SETI (Search for Extra Terrestrial Intelligence) is a more contentious issue than many people realize. Sure for most folks it’s just an innocuous screensaver, for the more hardcore it’s a “buy a dedicated machine to pump the units up” deal. But some, myself included, view SETI as a terrible waste of time and resources. Most people object on grounds that we are supposedly alone in the universe. I do not share in that objection; my objections are purely pragmatic and argued below.
The logical beginning point for a discussion of SETI is the previously mentioned chances of life existing elsewhere. Here we see the beginnings of trouble, since no one knows precisely how life began it’s very difficult to place a probability on life existing elsewhere. Many argue that life arising purely by chance is so infinitesimally small as to be nearly impossible. They will tell you that all the constants of the universe must be just so, a little more gravity: the universe collapses upon its self. A small change in the fine structure constant and the universe is unsuitable for life. As compelling as these arguments may be they are not germane to the discussion, few would argue that the universe in incapable of supporting life. (For the record the argument is folly: how many chances does a habitable universe get to form? Obviously enough).
Of more import to the topic at hand are the chances of life forming in a hospitable universe. The easy way out of this conundrum is to say that if it happened on earth it could happen elsewhere. The Urey Miller experiments that resulted in precursors to life add some credibility to this argument but, it must be said, no one has actually created life in the laboratory. The arguments against life occurring usually use probabilities, for example: a random collection of peptides assembling by chance that could reproduce has been calculated at one chance in 10^41 . This is a number so fantastically small that it is more likely that you will win the lottery, be bitten by a shark, and struck by lightning all at the same time …. IN NEBRASKA. And that series of events would be a commonplace occurrence in comparison. Of course that argument rings hollow, it assumes a complete randomness of molecules floating around with no other factors acting. Of course other disagree, if conditions are even slightly favorable, some argue, life will unfailingly arise. John Joe McFadden provides a quantum mechanical argument for such a view and Tim Thompson has opined that life is a thermodynamic consequence. The truth probably lies somewhere in the middle of these two extremes . In any event for our purposes let us consider life as a given. That gets rid of the pesky issue of the chances of life existing elsewhere. We’ll assume it does…in abundance .
At this point it is necessary to question one of SETI’s goals: Finding intelligent life. One can easily argue that finding any life at all is just as earth shattering (so to speak) as finding “advanced” organisms. Homo Sapiens are a successful organism, the most successful large sized (relatively speaking) animal on planet earth. It would be helpful to realize that, as successful as we are, we are but a small insignificant branch on the evolutionary tree. The reason for this is because the earth is ruled by microscopic organisms, you owe your continued daily existence to them. Sure they’re not cool to look at in zoos, and they’re not tasty but the disinterest does not change the fact: Earth is a planet overwhelmingly populated by the very tiny. Which leads us to the question: Is finding intelligent life important? No, finding life is important. Finding alien bacteria will be just as revealing as finding aliens playing Peasant’s Quest.
Let us remember that the acronym that is SETI includes the word “intelligence.” So the previous argument is not really applicable, life in general, falls outsides SETI’s scope. So SETI requires not only life it requires sentient life, and this an issue. When we look at evolution on our own planet we don’t see a bunch of super rapid speciation. Rather what we see is a slow transition from the parent species to the child species. Evolution is not measured in lifetimes but rather eras. So we must now address the issue of another livable planet evolving sentient life. The general argument against other planets evolving sentient is as follows: Earth is specifically suited to producing sentient life, it’s got a moon, salt and fresh water, hot and cold places, fairly frequent extinction events, etc. All these factors, so the argument goes, are a must for sentient life. Of course these arguments lack imagination. One could just as easily imagine a Koala bear saying: “Australia, a one of kind place, without these eucalyptus leaves no decent koala life would exist” Of course we would laugh at the koala, cause they look funny and all. The koala is still mistaken, no matter how cute: organisms adapt to the environment, not the other way around (it could be argued that humans are now adapting the environment to their whims but we’re going stay on topic). It’s just a bit of human hubris,
We now find ourselves in a universe with lots of hospitable planets and plenty of sentient life. So it’s a no-brainer, we should definitely look for alien life. This is where the wiggle room exits stage left. We need to take into account the tools we will be using to find the alien life. If they’re not fit for the job then the job probably shouldn’t have been started. So what do we have for tools? We’ve got radio telescopes and millions of PC’s crunching numbers. The theory is that if you stumble over a radio signal of obviously non-natural origins then you’ve found aliens. Here you’re looking for a repeating signal, perhaps a string of prime numbers or a radio show (“And now another looooong block of rock”). Which seems fairly straightforward but is in actuality much more complicated than most people realize.
How can such a simple concept become so complicated? Well, the universe is full of electro magnetic radiation. The sun bombards the earth with EM radiation known as “light” daily (most places anyway, sorry Portland). Of course light wouldn’t interfere with the signals SETI wants but other natural forms of EM radiation swarm through space. For example if you tune your TV to a station of pure static (for this experiment cancel your satellite subscription) and about one percent of the static is leftover from the big bang . And that’s only one example, point being it is not as simple as tuning a radio dial until one finds a nice clear transmission of ads for used hovercraft. SETI researchers are crafty types and employ various methods to get around this obstacle (hey, they’ve got more P.h.D.’s than some countries) but each workaround pays a price. Surveys that scan many frequencies lose clarity, survey’s that scan the “water hole ” are limited (thus relying on the aliens willingness to be found). It’s a tricky issue, one that is not yet fully resolved. So even with a vast array of telescopes collecting vast amounts of data finding a signal is will be about as much luck as dogged determination.
Of course that assumes there is a signal to be found. This is not a given though it is a fundamental tenet of SETI. The rationale seems to be that since we use radio (cheap, easy way of communicating) intelligent extra terrestrials will also use radio. There are major problems with this thinking: We’ve only been using radio since the thirties so if aliens were looking for us they’d be out of luck. (Well they’d be out of luck if they were farther away than 80 ly that they almost certainly are). This illustrates a big problem with SETI, you don’t just have to look you have to look in the right spectrum at the right time. To soon and aliens haven’t used radio, too late and the civilization is already gone.
Well that is a bit over simplified. It is now necessary to consider not only the level of advancement of the aliens (advanced enough to use radio) but also the backwardness, if you will, of said civilization. See if the aliens are more advanced than us (seems likely) they might have found better alternatives for dissemination of information and reality TV. Here some will argue that surely the aliens will spew some sort of EM ejecta and these will be detectable. This is not a certainty, we are already seeing concerns over WiFi and AM radio , it is not too much of a stretch to think that in the future all EM emissions will go the way of lead paint . So the problem is compounded. It may not be enough to be a civilization that is advanced enough to use radio, it is also possible that the civilization must be sufficiently unadvanced to still use radio. When one looks at the situation from this perspective one begins to wonder if we’re looking for aliens or just copies of ourselves.
This is surely the death knell for SETI, it’s becoming just too unlikely for a useable signal to be found. Not so fast my friend (hey, college football is nearly here). Earlier the allowance was placed that the universe was teeming with sentient life. Since the universe is very big (how big you ask? it’s everything) there are many opportunities for sentient life. So many that at there will be plenty of planets with plenty of civilizations of just the right level of technological advancement. Well that’s making it a trivial problem. Here we could use the Drake equation in ways it was never meant to be used and calculate the chances of life existing in a certain radius but that would be counter productive, we will allow relatively close aliens with the correct technology.
Thus far the objections have all dealt with the difficulty of life existing necessary difficulty of finding evidence of said life. Those objections have all been dismissed by using SETI friendly, though valid, reasons. Of course criticisms of SETI don’t stop there. There is the objection of the horrible waste if we find nothing. Finding nothing is a likely result and not only because life doesn’t exist but because we are looking in the wrong place and wrong time (or in the wrong area of the spectrum, etc, etc). People complain that all those computer cycles and all those hours on radio telescopes will be wasted. One of these is a valid complaint, time on radio telescopes is a competitive thing, and time taken for SETI projects is time that was not used for more productive scanning. The argument that the donated computer cycles were wasted seems a bit specious, those computers weren’t doing anything anyway . So now we must deal with the objection that if we find nothing we have wasted a lot of time and resources. To dismiss this argument we’ll need to first consider the null result. The null result is when you find absolutely nothing and it can be very scientifically enlightening. Consider the Michelson Morley experiment to measure the drift of the super luminous ether . That particular null result shook physics. Most null results aren’t nearly so interesting, Higgs Boson anyone? But nearly always they add a bit to scientific knowledge even if that bit is how not to perform the experiment in the future. A null result of the SETI experiment is no different in this respect, the null result will just take much longer (or perhaps an eternity). Here we are left with the nagging question: Is the effort of SETI worth the (probable) chance of a null result? The answer, for scientific purposes, is a resounding yes. The point of experimentation is to gather data, even null results. As unappealing as it sounds uninteresting experiments are necessary part of scientific investigation. In a scientific sense a null result SETI experiment is just as valid as finding aliens broadcasting on the moon, because if one knew what the result would be the experiment would not need to be performed .
Once the argument of the null result has been rejected we can surely, with confidence, say that SETI should proceed. Well not quite, we must question the utility of a positive result. If we actually discover Sentient Alien beings how does this benefit any utility to mankind? Some will argue that just the knowledge that we are not alone in the universe will be such an astoundingly profound discovery that it will shake the foundations of philosophy and reshape the political climate of the world. That particular discussion is better left to philosophers but I suspect the impact will be minimal (“I’ve misoverestimated my place in the Universe! Let’s get out of Iraq”). Others argue that we could communicate with the aliens and share technology. It as this point a bit of current scientific thought must come into play.
The idea that we may be able to communicate with aliens is nigh impossible given today’s technology. Let’s pick a SETI friendly distance for the discovery of an alien planet using radio and meeting all the other requirements. Arbitrarily we choose a distance of 500 ly. That’s not too far in comparison to the size of the known universe while certainly being a possible range. First thing we have to realize is whatever signal we get from that distance will be five hundred years old. That’s really dated information (if it were a message from an alternate earth we would learn that Columbus had just stumbled onto the Bahamas). So the information probably won’t have much to do with the current goings on of their society. Now we a forced to deal with the effects of relativity (keep you’re alien technology screams to a minimum for a moment. A message sent to a planet five hundred light years away, takes (surprise) five hundred years to get there. Five hundred for the reply to return so a thousand year round trip before we get the “first post” response. In this scenario we’re not going to be exchanging technology. Fortunately quantum mechanics comes to the rescue. While it’s a bit too complicated to get into here it turns out that if you could probably construct a device that gets around the “speed limit” using paired particles which have the interesting property of reacting instantaneously. That is to say if you have part a of a paired particle and perturb said half part b reacts without hesitation (for those interested in further reading on the subject try searching for quantum computing). So you could conceivably send a paired particle box to the alien home world, and, quantum mechanics being what they are, skip the whole speed of light limitation. So a real time conversation is no problem right? Well it’s not that easy, we still have to get the box to the alien planet. At this point most people will say that getting the box there will take five hundred years. It won’t. It will take much, much longer. The fastest man made object travels at roughly 20 km/s. That’s pretty damn fast, at that rate you could drive around the earth in slightly over one minute. ( Jon and Ponch aren’t gonna catch ya.) That’s not nearly fast enough for our project so let’s use the current max speed of 288,000 Km/h, well that’s the theoretical speed of an object sailing on the solar winds, so it’s not quite achievable yet. Still to slow, let’s assume that that increases in speed are not that tough and go with a mind bending top speed of 500,000 Km/h. As fast as that is it will still take an astounding, nearly incomprehensible: 1.08 million years. You’re not gonna see it, your kids won’t see it, your kids kids kids won’t see it. About the only thing you can say with certainty is that your first relative to see it won’t have wisdom teeth . Note that Homo Sapiens, us, haven’t existed for a fifth that long.
With that said we must jump into the realms of pseudoscience and unsupported belief. SETI supporters will strongly argue that anyone we make contact with will likely be much more advanced. They further argue that it is likely that they have found ways around the “speed limit” of the universe. Let us grant that that is a likely scenario. Let us admit that the aliens possess some super bitching faster than light travel stuff, perhaps really resilient rubber bands. We will hand wave away the experimentally verified aspects of relativity by assuming that while relativity holds at the scale we measure it is also woefully incomplete (after all paired particles violate relativity with reckless abandon). With those objections obviated we can now engage in unsupported conjecture. The first question when dealing with advanced aliens with uber cool technology is: Shouldn’t we let them find us? After all, they are the ones with the physics bending technology that is currently unavailable to mankind. So it might be wise to broadcast an unmistakable signal so the aliens will find the earth. Sure we’re spewing all kinds of radio waves into space but what we really need is a super awesome multi format alien attractor: High powered lasers coupled with over powered radio transmitters scattered in geo synchronous orbit so the earth resembles not so much a planet but a giant disco ball. The likelihood of attracting alien interest seems just as likely as actually finding a signal if not more so. If the earth is broadcasting a constant signal of “Come for the music stay for the beer” message then the really advanced non-radio using civilizations can find us.
That assumes, predictably, that we want the aliens to find us. One of the basic tenets of SETI is that any alien civilization contacted will be sufficiently advanced enough as to be peaceful. The question, of course, is: Is there any reason to believe that statement to be true? It has been suggested that alien life might be unencumbered by such petty concerns as politics and thus have been freed from mundane pursuits in some kind of unfamiliar technological nirvana. Is this likely? Here we only have human history as a guide , and history is not very favorable to that line of reasoning. It has been demonstrated that war, trade, and politics all favorably influence the adoption of new technologies. Naturally adoption of new technologies leads to further refinements, which in turn, furthers new technology. The tired of example of the Chinese developing gun powder but using it mainly for fireworks is applicable . Canons and muzzleloaders wouldn’t have been much of a leap but with threatening nations at a minimum and a monolithic leadership there was no incentive to develop the new technology as devastating weaponry. With this in mind we might be well served to wonder if we really want aliens to find us at all. Perhaps their society is ancient enough for peaceful advanced technological achievement but just as likely is that the technology was bred of war. It’s just as easy to conceive of light speed friendly aliens as aliens looking for someone else’s ass to kick. (Now the tinfoil hat crowd might argue that aliens are already among us. I will leave it to the reader to divine just what a colossal waste SETI is if that is true. Suffice it to say the fine people running SETI do not feel similarly.) As scary as the idea is that aliens might swoop out of the sky and start bashing everyone with folding chairs it’s also an extremely remote possibility. As far as we can tell with today’s technology interstellar travel will be at least a massive undertaking if not completely impossible, so let us not reject SETI on the grounds of fear.
Let the final nail in the coffin of SETI be one of resources. No, the argument will not be a question of strip mining the coal to power the plants that run computers. That argument would be asinine. Rather the argument should focus on the best use of resources. While investigation for the sake of investigation is noble, the superconducting supercollider was a sad loss indeed, the opportunity cost must be considered. Unfortunately, or necessarily, depending on your point of view we do not live in a world with limitless resources. All research decisions must be undertaken with an eye towards the competing projects. And this is the ultimate failure of SETI. When we discussed the null result earlier it was couched in purely scientific terms. In the real world, full of the unpleasantness of dogs slaughtered by cars and unwanted children, the null result must be more carefully considered and the benefits to science and society must be factored. Once one realizes that other distributed computing programs offer more likely, tangible, enlightening and useful results (try folding@home) rejecting SETI becomes a trivial decision.
At this point the intolerant self-righteous types will start to scream. They will opine that it is tantamount to cowardice not to fully support SETI however improbable or non-utile a positive result may be. They will wonder loudly about the state of the world if everyone shared this attitude. They will shriek “What if Columbus bought into the current wisdom and didn’t think the world was round?” (ask the American Indian) what if the Wright brothers thought mechanical flight was impossible per the current wisdom of the day? Where would we be now? It is only too easy to dismiss these arguments as mere uniformed ratings but let us avoid that temptation. We will note in both of those scenarios there was a strong economic motivation coupled with a legitimate tangible and probable benefit. SETI lacks all of these motivating factors. SETI is, in essence, looking for the sake of looking. A noble idea but one that possesses little real value.
To summarize: SETI is extremely speculative with results of very questionable utility. Every radio telescope using SETI, every scientist working on SETI, every dollar spent on SETI, every computer donating spare cycles could be used for something with a more useful and likely goal. And that is the biggest reason not to use SETI.
For a list of poorly formatted footnotes send an inquiry to firstname.lastname@example.org. The above borrows heavily from John Joe Mcfaddens “Quantum Evolution”, Where Does the Weirdness Go?” by David Lindley. “Physics for Scientists and Engineers” by a bunch of folks, “A Short History of Everything” By Bill Bryson, “The New Physics” edited by Paul Davies and various websites. All the books are well worth the investment of both money and time.