Perhaps I spend too much attention on NY Times columnists, but they are very thoughtful, usually.
For instance, Farhad Manjoo recently wrote a hopeful op-ed about the beginning of the end of NIBYism in Berkeley, where I live, to help increase housing options this built-up city. I’m certainly in accord.
But could it be Manjoo also wants to find homes for extra-terrestrials, since his prior op-ed was about trying harder to search for them?….
When I was about eleven, slow moving because of asthma, Enrico Fermi pushed me up a hill. Maybe I can return the favor by pointing out exactly why Fermi’s famous Paradox about “intelligent life” elsewhere in the universe still holds.
Life has existed on this planet for three to four billion years, but numerous other sun-like stars that surely have earth-like planets are much older, so if they hold life, they might have held it for billions of years longer. Billions of years is a long time.
“Intelligent life”—in practice—means life that is capable of sending out signals or objects (or even themselves) that can be recognized as the products of intention or planning.
Humans have only been “intelligent,” by this criterion for barely a century. That was when radio broadcasting became commonplace. For over half that time, in addition, we humans as a group have been exploding nuclear bombs, sending out satellites and interplanetary probes, altering landscapes in gigantic ways — not necessarily so intelligent—but noticeable from afar.
Let’s assume it’s possible for “intelligent life” in this sense to continue to “progress,” whatever exactly that might mean, for millions or billions of years—thousand or millions of times as long as we have been noticeably intelligent.
Of course some could have been waylaid by going to into total Zen-like contemplation or addiction to drugs or video games or similar ills. Others could have succumbed to complete environmental degradation, pandemics, or horrendous and fully destructive warfare. But presumably some would manage to survive such temptations or crises. (After all, after the atomic bomb was first used, many prognosticators were predicting the human race would destroy itself quite soon; three generations later, at least, the danger seems to have receded a bit; we’ve perhaps learned not to risk everything in futile [major] wars.)
Those who made it past such dark prospects but who still have that million-fold kind of head start, would surely have been able to make their presence known to us—if they wanted.
If they wanted… Well, if they are like us, why wouldn’t they have wanted? Humans have been encountering other humans for thousands of years—exploring, trading, sending missionaries, conquering, enslaving, colonizing or simply anthropologizing—but very rarely being shy about making their interloping presence known. Even ethologists—who study animal behavior in the wild—don’t usually see reasons to hide entirely, though they try not to influence the animals they observe. After all, animals are used to the presence of different kinds of animals all around them.
Intelligent beings in any kind of system that keeps altering—presumably advancing, in some sense—must have to learn the culture they happen to be born into. That requires they pay and receive attention. There’s no reason to believe, then, that they wouldn’t face, as we do, the same kinds of scarcities and competitions for attention that I’ve described as The Attention Economy. They would probably be interested in us, not so much as directly a source of attention—any more than we see earthworms as that—but as objects of study that could get a few of them some attention—for their interesting discoveries about us. But meanwhile, why wouldn’t we be aware of them?
If other civilizations have developed way beyond us, they’d mostly have no reason to be afraid of making their presence known to us. If there are lots of other civilizations out there, surely some wouldn’t see any need to hide. On the other hand, any who did want to hide could certainly do a very good job of it, using techniques we could hardly imagine. Either way, there’s no point in our looking very hard for them.
In other words, it makes little sense for us to devote any substantial effort to locating extra-terrestrials. If they are there, we would already know—unless for some unfathomable reason they really wanted us to be ignorant of them. As I’ve outlined, they would hardly need to be afraid of us, nor would it bother them if we knew they were around observing us. It would have to be some other reason. Almost surely, the more interesting, surprising, and worrisome fact is that we have no clear evidence of any such beings—because they almost certainly are not there.
So, “Why isn’t there anyone out there?” is what we should still be asking.
One possible answer is this: Even with conditions on a planet much like that of Earth billions of years ago, life originating could be fantastically unlikely. If so, virtually all earth-like planets would not have life. Until we understand much better just how life originated on earth we have no basis for concluding this answer is wrong.
Or suppose that it is fairly easy for life to originate, but intelligent life in the sense meant here is not so easy, in fact highly improbable. We do have evidence for that, in that it took billions of years of life here on Earth for us—as the only representatives of the detectable sort of “intelligent life”—to emerge.
While contemporary humans are the only species to show the kind of intelligence that beings far way would be likely to notice or that our own searches “out there” might look for, zoologists see many of the hallmarks of (nearly) that sort of intelligence in a variety of other species, some of which are as social as early humans probably were, some of which utilize very simple tools, and others of which have vocabularies of a few hundred “words.” Some of them have been around with probably the same level of intelligence for far longer than humans have, but they never happened to combine just the attributes that together gave humans a chance to to develop our level of technology.
Octopuses, for instance have amazing learning abilities and capacities to deal with the world, though they are not social, and seem to have nothing like a learnable, changing culture. Yet there are many species of similarly intelligent octopuses, cuttlefish, and squid, which means that their sort of intelligence has probably existed for many millions of years, without ever crossing the divide to our current sort of intelligence.
We just don’t know what key evolutionary or cultural development (or developments) set humans on the course to become intelligent in the peculiar way we are, nor how probable that was. Ethologists (or evolutionary psychologists) have only recently learned that great apes can plan at least part of a day in advance, carry very simple tools around for that sort of time, and have complex social norms and lives. At some point, proto-humans began to walk primarily on two legs, allowing them to carry stuff around more easily. They also shed their fur so they didn’t have to be groomed as much, which perhaps gave them more time to do other things, such as to begin to make stone tools well in advance of any particular use. As their evolution continued, they further enlarged their abilities to distinguish categories of various kinds relevant to their lives, and presumably to increase their repertoire of abilities. Eventually that probably led to an enlarged use of what amounts to sign language, and then, among our immediate Homo sapiens forebears, to spoken language and so on.
But more odd turnings apparently still were needed. In many parts of the world, early humans independently went through what is known as the agricultural revolution., but that was still probably not enough. In a very recent work, The WEIRDest People in the World, anthropologist Joseph Henchin argues that what led to the “scientific revolution” of seventeenth-century Europe and to the industrial and technological revolutions of the nineteenth century—immediately responsible for us becoming “intelligent” in the sense already described—was a chance decision about 500 C.E., by what is now known as the Roman Catholic Church, to outlaw cousin marriage among the faithful. This led to the breakdown of previously nearly universal dominance of clan structures that prioritized traditional knowledge and practices. Maybe anything like the Catholic Church existing and making such an edict is incredibly unlikely. On the face of it, this institutional possibility doesn’t seem so completely against the odds, but who knows? In actual human history, it’s only happened once.
Could there be countless other planets with life, even with agriculture and the equivalent of medieval cities, etc. where nothing like the end of clan structures has ever led to “modernity?” Just possibly.
Perhaps the ultimate moral of this, though we don’t for sure know to what we owe it, is—we might be alone. We better take good care of this rare, precious inheritance.
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