The Universe is so Ginormous, There Must be Other Life Out There!
This argument that has been repeated endlessly since at least 1961. Anyone who has any interest in space exploration and science generally is so familiar with it that for all practical purposes it is a matter of faith. Even such luminaries as Neil Degrasse Tyson, famous astrophysicist and science communicator, has uttered a version of it, helpfully illustrated above. Myself, I get tired of hearing it repeated uncritically. And there’s no question, it is repeated uncritically by many people, most of whom have no idea where the argument originated, and are often vague as to what the idea really means. The original Drake Equation was about intelligent tool-using life such as humans, ET as it were. The above is about life in general. Let me restate the argument in a way that is easier to parse:
“Considering the vast size of the Universe, with at least 100,000,000,000,000,000,000,000,000 stars, statistically speaking, Earth cannot be the only planet where life evolved.”
That, in a nutshell, is the oft repeated sentiment that aliens must be out there somewhere. The problem I have with this argument is that it is neither scientific nor logical. There are other other problems with how Mr Tyson chose to word his argument above, but I degrasse. (You were warned about my sense of humor.)
The big flaw, in fact fatal flaw, in the argument is this. We don’t know how likely the formation of life is from natural ambient chemistry. We’ve never seen Abiogenesis in the wild, we’ve never achieved it in the lab. We have a lot of theories, and we know about the creation of self-replicating molecules, and we certainly haven’t come up with any good reason why DNA life couldn’t have evolved in some primordial soup. We know it happened once, because here we are. However, in any scientific, statistical, or logical sense, one data point is the equivalent of zero data points. If the creation of DNA life is unlikely enough, it may have only happened once. No matter how big the Universe is, there is also no end to how low the odds on an event occurring are.
The typing monkeys demonstrate this. How likely is it that a monkey sitting at a keyboard randomly hitting the keys will type Hamlet by chance? Essentially zero of course. However, if we convert all mass in the Universe into typing monkeys, typing for the lifetime of the Universe, how likely is it that one of them will type Hamlet by chance? Still, for all practical purposes, zero. Is the creation of life as likely as a monkey typing Hamlet by chance? No one knows. And until we have a definitive answer to this question, speculating about life elsewhere is just that, speculation. Note I’m not saying there isn’t other life out there, I’m just saying that the affirmation that there must be other life out there is wrong.
And when it comes to intelligent language using life such as ourselves, the situation gets worse. First, the odds clearly have dropped. Of the as many as 40 billion species that have evolved on Earth, only one has evolved tool-using, language, and intelligence. So humans may have been an unlikely fluke. Secondly, we don’t even know if our kind of intelligence is a good idea or not. Humans do seem to have some very self-destructive tendencies, and our species has only been around an eye-blink of time, maybe species such as ours quickly destroy themselves? Human intelligence may be an evolutionary dead end, until we find others like us that have been around awhile, or we last a few million years, we simply can’t say.
Lastly there’s the science of it all. Again, bad news, SETI has come up with nothing so far. And despite Mr Tyson’s pronouncement above, SETI has covered a lot of territory at this point. If there are beings like us out there, no evidence of their existence has been found. Granted SETI has a lot of ground to cover still, and some excellent new ideas have been proposed recently, but at the very least the 1950s idea that the galaxy was teeming with intelligent aliens is now wishful thinking at best. Worse, we are starting to get a good picture of solar systems around other planets, and it turns out our solar system and Earth itself seem to be unusual. Again, a blow to the 1950s, Star Trek, and all that follows:
Picard: “We’ve entered the system Data, what do you see?”
Data: “Two hot Jupiters, and two giant super hot Earths.”
Picard: “Any sign of life?”
Data: “No Captain, another sterile system, like the previous 8,792.”
Picard: “If we don’t find life soon, even a slime mold, I’m going to snap.”
Data: “Sixteen other Star Fleet captains have been relieved of duty this year because they suffered psychological breakdowns due to boredom.”
Picard: “Worf, toss Data out the airlock.”
It kinda gets even worse if one steps back a bit further. What if DNA life isn’t really life? What if DNA was invented by real life for information storage, real life which we haven’t ever encountered? We’re just a lab spill that didn’t get cleaned up? Or in the analogy above, we examine a cup of water from the ocean that a scuba diver dropped his watch into, will that watch teach us anything about the ecology and biology of life in the sea? Mr Tyson, and people who make this argument, are in essence saying they can use the cup of water to prove their theory about what is or isn’t in the rest of the ocean, but other people’s theories make no sense. Excuse me? The bottom line is we don’t know how life appeared on Earth, so speculation about what is out there is just that, speculation. Speculation is never certainty.
I rest my case.
(The above image was lifted from Facebook and falls into a category that’s probably years or decades behind the law. I’m claiming it as Fair Use, and am in no way making commercial use of the image, and will remove it instantly if the original copyright holder asks. Many of the other things Mr Tyson says are right on, so no one should take this as an attack on him. In fact the guy is pretty smart, and his statement above is a beautifully crafted edifice of false arguments, so I wonder if he did it deliberately wondering if someone would call him on it?)
Doug's Darkworld 
Perhaps life forms are but a condensate of DNA.. One thing for sure is that life establishes order (at least for a while) when we are told that disorder is the natural path. Maybe life forms are like elements in the periodic table.. islands of stable dna (with radicals as variants).
We were told that oil came from dinosaurs, but how to entire planets of hydrocarbons exist then?
Probability and statistics should give us a clue that there are most likely many other planets and life forms out there.. to think otherwise is a bit silly.. and perhaps a bit too self centered thinking.
We are not the center of the universe IMHO. Hawking says we may very well not want to meet up with some of these other life forms that are out there.. he seems to think they exist.
Lets discuss the Drake Equation :)
John Galt
January 9, 2013 at 9:19 am
Four of the seven variables in the Drake Equation are simply wild guesses, only one of them is known with any degree of accuracy. So one can pick their values to get any result they want, it was never anything more than pop science. It’s only well known because it’s real easy to use it to “prove” there must be other intelligent life out there. It does nothing of the kind, it’s guesswork in scientific garb. Yes, I think it’s probable that life permeates the galaxy, if not the Universe. Probability isn’t certainty, and it’s unscientific and unfair to lay thinkers to claim it is, especially in a case where our data on the topic is essentially zero. In fact an equally interesting statistical argument, the Doomsday Argument indicates that humanity likely doesn’t have much of a future. My main point is insisting that the Rare Earth hypothesis can’t be true based on the number of stars in the Universe isn’t exactly a scientific or logical refutation of the hypothesis. —Doug
unitedcats
January 9, 2013 at 11:25 am
Of course it’s guesswork, but it’s reasonable guesswork that stands head and shoulders above the ever-popular assumption created by Oogity Boogity!
Don’t forget in your haste to equate anything less than certainty to be speculation (and with a few keystrokes thus relegating all of science to mere speculation) that no method is as accurate in prediction as the probabilities of quanta. In other words, there is knowledge value to reasonable speculation without demanding that we must obtain certainty first. And you put this knowledge value into practice daily, reasonably speculating on how your day shall unfold and finding compelling evidence of correlation between your predictions and what actually happens. You don’t demand certainty from your own reasonable speculations before undertaking your day. So to hold the Drake equation to a different standard of accuracy than you do for yourself to function in this world is rather revealing about the quality of your demand: it seems to me to be rather unreasonable, don’t you think?
tildeb
January 9, 2013 at 2:42 pm
My point is that the argument that there HAS TO BE other life out there, ridiculing the other possibility as the graphic above does, is neither logical nor scientific. I heartily support SETI and Abiogenesis research. Scientific speculation is fine, assuming your speculation is going to yield the results you are looking for isn’t. The Universe is under no obligation to conform to our speculations, no matter how scientific they are. The history of science is littered with experiments that didn’t yield the results that scientists expected, SETI is no different. Until proved otherwise, we may well be alone. —Doug
unitedcats
January 9, 2013 at 3:36 pm
We may be alone, but not likely given 1) the abundance of the chemical building blocks (throughout the local universe) needed for life as we know it to be, 2) the much higher number of planets of similar mass lately found in the habitable zones of nearby stars, and 3) the amount of time already passed to allow for abiogenesis to occur. The probability continues to increase so it is far more than simply idle speculation to reasonably think that life may indeed exist beyond this one small speck.
And I don’t know of any scientist worth the name who says there has to be a specific result for any experiment; instead, I not only find scientists are about the last lot to admit that any scientific knowledge is certain (except by a reliability comparison, for example) but that scientists are first in line to admit only tentative knowledge. This reluctance to be firm on what the rest of us call ‘fact’ is the only thing that allows people to get away with using terms like ‘speculation’ to describe the tentative element in all of good science for what in any other human endeavor would be considered a ‘for sure’ position… a position that you yourself rely on in your daily life to be equally ‘speculative’, such as expecting your cell phone to work, your computer to connect to the internet, your car starting, gravity remaining stable, and so on. Ask any scientist and the confidence we have in such ‘speculative theory’ is mitigated not by what conforms to the scientist’s speculations but solely by what works reliably and consistently well for everybody everywhere all the time. Actuarials for insurance companies use very similar formulas to the Drake equation and I don’t see any of them going out of business due to sheer speculation as I understand the term to mean. I don’t see mining companies going broke using similar formulas to calculate the size and quality of deposits. We use these formulas all the time not because scientists expect the universe to conform to their speculations but because they seem able to work. I don’t see that fact counting for anything in your criticism.
If you insist that we use the term ‘speculative’ to describe your own standard confidence, then and only then does your criticism avoid the charge of imposing a different standard on science (that informs why SETI is a reasonable experiment) than on what you use to practical benefit all the time.
tildeb
January 9, 2013 at 6:53 pm
There may be other life out there is speculation. There is other life out there is a conclusion. It is reasonable to think there may be other life out there. It is not reasonable or scientific to insist that there has to be other life out there, and that your hypothesis is the only valid hypothesis. The Rare Earth hypothesis is not pseudoscience, and until evidence proves it wrong, it remains a possibility. —Doug
unitedcats
January 9, 2013 at 7:23 pm
The first half of this post is a good point. I often hear lines to the effect of: “Under the right conditions, life will always arise.” Yes, by definition, it will. But how common are the right conditions? What *are* the right conditions? What is life, even? At this point, we don’t have good answers to any of those questions, and hence any comment about life beyond the earth must be speculation.
As it happens, I speculate that life is probably reasonably common, for the reasons outlined by tildeb. But it is just speculation – extrapolation from the one data point which we have.
I am not so sure of the second half of your post. SETI have not “covered a lot of ground”. Have you ever seen that ‘scale of the universe’ video? Have a look about 2:40 into it: http://www.youtube.com/watch?v=17jymDn0W6U – the distance travelled by radio signals from earth in the past century or so. It’s barely a skin on our solar system. Any species currently extant would have to be very close or very old for us to detect them, and any species we detect that isn’t right next door to us may not still be around by the time we detect them!
Unless life is ubiquitous, or for some reason is clumped together in the Milky Way, the chances are we will never detect intelligent life due to the sheer distances (and hence times) involved.
Andrew (@_byronmiller)
January 15, 2013 at 10:05 am
SETI is past simply listening for alien radio beacons. Though they’ve done a LOT of that, and numerous other approaches have been tried as well. And several promising new approaches are getting off the ground. I should write a blog about it someday. While no conclusions can be reached yet, the confident 1950s idea that the galaxy was brimming with intelligent life a la Star Trek is looking increasingly unlikely. Agree in principle though, if intelligent life is so rare that we are the only ones in the galaxy, whether or not it is found elsewhere is essentially an academic and likely unknowable question. — Doug
unitedcats
January 15, 2013 at 10:57 am
Latter, not later
Apocacrux
February 9, 2013 at 7:56 pm