Transcript document

The Fermi Paradox and the Great Filter
Or, Why Isn't Anybody There?
By Kenny Bolster
The Great Filter


This term is taken from the paper “The Great
Filter – Are We Almost Past It?” (1998) by Robin
Hanson
A paper expressing a similar idea with
somewhat better readability is Nick Bostrom's
“Where Are They? - Why I Hope the Search for
Extraterrestrial Life Finds Nothing” (2008)
What is the Great Filter?



We don't see evidence of aliens
According to our calculations, we should have
seen evidence of aliens already
The Great Filter is whatever unknown factor(s)
is/are preventing civilizations from colonizing
the galaxy
Advantages of Colonization
How to Take Over the Galaxy
Colonization Speed



Average distance between stars: 5.4112 lightyears
Acceleration possible using solar sails for
interstellar travel: 1 mm/s^2
Total diameter of the galaxy: 120,000 ly
Colonization Time
10,077,066.666... years
In 13,000,000,000 Years...
The Drake Equation
Hanson's Argument
1.The right star system (including organics)
2.Reproductive something (e.g. RNA)
3.Simple (prokaryotic) single-cell life
4.Complex (archaeatic & eukaryotic) single-cell life
5.Sexual reproduction
6.Multi-cell life
7.Tool-using animals with big brains
8.Where we are now
9.Colonization explosion
How to Find a Filter
How Right is the Right Star?
That First Magical Molecule
Little Bugs
The Incompetent Predator
Why Do We Get Naked, Again?
Something Like Actual Aliens
Cave-Aliens with Clubs
Is It Safe to Come Out Now?
So What's the Total?
We need something on the order of:
1
300,000,000,000
What Else Could Go Wrong?
Final Thoughts