Do radio waves attenuate and become noise or do they go on forever? [more inside]
posted by MrMulan on May 12, 2009 - 14 answers

First contact and apocalyptic sci-fi recommendations please. [more inside]
posted by turgid dahlia on Feb 2, 2009 - 44 answers

So, I've seen Sagan's Cosmos. I've seen The Universe. I've listened to Feynman's lectures on physics. What's next? [more inside]
posted by Optamystic on Apr 19, 2008 - 12 answers

I recall something that I believe I heard Carl Sagan say either in an episode of Cosmos or in one of his earlier books, that one could store enough information to hold an entire encyclopedia by putting a notch in a stick, if only one could measure where the notch lies to some absurd astronomically precise figure. Am I imagining this? [more inside]
posted by macinchik on Dec 6, 2007 - 14 answers

Carl Sagan filter: what is the thing that Carl is releasing into the wind so profoundly in this shot from the beginning of Cosmos? I always understood it to be a dandelion seed, but it doesn't look like one I would recognize... What is that thing?
posted by Gankmore on Oct 15, 2007 - 12 answers