It's time to open Door Number 16 of The Cosmic Shed Advent Calendar. You know the drill by now, you press play above or below, depending on how your page has set this out and what you are viewing it on. Alternatively, you download this episode to your phone or computer or Palm Pilot and listen at your leisure.
We'll pop some words here to hide the identity of today's guest(s) further down the page so you won't have the surprise spoiled when you listen. So far, we've enjoyed guests as diverse as singer songwriters, people who study the supermassive black holes at the centre of galaxies and people who played Cylons in Battlestar Galactica. Who will it be today?
Here's a picture to make the identities go even further down the page.
District 9 has been coming up a fair bit in the Advent Calendar
There's talk of Chemistry, X-Ray Crystallography and District 9, along with a song.
Guy and Tom.