Host: Benjamin Thompson
Welcome back to the Nature Podcast. This week, the emergence of megastudies in behavioural science.
Host: Shamini Bundell
And what the launch of the James Webb Telescope could do for astronomy. I’m Shamini Bundell.
Host: Benjamin Thompson
And I’m Benjamin Thompson.
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Host: Benjamin Thompson
There are different methods of encouraging people to do things, and figuring out which method is the most effective has important policy implications. A key question in behavioural science is how do you compare these methods to find the best one? This week, Nick Petrić Howe has been finding out about a unique experimental approach.
Interviewer: Nick Petrić Howe
The behavioural sciences are all about trying to understand how and why people do things. In recent years, this field has caught the attention of governments and policymakers who would like to like to encourage people to do certain things, like pay their taxes or go to the gym. Now, there have been many insights from behavioural science on such interventions, but to really drill down into what might work for whom, there needs to be studies specifically focusing on a particular idea and comparing it to a baseline – a placebo. Essentially, a randomised controlled trial, like you might find for a drug, but instead for something like a phone notification to remind you to pay your taxes. Again, such studies have yielded many insights, but they still have problems. For example, often these studies have been done in different places with different populations, so it makes it really hard to compare them to one another. This week in Nature, though, researchers have come up with a new method that can tackle some of these issues. Katy Milkman is one of the authors, and I called her up to find out more.
Interviewee: Katy Milkman
So, okay, I’m recording all this on my end. I will send you a .wav file afterwards if that works? And I’m excited. Do I sound okay to you? Is this close enough?
Interviewer: Nick Petrić Howe
Yeah, you sound like you’re coming in really well. Can you hear me okay?
Interviewee: Katy Milkman
Yes, I hear you very clearly.
Interviewer: Nick Petrić Howe
Great, that’s why I have the microphone right here. So, a good place to start, you’ve got a paper that’s just come out in Nature, and in this paper you come up with an experimental approach called the megastudy. I feel like I need to say that in sort of like an 80s narrator-like film voice.
Interviewee: Katy Milkman
Laughs. With your megaphone.
Interviewer: Nick Petrić Howe
With my megaphone. You’ve come up with this new experimental approach – the megastudy. So, what is it and how does it tackle some of these issues?
Interviewee: Katy Milkman
Yeah, so the megastudy, it is sort of a ridiculous name, but we like it, we’re having fun with it. The idea is that instead of doing science sort of the old-fashioned way – testing one hypothesis at a time, in isolation, with a single population – what if we actually tested dozens of hypotheses or at least more than ten, more than one, all at once in one massive randomised controlled trial. If you could test all sorts of different ideas at the same time, in the same population, with the same outcome measure, well, now suddenly you have huge reduction in the individual costs of those studies and you have comparability. Now, you can actually say, ‘Oh, look. This is more cost-effective than that.’ And you can also get people from different disciplines to have some more cross-pollination because normally an economist has an idea and a psychologist has an idea and a sociologist has an idea, and they do their own independent tests. If you pool them and have one, massive randomised controlled trial in which each of them gets to design their little study but it launches at the same time, well, now they’re having some kind of dialogue because they’re going to see each other’s results. They’re going to actually learn from each other about what ideas they had in a way that they might not have otherwise.
Interviewer: Nick Petrić Howe
So, this is testing a whole bunch of hypotheses at the same time, so is this with the same population, the same people and all of the parameters the same, apart from the one thing you’re trying to test.
Interviewee: Katy Milkman
That’s exactly right, and I’ll get a little less abstract. The paper talks about the idea of the megastudy but it also presents one to say this is what one looks like. And the megastudy that we ran was in partnership with a large, national fitness chain in the United States, and it was to encourage their members to exercise more regularly, and so we actually had 30 different scientists involved and in different teams, and each little team of scientists came up with a hypothesis and a study design, one, two, three, sometimes, different experimental conditions that they were designing to test their hypothesis. And then we pooled all of those different I’ll call them sub-studies into a megastudy, which had a total of 54 different experimental conditions.
Interviewer: Nick Petrić Howe
Of all the conditions that Katy and her team tried, 45% were more successful than the control at encouraging exercise.
Interviewee: Katy Milkman
A lot of them worked.
Interviewer: Nick Petrić Howe
The most effective was giving people a small reward for returning to the gym after a missed session, which sounds pretty good to me. But Katy also wanted to make sure that the results of the megastudy were telling them something beyond what was already known from conventional studies. After all, if we already know a good way to motivate people to go to the gym, then why embark on such a massive enterprise? And so, she built a sort of quality control into the study.
Interviewee: Katy Milkman
We also had built sort of a best practice experimental group that took all the things we knew from past scientific research on this topic and put them in, so that was a tougher bar to beat, and actually only I think 9% did.
Interviewer: Nick Petrić Howe
So, you may not have found the way to motivate everyone to do exercise, but to show the principle of the megastudy, do you think this was a success?
Interviewee: Katy Milkman
Oh, absolutely. It was such an exciting, new way of doing science for me and for all of my collaborators, and I think we all are really excited about the potential of this new way of doing science.
Interviewer: Nick Petrić Howe
Katy is excited, but it’s her baby, so perhaps this isn’t surprising. So, to get an outside take, I also spoke to Heather Royer.
Interviewee: Heather Royer
I’m Heather Royer and I’m a full professor in the economics department at the University of California, Santa Barbara.
Interviewer: Nick Petrić Howe
Heather studies health economics and has written a summary of Katy’s paper as a News and Views article.
Interviewee: Heather Royer
I think it’s an exciting method. One of the things I do worry is that we need to make it such that we encourage a diversity of opinions, and so trying to get people who are less well-connected in the research community to participate in the start of these megastudies I think is a really important thing to consider.
Interviewer: Nick Petrić Howe
And do you see yourself doing any such study in the near future?
Interviewee: Heather Royer
I’m very intimated by the whole enterprise. I mean, the studies that I’ve done involved 1,000 participants. This one has 60,000 participants. But it’s very exciting, I think. It would be cool to be able to test different types of interventions that I thought might work but have been hesitant to do so.
Interviewer: Nick Petrić Howe
And yeah, that’s something you touched on a little bit in your News and Views, is could this be a way to test interventions that perhaps don’t seem particularly likely, at least from the outset, to be very effective.
Interviewee: Heather Royer
Yeah, I think that’s one of the really exciting things about the megastudy, is that you could test things in doing your work that you thought that would be effective but have been hesitant to do so because you have a limited number of interventions that you can do in one RCT, and here’s, to some extent, an unlimited number of interventions you can do.
Interviewer: Nick Petrić Howe
Heather sees megastudies as a useful tool to narrow down a wide range of interventions and select the best candidate for more intense study. However, megastudies are huge and not the easiest or cheapest studies to organise.
Interviewee: Katy Milkman
I think that’s one of the biggest limitations of the megsastudy, is that it is really expensive. I am really bullish on megastudies being used more by policymakers and governments and scientists who are trying to really contribute to pressing problems. This is just another approach we can take, and I think the pandemic gave us a particularly nice example of when it might be really valuable to roll out a megastudy. When you have a pressing policy question, the need for insights is large enough that you’re ready to fund it at a level that would make a megastudy possible. We’ve actually done some work building on this idea to try to figure out if we can use megastudies to accelerate science on encouraging vaccination, and we’ve had a lot of big successes there, and that would never have been possible if we hadn’t started out with this project and sort of built the idea of a megastudy. We don’t have time to wait for scientists to do their own thing for a decade or two and come back with what they think is a good answer, right? We need to accelerate the speed of high-quality science to get to the bottom of it, so that’s where I see the future of megastudies.
Host: Benjamin Thompson
That was Katy Milkman from the University of Pennsylvania in the US. You also heard from Heather Royer from the University of California, Santa Barbara, also in the US. For more on megastudies, check out the show notes for a link to Katy’s paper and a News and Views article written by Heather.
Host: Shamini Bundell
Coming up, we’ll be hearing about the successor to the Hubble Space Telescope and what it could mean for astronomers. Right now, though, it’s time for the Research Highlights, read by Dan Fox.
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Dan Fox
The gigantic Haast’s eagle ruled the skies above New Zealand until it went extinct several centuries ago. Weighing in at as much as 15 kilograms, it was the largest eagle ever known. But was this enormous bird a fearsome hunter or did it survive by scavenging? To find out, researchers used fossils of the eagle to create computer models of its talons and skull. The team then compared these features to those of various living hunting and scavenging birds. Hunting birds typically have relatively long talons and tough beaks and skulls. The Haast’s eagle had talons and a beak like those in modern eagles, but the rest of skull was more vulture-like. Simulations show that it would have been good at pulling its head back, a motion commonly made by scavengers tearing tissue from a carcass. But it could also bite hard. The researchers think the eagle was capable of hunting and killing prey much larger than itself, which it would then feast on while on the ground, perhaps even by plunging its head into the still-warm carcass. Hunt down that research yourself in the Proceedings of the Royal Society B.
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Dan Fox
Comets and asteroids have bombarded many planets, including the Earth. But new research suggest that the seven Earth-sized worlds orbiting the star TRAPPIST-1 may have enjoyed a relatively undisturbed existence. A team of researchers simulated what might happen if the planets circling TRAPPIST-1 had been bombarded by space rocks during and after their formation. They found that the planets couldn’t have been impacted by anything larger than the Earth’s Moon without disrupting their fragile orbital relationship. These seven planets are thought to contain water, but their relatively unruffled history raises a new question about how it got there. Space smash-ups are thought to have supplied water to Earth and other planets, but the lack of collisions with the TRAPPIST-1 worlds suggests that their water must have already been there – perhaps in their molten interiors – and was not delivered later by comets or other impactors. This means that planets may have many ways to acquire water and other important ingredients needed for life. Read that research in full in Nature Astronomy.
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Host: Shamini Bundell
Next up, reporter Adam Levy is taking a look at a telescope decades in the making.
Interviewer: Adam Levy
When you think of space, what images come to mind? Breath-taking nebulae, the complexity of our neighbours in our Solar System, or maybe the fiery consumption of gigantic black holes? Whatever you think of, there’s a good chance that the photographs you’re picturing were taken by one particularly iconic telescope – Hubble. Three decades after its launch, the Hubble Space Telescope is still active and, for many purposes, the best tool astronomers have for observing our Universe. Which is precisely why its successor is such a big deal. The James Webb Space Telescope, or simply Webb, aims to vastly build on Hubble’s achievements, observing the cosmos like never before, hopefully. This collaboration between NASA, the European Space Agency and the Canadian Space Agency is scheduled to launch later this month and, even if everything goes smoothly, we’re still months away from first observations. To find out why Webb is such a big deal and just how nerve-wracking the launch is, I caught up with space correspondent for Nature, Alex Witze. She told me just how excited researchers are right now.
Interviewee: Alex Witze
In the run up to the launch for Webb, I mean, astronomers are super excited and super nervous, I would say, So, this telescope is by far the most ambitious and grand thing that NASA has ever tried to put into space. It’s like a US$10 billion technological marvel, and a lot of things have to go right for it to launch and for it to work properly. I think it’s fair to say that astronomers around the world are holding their breath to see if this launches and gets up properly.
Interviewer: Adam Levy
Now, what actually makes the Webb telescope’s design unique?
Interviewee: Alex Witze
You can think about it compared to the Hubble Space Telescope. Webb is going to be 100 times more sensitive than Hubble. It’s much larger and it’s much more complex, so you’ve got to build a big, complicated thing in space, and all of those things are not easy to do.
Interviewer: Adam Levy
One of the things that sets Webb apart from Hubble is its focus on longer wavelengths of light at the infrared part of the spectrum. This allows the telescope to see really far away and so really far back in time. What could we actually learn from these observations?
Interviewee: Alex Witze
Astronomers are going to do a lot of different things with Webb, but sort of the primary thing that got this started in the first place is the notion of pushing closer to observing events that happened after the Big Bang. Astronomers hope to see and probably will see some of the first stars that formed after the Big Bang and then how those stars started to assemble into galaxies soon thereafter. And then how did those galaxies evolve with time? How did it all start? That’s the question that Webb can push into that astronomers haven’t been able to do before. It will go deeper back in time than anyone’s been able to do.
Interviewer: Adam Levy
On the smaller scale, though it feels kind of funny to talk about any of this as small scale, are exoplanets – planets going around other stars other than our own. What does Webb hope to learn about these exoplanets?
Interviewee: Alex Witze
Webb is going to be great at looking at the atmospheres of these exoplanets. It’s going to be able to look for molecules in the atmospheres of these exoplanets, so maybe see things like oxygen, methane, carbon, which we haven’t been able to do with instruments before. And if you can detect that kind of stuff in the atmosphere of another planet, you can start to think about what’s geology like in those worlds, is there water on the surface, could there be life there? So, Webb is going to be able to look at these atmospheres of these exoplanets like nobody has before.
Interviewer: Adam Levy
We’ve been talking about a lot of what Webb will do or what it hopefully will do. How big a risk is there of failure here?
Interviewee: Alex Witze
It’s a really risky thing to launch a really complicated space telescope. And just to go back in history, if you read about the launch of the Hubble Space Telescope, they started looking at stars and galaxies and they realised it was out of focus because somebody had ground the mirror improperly and they had to send astronauts up there to install corrective optics to get it working properly, and that was not cool. So, Webb has a lot more that could go wrong with it than Hubble. You can be pretty sure that Webb’s mirror is going to be in focus because no one is going to make that mistake again, but there are just a lot of complicated things that have to happen. You have to launch, which is always risky because you’re on a giant rocket, launching into deep space. It has to unfold. It kind of folds itself up like origami to stick it in the rocket fairing and if anything sticks when its unfolding, you’re in a lot of trouble because it’s going to a point in deep space that astronauts can’t visit to fix it if something goes wrong. It takes about a month for hundreds of small steps to be done to get the thing unfolded and operational. It’s a lot.
Interviewer: Adam Levy
And I suppose this isn’t hypothetical, the idea of things going wrong, because the launch has been delayed many times.
Interviewee: Alex Witze
Yeah, there’s been a lot of issues during the whole development of the observatory. Some astronomers just kind of roll their eyes when they talk about Webb launching because it’s always been so far in the future. So, for instance, when they were building it in the clean room in the aerospace companies, a technician used the wrong solvent to clean some valves and that like messed them up and they had to fix all that stuff, and all sorts of crazy things have gone wrong. But they’ve tested, retested, tested again, retested, so the idea is that they’ve spent so much time and so much money testing everything that, fingers crossed, it’ll work when it gets to space.
Interviewer: Adam Levy
This has been decades in the making. How do you personally feel, as someone who’s been covering the space beat for a long time now, that the day is creeping nearer?
Interviewee: Alex Witze
Well, I have this folder on my computer that’s ‘James Webb Space Telescope’, and I have at least three different story folders within that that are all called ‘JWST (James Webb Space Telescope) Delay’ because it’s been delayed so many times and I’ve written about it so many times. So, it’s a little strange to actually have folders for like launch stories and first science stories. It’s like, ‘Oh right, that thing I’ve been writing about in the hypothetical for so long, like it might actually happen now.’ But there are people who have observing time on the telescope now who literally were not born when the telescope was first conceived, you could say, which to me just blows my mind. And some of these people will be using it for a field that didn’t exist when the telescope was conceived, like exoplanets science did not exist. It’s pretty mind-blowing.
Host: Shamini Bundell
That was Nature reporter Alex Witze chatting to Adam Levy. For more on the upcoming launch of the Webb Telescope, be sure to check out a feature written by Alex, and that’ll be in the show notes.
Host: Benjamin Thompson
Finally on the podcast, it’s time for the Briefing chat, where we discuss a couple of stories that have been highlighted in the Nature Briefing. And Shamini, you’re up first today. What have you got to discuss this time?
Host: Shamini Bundell
I’ve got some cool space science for you today, Ben. I’ve got a pair of supermassive black holes. They’re on their way to a collision. They’re the closest pair of supermassive black holes to Earth. And they’re just very exciting.
Host: Benjamin Thompson
Wow, okay. Well, listen, you’re excited, I’m excited to find out. A couple of questions though. The closest to Earth? How close are we talking here, and is this something that I should be worried about?
Host: Shamini Bundell
No, the distances and the timescales here are the ones that astronomers get excited by, not something that you have any concerns. But this is a very exciting discovery. This was reported in a New Scientist article, and researchers using the Very Large Telescope in Chile have spotted this pair of black holes. So, as to how close it is, we’re talking 89 million lightyears from Earth – quite a long way – but it is five times closer than the previously known closest pair of supermassive black holes. And when I say they’re just about to collide, in maybe 250 million years.
Host: Benjamin Thompson
So, maybe I shouldn’t set an alarm then just yet. So, close and soon in astronomical terms then, Shamini, but what are researchers expecting to see then when these two black holes collide?
Host: Shamini Bundell
Well, so, they’re not planning on waiting 250 million years for them to collide, but for astronomers this is kind of like a snapshot, and it is relatively close compared to other pairs that we know, so the researchers are quite excited to be able to see them, they describe it as in the act of the merging process, so a snapshot that they don’t actually get to observe very often.
Host: Benjamin Thompson
And we’ve covered black holes on the podcast before and of course they are, in many cases, quite difficult to spot because you obviously can’t see them, right? So, how were these ones seen then as they sort of inch closer together?
Host: Shamini Bundell
Well, these ones are actually apparently even harder to spot than usual. So, some black holes actually give off light as matter sort of goes into them, and apparently that’s the usual method for detecting black holes. These black holes have been described as ‘silent’ and actually, despite being relatively close, no one’s spotted them before. But they were able to look at the movements of nearby stars and basically figure out that they were there. And the other interesting thing about this sort of particular discovery is that in this pair there’s one big one and for an idea of scale, the big one is 154 million times more massive than our Sun and it’s in the centre of this particular galaxy. But the other one is just like a little bit to the side of it, just sort of off to the side in this galaxy.
Host: Benjamin Thompson
Galaxy-adjacent.
Host: Shamini Bundell
Well, still in the galaxy but it’s like not at the centre, and they reckon that it was probably part of a smaller galaxy that then got sort of swallowed up by the bigger galaxy. And one thing that the researchers point out is that of course when you’re looking for black holes, centre of galaxies is a good place to look for them, but if you kind of account for all these sort of off-centre, secondary black holes in galaxies, that could actually increase the number of known supermassive black holes in the Universe by as much as 30%.
Host: Benjamin Thompson
So, by discovering this coming together then, it increases maybe the chances of seeing other such phenomena elsewhere in the Universe.
Host: Shamini Bundell
Yeah, finding this pair could be the start of a huge increase in the number of supermassive black holes that we know are out there in the Universe, and hopefully on future Briefings I shall excitedly be telling you about all the new supermassive black holes that have been discovered.
Host: Benjamin Thompson
Well, Shamini, why don’t I step up now and your story, you said a telescope in Chile was very much central to finding this pair, well let’s stick in Chile for my story, and this was reported in The New York Times and it’s from a paper that was published in Nature, and it’s about a new dinosaur that’s been discovered.
Host: Shamini Bundell
Yay, I love dinosaurs! We’ve got black holes and dinosaurs – this is an excellent episode. Is it one of my favourite kinds of dinosaurs? Like cool, raptor-like meat-eater, long necks? What are we talking about?
Host: Benjamin Thompson
Well, Shamini, this is quite a small dinosaur as things go, about six feet long, about two feet tall and estimated to be over 70 million years old, and its name is – apologies if I get this wrong – Stegouros elengassen and it is an ankylosaur.
Host: Shamini Bundell
Yes, wait, ankylosaurs have sort of got lots of sort of hard armoury bits all over their body and then a big club on their tail, maybe for whacking predators with.
Host: Benjamin Thompson
Well, Shamini, that’s the one that I think of as well. This one is kind of different, and it’s maybe opening up some questions and helping scientists to understand more about the evolution of armoured dinosaurs.
Host: Shamini Bundell
So, what’s weird about it then?
Host: Benjamin Thompson
Well, I think, number one, then, is that it doesn’t look like a lot of other ankylosaurs. So, it’s pelvis is actually sort of reminiscent of stegosaurs, but it’s teeth are reminiscent of ankylosaurs, and those are kind of related dinosaurs, so it’s a bit of a mish mash there. But you mentioned the kind of club tail, which I think is maybe what we think of when we think of ankylosaurs. But in this case, this new species has got a different structure on the end of its tail, which maybe was a weapon or what have you, and it’s one that’s never been seen before. And look out for a link to the story in the show notes so you can actually see what this looks like. But let me try and describe it to you. It’s kind of seven flattened kind of bony deposits that come out of each side of the tail and some of them are fused together, and they make this kind of shape, I guess, reminiscent of a palm frond. And one of the quotes in this article is amazing, that apparently a blow from this tail would be like being whacked in the shins by a battle axe apparently, so it’s certainly unusual to science, this structure.
Host: Shamini Bundell
Ouch, yeah. So, I’m looking at the photos in the article. It is really weird because, yeah, the plates just sort of stick out sideways like a double-sided axe, and you can imagine that could be quite a good weapon as an alternative to a club. I imagine they think this is still a sort of defensive structure.
Host: Benjamin Thompson
Well, yeah. In the title of the paper they call it ‘bizarre tail weaponry’ so I think that’s maybe the thought, but exactly whether it’s used for defence or if it’s used for showing off to other members of the species, that’s one of those things that it’s going to be really, really hard to ever answer, Shamini. But what this work does do, I think it sheds some new light on the evolution of these kind of armoured dinosaurs. Now, there are a range of types of ankylosaurs, but while ankylosaurs from the northern land mass of what was one the supercontinent Pangea are pretty well studied, those from the southern land mass, which contain what is now Chile, and it was the southern tip of Chile where this dinosaur was found, now these are a lot rarer and less well understood. And the researchers suggest that this new species has a couple of cousins maybe from the southern land mass, but they were much less well preserved than this current find, and so they’re using this to try and piece together the armoured dinosaur family tree.
Host: Shamini Bundell
Oh, so they’re trying to figure out how this one is related to all the other ones and how the dinosaurs are related to each other. I just kind of love that like because fossils are relatively rare, we’re still just discovering entirely new dinosaurs. It’s very exciting.
Host: Benjamin Thompson
Yeah, and what I didn’t know as well is that the sort of tail defences didn’t arise in evolution very often – I think there’s an ancient armadillo that’s got a weaponised tail – but they did arise a few times in the ankylosaurs. So, they’re pretty neat group of dinosaurs, no doubt, and I’m sure this is going to give more of a drive to look in these kind of southern areas for more of these dinosaurs to try and again piece together their family tree.
Host: Shamini Bundell
Well, that’s brilliant. Thank you, Ben. I always love it when you bring dinosaurs to the Briefing chat. Listeners, if you want any more of the stories that we’ve discussed, we’ll be putting the links in the show notes. And while you’re there, you’ll also see a link for where you can sign up to the Nature Briefing, and if you do that you can also get stories like these ones emailed directly to your inbox.
Host: Benjamin Thompson
And that’s all for this week’s podcast. But as always, you can keep in touch with us on Twitter – we’re @NaturePodcast. Or you can email us – podcast@nature.com. I’m Benjamin Thompson.
Host: Shamini Bundell
And I’m Shamini Bundell. Thanks for listening.