If the universe is so full of life, meaning billions of planets with billions of life forms each, which seems statistically probable, then why haven’t we made contact with any of our interstellar neighbors?
The answer you make up will deeply inform your fictional future. The answer we have yet to discover casts a dark shadow across our actual future.
“Two possibilities exist: either we are alone in the Universe or we are not. Both are equally terrifying.” – Arthur C. Clarke
There are three questions you have to answer to satisfaction in order to work out the future:
- What is the answer to Fermi’s paradox?
- How do we resolve the inevitable Robot Uprising?
- Is it possible to go Faster than Light.
This is about question #1.
Fermi’s paradox is not a formal theorem, and despite “common knowledge” has never been proven or disproven. It is a question to which we have no answer. Like Why do people still watch Gotham?
It does not spring from any formal scientific paper. Like Murphy’s Law, is is basically folklore. Enrico Fermi and a few colleagues were at lunch. Fermi has the New Yorker open to a cartoon about aliens [the one below – I think] and he wondered out loud “Where are they?”
This began a long conversation the wandered into speculative mathematical probabilities (The Big Bang Theory stereotypes are based on real people) about the likelihood of aliens, and even before Hubble, the gang concluded that there should or at least could be other alien civilizations, so why haven’t we met any?
The farther we creep out into space, both physically and electronically, the more puzzling this becomes.
The answers basically fall into three groups:
- Space and time are really vast and we haven’t been looking that far for that long.
- Aliens are too weird or too advanced for us to communicate with.
- We are alone.
Most people who think and write about this lump group 1&2, dividing the answers into They exist/ They do not exist sub-groups. However, the facts behind the vastness of space vs the puniness of our efforts do not eliminate either possibility.
The Search of Extraterrestrial Intelligence (SETI) has only been going on in a serious way since the 1970’s and even then inconsistently funded (it hasn’t seen federal money since 1986). This gives us a less than 50 light year search range, within which we have been selective due to constraints on resources. Pick any star you see in the night sky. Chances are, we haven’t seriously listened to it.
At that pace, the answer could remain forever a mystery until flying saucers actually land on our yards.
Let’s dispense quickly with the possible answers that make no sense:
If aliens are already among us, we’d know. The government isn’t that smart of over that long of time. We are not in a damn zoo. There are a host of crackpot websites that go to great length to claim the opposite, and this is not one of them.
If they visited in the prehistoric past, looked around, saw nothing of concern and left, we would never know, so that answer is basically useless – even if true.
In the other category, intelligent life cannot be rare, much less singular across the heavens. Hell, it isn’t even that rare on Earth. Dolphins use language. Octopi use tools. Ravens and apes use both. And that’s one snapshot of four distinct ecosystems across about a billion years of complex lifeforms, any one of which could have created some intelligent species which we have not uncovered. We’ll come back to this.
If you want a complete rundown of all the possible answers, I refer you to my sources. There are several good summaries, and I don’t mean to repeat them.
For my relatively optimistic space opera fiction I chose Nobody Listens to Radio But Us. More advanced aliens have developed some sort of quantum communication that works instantaneously across distance, and they no longer modulate anything i the EM spectrum because that takes too long. Radio is the galactic equivalent of smoke signals.
We encounter them physically before we ever make remote contact.
(How does the quantum communicator work? You handwave over the unobtanium.)
Several other answers can be made to work just as readily. If you are making up a future history, this is a required chore. Unless you decide there are no aliens, which can fit the facts, but presents an existential darkness problem.
If you read the sources they talk about the Filter, the as-yet-undetermined factor that prevents an explosion of space-faring civilizations. There are two versions: we are one of the rare species to pass it OR we have yet to hit it.
It may be that while life is common, complex life is rare, and us having spines and fingers and the like make us buy far the exception among the stars, and this is why we are lonely. That still fits within known facts, but I don’t buy it.
The human experience has been this: We think we’re unique. We look around to prove we are unique. We find out we are not special. We move the line until we feel special again.
I was told in grade school we are the only species with language and tools. You Tube can tell you differently in one or two search terms. And this requires no space-based observations, just perspective adjustment.
The answer that I am afraid is not fiction is that this barrier is real, and we are upon it. Earth is beginning a Sixth Great Extinction, and the variable is us, and our super-special technology.
Between global warming, the plastic layer, and just our callous regard for sustainability, we have shit in our own nest and set it on fire. You can shake your fist in denial, and I’m going to point to the rest of the world and say “scoreboard”.
It may be that highly-advanced technological civilizations kill ecosystems; that by the time you can scoot out into space, you have already doomed yourselves.
Time and space are vast, our efforts to find the neighbors are feeble, perhaps futile, leaving the answer to Fermi’s lunchtime distraction a long way off. I rather hope we will be around long enough as a species to discover it.
But that’s only a hope.
A lot of folks have given this thought. The first thing they note is that the Fermi Paradox is a remarkably strong argument. You can quibble about the speed of alien spacecraft, and whether they can move at 1 percent of the speed of light or 10 percent of the speed of light. It doesn’t matter. You can argue about how long it would take for a new star colony to spawn colonies of its own. It still doesn’t matter. Any halfway reasonable assumption about how fast colonization could take place still ends up with time scales that are profoundly shorter than the age of the Galaxy. It’s like having a heated discussion about whether Spanish ships of the 16th century could heave along at two knots or twenty. Either way they could speedily colonize the Americas
One possible explanation is that interstellar travel is just too costly. Consider how expensive it would be for us to populate another star system. Imagine sending a small rocket to Alpha Centauri, one that’s the size of the Mayflower (180 tons, with 102 pilgrims on board). Your intention is to get this modest interstellar ark to our nearest stellar neighbor in 50 years, which requires about 150 billion billion joules of energy.
Wait But Why lays it all out with lots of pictures.
Scientific American disbelieves.
University of Oregon takes a deeper dive.
Space.com – good listicle
Sixth Mass Extinction