MARY LOUISE KELLY, HOST:
It's time now for our science news roundup from Short Wave. That is NPR's science podcast. I'm joined today by Regina Barber and Berly McCoy from the show. Hi you two.
REGINA BARBER, BYLINE: Hi.
BERLY MCCOY, BYLINE: Hello.
KELLY: As always, y'all have brought us three science stories that caught your attention recently. What do you have in store for us?
BARBER: So we have one story indicating that people might not be as good at detecting AI content as we think we are.
MCCOY: Plus another about a new, wandering supermassive black hole.
BARBER: And lastly, how pumas can make roads safer for humans.
KELLY: Let's take them in order. Start with AI and how we are lousy at detecting it. What kind of AI content are we talking here?
BARBER: So we're talking short stories. So this paper that was recently published in the journal Judgment and Decision Making included a few experiments. In the first one, participants read one of several short stories - some written by people, some of them AI-generated. Then they rated them. But here's the catch. Participants were either correctly or incorrectly told that their story was written by a human or AI.
KELLY: I feel like I would be great at this. I want to do it.
BARBER: I would be terrible at it.
KELLY: Berly?
MCCOY: Who knows? Everything's an experiment. In the other experiments that these researchers did, participants got a pair of stories. One was human-written and one was AI-generated, and they were asked to identify which was which. And these researchers found some key things. First, most participants couldn't tell which stories were AI-generated and which were human-written. And second, they tended to prefer AI stories, especially if they thought those AI stories were written by humans.
KELLY: OK. So what people said they preferred, human writing, and what they actually preferred was often different.
BARBER: Yeah, yeah. So this fits with a growing body of research suggesting that people's beliefs about AI involvement in a message influences how they feel about that message.
KELLY: Expectation bias.
BARBER: Exactly. So Deena Weisberg says that it's a sign that large language models have gotten a lot better over the past few years.
DEENA WEISBERG: I personally feel confident in saying this. The time has passed when it is simple to just be able to tell what a human has written and what an AI has written.
BARBER: Deena's an associate professor of psychological and brain sciences at Villanova University and the senior author of this study.
MCCOY: And now she did caveat that these results might be because of the length of these stories. So they were all around a thousand words each. And when we talked to some other experts in the field who have done similar research, they emphasize that length is often a key factor in our being able to detect AI-generated content.
We also talked to Mohit Iyyer, an assistant computer science professor at the University of Maryland, and he wasn't involved in the study, but he told us that because AI-generated content tends to be pretty formulaic, the longer they are, the worse their quality is.
KELLY: AI got nothing on Tolstoy. OK.
MCCOY: (Laughter) I know, right?
KELLY: Go back to the study 'cause I'm trying to figure out why. Like, why do people prefer AI-generated content?
MCCOY: Yeah. Deena had this hypothesis.
WEISBERG: The AI-written stories were very obvious and, I think, more predictable in their flow, which isn't surprising given how AI generates text. And the human-written stories were more difficult to read. They were more subtle. They didn't spoon-feed you the themes in quite the same way.
BARBER: So in that way, they're easier stories to read.
KELLY: Topic two. OK. So Berly and Gina, you said topic two is wandering, supermassive black holes. What even is that?
BARBER: Yeah. So supermassive black holes are these objects in space that are millions of times more massive than our sun. And all the ones, except for two that have been found, are in the center of galaxies - hence wandering. This is one of those two.
MCCOY: OK. But don't worry, Mary Louise, this wandering black hole is 750 million light years away from us.
KELLY: OK. So we got a little bit of time, but if it's that far away...
MCCOY: Yeah.
KELLY: ...How did they find it?
MCCOY: It ate a star.
KELLY: It ate a star?
BARBER: Yeah.
KELLY: Poor star.
BARBER: Yeah.
KELLY: And now I'm nervous again.
BARBER: No, no, no. Don't be. It's fascinating, really, 'cause it's most likely not really, like wandering, like you said. It's not going to come towards us. It's really probably orbiting a very, very far away galaxy. Usually, black holes are invisible unless they're feeding on something. So the way scientists detected this one was by observing a flash of light created when the black hole ripped apart and ate a star.
JILLIAN RASTINEJAD: It's like this little black hole holds up a flashlight, and is, like, here I am. Look at me.
MCCOY: So that's Jillian Rastinejad an author on the paper that came out in the Astrophysical Journal Letters about this black hole. And her colleague, Robert Stein, at the University of Maryland, trained an algorithm to recognize the pattern of these special light signatures that indicate that a supermassive black hole ate a star.
ROBERT STEIN: They are very rare, but we started to find them in the centers of galaxies. And what we did was we trained the AI algorithm to recognize this very characteristic pattern of light.
KELLY: Regina, stay with that point he just made, that these are very rare. Why have scientists only found two of these black holes "wandering"...
BARBER: Wandering.
KELLY: ...I'm using air quotes...
BARBER: Yeah.
KELLY: ...Wandering outside galaxies?
BARBER: Yeah. So that flash of light is rare, but on top of that, we were only looking for those flashes of light in the center of galaxies. And it kind of blew my mind that astrophysicists - we never thought to look at anywhere else until Yale theoretical astrophysicist Priyamvada Natarajan and her team proposed the possibility of wandering supermassive black holes and how to find them with this, like, special light signature. And she says this discovery is a huge leap forward to learning more about black holes, which are still pretty mysterious.
PRIYAMVADA NATARAJAN: But it looks super exciting, right? So you could find dozens and dozens per year. That's our prediction.
KELLY: Let me drag us back to Earth.
BARBER: Yeah.
KELLY: Topic three, which is how pumas could make roads safer for human drivers. And we should say a puma, that's - what? - it's a mountain lion, right?
MCCOY: Right. Or they're called cougars sometimes, too.
KELLY: OK.
MCCOY: So here, the researchers looked at puma movement in the Olympic Peninsula in Washington State, and they found where these big cats were most active, the number of vehicle deer collisions were 76% lower than in areas where pumas were least active.
KELLY: Seventy-six percent lower - that's huge. OK. Vehicle deer collisions, 76% lower. Is that because - why? - 'cause pumas are eating the deer, there's fewer to hit?
BARBER: So I thought that, too, but it's not that. So researchers controlled for deer numbers and still found this huge difference in collisions. And the team says it's because the pumas are likely changing deer behavior both by prompting deer to be more active during the daytime, which makes them more visible to people driving versus in the nighttime, and by pushing them to more remote places away from roads.
KELLY: That's interesting. Why are pumas pushing them away from roads?
MCCOY: So the researchers think it's because roads break up the landscape and make for really effective hunting grounds for pumas. So think about, like, a road by a forest. The road is essentially a place the deer would be out in the open. Meanwhile, a puma could be hiding in the forest, waiting to ambush them. So the deer avoid it, opting for more secluded areas. And this study was recently published in the journal Current Biology.
KELLY: I'm thinking about applications. I'm guessing y'all are not about to tell me we should just release a bunch of mountain lions to make our roads safer?
BARBER: Yeah. Not quite yet, or maybe ever. But lead author Justin Suraci from Conservation Science Partners said it could add to the conversation some people are having in places where pumas are starting to come back naturally.
JUSTIN SURACI: And, you know, one response to that could be, it's a predator, get it out of here. But another response could be to allow that natural recolonization to occur. And I think this at least provides an argument in favor of that.
MCCOY: Otherwise pumas coming back could be a hard sell to folks who may be worried about safety or hunting competitors.
KELLY: Fascinating. All right. We've been speaking with Berly McCoy and Regina Barber from our science podcast Short Wave. Thanks you two.
BARBER: Thank you.
MCCOY: Thanks.
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