My thoughts on the Fermi Paradox.

Chances are if you clicked on this article, you already know what the Fermi paradox is, but if not, here is a summary:

There is an inconceivable number of galaxies, solar systems, and planets all throughout the universe, and since the universe has existed for approximately 13.8 billion years, surely other civilizations would have evolved by now and been able to contact us with some form of electromagnetic radiation or even be able to come here. Yet, we see no conclusive evidence of alien life, so why is that?

This question is called the Fermi paradox because some form of this question was asked by the physicist Enrico Fermi in the summer of 1950. Ironically, Fermi’s work in developing the atomic bomb might actually be the answer to his question, but I’ll get to that later.

First of all, it is important to recognize a few key things:

1. The conditions necessary for life were only present billions of years after the big bang, due to the more extreme conditions shortly after the big bang, and due to the fact that heavier elements only existed after massive stars went supernova and blasted their guts into the universe, which took a little while, and possibly after neutron stars collided, and spilled their guts into the universe.

2. As you look further away from Earth, you are looking back in time, so for every n light years away from Earth we look, we are looking n years into the past. Any civilization that started sending radio waves out at around the same time we did that is over 150 light years away from us would be invisible.

3. Life on Earth developed very soon after it first formed, but it took billions of years for multicellular life to develop.

4. There are several species on Earth with near-human intelligence, complex social connections, and the ability to create tools (chimpanzees or elephants, for instance), but none of them have built computers, gone to the moon, or invented pizza.

5. We still might end up destroying ourselves :(

Based on these things, we can assume that:

a. Life probably didn’t develop much longer before it did on Earth.

b. Any civilization is likely to be too far away for us to detect.

c. It takes a long time for life to become multicellular.

d. Even an intelligent, social life form might not want to or be capable of inventing anything more than a simple tool.

e. Even a civilization such as ours isn’t guaranteed to survive that long, however, since we have sent radio waves into space, even a species as advanced as us should still be able to send some signal out there, so this isn’t really a solution.

On a slightly different tangent, it is assumed that there are various “filters,” events that prevent life from becoming intelligent civilizations, and perhaps a “great filter” which is, naturally, the greatest filter.

I will briefly sum up the more disturbing option for the great filter, which is that civilizations all end up getting destroyed by *inhales* nuclear war, climate change, a massive asteroid impact, solar storms, magnetic pole reversal, population collapse due to lack of reproduction, a super-intelligent AI that wreaks havoc, or something else that I didn’t consider.

Now that we got that over with, let’s discuss more optimistic great filters. Since we have yet to discover life on other planets, based on our knowledge, the great filter is simply that it is just really, really unlikely for life to form even given the right conditions, and Earth is just lucky.

If we discover single-celled life forms on other planets (Mars, for instance), then that means that the great filter (based on our knowledge) is the difficulty of multi-cellular life development, if we discover multicellular life the great filter is the difficulty of intelligent life development. If we discover intelligent life, then the great filter is the difficulty for intelligent life to create a civilization, and, if we find an intelligent civilization, the Fermi paradox no longer applies.