Phil Plait: How Can Mistakes Lead To Scientific Advancement?

May 24, 2019
Originally published on May 28, 2019 11:16 am

Part 3 of the TED Radio Hour episode Setbacks.

About Phil Plait's TED Talk

When it comes to scientific research, mistakes are not only part of—but also crucial—to the process. Phil Plait explains how small setbacks can play a critical role in making big discoveries.

About Phil Plait

Phil Plait has gained a unique perspective on science and how the public understands it. He spent a decade working on data for the Hubble Space Telescope, and on public outreach advocacy for a half dozen different NASA astronomical satellites.

He's written books on scientific misconceptions, cosmic catastrophes and even a collection of satirical nerd insults, each showcasing his passion for science as well as his sense of humor.

His popular blog, Bad Astronomy, covers everything from interesting scientific events here on Earth all the way out to the edge of the observable universe. He's given talks about science around the world, he has appeared in several TV shows, including writing and hosting "Crash Course Astronomy," a 46-part introduction to astronomy on YouTube.

Copyright 2019 NPR. To see more, visit https://www.npr.org.

GUY RAZ, HOST:

On the show today - ideas about setbacks, failures and how to learn from them. And when it comes to something like science, mistakes can actually be pretty crucial to the process.

PHIL PLAIT: Oh, absolutely.

RAZ: This is astronomer Phil Plait.

PLAIT: You know, we get a biased impression of how science works from, for example, the media, like, you know, movies and TV shows where you get the lone genius idea, somebody scrawling away in their basement and then figuring out some huge discovery. It's not like that at all, for one thing. You know, you go to school. You have mentors. There are colleagues that you work with and talk to. You try to figure things out. But it's also not just this flash of insight that suddenly reveals everything. You have this idea. You try to figure out if it's right or wrong. You make a lot of mistakes along the way while you're investigating it.

RAZ: And not just mistakes but sometimes complete dead ends. Here's more from Phil Plait on the TED stage.

(SOUNDBITE OF TED TALK)

PLAIT: Many years ago, I was working on Hubble Space Telescope, and a scientist I worked with came to me with some data. And he said, I think there may be a picture of a planet orbiting another star in this data. We had not had any pictures taken of planets orbiting other stars yet. So if this were true, then this would be the first one, and we would be the ones who found it. That's a big deal. I was very excited. So I just dug right into this data. I spent a long time trying to figure out if this thing were a planet or not. The problem is planets are faint, and stars are bright. So trying to get the signal out of this data was like trying to hear a whisper in a heavy metal concert. It was really hard.

I tried everything I could, but after a month of working on this, I came to a realization - couldn't do it. And I had to tell this other scientist the data's too messy. We can't say whether this is a planet or not. Then later on, we got follow-up observations with Hubble, and it showed that it wasn't a planet. It was a background star or galaxy, something like that. Well, not to get too technical, but that sucked.

(LAUGHTER)

PLAIT: I was really unhappy about this, but that's part of it. You have to say, look; you know, we can't do this with the data we have. And then I had to face up to the fact that even the follow-up data showed we were wrong. Emotionally, I was pretty unhappy. But if a scientist is doing their job correctly, being wrong is not so bad because that means there's still more stuff out there, more things to figure out.

(SOUNDBITE OF MUSIC)

PLAIT: There are times when there's an idea, a fundamental idea, in science. And over time, the cracks start to show in it. And they're always at the edges. You know, it's not that big of a thing. But they start to pile up. And then it takes a long time for people to come along and say, we have an issue here. We need to figure out what's going on. Somebody comes along and drives a wedge right into those cracks and splits it right open.

I don't know how much farther I can push this analogy. But that does happen, and you have scientific revolutions. Quantum mechanics came about that way. Relativity came about that way. It's very difficult. It's generally a few things at first, and then they grow bigger and bigger, typically as we get more and more data, we get better equipment to measure the universe.

RAZ: Yeah. So has there ever been, like, a massive mistake in astronomy, like - like, in a public way that you can think of? And then how did people react?

PLAIT: Well, back in the 1990s - and even for decades before - one of the biggest questions we had in astronomy was are there planets, like the planets in our solar system, orbiting other stars? We figured there were other planets out there - but how to prove it, how to show it. So you can't just take a picture and show one. So what you have to do is you have to look for indirect effects as the planet is orbiting the star. And it's maybe tugging on the star. Maybe you can observe that tugging. And people had been trying it for years, and nobody had been able to do it.

Well, in 1991, Andrew Lyne and Matthew Bailes reported that they had actually detected this around not just a star, but what's called a neutron star. That is an extremely dense, very small object that is left over from a star that exploded as a supernova. Well, the beauty of neutron stars is that they spin at a very regular rate, and we can measure that spin very accurately. If there are planets orbiting an object like that, they will affect those measurements, and we can measure them.

And so what Lyne and Bailes announced in 1991 is that they had found this. They had found that a neutron star had planets orbiting it, and they were affecting the way the signals were coming from the star. It was super exciting. I mean, this is it.

RAZ: Yeah.

PLAIT: This is evidence of planets around another star. Well, then it turned out they had made a mistake. In all of the processing they had done to sort of get this signal out of their data, they had basically neglected to account for some of the Earth's motion around the sun, which affects their observations. And when they - when they realized that and put it in, their planet went away. And that was - as a scientist myself, that is something that is hard to grasp, how that must feel...

RAZ: Yeah.

PLAIT: ...When you realize that.

RAZ: After you announced it - you announced it to everybody.

PLAIT: Yeah, that's tough.

RAZ: Yeah.

PLAIT: So at another meeting some months later, Andrew Lyne basically had to stand up and say, yeah, about that result that we had, I apologize. We made a mistake. Here's the mistake we made. Here's how this all works out. When you process the data correctly, that planet disappears. Now, you can imagine a politician doing this and being ostracized from their party or...

RAZ: Yeah.

PLAIT: ...Somebody else admitting this mistake, and their company collapses or something like that. But that's not science. What happened at that moment was at that meeting, everybody started applauding. He got an ovation for saying this, for admitting his mistake and saying, you know, let's not make the same mistake again. He was supported by the scientists because they knew just how hard that admission was and how important it was that we understand what our data are actually telling us. So that, to me, says a lot about how scientists think and how science works.

And there's an addendum to the story that I love as well. Right after Lyne was done, another astronomer, Alexander Wolszczan, stood up and said, yeah, we actually observed this other pulsar. We processed our data correctly, including the part that the other guys missed. And yeah, we found a planet. And in fact, we found two planets. And it turns out, yeah, he was right. They found two planets orbiting this neutron star. A third one was found later. And those were, in fact, the first planets - well, at least announced - that turned out to be real, that were confirmed. And so the story has a truly happy ending.

(SOUNDBITE OF TED TALK)

PLAIT: And at that point, the floodgates were opened. In 1995, a planet was found around a star more like the sun. And then we found another and another. We kept getting better at it. We started finding them by the bucket load. We started finding thousands of them. We built observatories specifically designed to look for them. And now we know of thousands of them. We even know of planetary systems. This is incredible. Think about that. For all of human history, you could count all the known planets in the universe on two hands, nine - eight? - nine? - eight, eight.

(LAUGHTER)

PLAIT: But now we know they're everywhere. Every star - for every star you see in the sky, there could be three, five, 10 planets. We think that planets may outnumber stars in the galaxy. This is a profound statement. And it was made because of science. And it wasn't made just because of science and the observatories and the data. It was made because of the scientists who built the observatories, who took the data, who made the mistakes and admitted them and then let other scientists build on their mistakes so that they could do what they do and figure out where our place is in the universe. That is how you find the truth. Science is at its best when it dares to be human. Thank you.

(APPLAUSE)

RAZ: That's astronomer Phil Plait. He runs the blog "Bad Astronomy." You can see all of his talks at ted.com. On the show today, ideas about setbacks. I'm Guy Raz, and you're listening to the TED Radio Hour from NPR. Transcript provided by NPR, Copyright NPR.