Hello everyone, welcome to the Mindscape Podcast. I'm your host Sean Carroll. The thing about science,

as with many other intellectual areas, is that there are a whole bunch of interesting questions out there,

and the questions linger on, but the rate at which we make progress on different questions is highly variable.

We can have a question sitting around for a very long time and not a lot of progress is made,

and then suddenly things change extremely rapidly. So there are fields of science,

really tiny or really big subfields, that are undergoing tremendous revolutions even as we speak.

And one of these is the study of exoplanets, planets around stars other than our sun.

When I was in graduate school, we didn't have any exoplanets. None had actually been discovered.

These days, over 5,000 exoplanets have been discovered. So there's a lot to say about this whole science,

not just what the exoplanets are, what their characteristics are, but of course we're going to care about the possibility of life on other planets.

But let's not skip right to the weird stuff about life and aliens and things like that. Let's get down and dirty.

Let's ask, how do you go about finding exoplanets in the first place?

Today's guest, John Asher Johnson, literally wrote the book on this subject. He's the author of,

how do you find an exoplanet, which is sort of a semi-technical book. If you are happy with a couple of algebraic equations,

you'll get a lot out of it. And in the book, he goes over all sorts of different ways, because there's more than one method

for finding planets around other stars. You can look at the wobbles of the stars,

you can look at transits, little eclipses, you can look at gravitational lensing, and so forth.

We now have not just planets that we found with telescope space here on Earth, but also missions on satellites that are dedicated to finding new planets.

And as I'm recording this, we're in the process of ramping up the James Webb Space Telescope, JWST,

which will be really, really able to examine exoplanets with much higher precision than we've ever done before.

So finding them is one thing, studying them is yet another one.

So I talked with John about where we are, how we got there, where we're going to go in the near future,

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