Hello and welcome to Backchat. If the Nature podcast is the established solar system we know and love,

backchat is a rogue exoplanet that you think you saw in your data, or maybe it was just wishful thinking and overtiredness.

It's the first Backchat of 2016. Did you miss us? I'll take that as a yes. We've been digesting the science news,

ready to bring you the tastiest morsels. I'm

Kerry Smith and I'm pleased to have with me, Davide Castelvecki. Hello, I am Davidi

Castelveki. I'm a physics reporter and also mathematics and computer science occasionally.

And also joining us, you and Calloway. Hello, I'm a life sciences reporter. I cover most recently chickens.

And Alexandra Witsy on the line from Boulder, Colorado.

Yes, hi. I cover Earth and Planetary Sciences, however you want to define a planet.

Excellent. We'll come to that.

Now, coming up, the selfish gene 40 years on, does Richard Dawkins' first and most

famous book stand the test of time? Ewan Calloway, DNA aficionado, has been reading the book

for the first time, ladies and gentlemen, and we'll be filling us in on how that has been going

for him. Also in the show, rumours in science. There are whispers again of an announcement

about gravitational waves, and Davidae is

ready to tell us later how true those rumours might be and how excited he is about them. And we'll

be talking about Planet X, not a new sci-fi film with Matt Damon, Moore's the Pity, but a potential

new friend for all the other planets in our solar system. In fact, Alex, I think we should just

start with this, since this is a story that seems to have completely passed me by before now. There's another

planet? Yeah, so this is a hypothetical planet that may exist, and it's absolutely gotten

everybody fascinated in this past week. What's happened is there's a pair of astronomers at

Caltech who say that based on the way other objects, very far distant objects in the solar system move, they think there's a big giant planet out there, kind of a gravitational bully, kind of pushing all these other guys around.

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