Is anybody out there?

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Image from russellsastronomy.com.

The Fermi Paradox, named for the famed Italian physicist Enrico Fermi, asks a simple but profound question: Where is everybody?

In other words, are we Earthlings alone in the universe?

It’s not as simple as it seems.

As Fermi and, later, Michael H. Hart observed, given the overwhelming number of stars in the galaxy (and the universe), there’s a likelihood of a substantial number of Earth-like planets revolving around them — or at least planets that have the capability to sustain life. Some of those planets must have advanced civilizations capable of interstellar travel.

Right?

And yet, in the recorded history of humanity — which, admittedly, is relatively short given the age of our planet and the Milky Way galaxy in general — we have never been visited by extraterrestrials.

A couple years ago, I read a fascinating breakdown of the Fermi Paradox on Gizmodo, which was reprinting (so to speak) a Wait But Why? essay from Tim Urban. I stumbled on it again recently and ended up falling down an Internet rabbit hole (or, perhaps, a black hole) of debate and discussion. One story in Scientific American noted that the Fermi Paradox is miscredited to start with, since Fermi never even brought up the subject — not specifically, anyway. (He was allegedly making an observation about a New Yorker cartoon and wondering about interstellar travel, not civilizations.)

Be that as it may, it leads to a sobering group of hypotheses.

Maybe there are other civilizations out there, but they’ve chosen not to contact us. Frankly, I couldn’t blame them — humanity’s a mess! — but there’s no reason not to contact, say, dolphins. (Oh, how sweet it would be if Douglas Adams were right.)

Or maybe there are no advanced civilizations. They’ve fallen victim to the Great Filter, a hypothesis that argues that life can’t get past certain stages. Maybe that stage is single-celled organisms; maybe it’s something beyond where we are now. One recent paper suggested that life itself may create the kind of atmosphere that allows for more life — and, if it doesn’t, then the planet becomes lifeless.

Regardless, eventually life gets extinguished. And considering that humanity’s existence on Earth is a mere eyeblink in the 4.5 billion years of this planet, it’s logical to assume that we may have missed our connection with another civilization, which passed out of existence around the time of the dinosaurs.

(That brings up another concept, which is where such civilizations exist(ed). Alpha Centauri, the closest star system to our solar system, is more than 4 light-years away — meaning it would take more than four years traveling at the speed of light to get there. If another civilization is thousands or millions of light-years away, signals of its existence may not reach us for some time; hell, the light from its star(s) is taking eons to reach us. And even if those signals do find us, unless we’ve developed warp drive or hyperspace jumps by that point, good luck in visiting our new contacts.)

There are more positive theories. Maybe we have been visited already. Maybe the idea of physical contact is foolish to advanced civilizations. Maybe we’re just listening and looking in the wrong places. (Or — one more negative theory — maybe any advanced civilization is waiting for the right moment to add us to their cookbooks.)

It’s a lot to chew on.

Right now, life on the Big Blue Marble seems as fraught with uncertainty and challenge as ever. (There are theories about that, too.) It’s times like this that make me look to the sky and ponder the Fermi Paradox.

But I also think of something else. While we wonder if there are other civilizations out there, we should realize that we, too, are the remnants of the Big Bang. Billions of years of the universe are contained within our bodies.

We are, literally, all connected to the universe.

And that’s not a paradox at all.

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