement, artificial intelligence, constructive reports; all clever ideas, but did it work?

Brendan Maher: So when they just give basic feedback like you did something wrong on this game and you're going to be banned for six weeks, about 50% of people would, sort of, reform. Three months later they wouldn't do anything offensive. When they started giving those rich report cards, it increased to about 70% and then when they gave it immediately, powered by this machine learning approach, it increased to about 92% reform. That's a pretty incredible recidivism rate.

Noah Baker: And it isn't just about clever punishment. Lin also tried to reduce toxicity at the source, using a psychological principle called priming. The idea is that exposing a person to a particular stimulus can influence how they react to the situations that follow. In this case the stimuli where text tips which would pop up on loading screens or at various other points during the game.

Brendan Maher: And the tip could be something positive like, you know, players do really well when you give them a positive reinforcement.

Player: Yeah and also there's one that says players who follow the rules of the game, The Summoner's Code, as it's known win 27% more games.

Noah Baker: Whether priming really works has been called into question in recent years because the effect can be hard to reproduce. But the gigantic world of League of Legends allowed Riot Games to take a really robust approach.

Brendan Maher: They tested something like 216 different permutations of different phrases and different colours and different placements on the screen and they actually get really robust results because they're able to do millions and millions of tests a day and you know they found that these kinds of tips actually do have an effect. You know sometimes 5 to 10 or 11% change in the amount of verbal abuse and offensive language that goes out in the game.

Noah Baker: All these efforts and various others have led to Riot Games reporting significant reductions in toxic behaviour. At the video games bar, Nick agreed that the tide is turning.

Nick: Now there's much more of a zero tolerance kind of policy within the community, that's been embedded there, because I think people have sort of subconsciously realised that that kind of stuff does bring your game play down. It does affect you in a negative way even if you are not participating, if you're not instigating it, it's something thatI think the community has turned against in a big way.

Noah Baker: Riot's efforts are continuing and other games companies are following suit. Some people are even suggesting that the steps Riot is taking could resonate throughout the web.

Brendan Maher: For one thing, there's a lot of players playing this game, and if they start taking ownership of the culture and saying that you know this kind of behaviour is not something that we want to live with and we know that there are ways to stop it, then you know that could have a significant effect across the rest of the internet.

Noah Baker: The techniques that Riot Games are using probably won't work on all online forums but they're already working with companies like Reddit and perhaps their methods could be adapted. For now though, here's hoping though that on League of Legends at least toxicity keeps on falling.


Adam Levy: If you want to know more about Riot Games, toxicity or League of Legends, check out Brendan's feature, that's at

Kerri Smith: Finally this week then, it's the news and US chief of Correspondence Lauren Morello joins me. Lauren, hello.

Lauren Morello: Hi Kerri.

Kerri Smith: Now a new NIH funded program worth almost 6 million dollars is due to launch in May. Will you tell us what the NIH are starting to fund?

Lauren Morello: So this is a NIH funded study. It's the largest ever study of transgender children and teenagers and they're going to be studying two different things. One group of younger teens is going to be given drugs that block puberty which is a standard treatment for kids who are transgender. It kind of buys time for their bodies to mature before they're given hormones to help their bodies match the gender that they identify with. And the second group of kids in this study is going to be older teens who are getting those hormones. Nature 531, 560 (31 March 2016)

Kerri Smith: And are they looking at kids who would ordinarily have got these anyway in kind of observational, like epidemiology kind of way or is this a kind of a randomised control study basically?

Lauren Morello: No this is a longitudinal study, it's an epidemiological study. These are kids who would have gotten these treatments anyway. There's not a lot of good data out there on how these kids do and for example, the standard of care right now is to delay giving hormones to a transgender teen until he or she is 16 and I don't want to say it's entirely arbitrary but clinicians and researchers don't have as much data as they'd like to back that up and so this study is going to be looking for data that's going to help physicians refine the standard of care.

Kerri Smith: And how long do they project that they will follow these kids for?

Lauren Morello: They're hoping to follow them for at least five years. After that I think it depends on the vagaries of whether the NIH wants to keep supporting the study.

Kerri Smith: I see and they're starting to recruit participants for the study in May.

Lauren Morello: Yes, they're going to be recruiting 280 teenagers at four different sites around the United States.

Kerri Smith: Are there major questions in the air still about which of these treatments is better? How to treat transgender teens?

Lauren Morello: Well, one area that's pretty contentious is whether to allow or to encourage prepubescent children and young teenagers who are transgender to live as the gender they identify with or whether they should be counselled to kind of wait and see for a couple of years because a lot of children who identify with a gender other than the one they were born with don't keep that gender identity over the long term. They revert to their gender of birth by the time they're adults, but teenagers who identify as transgender generally end up doing so for life, so there's this question of whether to take a wait and see approach or encourage them to live as their preferred gender or in some rare cases I think to try to convince them to identify with their birth gender.

Kerri Smith: So, the first story there, obviously the study will start recruiting in May and that's some much needed money going towards funding initiatives looking at transgender teens. Now, the second story is also kind of about funding but unfortunately is a funding cut, the National Science Foundation has decided to postpone any further funding for biological collections. Nature 531, 561 (31 March 2016)

Lauren Morello: Right I guess technically it's funding freeze, but what NSF has announced is that they are not going to be awarding any new grants for the foreseeable future to support biological collections and that sounds pretty nerdy and clinical but what we mean by biological collections are things like fish larvae that US regulators use to set fishing quotas every year but also things like fossils and preserved plants and things like that that you would find in a science museum.

Kerri Smith: And NSF have traditionally funded this to the tune of what exactly?

Lauren Morello: They usually spend between 3 to 5 million dollars a year on this which is really you know a drop in the bucket given that their budget this year I think is 7.5 billion dollars. I mean, the other thing that's worth noting is that NSF is the only source of grants for this kind of thing.

Kerri Smith: So why is this funding being cut, as you said, it's not much of the NSF's budget?

Lauren Morello: That's also mysterious. We asked the NSF and they told us that they're evaluating the program and as such they can't tell us whether this funding freeze is temporary or whether it's actually a permanent funding cut. They are aiming to finish this evaluation by the end of the current budget year which ends at the end of September and they're talking about may be restarting this program with a new focus. Scientists are pretty unhappy about this.

Kerri Smith: So I guess they shall have to wait until at least September for the evaluation to be concluded to see if the money will start coming again. Now finally a little piece of breaking news and it's literally about something that is breaking. This is the Japanese Space Observatory Hitomi. Nature

Lauren Morello: That's right. This is the Japanese Space Agency's flagship space observatory launched last month and has been going through, you know, initial testing to make sure that everything works before it starts gathering data and unfortunately it went off line this last weekend.

Kerri Smith: What happened, what do we know about why it stopped communicating?

Lauren Morello: It's a little mysterious and there's some ominous reporting coming in. The United States Joint Space Operation Center which tracks space debris has spotted I think five objects that are in the areathat the spacecraft was in around that time it went silent and the centre is saying that these are pieces of a "breakup". So the question is whether the space craft broke up, you know did it have some instrument problem that caused it to explode, did it get hit by a piece of space debris that crossed its orbit or is this debris just a sign of a problem that is less serious and potentially not disabling? You know, there may be a problem with one little instrument?So right now the Japanese are trying to get back in touch with Hitomi. They've detected at least one signal since they initially lost communications with the satellite. So it's a bit like Schrödinger's cat right now I guess, no one knows whether it's alive or dead, they haven't opened that box. You know, I think it's worth mentioning Kerri that Japanese Space Agency has a history of essentially saving spacecraft that seem like they were doomed. In December, they managed to manoeuvre a spacecraft called Akatsuki back into orbit around Venus five years after an engine failure left the spacecraft floating of course and everybody thought the mission was over. That said, it's also worth mentioning that two different versions of this spectrometer on Hitomi have met with fairly gruesome fates, but you know like we said it's too early to tell which way Hitomi is going to go and JAXA has pulled a rabbit out of his hat before.

Kerri Smith: Yeah, got to admire their persistence Loren. Thank you very much. Next time, spotting the remains of dead stars buried deep in our own Earth's crust. I'm Kerri Smith.

Adam Levy: And I'm Adam Levy.