What is the Fermi Paradox?

Question

Please literally explain it like I’m 5! TIA

Edit- thank you for all the comments and particularly for the links to videos and further info. I will enjoy trawling my way through it all! I’m so glad I asked this question i find it so mind blowingly interesting

In: 4425

Answer 1

Other responses have gotten the basic framing correct: Our galaxy is large, and much of it is much older than our Solar System. Taking basic wild-ass-guesses at various parameters that model the probability of intelligent life forming in the galaxy, we’re left in a position that it seems likely that it has developed. If the civilizations don’t die out, it ‘should’ be possible to have some form of probe/ship/exploration spread out over the galaxy in something on the order of 100’s of thousands of years, which really isn’t very long in comparison to the age of the galaxy.

We don’t see any evidence of this type of activity at all. This is the ‘paradox’ – it ‘should’ be there, but it isn’t.

Where the Fermi Paradox gets it’s popularity though is in the speculation around “Why don’t we any signs”. There is seemingly endless debate possible. To wit:

– We’re first. despite the age of the galaxy, we’re among the first intelligent civilizations, and nobody has been around long enough to spread.

– We’re rare. Variation on the above – intelligent life just isn’t as common as we might think.

– There is a ‘great filter’ that kills off civilizations before they can propagate across the galaxy.

– The Dark Forest: There is a ‘killer’ civilization that cloaks themselves from view but kills any nascent civilizations to avoid competition. (Or, an alternative version is that everyone is scared of this happening, so everyone is hiding)

i think the Fermi Paradox frequently seems to get more attention than it deserves, largely due to the assumption that spreading across the galaxy is an inevitable action for an advanced civilization. I’m not entirely convinced of this – if FTL travel isn’t possible (and I don’t think it is), then the payback for sending out probes/ships to destinations 1000’s of light years away seems to be effectively zero, and so I don’t see how it’s inevitable. But, there’s no question it generated a lot of lively debate.