Mycroft
Ministry of Serendipity
For the uninitiated, the Fermi Paradox (basically) posits that if an alien civilisation exists at all, we'd have seen some kind of evidence of it by now.
But this doesn't work for two main reasons:
1) The size of the universe
in relation to
2) The speed of light.
Now the closest star to us is the Sun. It's 150 Million Kilometres away and it takes light eight minutes to travel that far.
So the sun is 1.521 x 10^-5 light (0.000016) years away.
So it takes light 8 minutes to travel 0..000016. Now make that one light year. It now takes light 365 days to travel that one light year.
Now make that 100,000 light years (roughly the size of the galaxy).
Now make that 2.2 Billion light years (next galaxy)
Now make that 13.8 billion light years (theoretical size of the observable universe so far).
Why does the paradox fail?
Because even within the rather small scope of 100,000 years, an entire civilisation of aliens could have risen, and become extinct.
In 13 billion years, countless civilisations could have lived and died.
And light from those events wouldn't have reached the earth yet (and, indeed, may never will).
But this doesn't work for two main reasons:
1) The size of the universe
in relation to
2) The speed of light.
Now the closest star to us is the Sun. It's 150 Million Kilometres away and it takes light eight minutes to travel that far.
So the sun is 1.521 x 10^-5 light (0.000016) years away.
So it takes light 8 minutes to travel 0..000016. Now make that one light year. It now takes light 365 days to travel that one light year.
Now make that 100,000 light years (roughly the size of the galaxy).
Now make that 2.2 Billion light years (next galaxy)
Now make that 13.8 billion light years (theoretical size of the observable universe so far).
Why does the paradox fail?
Because even within the rather small scope of 100,000 years, an entire civilisation of aliens could have risen, and become extinct.
In 13 billion years, countless civilisations could have lived and died.
And light from those events wouldn't have reached the earth yet (and, indeed, may never will).