As the story goes, famed physicist Enrico Fermi looked up one starry night, noticed thousands of visible stars and the billions more they represent, and wondered “Where is everybody?”
If the physicist knew then what we know today, might he have asked that famous question? Fermi, who died in 1954, certainly missed a lot of recent developements in the field.
For no particular reason, I have been mulling that over quite a bit lately. I can construct a fairly detailed argument that:
a) life is not all that rare in the universe; indeed, it may be relatively common.
b) intelligent, technologically advanced life, OTOH, may be exceedingly rare.
As an exercise, I started jotting down a list of things that made Earth if not unique, then at least the result of a relatively rare sequence of events that perhaps makes it a somewhat special. Size, solar system sweet spot, non-binary star, galactic location, core composition, magnetic field, rotation, axis, moon, etc.
I was most of the way through assembling my list when in my research I stumbled across a book titled of all things, Rare Earth: Why Complex Life is Uncommon in the Universe.
Written by paleontologist Peter Ward and astronomer Donald Brownlee. They make the case in far greater detail than I could ever assemble that complex life is indeed uncommon in the universe. My list making was brought to a halt, and I just ordered the book.
I had never heard of the Rare Earth thesis before — has anyone else? Regardless, it appears consistent with much of what we have learned about cosmology since Fermi’s death.
I am curious:
What interesting issues, questions, theses – outside of your chosen profession, expertise, or area of study – are you thinking about?