As both a con­sumer and pro­ducer of SF, I con­fess to being enam­ored of the idea that there is extrater­res­trial life out there. I get a kick out of the idea of Little Green Men in small, disc-​​shaped craft flit­ting hap­pily from star to star, and I like the way SF per­mits us to ques­tion our­selves in ways that many other enter­tain­ment gen­res do not.

Films such as The Day the Earth Stood Still — and tele­vi­sion shows such as the Twilight Zone episode “The Monsters are Due at Maple Street” — served an extra­or­di­nar­ily cru­cial social need, ques­tion­ing the wis­dom of bel­liger­ence, the mer­its of clan­nish ten­den­cies, the value of naked aggres­sion in the face of the unknown.

The orig­i­nal Star Trek series served the dual pur­pose of being American democratic/​progressivist pro­pa­ganda and show­ing us a future, sug­gest­ing that human­ity had a future — and in the late 1960s, that was not a given.

Movies such as E.T. can reach deeply into the com­pas­sion of the human, let­ting us see as beloved that which is least human — yet, graced with intel­li­gence, still rec­og­niz­ably kin to us.

Nevertheless, as much as I enjoy such fare, I have to rec­og­nize at the end of the day that it is not, strictly, sci­ence fic­tion; it’s closer to fan­tasy. Even my belief in extrater­res­trial life is merely that; it’s a con­fes­sion of faith, not any­thing I can ratio­nally ground in the plausible.

I’m intro­duc­ing a new cat­e­gory of post at TI with this writ­ing: UFnO. It’s going to deal exclu­sively with why I’m essen­tially cer­tain that Earth never has been vis­ited by extrater­res­trial life, is not now being vis­ited by extrater­res­trial life, and — here’s the kicker — never will be vis­ited by extrater­res­trial life. Along the way I’ll be going into why, exactly, I don’t believe we will ever encounter intel­li­gence in the uni­verse, regard­less of how advanced we become.

I don’t cur­rently have any plans to actively pur­sue claims on an indi­vid­ual basis. I don’t really think it’s nec­es­sary. For instance, show­ing how at least some “crop cir­cles” have been made by very human pranksters, I believe, effec­tively casts doubt on the non­hu­man ori­gins of all “crop cir­cles” by rais­ing the par­si­mo­nious like­li­hood that any one “crop cir­cle” might have been pro­duced by a human agent.

That is, it’s much more likely that any one “crop cir­cle” was made by a human or group of humans than that it was made by aliens or spooky super­nat­ural forces that we have yet to dis­cover, since we know for a cer­tainty that humans make “crop cir­cles”, but we have yet to con­firm that aliens have ever made one.

Thus debunk­ing “crop cir­cles” indi­vid­u­ally becomes a waste, and could become obses­sive. And, as any­one who pays atten­tion to the net knows, the last damned thing we need is another obses­sive Web site.

I’ll begin by play­ing fair and debunk­ing my own faith in life off of Earth — or, more accu­rately, show­ing exactly why it’s faith, not a sen­si­ble or defen­si­ble per­spec­tive to believe that there may be life out there somewhere.

The First Problem: Paucity

Let’s start with what we know, what we can be totally cer­tain of: Life exists here, and doesn’t seem to exist any­where else on any of the plan­ets or moons within our reach in this solar sys­tem. There may be some places in Sol’s demesne where life could have gained a toe­hold once (Mars); there may be places where some form of life — as we’d rec­og­nize it — may be eking out an exis­tence now (Europa); how­ever, there is only one world within our detec­tion radius that inar­guably is teem­ing, and we’re cur­rently on it.

(I’m aware that there are some who would argue that life could take forms other than the carbon-​​based that we rec­og­nize, but until some­one with the appro­pri­ate degrees in the appro­pri­ate sci­ences can clearly demon­strate how such non-​​carbon-​​based human-​​recognizable life could exist, let alone what it would resem­ble, I’ll rel­e­gate such objec­tions to the realm of the suf­fi­ciently improb­a­ble to ignore. This could be arro­gance, but to me it’s sim­ply prac­ti­cal. As soon as we open the door to, say, “sen­tient energy”, we quickly find our­selves bogged down in all sorts of silly ideas.)

This doesn’t tell us as much as would be desir­able. We really can’t infer a damned thing from the appar­ent rel­a­tive steril­ity of our solar sys­tem, but we can infer that there must be at least some con­di­tions in place before life can really be expected to appear.

The first is some kind of sta­bil­ity, but it doesn’t have to be over­done. Life is aston­ish­ingly robust, sur­viv­ing in con­di­tions here that are, in some cases, incred­i­ble. There are bac­te­ria that live near sub­o­ceanic vol­canic vents, thriv­ing in the dark­ness in water that would poach any fish — or human — that got close. This sug­gests that con­di­tions for the devel­op­ment and per­sis­tence of life might not be par­tic­u­larly frag­ile, which could give us rea­son to hope that, even­tu­ally, we’ll find traces on Mars which sug­gest life did exist there, at least for a while.

What can’t hap­pen is total envi­ron­men­tal col­lapse, which absolutely did hap­pen on Mars. The atmos­phere leached away, and along with that went liq­uid water and, if they ever existed, any­thing that had been able to develop and evolve in the early morn­ing of our solar sys­tem. Take away water and (pos­si­bly) some kind of air, and you’ve basi­cally guar­an­teed extinction.

The sec­ond pre­req­ui­site for life appears to be water. There isn’t a hell of a lot of that in liq­uid form any­where but on Earth; it’s fea­si­ble that Europa may have liq­uid water some­where under its lay­ers of ice, and pos­si­bly enough raw mate­ri­als to even sus­tain life, assum­ing it got started there.

But that leads to a first major ques­tion about life. We have an idea what con­di­tions it needs to sur­vive — liq­uid water seems to be the bare min­i­mum, plus of course nutri­ents and such — but we don’t know exactly what it needs to get started. Did life begin with RNA? Or with RNA-​​like pro­teins moil­ing about in some rich pri­mor­dial broth? Well, how, exactly?

Crystaline lat­tices in clay, for exam­ple, are inter­est­ing to dis­cuss, but if they were what taught RNA how to be RNA, what does that say about the like­li­hood of life else­where in this solar sys­tem? Does Europa have clay deposits? Did Mars?

Life appears to be robust — but there are some pretty good cir­cum­stan­tial rea­sons to think it might be rare.

The Second Problem: Scale

What does rar­ity mean, though, in a galaxy as large as (for instance) the one we inhabit? The Milky Way con­tains some­thing between 200 to 400 bil­lion stars, of which per­haps 60 to 120 bil­lion are suf­fi­ciently like our own to pro­duce con­di­tions sim­i­lar to what we find in our solar sys­tem. (Yes, I real­ize that sec­ond link is to an analy­sis of the Drake Equation, which I’m pre­sent­ing here in a less numbers-​​intensive way.) We have to take into account that our solar sys­tem might lie in a hab­it­able galac­tic zone — if so, we may be left with a pal­try 20 to 40 bil­lion stars that could have life-​​sustaining plan­ets orbit­ing them.

That’s a huge num­ber, though, of stars like our own that may have worlds like our own orbit­ing them. An absolutely huge num­ber, which would make it seem almost cer­tain that mil­lions, per­haps bil­lions, of them have ter­res­trial plan­ets — on which one, surely, life may be found. Right?

Guardedly, yes … or at least maybe. It’s plau­si­ble, it’s not infea­si­ble, that life exists some­where, but it is absolutely not certain.

And this is where the real prob­lem of scale rears its head.

There’s a star very sim­i­lar to our own in local space; it’s called 18 Scorpii, so named because it’s the 18th bright­est star (by visual mag­ni­tude) in the con­stel­la­tion of Scorpio. It has nearly the same mass, bright­ness and spec­trum as our own star, and is almost cer­tainly the same age. It’s not quite Sol’s twin, but it’s close enough.

It is also about 30 light-​​years away.

That means that if we were to send a mes­sage to a planet orbit­ing 18 Scorpii, it would take 30 years for that mes­sage to arrive, assum­ing (1) a ter­res­trial planet orbit­ing it; and (2) life on that planet capa­ble of inter­cept­ing and com­pre­hend­ing our mes­sage attempt, whch would almost cer­tainly take the form of radio. So we’d have to wait 60 years, at least, before we even got a reply.

Well, we’ve waited at least that long — and heard nothing.

Wait, you may be think­ing; we sent a mes­sage already? In 1945 or so?

We have indeed been send­ing mes­sages out to space, and we began well before 1945. Actually we’ve been send­ing mes­sages since 1897. This means that our self-​​possessed mono­logues and dia­logues have been pour­ing more or less con­tin­u­ally out into space for nearly 110 years in an ever-​​expanding sphere that, by def­i­n­i­tion, is now 220 light-​​years in diameter.

If we fol­low our pat­tern with 18 Scorpii and give our Little Green Men the chance to respond to our mes­sage, we have a sphere approx­i­mately 100 light-​​years in diam­e­ter from which we could expect to hear a reply any time — and that sphere con­tains more than 500 stars sim­i­lar enough to our own to sat­isfy our life-​​nurturing requirements.

To date, we have heard nothing.

Radio and sim­i­lar com­mu­ni­ca­tions chan­nels are prob­a­bly all we’ll ever have for talk­ing to the neigh­bors, because of the absolutely insane dis­tances between stars. (I’ll go more into that in another post.) The point here is that it seems rea­son­able to pre­sume that the 500 or so stars like our own which might have intel­li­gent life as we know it don’t appear to, at least not yet.

(And yes, the stars in ques­tion should be like our own. Larger stars put out a lot of radi­a­tion and don’t sur­vive very long; smaller stars are low-​​radiation and might not even have planets.)

The Third Problem: Intelligence is Not the Goal

Where we get our teeth kicked in is when we real­ize that there is noth­ing, absolutely noth­ing, in the process of evo­lu­tion that guar­an­tees intel­li­gence (though sev­eral cetacean, cephalo­pod and pri­mate species here seem to have acquired quite a lot of it), and even given the pres­ence of intel­li­gence, there’s no fur­ther guar­an­tee of tech­nol­ogy.

Of the cur­rent intel­li­gent species on Earth, only two are observed to be tool-​​making ani­mals. Of those two species, only one has devel­oped radio. This means that we, though we imag­ine our­selves to be the pin­na­cle of nature’s design, don’t really need to be here; intel­li­gence sim­ply isn’t part of any grand scheme, whether god­dish or evo­lu­tion­ary in nature.

From the stand­point of most other species, we were objects of indif­fer­ence for mil­len­nia, though lately of course we’ve become rather dan­ger­ous. But the way we view the world — indeed, evo­lu­tion itself — we have a bias that all the muta­tion, nat­ural selec­tion and spe­ci­a­tion has led to us, took place in order that we might be, when in fact no such thing has occurred.

If technology-​​bearing ani­mals — one of one hun­dred mil­lion or so species — arrived here on Earth as an unex­pected byprod­uct of results of a sto­chas­tic process, how likely is it that such crea­tures have evolved else­where? (We aren’t the only intel­li­gent, tool-​​making species ever to have lived here; we’re just the most recent, but all the tool-​​wielders are on the hominid line with us.) The odds against our brand of intel­li­gence aris­ing again here, given iden­ti­cal ini­tial con­di­tions, seem to be at least 100,000,000:1.

We can’t mean­ing­fully mea­sure the odds of intel­li­gence on other worlds, with unknown ini­tial con­di­tions and devel­op­men­tal fea­tures. It might be more likely; it might be less. The safest bet is to assume it’s about the same as here, and what we must con­tin­u­ally remind our­selves — what hurts our ego most — is that evo­lu­tion is not a process that moves toward a goal such as intel­li­gence; there is absolutely no inevitabil­ity in the aris­ing of self-​​awareness or tech­nol­ogy on any species track anywhere.

So the pres­ence of life on a world — any world — even this world — is not an auto­matic sign that intel­li­gence has, does, or ever will exist there.

Too Few Facts

Let’s revisit our mod­i­fied Drake, using what we under­stand now about the odds against intel­li­gence aris­ing on Earth. Say we have rea­son to be very opti­mistic and can def­i­nitely put life on one planet orbit­ing each of 120 bil­lion sun-​​like stars.

We’re left with just 120 worlds that could arguably have ani­mals like us on them, ani­mals with inter­nets and tele­phones and radio and annoy­ing polit­i­cal debates. (Of course, this assumes evolution’s timescale is the same on each world — a topic for yet another discussion.)

120 worlds is not very many.

It’s so few, in fact, that the only word to express the idea of extrater­res­trial intel­li­gence is faith.

Do I believe?

In life out there, yes. In extrater­res­trial intel­li­gence? There, I’m a bit more like Fox Mulder. I want to believe, but right now, I can’t. I’d need to see some real evi­dence first, and in later posts I’ll detail why I con­clude that we have yet to find any.


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