Today, we present the third and final installment of my interview British astronomer Stephen Webb on the subject of Fermi’s paradox. Please check out parts one and two if you missed them. Otherwise, press play on the embedded player, or pull up the transcript—both of which are below.

We open by talking about some of the amazing instruments and projects that are coming online in the coming decade—both to extend the search for extraterrestrial life and to advance the much broader field of astrophysics. There’s some profoundly exciting gear on the horizon, which will do business under such wild and whimsical names as “The Extremely Large Telescope.”

We then talk about some of the signals this new apparatus might detect, which could be highly suggestive of life. Either oxygen or methane in a distant planet’s atmosphere would be electrifying, but not entirely definitive proof. Both of them together put the matter beyond a reasonable doubt (although there would still be many doubters, to be sure).

The episode concludes with a conversation between me and Tom Merritt, who you may know from his decades of presenting tech news to the world on CNET, TechTV, Leo Laporte’s family of online shows, and now through his very own Daily Tech News Show.

At the end of the early episodes of my podcast (and this is one of them), Tom and I would discuss how the day’s subject ties to the novel After On—and Fermi’s paradox indeed figures into its storyline. We would also talk about the interview itself with minimal reference to the novel. For this serialization on Ars, I’ve cut out the first part of our wrap-up conversation. A couple of passing mentions of the novel remain, but these are not spoilers, and you won’t get lost in the conversation if you haven’t read it.

If you enjoy my interview with Stephen Webb, please consider browsing the full archive of the After On podcast on my site. Alternatively, you can find it in your favorite podcast app simply by searching for “After On.” I’ve posted deep-dive interviews with dozens of world-class thinkers, founders, and scientists—tackling subjects like cryptocurrency, astrophysics, drones, genomics, synthetic biology, neuroscience, consciousness, privacy & government hacking, and a more.

Last, if you’re curious about the latest episode in the main After On podcast feed, this week we have an interview with a chemist and DNA architect named Floyd Romesberg.

If you have any recollection of your high school biology, you probably know that DNA is written in an alphabet of just four letters. Floyd has added two new entirely artificial letters to that ancient alphabet. The science is amazing, the ramifications could be astounding—and on top of that, it’s just a great conversation. Click right here to hear it, or search for "After On" in your favorite podcast software.

And of course, I hope you’ll join me here again on Ars next week, when we’ll be serializing another episode from my podcast’s recent archives.

This special edition of the Ars Technicast podcast can be accessed in the following places:

iTunes:

https://itunes.apple.com/us/podcast/the-ars-technicast/id522504024?mt=2 (Might take several hours after publication to appear.)

RSS:

http://arstechnica.libsyn.com/rss

Stitcher

http://www.stitcher.com/podcast/ars-technicast/the-ars-technicast

Libsyn:

http://directory.libsyn.com/shows/view/id/arstechnica