Another Potential Solution to the Fermi Paradox | Vol. 3 / No. 32.4

A new(ish) paper up on the arXiv servers poses an interesting solution to the Fermi Paradox — basically put, if we’re normal, then we’ve got a while to wait.  | Photo: Hubble / NASA


The Fermi Paradox basically asks the question: “where is everybody?” In a universe as big as ours, with so many planets and so many stars, why haven’t we run into extraterrestrial life yet? The Wikipedia article on the so-called paradox lists a lot of possible explanations, everything from variations on “intelligent life destroys itself before it can communicate,” to “they really don’t want to talk to us, in particular,” to “we’re painfully, eternally alone in the universe.”

It’s based on a few assumptions, and one of them is that there are many billions of stars and planets that are much, much older than us. If that’s the case, why haven’t we found any signs of them yet?

Well, this new paper seeks to answer that question using something called the Mediocrity Principle, which, simply put, is that we’re not special. If you randomly select from a number of categories, you tend to select from the most populous category. Since we’re here, most life is like us. The Fermi Paradox actually relies on this principle itself — if we’re normal, then there should be more like us, looking for people like us.

Basically, using some mathematical modelling (and more than a few let’s say interesting assumptions) the authors conclude that the silence we’re perceiving is to be expected for hundreds of years yet. Essentially, there hasn’t passed enough time for the few expected civilizations in our galaxy (they estimate just over 200) to transmit signals far enough for it to be likely that we’d have encountered any — or that ours had been encountered — at least not yet. If, in 1500 years, we still haven’t heard from aliens, then we might start to worry a little.

As George Dvorsky points out in a great little explainer over at Gizmodo, there are a few problems with this line of thinking, part of which is that the Fermi Paradox actually expects aliens to have actually colonized the whole galaxy by now (not just tried to contact it), by traveling at sublight speeds on very very long journeys. But on the other hand, if most civilizations are like ours, they’ve got a ways to go before they dedicate themselves to the permanent colonization of the space between planets that such a style of slow colonization would entail.

As with all Fermi Paradox solutions (and the so-called paradox itself) it relies on a lot of guesswork assumptions, any of which could cause its conclusions to be wildly off, but it’s fun to think about anyway, isn’t it?

You can check out the paper at and read Dvorsky’s explainer at Gizmodo for more.


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Richard Ford Burley is a human, writer, and doctoral candidate at Boston College, as well as an editor at Ledger, the first academic journal devoted to Bitcoin and other cryptocurrencies. In his spare time he writes about science, skepticism, feminism, and futurism here at This Week In Tomorrow.