The Fermi Paradox - Part 1

This post is intended for those unfamiliar with the Fermi paradox. If you've already read a thing or two about it, I invite you to skip this one and wait until Part 2.

This is a companion post to Episode 2 of the Wow! Signal Podcast.  You can go over there and get the audio version with cool music.

For the purpose of this post, we are going to take as a given the null hypothesis about alien visitors to Earth - that this has never happened.  This is what the controversial astrophysicist Michael Hart called Fact A.

It turns out that accepting Fact A presents an interesting dilemma; first recognized by the distinguished physicist Enrico Fermi in 1950.  The unsolved problem is, that we would expect alien visitors on our planet, given a set of very reasonable assumptions. It’s really not such an extraordinary claim, after all. Assuming Fact A, this presents us with a puzzle. Either one or more assumptions have to go, or something really weird is going on.

Douglas Adams once famously wrote:

"Space is big. You just won't believe how vastly, hugely, mind- bogglingly big it is. I mean, you may think it's a long way down the road to the chemist's, but that's just peanuts to space."

But space is also hugely old The entire history of Homo Sapiens is only about one twenty-thousandth the age of the Earth, and the age of the Earth is less than a third the age of the universe. What would seem to be likely is that at least local to our galaxy, time eventually overwhelms space with respect to galactic colonization.

Did the Hitchhiker's Guide to the Galaxy Get It Right?

The late, great DNA

More than 30 years ago, Douglas Adams wrote his famous Hitchhiker's Guide novels around the idea that the Earth was a giant, purpose built computer simulation intended to answer a question (actually, to question an answer) of staggering difficulty.  Of course, this was all in good fun, but the idea is actually very interesting.

Maybe Adams just didn’t think big enough.  There has been much discussion in the last few years about whether our entire universe is in fact a computer simulation (by hyper intelligent, pan-dimensional mice, if you like).  This was first seriously proposed in a 2003 paper by Nick Bostrom,  We don’t know how to build or program such a computer ourselves, but we can imagine that it could be built, and if our universe is a simulation, there is no way to know what actual constraints might exist.  

What Life on Mars Could Mean

I am optimistic that some time in the coming 30 years we will discover strong evidence that life once existed on Mars, or even exists now.  If you ask Gilbert Levin, he'll tell you we already have that evidence from the Viking lander's Labeled Release experiment.

This is nothing new to those who follow the discussion on Mars life,  but if we do find Martian life, past or present, it could have any of four possible implications for the origin of life, in ascending order of fascination:

1. Life originated on Earth and migrated to Mars on Meteorites.
2. Life originated on Mars, and migrated to Earth on Meteorites
3. Life originated somewhere else (probably Venus), and migrated to both Earth and Mars.
4. Life originated independently on both Earth and Mars.

Number 4 is by far the most interesting of the four possibilities.  It implies that the origin of life is not a rare event.

If not Mars, then we hope to reach this conclusion by studying Enceladus, Titan or Europa.  The odds of cross-contamination there are much reduced.  Is it possible, that whenever you have a sufficiently diverse mix of ingredients in sufficient amounts, and a stable flux of energy through a system for a long time, that the chemistry progressively gets more complex and eventually some of it becomes self replicating?

If so, then probably then entire universe is teeming with life, and some of it is looking at us and wondering; who's there?