Saturday, August 11, 2012

Searching for fellow citizens of the Universe

kw: book reviews, nonfiction, biographies, exobiology, space aliens

Take a look at this artist's rendering of the Milky Way galaxy. The yellow and blue circle left of center represents the volume that can be reached with the SETI listening program, with a radius of about 200 light years (The new kilometer-scale array ought to increase that, at the cost of fewer simultaneous targets). Using an accepted scale height of the main disk (the spiral arms) of 1000 light years, or an effective thickness of 2000 ly, and a radius of about 50,000 light years, the (very rough) effective volume of our Galaxy is about 16 trillion cubic light years. The SETI listening volume is four million cubic light years.

To date, after listening very hard to one four-millionth of the Milky Way ("the Galaxy"), we have not recorded any radio signal from any other civilization. If, as Carl Sagan believed—and he has plenty of company—there are about a million alien civilizations in the Galaxy, there is about one chance in four that one of them is in range of the SETI program, to date. With one proviso: that "they" are broadcasting a signal quite a bit stronger than our own radio and TV "spill".

Further, megawatt TV broadcasting began in the 1950s, and will soon come to an end. Nearly everything is now on cable or glass fiber. I suspect any aliens out there also discovered ways to get their entertainment without using megawatt broadcasting, in less than 100 years, as we have. And by the way, now that TV and much radio is digital, and compressed, with suppressed carrier technology, if anyone "out there" detects our more recent signals they won't be able to decipher then, unless they have stumbled upon exactly the same MPEG and framing standards that we use. Our signals may as well be encrypted.

Carl Sagan didn't create the SETI program, Frank Drake did. Sagan had too much else to do, but he and Drake were friends, and Sagan was always a friend to Drakes' radio listening programs. In 1975 the two went to Arecibo Radio Observatory in Puerto Rico and listened for any signal from the Andromeda galaxy. They were hoping, if there are a million civilizations in our Galaxy, there would also be a million in the even larger Andromeda galaxy, and perhaps at least a few of them employed multi-terawatt radio beacons. Maybe one would be pointed this way? They didn't detect any. Actually, even listening with the 300 meter dish at Arecibo, it would take an alien beacon with a trillion trillion watts to punch a signal this far.

Captured by Aliens: The Search for Life and Truth in a Very Large Universe, by Joel Achenbach, was published in 1999, nearly three years after Carl Sagan died. It is in part a biography of Sagan, but even more, it is a chronicle of belief in extraterrestrial aliens throughout the United States. We find two attitudes toward the existence of alien civilizations, either "Of course!" or "Of course not!!". Very few people are indifferent or neutral.

Sagan was unusual. Though he passionately believed that there must be someone else in the Universe besides us, he was a scientist through and through (and often rather a jerk about it). This made him what Achenbach calls the Gatekeeper. As a very public, very popular astronomer and popularizer of science, he received tens of thousands of letters (and later, e-mails), frequently with someone's grand idea: how to go faster than light or travel in time (they come to the same thing), or for anti-gravity devices, or for ways to detect "the aliens among us", or about UFO's and government conspiracies to conceal their existence, or from people who believed that they themselves are aliens. As much as Sagan wanted to believe at least some of what he was told, he always checked an idea out scientifically. Thus, he had no truck with New Age and spiritualistic approaches.

His desire was his Achilles Heel. Achenbach notes that, time after time, often in a public forum, Sagan would bring himself to the edge of some looney position, only to swerve away at the last moment. He was an expert at having second thoughts, which usually kept him out of totally going bonkers.

Not so for many others. During the near-decade of research for this book, Achenbach attended a wider range of conferences and seminars on the general theme of "alien studies" than we might imagine could even exist. Of course, he was in Roswell, NM for the fiftieth anniversary of the alleged "flying saucer" crash in July 1947 that made Area 51 famous, and jump-started the fame of Major Jesse Marcel. Marcel's description of the materials as being unlike anything from Earth got into the news, and stuck in everyone's memory. Marcel's son is still a popular figure at "flying saucer" conventions. Twenty-odd years of study by the Air Force, culminating in Project Blue Book (terminated 1969; I remember that), just fed into the conspiracy theories of the suspicious.

But the real stars of the book are not the conventions so much as the conventioneers, the many people with a huge spectrum of beliefs. This says more about us than about aliens; in the absence of any clear evidence that any aliens exist, it is impossible to actually say anything about them! Humans want to believe. In spite of the rise of science, half or more of people in Western cultures still believe in a god or God of some sort (Elsewhere, it is much more than half). For many avowed Atheists, their aggressive non-belief is a religion in itself. And for many, science has become Science, a religion in its own right. Here again Sagan shines. He was never willing to call himself an atheist. I suppose we would call him an agnostic, one who "doesn't know", but he didn't use that word either. Stephen Jay Gould was the most adept at answering belief questions, whether about God or aliens: "No data."

There is an interesting journey among the ranks of "abductees". Achenbach is himself subject to sleep onset paralysis. All of us (except sleepwalkers) have our muscular system switched off just as we go to sleep. For some people, it sometimes happens a few minutes earlier. It can be terrifying. Fears are amplified, and hallucinations are frequent. I have a related "condition". When I am tired enough to be woozy, simply closing my eyes is enough to start a dream, even though I am mostly awake. I frequently hear voices in this state, but I can tell I am dreaming, and it stops immediately if I open my eyes. It is probably related to what schizophrenics suffer; they can't shut it off so easily. Sleep researchers consider that all "abduction" experiences have sleep onset paralysis as their source. Lots of people disagree.

During the final chapters, Achenbach takes a journey in a more spiritual direction. Not that he is a spiritual person, but he saw how many people, when faced with evidence that contradicted their belief, or especially when there were simply, "No data", would respond, "But I feel it is so." This is equally true of the "Of course not" folks, and some have gone to the extent of producing statistical analyses of how long our own civilization might last (one published paper states from 7,000 to 7,000,000 years, with "90% certainty"), or of the probability that "anyone" might be "out there". Strangely, even the most anti-scientific of the "I feel so" crowd want some sort of scientific patina upon their belief system. I say, if you aren't going to take science's answer, at least be honest that your position is based on something other than science.

In one section near the end, he recounts and updates the stories of some of the people he has written about. I just had to look up a few of them to see how they have fared in the thirteen years since:
  • Frank Drake, now 82 and Chairman Emeritus of the SETI Institute, continues active work with SETI. He has been at it for 52 years.
  • Jill Tarter, who worked with SETI nearly as long, recently retired from active service to go into fund-raising for ongoing SETI programs.
  • Dick Joslyn, who left the Heaven's Gate cult a few years before they suicided, died of Aids in January, 2000. Achenbach interviewed him for a chapter on the cult and "alien cults" in general.
  • A facilitator of Starseed (a group who think they might be aliens), Miesha Johnston continues the weekly meetings, and also holds meetings for abductees, or those who think they might have been abducted. Her former friend Jan Bingham, who really thought she was a Pleiadian, seems to have dropped out of sight.
  • Dan Goldin, who was NASA administrator from 1992 to 2001, a strong advocate for a human space program and for searching for extraterrestrial life (but mainly focused on bacteria), is presently involved in robotics research.
This could be seen as a sad book. We don't know anything more about aliens, or ETs, or whatever, than we did in 1947 when pilot Kenneth Arnold reported seeing nine shiny objects that moved "like saucers skipping on water", and estimated they were moving about 1,200 mph (1,900 kph). We really haven't progressed since the time of Ezekiel, who saw "a wheel in a wheel" with a rim "full of eyes". He was probably reporting a dreamlike vision, but a lot of people think it was an alien spacecraft. These have never been explained, nor have many, many other unusual sightings and experiences. Like Achenbach, I'd like to see a spacecraft land and someone come out to greet us. Failing that, a radio or light signal that clearly comes from off-planet (at least, farther away than our Moon), and not from one of our own Pioneer or Viking robotic craft.

Note, Pioneer Ten's transmitter used 8 watts until it was shut down in 2003. It was barely detectable from 67 AU (an AU is 149 million km; a light year is 63,500 AU). Pioneer used a directional antenna, but I don't know its gain. This implies it would take a signal of 7 million watts to be detected at a distance of one light year, and about 80 million watts from the distance of Alpha Centauri (or a lot larger antenna and "only" a few million watts—and it would have to be pointed right at us). Out at 200 light years, based on 7 million watts at one light year, an alien would have to really want to get through to us: it would take 280 billion watts with the Pioneer antenna, or at least 2-3 billion watts with one that had 100x the gain (about the size of Arecibo's dish). We are not going to hear anybody's accidental, unfocused signal at stellar distances. We just aren't.

I have to agree with Joel Achenbach's conclusion. We detect ourselves. We project our own hopes and dreams and fears and loves and hates upon imagined aliens. Yet we don't know whether dolphins or whales or apes or octopi have languages. How will we ever learn to understand a form of life that didn't originate here?

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