Ask MetaFilter questions tagged with sagan

So ET won't be picking up the Olympic Games in 1936 Berlin?

MrMulan — Tue, 12 May 2009 11:18:32 -0800

Do radio waves attenuate and become noise or do they go on forever? In Carl Sagan's Cosmos and his novel Contact, he writes how radio waves go on forever. I just finished seeing the Discovery Planet special "Life after People", where in the closing segment, the narrator states that new research has shown that radio waves probably attenuate after 4 light years to become nothing more than noise. This occurs because of cosmic dust, radiation, planetary systems, asteroids, ect.

I thought radio waves go on indefinitely in a vacuum, and space is mostly a vacuum because of the distances involved, even with all the cosmic dust and whatnot.

So has another cherished belief of mine hit the dustbin?

No One Would Have Believed...

turgid dahlia — Mon, 02 Feb 2009 15:16:57 -0800

First contact and apocalyptic sci-fi recommendations please. I am a big fan of first contact science fiction, first contact being the moment wherein the human species – generally the protagonists – make contact with extraterrestrial intelligences or artefacts. I’m thinking along the lines of Sagan’s Contact, most of Stanislaw Lem’s work (The Invincible, Solaris, His Master’s Voice and the wondrous Fiasco), but particularly Clarke’s Rendezvous With Rama, Pohl’s Gateway, Budrys’ Rogue Moon and Bear’s Eon.

I find the latter sorts of stories particularly thrilling. An abandoned BDO (Big Dumb Object) filled with mysteries and terrors, which must be explored and scientifically understood. They are equal parts creepy and fascinating.

Of course, it doesn’t have to be an intelligence or an artefact. Baxter’s Moonseed was remarkable, and that was basically about a kind of dirt.

And for me, apocalyptic sci-fi (I’m thinking Footfall, The Forge of God, Blood Music, etc.) is great because it’s fun to watch the human race get wiped out, or nearly so. I know this is technically two questions but I figure science fiction aficionados would be happy to share their favourites in both genres.

So I guess I’m just after suggestions along those lines: hard (preferably) sci-fi about humankind’s first experience with a mysterious alien force, be it hostile, neutral, friendly, or simply extinct; and hard (preferably) sci-fi about humankind being taken to the very brink of continued existence.

Please God don't make me read.

Optamystic — Sat, 19 Apr 2008 18:39:36 -0800

So, I've seen Sagan's Cosmos. I've seen The Universe. I've listened to Feynman's lectures on physics. What's next? Are there any other television series that will rock my universe?

Help Figuring Out this Stick Thing

macinchik — Thu, 06 Dec 2007 20:18:37 -0800

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? Could have something to do with Anaximander, a pre-Socratic Greek philosopher.

This one has been bugging me for decades...

Pass it over here, Carl...

Gankmore — Mon, 15 Oct 2007 18:25:32 -0800

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?