Is There Life on Mars and Venus?
You may have heard that the scientific community is buzzing with excitement over the discovery of Gliese 581g, an Earth-sized planet circling the red dwarf star Gliese 581, 20 light-years from Earth in the constellation Libra. Five other planets orbiting this star were already known, but what's exciting is that the new one is smack in the middle of the star's habitable zone, making it the best candidate ever discovered for an extrasolar planet with liquid water. And where water flows, is it possible that life follows?
This finding is a major blow to the creationists who insist that Earth must be the only life-supporting planet that exists. As the scientists who discovered Gliese 581g pointed out, finding a habitable planet this easily means that we've either been incredibly lucky, or such planets are common.
But I wanted to turn my attention a little closer to home for the moment. You might think, given the effort scientists are putting into finding Earth-like planets beyond the solar system, that we've exhausted all possibilities for discovering alien life any closer to home. Surprisingly, not only is that far from the truth, we have evidence which could imply the existence of life dwelling on our very nearest planetary neighbors.
Take Venus. Despite being Earthlike in size and composition, Venus has a surface of crushing pressure and 900-degree temperatures, making it almost certain that no life could survive - on the surface. But the surface isn't the only environment on the planet where life could conceivably exist. The planetary scientist David Grinspoon, in a daring feat of imagination, hypothesized that free-floating microbial life could exist in Venus' atmosphere. In the upper reaches of the Venusian atmosphere, the temperature is a far more hospitable 80 degrees, with the same pressure as Earth, and some evidence even suggests the presence of water. It's possible that life began on Venus' surface billions of years ago, but as the steadily increasing greenhouse effect turned the surface into an inferno, it escaped into the atmosphere, drifting high above the killing heat.
And this hypothesis isn't pure speculation. There's some tantalizing evidence which could indicate the presence of life in Venus' clouds.
The astrobiologists Dirk Schulze-Makuch and Louis Irwin pointed out that Venus' atmosphere contains very little carbon monoxide. This is curious, because lightning and ultraviolet radiation should be producing this gas in large amounts. Even more suggestively, Venus' atmosphere contains significant amounts of three other molecules - hydrogen sulfide, sulfur dioxide, and carbonyl sulfide - which, at least on Earth, are only produced by life or by volcanic activity. Venus does have active volcanoes, but not as many as Earth (since it has no plate tectonics), and it's not certain whether it's enough to account for the measured abundances. It's possible that some as-yet-unknown chemical pathway is breaking down carbon monoxide and producing these other compounds. But it's also possible that what we see in our spectroscopes is the metabolic signature of Venusian life, drifting in the planet's clouds and thriving to such an extent as to alter the balance of its atmosphere.
Mars has been explored much more thoroughly than Venus, and it too has given evidence to tantalize us. The two Viking spacecraft which landed on Mars in the 1970s carried experiments designed to test for the presence of life. The most surprising of these was the so-called labeled release experiment, which added water and nutrients to a sample of Martian soil. The nutrients were "tagged" with radioactive carbon-14, and the assumption was that, if there were microbes in the soil, they would metabolize them and release radioactive carbon dioxide gas. And when the experiment was run, the carbon dioxide was indeed detected. Even more excitingly, when the experiment was repeated after heating the soil to sterilizing temperatures, no gas was detected - as if any microorganisms in the soil had been killed off.
However, Viking's gas chromatograph found no evidence of organic compounds in the soil. That seemed to be the death knell for possible life - until, in 2008, NASA's Phoenix lander discovered a compound called perchlorate in Martian soil. Perchlorate becomes a strong oxidizing agent when heated, as the gas chromatograph does, and some scientists feel that this would have rapidly broken down any organic molecules and would explain why they didn't show up in the analysis. The evidence from the Viking experiments is still much-debated and ambiguous, but it certainly doesn't rule out the possibility of life.
Also, like Venus, Mars has anomalous chemical compounds in its atmosphere: in this case methane, which was detected by the European Space Agency's Mars Express spacecraft. This molecule would rapidly decompose under Martian conditions, so for it to exist there means that something must be continually replenishing it. As with the anomalous compounds on Venus, it could be released by volcanic activity - except that Mars has no known volcanism, and is believed to be geologically dead. It's possible that the methane is being produced by a geologic process called serpentinization. But it's also possible that Mars is home to methanogenic bacteria, producing the gas as a product of their metabolism. Most likely, Martian methanogens would live far below the surface, deep underground where it's warmer and there may be liquid water - similar to archaea on Earth that live in similar conditions deep within the crust.
The idea of life existing on either or both of these planets shouldn't be too surprising. Although Venus is a suffocating inferno and Mars a freezing dry desert, both planets had clement pasts with surfaces where liquid water flowed. Both these planets, during the formation of the solar system, presumably received organic molecules from the same source as Earth's. Depending on your assumptions about how likely abiogenesis is, life could well have started on all three planets at about the same time. We won't know for sure, of course, until we've had a more detailed look - but it's worth remembering that even the nearest shores of our vast and awesome cosmos may yet contain marvels we haven't dreamed of.
The Case for a Creator: All the Starry Heavens
The Case for a Creator, Chapter 7
Chapter 7 of Case is about the argument from planetary fine-tuning. This time, Strobel has two interviewees: Guillermo Gonzalez and Jay Wesley Richards, both affiliated with the Discovery Institute. Since we're keeping count of scientific "authorities", which is whom Strobel claims to be interviewing, let me point out for the record that Gonzalez has a legitimate Ph.D in astronomy from the University of Washington. Richards, meanwhile, is another Christian theologian, with a Ph.D from Princeton Theological Seminary.
You may have heard of Guillermo Gonzalez from a fracas in 2007, when he was denied tenure at Iowa State University. Naturally, the Discovery Institute went into a frenzy of claims that it was entirely due to anti-ID prejudice - despite Gonzalez's unimpressive publication record and failure to attract significant research funding during his time there (remember: authorities!). But even if his pro-ID views played a role in the decision, that would be entirely appropriate, since tenure decisions are supposed to be based on the quality of the candidate's work. For the record, Gonzalez is now a professor at Grove City College, a private Christian university in Pennsylvania - the kind of place where those strictly-scientific, not-in-any-way-motivated-by-religion ID folks seem to keep ending up. (Bill Dembski, for another example, is now a professor at Southwestern Baptist Theological Seminary in Fort Worth.)
But, moving on. As I said, this chapter is devoted to Gonzalez and Richards' argument that a multiplicity of factors make the Earth uniquely suited for life - indeed, that it's the only planet in the galaxy or even the universe that is so disposed - and that fine-tuning by God is the only way to explain this. Lest you think I'm exaggerating, here's a passage from Michael Denton's Nature's Destiny that Strobel favorably quotes in the introductory remarks of this chapter:
No other theory or concept ever imagined by man can equal in boldness and audacity this great claim... that all the starry heavens, that every species of life, that every characteristic of reality exists [to create a livable habitat] for mankind... But most remarkably, given its audacity, it is a claim which is very far from a discredited prescientific myth. [p.158]
Strobel also cites Peter Ward and Donald Brownlee's book Rare Earth, an argument by two non-ID-affiliated scientists that complex, intelligent life is an extremely unusual phenomenon. But Ward and Brownlee don't believe that life as such is necessarily rare - they believe that microbes, which are far more resilient than us large, fragile creatures, may be more common in the cosmos. Remarkably, even this is too much for Strobel to accept: "...Ward and Brownlee uncritically buy into the idea that microbial life may very well be more prevalent" [p.156, emphasis added].
I want to focus on this before moving on to the rest of the chapter. After all, if you think about it, this is a very curious position for Strobel to take. As we've said before, intelligent design, according to its founders, is supposed to be about science. And science is based on observation. Since we've never done any close-up observation of any planet outside our solar system, there should be no grounds for excluding the possibility that there may be life on one of them. Even if one agrees with every argument that's given later on in this chapter, it doesn't follow that life is a one-of-a-kind unique event, only that it's rare. Yet Strobel is clearly uncomfortable with the idea that any life of any form might exist elsewhere in the universe, even if it's only extremophile alien microbes.
Why should this be problematic? After all, didn't he just spend the previous chapter arguing that the laws of the cosmos have been fine-tuned to extraordinary precision to allow for life to exist? It would be incredibly wasteful to go to that much trouble just for the sake of one tiny planet in a universe of ten billion trillion stars. If intelligent design is being presented as a scientific hypothesis, it seems to be an a priori possibility that the intelligent designer might have created life on many different planets. Shouldn't this hypothesis be given at least some consideration?
But instead, Strobel brushes past it without a backward glance, and this tells us something. When discussing an issue where the truth is still unknown - and the question of extraterrestrial life surely qualifies - a genuinely scientific book would present the competing possibilities and evaluate them fairly (remember "teach the controversy"?). For a journalist like Strobel, this would be an ideal place to interview people with different views and see how they stack up.
This book, however, ignores every alternative and homes straight in on the conclusion that its author has clearly chosen ahead of time: that life on Earth is a one-of-a-kind unique phenomenon. And since this conclusion isn't supported by scientific evidence (how could it be?), it must derive from the author's personal religious faith. In other words, this chapter is another piece of evidence showing what we all knew already - that this book's claim at being "science" is really just a pretense, a form of window dressing, that uses scientific language to disguise a conclusion that comes first and foremost from evangelical Christian religious beliefs.
Other posts in this series:
The Case for a Creator: Strange New Worlds
The Case for a Creator, Chapter 6
The cosmological fine-tuning argument is one of the more interesting claims in the intelligent-design movement's toolkit. In fact, I'd go so far as to say that it's the best argument they have. I'll let Robin Collins make the point as strongly as he can:
"Over the past thirty years or so, scientists have discovered that just about everything about the basic structure of the universe is balanced on a razor's edge for life to exist. The coincidences are far too fantastic to attribute this to mere chance or to claim that it needs no explanation." [p.131]
The fine-tuning argument usually takes the form of claiming that the underlying physical constants of the universe need to be precisely calibrated for beings like us to exist, and even a tiny change one way or another would result in a cosmos completely incompatible with life. ID advocates will point to examples like the strength of gravity, the value of the cosmological constant, the binding energy of protons and neutrons - and they love to stack up the zeroes when describing the allegedly inconceivable odds:
"The fine-tuning has conservatively been estimated to be at least one part in a hundred million billion billion billion billion billion. That would be a ten followed by fifty-three zeroes. That's inconceivably precise." [p.133]
I said that the fine-tuning argument is the best argument ID has. Of course, this isn't to say that it proves the existence of a god, just that it's not blatantly wrong like the design argument or the ontological argument. It does seem to be true that a small change in the physical constants would result in a drastically different universe and would make life like ours impossible. This doesn't prove the existence of a god (or some other superintelligence that controls the values of the constants), but that is one possible way to explain the observation.
However, there's a follow-up question that needs to be asked. Assume for the sake of argument that the constants can vary at random. Now the question is this: How many different sets of physical constants would allow for life of any sort?
After all, if you're going to calculate how likely it is that the laws of the cosmos would allow for life to exist, you need to know two things: how many possible sets of laws are there, and how many of those sets of laws permit life. Strobel and Collins assume that the first number is a very large one (Strobel says the odds against any particular set of values are "infinitesimal" [p.135]), but never even ask how large the second is. If there are a trillion trillion possible universes, but two-thirds of those could give rise to intelligent beings of some kind, then the odds against our being here are not very large!
Granted, any kind of life that could exist if the physical constants were altered would probably be extremely different from us. We might not even recognize it as life if we encountered it. But Collins is far too hasty in dismissing the possibility out of hand without any real evidence. For instance, he says, if the force of gravity was stronger relative to the other fundamental forces:
"As astrophysicist Martin Rees said, 'In an imaginary strong gravity world, even insects would need thick legs to support them, and no animals could get much larger.' In fact, a planet with a gravitational pull of a thousand times that of the Earth would have a diameter of only forty feet, which wouldn't be enough to sustain an ecosystem. Besides which, stars with lifetimes of more than a billion years - compared to ten billion years for our sun - couldn't exist if you increase gravity by just three thousand times." [p.132]
Granted, those would be serious problems for life like us. What about life not like us?
The American physicist Robert Forward, who died in 2002, was a prolific scientist (he published hundreds of papers during his lifetime, far exceeding the scientific output of the entire ID movement so far). He was also a science fiction writer. Among his novels was Dragon's Egg, which describes an intelligent species living on the surface of a neutron star. They're made of ultra-dense matter and are the size of sesame seeds, so the massive gravity and smaller diameter of their world aren't problematic, and because nuclear reactions occur much more quickly than chemical reactions, their existence is greatly accelerated relative to ours (their "year" is about 30 seconds long), thus answering Collins' concern about shorter stellar lifespans. Although this is obviously speculative fiction, nothing in it is impossible according to our current understanding. Forward described his book as "a textbook on neutron star physics disguised as a novel".
Collins also says that if the strong nuclear force were slightly weaker, our universe would be composed purely of hydrogen, and:
"...regardless of what they may show on Star Trek, you can't have intelligent life forms built from hydrogen. It simply doesn't have enough stable complexity." [p.134-135]
Fred Hoyle - the astronomer whom Strobel favorably quotes earlier in this chapter as recognizing the apparently fine-tuned nature of the universe - did not agree with this. Like Forward, he was both a scientist and a science fiction writer. His 1957 novel The Black Cloud depicts an enormous alien intelligence in the form of a sentient interstellar cloud of hydrogen (plus, to be fair, some other trace elements). Hoyle said of the novel, "there is very little here that could not conceivably happen" (source).
Neither of these novels are science textbooks, of course. It may well be that Hoyle's or Forward's visions of alien life are ultimately not possible in our universe. But even if you believe their conclusions are unfounded, there is little more reason to believe Collins' strategic pessimism. If we had known only the physical laws of our universe, we could hardly have predicted, from first principles alone, that it would contain life. We simply don't have the knowledge to proclaim with confidence what other interesting possibilities may be inherent in other sets of physical laws. In the set of possible worlds, there may be strange lifeforms we've never even dreamed of. There are no grounds for Strobel's confidence that our universe is the only possible one that could give rise to life and sentience.
Other posts in this series:
Book Review: UFOs, Ghosts, and a Rising God
(Editor's Note: This review was solicited and is written in accordance with this site's policy for such reviews.)
If you've been around the atheist blogosphere, you probably know the name Christopher Hallquist, author of the blog The Uncredible Hallq (I've always wondered, does he get more skeptical when he gets angry?).
Well, it seems he's come into his own, because last month in the mail I got a copy of his new book, UFOs, Ghosts, and a Rising God: Debunking the Resurrection of Jesus, which was published earlier this year by Reasonable Press. Here follows a short summary of the book and my review.
The book begins with a brief history of skepticism, from the Roman con-artist Alexander and his nemesis the satirist Lucian, to Franz Mesmer and the spiritualism craze of the 18th century, complete with mediums who could levitate, summon ghosts on command, or communicate using psychic powers. Since most of us rightly consider these claims to be dubious, Hallquist argues, we should apply David Hume's criteria for judging miracle tales and conclude that the Christian resurrection story, which is much longer ago and even less well documented, is even less likely to be true.
There are some great nuggets of information in here, particularly Hallquist's account of an e-mail conversation with Craig Blomberg, one of the experts interviewed in Lee Strobel's The Case for Christ. Blomberg complains that Strobel's book "heavily paraphrased" [p.50] and oversimplified their actual conversation, and that he ultimately gave up on trying to correct all the inaccuracies that Strobel introduced. There follow discussions of textual evolution in the New Testament, of the way legends tend to grow and mutate in the retelling, and the general lack of skepticism or a tradition of critical inquiry in the ancient world. Another bit I particularly liked: to drive the point home, Hallquist quotes a Christian magician, Andre Kole, who defends the historicity of Jesus' miracles even while complaining that people tend to misremember his shows and believe he performed far more impressive tricks than he actually did! [p.75]
Building on this argument, Hallquist argues that Jesus may have been similar to a modern faith healer, performing "miracles" that relied mainly on the placebo effect and his devotees' faith in him. These stories then grew in the telling, becoming far more impressive than they originally were.
As for the alleged resurrection and post-death experiences, Hallquist notes that even the Gospels portray the risen Jesus as a strangely ethereal phenomenon, appearing and disappearing without warning depending on who seems to be looking, and often describes his glorified body in mystical, visionary terms. He discusses the modern parallel of UFO abductions, pointing out their similar dreamlike and hallucinatory qualities, and brings up the nice point that stress - such as at the death of a loved one - can make such visions more likely to occur. The closing chapters ably dismantle some common apologist arguments relating to biblical prophecy, the Shroud of Turin, and religious attitudes toward skepticism and doubt.
Having finished the book, I have just two complaints, one small, one large. First, the minor: There were a lot of typos in this book - grammatical missteps, missing letters, missing words or incorrect punctuation. On average, I counted one such every few pages at least. It obviously doesn't detract from the soundness of the arguments, but it was distracting. I imagine Reasonable Press, a fairly small printing house by the look of it, doesn't have a great deal of money to invest in proofreading, but still.
Second: The one hypothesis that this book doesn't consider, and that I found conspicuous by its absence, was that Jesus was an entirely mythical figure who was gradually "historicized" into a real human being. All the arguments Hallquist presents about legendary development, exaggeration of rumors and the like would apply equally well, maybe even better, to this hypothesis. This is an alternative that I think deserves serious consideration, and if there's a future edition, perhaps it will address it.
With those caveats, this is a short, smart book, one that's worth your while to pick up and read. Most of the skeptical material on Jesus' resurrection was not new to me, but if you haven't read extensively on the topic, it's a useful and fairly comprehensive primer on how an atheist can best respond to these apologetic claims. What I personally found most illuminating was actually the background material - the mediums and spiritualists of past eras who claimed supernatural powers, and the skeptics, like Harry Houdini, who took them on. This is material that I think will be new to most readers, and there are some powerful lessons to draw on here. Hallquist cleverly points out that plenty of spiritualist "miracles", like the alleged levitation of one D.D. Home (which was supported by three signed eyewitness testimonies) are backed by evidence as good as or better than the evidence for anything in the Bible.
Strange and Curious Sects: Raelism
As humanity's understanding of the universe evolves, our religious beliefs change along with it, and the result is that every new religion bears the stamp of the time and place in which it first arose. Mormonism is an example - Joseph Smith used "seer stones" to translate the Book of Mormon, and claimed that the Native Americans were descendants of ancient Hebrew tribes, at a time in American history when both those ideas were in vogue. Today's post concerns a more recent, yet equally strange sect that even more obviously exemplifies this characteristic.
Claude Vorilhon was a French race-car driver and former pop star. But in December 1973, according to his publication The Book That Tells the Truth, he witnessed a flying saucer landing in the Auvergne region of France. An extraterrestrial being emerged from the craft and spoke to Vorilhon. This being gave its name as Yahweh, and identified itself as a member of a race called the Elohim. If you're interested, here's what it looked like:
The extra-terrestrial human being was a little over four feet tall, had long dark hair, almond shaped eyes, olive skin, and exuded harmony and humor.
"Yahweh" claimed that the Elohim had created all life on Earth through genetic engineering, and that this event was misremembered by cultures throughout the world whose sacred texts speak of creator-gods that came from the sky. The Elohim, it explained, had been watching humanity and guiding our progress through specially-chosen prophets whom they educated, including Buddha, Moses, Mohammed, and Jesus (who was a human-Elohim hybrid, and whose miracles were accomplished through alien technology). Now that humanity has reached a high enough level of scientific development to understand this, the Elohim intend to reveal their existence, and they've chosen Vorilhon (who later renamed himself Rael) as their messenger.
Raelism was an early hit, most likely due to people who were already UFO devotees. Rael's first public conference, by his own account, attracted about 2,000 people. Today the religion claims 70,000 members in 97 countries, including notable followings in South Korea and Japan.
The Raelian religion is most noted for its enthusiasm for genetic engineering and human cloning, the better to follow in the footsteps of our alien creators. A Raelian front group, Clonaid, made a sensation with their claim in 2002 to have successfully cloned a human being. No evidence for this was ever presented, and the claim is widely considered to be a publicity hoax. According to Rael's book Intelligent Design: Message from the Designers, the Elohim have also proven scientifically that our universe is just one atom of an infinitely larger cosmos, and that each atom in our universe contains a smaller universe in turn, and so on ad infinitum.
Interestingly, Raelism officially describes itself as an atheist religion, in the sense that it does not demand belief in supernatural beings. That said, in every other respect, it exactly resembles traditional religion, right down to miracles (done with advanced alien technology - for instance, Raelians believe that a "repulsion beam" parted the sea so that the Israelites could cross it), prayer (which is explained to put one in telepathic communication with the Elohim), and life after death (Rael claims the Elohim can recreate an entire person, including personality and memory, from a single cell of their body, and that they have already done so for several thousand people who were taken to their home planet - they also plan to recreate the wicked, so that they can be punished as they deserve). And just like all other religions, Raelism's gods are systematically immune to disproof: they refuse to reveal themselves to humanity until we obey Rael's wishes to build an "embassy" for them.
The Raelians are also enthusiastic about intelligent design, for obvious reasons, and denounce evolution as "a myth". Rael himself repeats many standard creationist cants, like this one:
The evolutionists are also false prophets, false informers, people who lead the majority of the population away from the truth about our creators, the Elohim. This population, which easily swallows and dumbly believes in everything said by these narrow-minded high priests in white coats... is purposely kept ignorant and so inevitably believes that which officialdom says is true. Can you begin to imagine what the Elohim feel when they see that humans attribute their masterpiece to random chance?
As I've noted before, alien-abduction enthusiasts often sound just like medieval believers in succubi and incubi, the only difference being that they've dressed up their claims in pseudoscientific terminology. But Raelism, like its ideological cousin Scientology, goes one step further by turning belief in aliens into a bona fide religion. When more religions are founded in the future, as they inevitably will be, I expect more than one will follow Rael's lead and package their delusions in language reminiscient of the fashionable science of the day.
Other posts in this series:
Do You Really Believe That? (Xenu/Thetans)
Although past installments of "Do You Really Believe That?" have skewered absurd beliefs from other sects, I doubt any religion has doctrines as laughably ridiculous as Scientology's beliefs about "space opera". Today's post will explore the most infamous of those.
According to Scientology founder L. Ron Hubbard, Xenu was an alien overlord who, 75 million years ago, was in charge of a "Galactic Confederacy" consisting of 76 planets, including Earth (which, according to Hubbard, was then called "Teegeeack"). This planetary confederation was desperately overcrowded, and to solve this problem, Xenu devised a genocidal plan. Luring billions of citizens to government offices under the pretense of tax inspection, he dosed them with paralyzing drugs, flew them to Earth, then unloaded their bodies around the bases of volcanoes and detonated hydrogen bombs inside the volcanoes, killing them all. (It's been speculated that this story was the inspiration for the cover art of Hubbard's Dianetics.)
The dead aliens' souls, which Hubbard referred to as "thetans", were then captured using an "electronic ribbon" and taken to "implant stations", where they were forced to watch a movie containing various misleading beliefs about the existence of God, the Devil, Jesus, and so on. After this process of brainwashing, the thetans were released and took up residence inside the bodies of living beings on Earth. According to Scientology, these "body thetans" still exist in each of us, causing all the physical and mental illnesses that human beings suffer from. (You can read this story in Hubbard's own handwriting at Operation Clambake; see also this mirror.) Naturally, Scientology claims to be able to exorcise these wayward alien ghosts - for a price.
Due to Scientology's pervasive secrecy, it's difficult to be certain how widespread the knowledge of this doctrine is within the church. Outside reports agree that the story of Xenu and body thetans is only told to high-ranking Scientologists, and church spokesmen have publicly denied that Scientology believes or teaches any such thing. However, when ex-Scientologist Steven Fishman submitted this material as part of his affidavit in a 1993 lawsuit against the church, Scientology lawyers claimed that it was a trade secret and protected by copyright - impossible, of course, unless it was genuine. In a rather different line of defense, L. Ron Hubbard himself claimed that anyone who read the Xenu story without the preparation of Scientology auditing would get pneumonia or some other fatal disease. (Readers are invited to judge the truth of that claim for themselves.)
Scientology's public denial of this story potentially serves any number of different purposes. Like many ancient religions, the church depends on its possession of alleged secret knowledge to reinforce the distinction between believers and outsiders. The leak of these stories threatens to break down these barriers, and to expose for mass consumption the holy secrets that are supposed to be revealed only to trusted initiates. (Ancient Gnosticism might not have done so well if we had had an Internet back then.)
But another reason, perhaps equally important, is that Scientology higher-ups are aware of how sheerly ridiculous these stories sound to a person not thoroughly enmeshed in the church's teachings. It's difficult, I would imagine, to maintain an aura of imposing mystery when everyone on the street knows you believe that the Earth was once called Teegeeack and was inhabited by hundreds of billions of alien beings who dressed exactly like humans in the 1950s. The similarity of this doctrine to laughably bad D-grade science fiction is just too apparent. Perhaps only a person who's already heavily invested in Scientology, who's spent too much and has too much to lose by walking away, can be trusted to hear these secrets without reacting in amusement and ridicule. But that makes it all the more important that lay Scientologists hear the story of Xenu, and that's why I ask: Do you really believe that?
Other posts in this series:
Popular Delusions VII: Alien Abduction
Back in August, in "Some Thoughts on Fermi's Paradox", I proposed some explanations for why there's no evidence of intelligent alien species. But I left out what seems like the most obvious explanation of all: they do exist, and they're already here.
This may well be the most popular answer. To judge by polls like this one from 2002, almost half of American adults believe that intelligent aliens have visited the Earth. (Ironically, The Onion actually gets this percentage right in its deadpan take.) And it's not just visiting Earth, either: the same poll shows that 20% of Americans - which is on the order of 60 million people - believe that some human beings have been abducted by aliens or have otherwise physically interacted with them. Even some fringe Christian groups believe in this, although they tend to believe that aliens are demonically aligned, if not demons themselves.
I've written previously about sleep paralysis, which figures into many claims of hauntings and is probably at the root of most alien abduction claims as well. The common symptoms of sleep paralysis - inability to move, strong sensation of a menacing presence, mild hallucination - are perfect parallels to the usual elements of an abduction story.
To complete the tale, many alien abduction claimants undergo hypnosis to "remember" their experience. In reality, hypnosis makes a person highly suggestible and prone to confabulate. When primed with leading questions by the therapist, a subject under hypnosis is very likely to invent details which they later believe to be real memories. In fact, some studies have shown that abduction claimants are more likely than the general populace to concoct false memories. In this way, alien abduction becomes a self-sustaining phenomenon, as the stories and images in popular culture seed the abduction reports of the next generation of true believers.
What I've always wondered is, if aliens are really visiting Earth and abducting us, why is it so easy for people to find out about it? To judge by the accounts of abductees, it is extremely easy to recover the details of their experience under ordinary hypnotic regression. I would imagine that a race advanced enough for interstellar travel would either not care about concealing themselves, or would be able to hide their presence so effectively that we would be completely unable to detect them.
Even today we have drugs, such as scopolamine, that can block the formation of memories (it's often used by date rapists and other criminals, and in the past was given to mothers in labor), and as an added bonus, makes recipients highly cooperative and suggestible. Hypnosis is ineffective at helping a person recall what they did under the influence of this drug, because the memories are never stored in the first place. Wouldn't highly advanced aliens have something at least as effective as this?
And for that matter, why would they need to keep abducting us? Couldn't a species so advanced just abduct one human and then reverse-engineer our genome to run whatever experiments they wanted? And couldn't they come up with implants and sensors that could be read out remotely and wouldn't need repeated visits? (Don't aliens have Wi-Fi?)
Ultimately, alien abduction has simply become another modern-day religion, with advanced extraterrestrials taking the place of gods, angels and devils. Like latter-day prophets, some of them come to warn us of planetary catastrophe or guide us toward salvation. Others, like demons, come to torment and terrify us. Some true believers have created elaborate Manichean cosmologies where some aliens are good and others are evil. And, like all religions, these convoluted and fantastic claims are always advanced without a scrap of real evidence.
Other posts in this series:
Some Thoughts on Fermi's Paradox
The Drake equation, developed in the 1960s by the astronomer Frank Drake, laid the foundation for the scientific search for extraterrestrial life. This equation provides a way to estimate the number of intelligent, communicating civilizations in the Milky Way galaxy by combining all the prerequisites for the existence of such civilizations.
The remarkable thing about the Drake equation is that even seemingly conservative values for its various factors tend to predict a galaxy overflowing with life and intelligence, with tens, hundreds or even thousands of extraterrestrial civilizations. (Try it out and see for yourself.) Yet, indisputably, the observational evidence does not match that expectation. We know of no convincing evidence that there are any other intelligent species in the cosmos.
This is Fermi's paradox, named after the physicist Enrico Fermi who is said to have first posed it, and it cries out for an explanation. Some people have proposed that intelligent life is much harder to develop than we think, and we are indeed the only sentient species in the galaxy. Others hypothesize that intelligent life arises frequently, but tends to destroy itself through resource exhaustion or planetary war just as quickly.
Personally, I doubt that either of these are the case. We now know that planetary systems are abundant in our galaxy. The geologically rapid appearance of life on Earth, dating back to within a few hundred million years after the world had cooled enough to make it possible, suggests that on a planetary scale life is not so hard to come by. And once life exists, intelligence seems like a fairly obvious adaptation - a "Good Trick", as Daniel Dennett puts it, one that has utility in a wide variety of contexts and would be likely for evolution to stumble upon eventually. Perhaps some intelligent species destroy themselves, but surely not all of them do; there must be at least a few who are intelligent enough to recognize their danger and avert it. Both these hypotheses seem unlikely to me on statistical grounds. But then, why have we not detected signals from other intelligent life? I'll survey a few explanations that seem at least possible:
The "we came first" hypothesis. No matter how many intelligent species there are, one must come first. It may be that, by some astonishing stroke of luck, humanity is the first. Or, a slightly weaker alternative: we are not the first but one of the first, and other civilizations have not existed long enough for their signals to traverse the vast distances of interstellar space to reach us.
I am well aware that many other hypotheses which granted humanity a special or privileged place in the grand scheme of things have been disproven. This explanation might seem to be another suspiciously anthropocentric speculation. Especially, given the vast periods of cosmic time that elapsed prior to our appearance and the exponentially rapid development of high technology and culture in our own species as compared to geological time, it might seem that there have been ample opportunities for others to precede us. However, that need not be the case. There could, for instance, be some previously undiscovered property of the universe that only makes the existence of complex, intelligent life feasible after a certain point in time, and so our appearance as one of the first sentient species would be no coincidence.
The smoke-signal hypothesis. Imagine that at some point in the distant past, before European contact and the age of colonialism, a native civilization in the Americas or the Pacific islands wondered if they were the only human society in the world, or if there might be other, more advanced civilizations across the vast and uncharted oceans that surrounded them. Imagine that this society was accustomed to communicating over great distances with smoke signals, and assumed that a more advanced society would do the same thing, only on a larger scale. Accordingly, they dispatch watchers to the peak of a nearby mountain to search the horizon for vast columns of smoke that these hypothetical societies might be using to signal across oceans. Finding none, the watchers return and report that as far as they can tell, their civilization is alone in the cosmos.
This analogy may apply to our own situation. We are searching the sky for radio waves and other forms of electromagnetic radiation, assuming that this is how a more advanced species would communicate. However, it may be that there are advanced civilizations using something else far superior, something which we do not even know about yet, and that these civilizations have no pressing interest in making contact with a species at such a primitive stage of development that they do not know about this other means.
The zoo hypothesis. One suggestion I find particularly ironic is that there are advanced civilizations that are well aware of our existence, but are deliberately choosing to conceal themselves from us so as not to panic a species at an insufficient level of intellectual development to handle such a discovery wisely. We could imagine this as something like the "Prime Directive" of Star Trek, the rule that forbids advanced spacefaring civilizations from disrupting the normal course of development of those that have not yet attained this technological level. Less charitably, we could interpret it in the way the term "zoo hypothesis" implies - to them, we are like animals in a zoo, living out our lives placidly with no clue that we are being gawked at by watchers on the other side of the one-way glass.
The infeasibility hypothesis. Futurists often predict that technology will increase without limit. The astronomer Nikolai Kardashev, for example, proposed a three-point scale for species able to harness all the power available in a single planet, star, or galaxy respectively. A Type III Kardashev civilization would be advanced beyond imagining, and even a Type II would be vastly superior to anything humanity can currently hope to match. However, perhaps the error is in assuming that this is an inevitable or even possible progression. Perhaps it is just too hard to become the kind of planet-shaping society many futurists envision. The laws of physics may not allow it: perhaps the materials that can possibly be created are too weak, the energy we can usefully collect too small. If that is the case, technology levels equal to or slightly above that which is currently possessed by humanity may be the limit dictated by the cosmos, and interstellar communication and travel may never occur because it is impossible to engage in the kind of engineering that such an endeavor would require.
The missed signal hypothesis. Intelligent aliens do exist, they are trying to make contact, and they are transmitting the right kind of signal - but we're not listening. Programs such as SETI have been mocked by politicians as frivolous wastes of money (meanwhile, those same politicians almost always vote for the development of powerful new destructive weapons systems), and at the moment depend largely on private sources of funding. As a result, there are large sections of the sky whose radio coverage is poor or nonexistent, and there is no way of knowing until we look if there are signals arriving from those regions that we are missing. The cosmos could be awash in intelligent signals that we, in our inward-looking myopia, have completely failed to see.