The Paradox
• “The belief that the universe contains many
technologically advanced civilizations, combined
with our lack of observational evidence to
support that view, is inconsistent. Either this
assumption is incorrect (and technologically
advanced intelligent life is much rarer than we
believe), our current observations are
incomplete (and we simply have not detected
them yet), or our search methodologies are
flawed (we are not searching for the correct
indicators).”
More Simply
• The view that there are advanced
civilizations is inconsistent with the fact
that we haven’t found any
This could be due to:
• There are either very very few or no other
existing advanced life forms
• We just haven’t found them yet
• We aren’t searching in the right way
Main reasons why other intelligent
life does not exist
• Inhospitable universe destroys complex
life
– Ice Ages, Meteors, Supernovae, Gamma Ray
Bursts
• Intelligent life destroys itself
– Nuclear War, Biological War, Malthusian
Catastrophe
• Intelligent life destroys others
– Advanced civilizations in the same galaxy
compete for resources and destroy each other
Spreading throughout the galaxy
• If an alien culture had the intelligence to
populate more than one planet, it would
inevitably populate the whole galaxy
– Manifest destiny
Enrico Fermi
• Italian Physicist
• Worked on beta decay
• Worked on the development of the first
nuclear reactor
• Helped develop quantum theory
• Won 1938 Noble Prize in Physics for work
on induced radioactivity