This week in science: gravitational waves, nature-inspired robots and Orca attacks
ARI SHAPIRO, HOST:
Time now for some science news with our friends at NPR's Short Wave podcast. Regina Barber and Geoff Brumfiel are here now for our science roundup. Good to have you both here.
GEOFF BRUMFIEL, BYLINE: Hi, Ari.
REGINA BARBER, BYLINE: Hey, Ari.
SHAPIRO: As usual, you've brought us three stories this week. Give us a tease.
BARBER: We've got a story about newly discovered gravitational waves and a new robot that borrows engineering from the natural world.
BRUMFIEL: And speaking of the natural world, we've got some ideas about why killer whales might be attacking boats off the coast of Europe.
SHAPIRO: I'm obsessed with those killer whales, but I'm a save-the-best-for-last kind of guy. So Regina, I know you love robots. Why don't you kick us off with that story?
BARBER: I do, but this new robot is unlike many we've seen before. Scientists describe it in the journal Nature Communications this week, and they're calling it the Multi-Modal Mobility Morphobot - or M4 for short.
SHAPIRO: This sounds like something out of "Transformers" - the Morphobot. What does it actually do?
BARBER: It's made to adapt in real time to different situations - like, think search-and-rescue operations - where time is crucial. It can combine two abilities - ground and aerial search - into one, and it has many more abilities. And one team scientist said that this could be revolutionary.
BRUMFIEL: If I had a dollar for every time I heard that something a scientist was building could be revolutionary, well...
SHAPIRO: Skeptical, huh?
BRUMFIEL: A little bit.
BARBER: (Laughter). OK, OK. But this new robot can perform eight specific tasks that help it adapt to all kinds of environments. Are you ready for all eight?
SHAPIRO: It slices. It dices. It even sautees.
BARBER: Yes, yes. It can roll. It can crawl. It can crouch under things. It can balance. It can tumble over objects. It can scout ahead, fly like a drone, and pick up things and transport them. It has these four wheels that help it do all those things, but sometimes it only needs two.
SHAPIRO: So basically, straight out of "Black Mirror." What does it look like?
BARBER: I think it's happier than "Black Mirror." But if you watch videos of this thing, it looks like a cart about the size of a - like, a medium terrier. And it has wheels that shift, so the robot can actually stretch like a cat in the sun. It's about as heavy as a chubby cat, actually, and it can limbo under things. And inside these wheels are propellers, so they rotate direction when it needs to fly like this big drone.
SHAPIRO: I mean, it sounds like, it's a bird. It's a plane. It's a cat.
BARBER: Yeah. Like, there's a whole natural world theme here. In fact, the scientists say they drew inspiration from all these different ways animals repurpose their limbs. Some they mentioned as inspiration in the paper were meerkats standing on their hind legs to kind of scout, birds that use their wings to crawl up inclines, sea lions that use their flippers to swim but also to walk on land. And as they work to move this beyond the prototype stage, it's all about repurposing what we already have. And also, I should note that this research was funded by NASA's Jet Propulsion Laboratory because shape-shifting robots like this might also be really useful in space.
SHAPIRO: Well, speaking of space, Geoff, for our second story, you have some news about giant gravitational waves. Tell us more.
BRUMFIEL: Yeah, indeed. So gravitational waves are, of course, wrinkles in the fabric of space and time itself.
SHAPIRO: Of course.
BRUMFIEL: You know, scientists have been hunting for them for the past decade or so, and now they found really compelling evidence for the biggest waves they've ever seen. These are similar in size to, like, the entire Milky Way galaxy.
SHAPIRO: This is bending my brain. What does such a wave even do?
BRUMFIEL: Yeah. I mean, basically, gravitational waves are created by distortions from really heavy objects. It kind of makes space and time itself wiggle like Jell-O. They were first discovered in 2015 using a bunch of lasers and mirrors in different parts of the U.S., and they've actually seen things like the collapsing core of a star that's about to explode. But the lasers and stuff only work for short wavelengths, and so they've had to come up with this really novel way of tracking down these super-long-wavelength, galaxy-sized waves.
SHAPIRO: How on earth do you measure a gravitational wave the size of a galaxy?
BRUMFIEL: Well, you don't do it on Earth. That's the answer.
SHAPIRO: Oh, OK.
BRUMFIEL: You have to go out beyond the Earth. And so they actually used a special kind of star called a pulsar.
BARBER: Yeah, I actually love pulsars. Fun fact - they're super-fast-spinning stars that are leftover stuff from explosions - supernova - and they send out radio signals like a metronome from their poles. And this signal, if it's towards us and we can observe it, they're like clocks in the sky.
BRUMFIEL: That's right. So this group called NANOGrav used 68 of these pulsars spread across the Milky Way. And basically, they watched them all really carefully to note any changes in how they ticked - how the sort of natural clocks ticked away. And then, by looking at how the ticking of these pulsar clocks changed relative to each other, they could actually detect the waves as they kind of wiggled the whole galaxy.
SHAPIRO: This sounds really cool, but what does it all mean, Geoff?
BRUMFIEL: Isn't the wonder of the universe enough for you, Ari?
SHAPIRO: I thought scientists always wanted meaning. Like, what does it do?
BRUMFIEL: Well, honestly, they kind of still don't know what it means. There's a couple of things. It could mean that they're catching the collisions of huge black holes billions of times the mass of the sun, or it could be a signal from the dawn of the universe itself. They've got to keep listening to try and figure it out. Anyway, we can talk about whales now.
SHAPIRO: Yeah, let's talk about whales instead 'cause...
SHAPIRO: ...Our third story's got real eat-the-rich vibes.
SHAPIRO: What's going on with the orcas?
BRUMFIEL: (Laughter) Right. So, you know, for people who haven't seen this, it's been happening for more than a year around the Strait of Gibraltar - this waterway that boats have to slip through to get from the Atlantic to the Mediterranean Sea and back. Pods of orcas have been attacking boats - biting off parts of a rudder or just sometimes ramming them.
BARBER: Yeah. Our colleague Scott Neuman looked into this recently, and he found that scientists and sailors say the attacks seem to be happening more. And it doesn't appear that anyone has been seriously hurt, but the question is why? Like, why are these orcas doing this?
SHAPIRO: It seems significant that this is only happening in one specific part of the world, right?
BRUMFIEL: Right. I mean, at least one scientist believes that a female leader of a group of about 40 orcas may have had, like, a traumatic experience with a boat or a fishing net, and that she's basically teaching her podmates to respond with aggression - to take revenge on other boats.
SHAPIRO: I want to guess who would play her in the movie. But I'm not going to compare any famous actress to a whale, so I'll just keep my mouth shut.
BARBER: (Laughter) It's like "Avatar" - the new "Avatar." But other scientists are skeptical of this idea because there are plenty of places around the world where orcas have interacted with people with boats and where they haven't seen them turn on boats like this.
BRUMFIEL: And another theory is that the orcas are just playing around - that they actually like how, like, a boat rudder feels on the back of their body, and so they bite the rudder. They're doing it because they're frustrated it's not moving.
SHAPIRO: Oh, like the way my dogs get frustrated when I stop playing with them when they have a toy.
BRUMFIEL: Yeah, maybe. I mean, that's the theory. But, you know, these are just theories, and scientists really don't know for sure what's going on.
BARBER: But we do know, according to this one study, that, since 2020, there have been more than 500 encounters between boats and orcas in this area. And they don't seem to be slowing down.
BRUMFIEL: So Ari, the next time you're on the ALL THINGS CONSIDERED yacht off the Iberian coast, just keep an eye out.
SHAPIRO: I think that's considered news you can't use.
SHAPIRO: Science correspondent Geoff Brumfiel and Regina Barber from NPR's science podcast Short Wave, where you can learn about new discoveries, everyday mysteries and the science behind the headlines. Thank you both.
BARBER: Thank you, Ari.
BRUMFIEL: Thank you.
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