by Ben Miller
CHAPTER TWO
SETI
In which our author introduces us to the scientific search for alien radio signals, known as SETI, acquaints us with the famous Drake Equation, and investigates the strange phenomenon of UFOs.
It was the summer of ’67, and Jocelyn Bell Burnell’s1 wildest dreams were about to come true. As a research student under the eminent astronomer Antony Hewish, she had spent the previous two years helping build a brand new radio telescope at the Mullard Radio Astronomy Observatory just outside Cambridge. Now that same machine was ready to explore the virgin heavens, and she alone would be the confidante of its secrets.
A radio telescope, of course, makes an image of distant stars and galaxies using the radio waves they give off. Not that the average radio telescope looks particularly like the sort of thing Admiral Nelson defiantly held up to his blind eye; in fact, the one that Bell Burnell was in sole charge of looked more like two rugby fields laid end to end and covered in TV antennae.
This being the mid-sixties, the output of Bell Burnell’s telescope was not the hard drive of some freon-cooled supercomputer but four three-pen chart recorders, whose inkwells and chart paper needed replenishing every morning and which produced 96ft of recorded chart paper every day. And after a few weeks spent getting her eye in, Bell Burnell noticed something very strange indeed.
The telescope she was using had been purposely designed to investigate a newly discovered kind of radio source called a quasar. A quasar is a galaxy at the very beginning of its life, blasting out radio waves as the supermassive black hole at its center feasts on extremely high-temperature gas and dust. Bell Burnell was soon able to pick out good candidates for quasars, and to discard unhelpful noise from earthbound radio sources such as dodgy spark plugs on passing mopeds on the nearby A603 highway. But there was another type of signal she could not account for: a rapid juddering of the chart pens that produced a quarter-inch or so of what she called “scruff,” which cropped up roughly once every 3000ft of chart paper.
It didn’t take Bell Burnell long to work out that the “scruff” must be coming from the same patch of sky; in fact, it was in step with the distant stars, implying it was well outside the solar system. To see the “scruff” in more detail, Bell Burnell began to set the chart paper to run faster every time the telescope scanned that particular corner of the cosmos. The results were extraordinary. The “scruff” resolved into a signal. There on the chart paper was a regular pulse, with each pulse precisely 1⅓ seconds apart.
Bell Burnell was stumped. What on earth, or rather what not-on-Earth, could it be? Stars and galaxies glow, they don’t pulse. Pulses mean life. And then an extraordinary thought struck her: Could this be a message from an alien civilization?
FLYING SAUCERS
We’ll return to the story of Jocelyn Bell Burnell and her mysterious radio pulses at the end of the chapter; suffice it to say that her exemplary detective work and scientific nous will provide an exquisite counterpoint to some of the undeniably entertaining but rather bonkers UFO stories which follow.
I can imagine that some of you already feel offended. You picked this book up in the hope that it would be about UFOs, and you feel like you’ve been short-changed. Maybe you’ve seen a UFO—which simply stands for Unidentified Flying Object—or you know someone else who has. I think it’s worth getting something clear from the start: I have an open mind. To me, that’s what science is all about. It also means not accepting a theory as correct unless it is supported by high-quality evidence, no matter how much you want it to be true. UFO stories are great fun, and I enjoy them as much as anyone; I just don’t believe that they have much to do with real-life extraterrestrials.
That said, I think it’s worth giving a potted history of the UFO phenomenon so that we can put the real science of alien life in context. So many people see UFOs, report contact from UFOs, and recount abduction by UFOs that something must be going on. What is that something and when did it start?
The term UFO was coined by the US Air Force in the 1940s to describe anything seen in the sky that cannot easily be explained in terms of known craft or natural phenomena. Toward the end of the nineteenth century, witnesses began to report sightings of alien airships; these were then followed by sightings of alien rockets in the first part of the twentieth century. But the phenomenon as we know it really took off with the appearance of that alien design classic, the flying saucer.
So when did the first flying saucers appear? Strangely enough, there’s a precise answer to this question: Tuesday, June 24, 1947. Because that was the year amateur pilot Kenneth Arnold made an extremely memorable business trip.
UP UP AND AWAY
At two o’clock that afternoon, the thirty-two-year-old Arnold took off from Chehalis in Washington State in a three-seater, single-engine Callair, heading for Yakima some 120 miles due east, on a course that would take him past Mount Rainier in the Cascade Mountains. A military plane had crashed on the mountain the previous winter, killing thirty-two marines, but because of the snow the wreck had never been found. It was a beautiful clear day, and with the snow receding—and the incentive of a five thousand dollar reward—Arnold decided to go check it out.
As his plane emerged from searching one of the canyons at the foot of Mount Rainier, Arnold saw a bright blue flash, and thought for a moment that he must have caught a reflection from a plane very close by. Alarmed that he might be on a collision course, he scanned the sky around him, but could see no craft in the immediate vicinity. A second bright blue flash then lit up his cockpit with the brilliance of a “welder’s arclight,” and in the distance he saw “to the left of me a chain of objects which looked to me like the tail of a Chinese kite, kind of weaving and going at terrific speed across the face of Mt. Rainier.”
At the center of each craft there was a bright blue light, pulsing in a way that he later said reminded him of a human heartbeat. From their diagonal formation and high speed he thought at first they must be some kind of military planes. For Arnold, the really strange thing was that the craft didn’t have any tails; silver in color, they looked “something like a pie plate that was cut in half with a sort of convex triangle in the rear.” Never having seen anything similar before, Arnold decided that the tails must be concealed with camouflage paint, and “didn’t think too much of it.”
Being a good pilot, Arnold glanced down at the second hand on his watch and timed the fleet of ships as they made the journey from Mount Rainier to Mount Adams, clocking the trip at one minute and forty-two seconds. That got his attention. The two peaks were separated by some fifty miles, so the speed of the fleet must have been something like twenty-five miles per minute, or 1,500 mph. That was truly extraordinary. At the time the air speed record was less than half of that, at around 620 mph. He counted nine craft in total, judging their closest approach to be twenty-three miles, and their wingspan to be at least 100ft across.
After landing at Yakima, Arnold went to the office of his friend Al Baxter, the general manager of a crop dusting company called Central Aircraft. Bemused by the story, Baxter called in two of his flight pilots and a helicopter pilot for a second opinion. The best explanation they could offer was that Arnold had spotted some test missiles from the nearby army air base at Moses Lake.
One of the local papers, however, saw something else in the story. Were the strange craft really military planes, or something else altogether? The day following Arnold’s encounter, a very brief column appeared in the East Oregonian inaccurately stating that Arnold had observed a “saucer-like aircraft.” The paper’s editor, Bill Bequette, decided to put the story on the Associated Press wire to see if the US military would respond and clear the matter up. The wire stated that Arnold had seen “nine bright saucer-like objects flying at “incredible” speed . . . “It seems impossible,” Arnold said, “but there it is.”
When Bequette got back to the office after lunch, the phone was ringing off the hook.
SURFING THE WAVE
/> Arnold’s sighting caused something of a media frenzy, and launched what is known as “The 1947 Wave” of UFO sightings. Many of these sightings were also of flying saucers, metallic, disc-like craft that traveled at great speed. Others were of rockets, balloon-like craft, and balls of light. Three days after the Arnold incident, a rancher named William Brazel found some strange-looking debris on his ranch outside Roswell, New Mexico, and called the local Army Air Force base saying he had found a flying saucer. The base’s PR officer passed the report on to the press, and news spread that the US government had recovered a crash-landed flying saucer. The phenomenon spread, and by the end of July 1947 there had been a total of forty-five UFO sightings across America, seventeen of which were of flying saucers.2
After the flying saucer sightings of the 1940s, the 1950s saw the UFO phenomenon ramp up a notch with the emergence of the so-called “contactees.” These were people who claimed to have communicated with aliens. One notable case was that of George Adamski, who said that an alien spaceship made of translucent metal had landed next to him in the Colorado Desert and a blond Venusian named Orthon had warned him of the dangers of nuclear war via telepathy.
The 1960s then saw the first abduction stories, beginning with Betty and Barney Hill’s encounter with a UFO on a nighttime drive through White Mountain National Park, New Hampshire, in 1961. Both of them remained troubled by the event, and two years later they recalled under hypnosis that they had been kidnapped by little grey aliens with large black eyes who had, among other things, examined their genitals and showed a keen interest in Barney’s dentures.
The crop circle phenomenon then briefly took over in the 1970s, reaching a peak in the late 1980s. In 1991 two Englishmen, Doug Bower and Dave Chorley, admitted responsibility for the hoax. They had been inspired by the 1966 case of the Tully “saucer nest,” when a farmer from Tully, Queensland, Australia, reported seeing a saucer-like craft rise up from a swamp and fly away, leaving behind a flattened circular area of grass.
And that, in a nutshell, is the UFO phenomenon. Kenneth Arnold is reported as seeing flying saucers in 1947, followed by a wave of sightings across the US. The first contactees of extraterrestrials appear in the 1950s, followed by the first abductees in the 1960s. Crop circles come and go in the 1970s and 1980s and are shown to be a hoax. UFO reports still occur today, and are now mainly of the abductee type. Clearly something is going on here, but what exactly is it? Could it really be true that aliens are visiting our planet?
THE ALIENS ARE COMING
The science on this is pretty clear: Yes, it could. It’s true, the distances between the stars in the galaxy are prohibitively large, making any journey between alien worlds a considerable challenge. Our nearest star is a red dwarf called Proxima Centauri, which is 4.24 light-years away, and which may or may not have planets—we’re not sure. As we learned at the beginning of the last chapter, the farthest mankind has managed to send a spacecraft is the Voyager 1 probe, which thirty-five years after its launch is only just reaching the edge of our solar system at a measly distance of 0.002 light-years.3 But who’s to say what superior technology a long-lived intelligent civilization might create? Why shouldn’t a souped-up alien spaceship be able to fly at an appreciable fraction of the speed of light? Or shortcut between distant regions of space by harnessing the energy of a star to create an Einstein-Rosen bridge, better known as a wormhole?
OK, the wormhole thing is pushing it. But basic calculations show that even aliens with reasonably fast spaceships could rapidly colonize the galaxy if they so choose. In fact, the astronomer Paul Davies has calculated that a single alien civilization with ships traveling at only (only!) a tenth of the speed of light could cross the entire Milky Way Galaxy within four million years.4 Unless there’s something extremely special about us or the Earth, the Milky Way should be awash with civilizations older and more technologically advanced than ours. Surely one of them would have visited us by now?
THE FERMI PARADOX
The most famous statement of this line of reasoning was made by the eminent Italian physicist Enrico Fermi and is known as the Fermi Paradox. Fermi is something of a hero figure among physicists, a brilliant theoretician who was also a gifted experimental scientist. Awarded the Nobel Prize in 1938, Fermi used the award ceremony in Stockholm as an opportunity to escape Mussolini’s Fascist Italy and emigrate to the US with his Jewish wife Laura.5
In fact, among scientists Fermi is as famous for his powers of estimation as he is for his contributions to the Manhattan Project and his Nobel Prize. Should you be wondering, the relevance to the search for extraterrestrials is as follows. In 1950, Fermi paid a visit to Los Alamos, where Teller was working on the successor to the atomic bomb, known as the hydrogen bomb. That summer had seen a strange phenomenon in New York: the mass disappearance of public trash cans. It had been a good summer for UFO sightings, too, and as they walked to lunch one of Fermi’s colleagues told him of a cartoon that he had seen in The New Yorker, where a flying saucer was pictured unloading New York trash cans on its home planet.
Fermi joked that the cartoon presented a reasonable scientific hypothesis, because it explained two separate phenomena. Teller recalls that a serious discussion then followed about whether flying saucers were real, with no one in the group feeling particularly convinced. Fermi then inquired as to the probability of faster-than-light travel. What were the chances that they would see material evidence of a solid body traveling faster than the speed of light within the next decade? Teller put the odds at a million to one; Fermi was more optimistic, putting them at one in ten.
The group entered the Fuller Lodge canteen and settled down to lunch, making small talk as only physicists working on the most powerful weapon in the history of humanity can. Then, halfway through the meal, out of the blue, Fermi suddenly asked, “Where is everybody?”
His companions immediately grasped that Fermi was talking about extraterrestrials, and burst out laughing. One of the scientists present, Herbert York, recalls that Fermi
followed up with a series of calculations on the probability of earthlike planets, the probability of life given an earth, the probability of humans given life, the likely rise and duration of high technology, and so on. He concluded on the basis of such calculations that we ought to have been visited long ago and many times over. As I recall, he went on to conclude that the reason we hadn’t been visited might be that interstellar flight is impossible, or, if it is possible, always judged to be not worth the effort, or technological civilization doesn’t last long enough for it to happen.
In other words, after running the numbers Fermi concluded that intelligent civilizations must exist, but for one reason or another they are staying put. But if they aren’t going to come calling on us, how do we get to meet them? The answer: radio waves.
OPENING THE WINDOW
At least that was the conclusion of a paper entitled “Searching for Interstellar Communications” by Giuseppe Cocconi and Philip Morrison of Cornell University, published on September 19, 1959, in the scientific journal Nature.6 They pointed out that there happens to be very little noise on Earth over a certain range of the radio spectrum, known in the trade as the microwave window. For frequencies below this window there’s lots of noise because of absorption and emission by interstellar gas and dust, and above it there’s lots of noise because of absorption and emission by the Earth’s atmosphere. If aliens wanted to contact us, they reasoned, they would most likely send radio waves tuned to sit in this particular window.
THE DRAKE EQUATION
Frank Drake was nervous. It was November 1961, and in a few days’ time he would be hosting the first conference of SETI, the Search for Extraterrestrial Intelligence. Among the attendees would be one of his heroes, the Russian émigré astrophysicist Otto Struve. During his navy scholarship in electronics at Cornell in the early fifties, Drake had attended one of Struve’s lectures, and had been gripped by his claim that at least half of the stars were orbited by planet
s. Just think: If half of the stars had planets, that was a lot of potential alien real estate.
In April that same year, Drake, unaware of Cocconi and Morrison’s paper, had come to much the same conclusion concerning the microwave window and its suitability for alien communication. Audaciously, he had pointed the newly built 85ft radio telescope at the National Radio Observatory in Green Bank, West Virginia, at our two closest Sun-like stars, Tau Ceti and Epsilon Eridani, and listened. If those two stars had planets, and those planets were home to intelligent life, then maybe he might be able to pick up a signal.
Throughout the spring and summer of 1960, Drake had listened to the two stars for a total of 150 hours but found nothing. Nevertheless, a vital first step in humanity’s communications with extraterrestrials had been taken. A fan of L. Frank Baum, he had named the project Ozma, after the Fairy Queen of the far-off land of Oz, and now other eminent scientists wanted to join him on the Yellow Brick Road. Not only would his hero Otto Struve be among the ten at Green Bank, but so too would neuroscientist John C. Lilly, famed for his work on dolphin communication;7 Melvin Calvin, a chemist who would win a Nobel Prize for his work on photosynthesis on the first night of the conference; Philip Morrison, one of the two authors of the Cornell paper; and the gifted astronomer and adviser to NASA Carl Sagan.
