Today we present the second installment of my interview with British astronomer Stephen Webb on the subject of Fermi’s paradox. Part one ran yesterday—so if you missed it, click right here. Otherwise, you can press play on the embedded player or pull up the transcript—both of which are below.

This time, we open by talking about the second large category of possible solutions to the paradox: that intelligent aliens are out there, but we just haven’t detected them yet. Webb's book Where Is Everybody includes freestanding chapters on 25 such solutions, but of course we only tackle a subset here.

We then go on to the third major category—which is that we are quite alone in our galaxy, and perhaps in the entire universe. This idea tends to be a dismaying possibility to science-fiction authors like me (and is inimical to the entire premise of my first novel!). But it can also be seen as an optimistic—and indeed even relieving—interpretation. Stephen and I discuss why.

Stephen then lays out the solution to Fermi’s paradox that he personally deems to be most plausible. No spoilers here—please listen to the recording!

If you enjoy this installment and just can’t wait for Part 3 (which goes up on Ars tomorrow), you can find it in my podcast feed, where it first appeared in September of last year. A full archive of my episodes can be found on my site, or via your favorite podcast app by searching for “After On” (the podcast’s title).

There you’ll find deep-dive interviews with other world-class thinkers, founders, and scientists—tackling subjects including synthetic biology, cryptocurrency, astrophysics, drones, genomics, neuroscience, consciousness, privacy & government hacking, and a whole lot more.

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