|Arecibo. World's largest dish, radio telescope. Puerto Rico.
As the world prepares for the 2004 Olympics in Athens, one can ask the question: Are we on Earth the only ones who will watch the games?
Recall that a key story point in the Carl Sagan novel, "Contact", relies on the unique premise that we are not the only onlookers. Sagan's scenario depends on the 1936 Olympic Games in Berlin as symbolically transmitting our existence beyond the solar system. Earth inhabitants showed their interest in contests for national pride and athletic skills to a listening audience on the nearby star Vega. In the novel and screenplay based on the book, our own message in a bottle then boomerangs back to us, as a greeting from another world that they have heard us.
The plot device that the Earth leaks intelligent signals has appeared in many science fiction stories of first contact. Broadcasting early radio shows or even reruns of "I Love Lucy" to another culture on the home world, much less another planet, has long been a source of potential bemusement. How would such a randomly selected reflection of our culture be interpreted?
Perhaps Sagan chose to single out first transmission as the 1936 Berlin Games because the content is so antithetical to what we might have hoped for. Or in an ideal case, a warlike contest of brawn and nationalism seems less than what one might have planned as a friendly greeting. What as a species could show us as less prepared for greeting another civilization than the way we greet each other? After all the '36 Games advertised the politics of a nationalistic Germany, on the precipice of the bloodiest war in human history, when virtually no part of our globe could remain untouched by battle and conflict. Even the notion of competitive games or a contest to rank national and individual power, while oftentimes used historically to trigger truces or peace talks, also represents a metaphor for unabashed cultural ambitions and seemingly arbitrary or artificial borders that simply disappear when viewed from space.
In that context, what maturity can humans portray to species even more unlike ourselves, not just athletically but intellectually, culturally or morally? As David Grinspoon noted on this dilemma in his book, "Lonely Planets: The Natural Philosophy of Alien Life", an advanced civilization observing happenings on Earth might easily reply to our first signal: "Humans of the planet Earth, you want to encounter other beings? First you have to learn to live with your different people?" Was this challenge encapsulated by the 1936 Berlin Olympics?
|The first TV transmission from Earth, the 1936 Berlin games, and now the farthest strong signal from an electromagnetically-leaking planet. Because of the Second World War these were to be the last Olympics until 1948. "These are not great examples of our civilization." -Woody Sullivan
Credit: National Archives, USHMM Photo Archives
From his years in designing SETI strategies, University of Washington Professor, Woody Sullivan thinks what Hollywood did with Carl Sagan's book, "Contact", particularly the first half, is about as close as a popular film can get to what it's like to do real SETI research. Much of the opening sequence owes a debt to Sullivan, since he spearheaded the scientific understanding that the Earth is leaking electromagnetic signals all the time, mainly from TV and some military radars. Twenty-five years ago, "most SETI was set up mainly to look at beacons from another civilization. But we don't have a devoted beacon broadcasting from Earth even. A priori, we don't know that a civilization would set up a beacon. But we Earthlings are leaking all the time, just from our daily activities."
Just as the film, "Contact", begins, the viewer is taken on a voyage, as if riding such a signal from the depths of the universe until it zooms back towards Earth. Before Sullivan's work, previous SETI strategists more often thought of broadcast sources from another civilization as likely to be directed beacons, or singularly devoted transmitters. Instead Sullivan supposed a viewpoint about the more constant background noise, one that unavoidably might date back to the film's key plot-point when the advanced civilization finds the first terrestrial TV broadcast--the carrier signal when Adolf Hitler hauntingly introduced the 1936 Olympic Games in Berlin. "These are not great examples of our civilization," said Sullivan.
"I call this eavesdropping," continues Sullivan. "Sometimes when you eavesdrop, you get a better idea of what is really going on, say at a party. So when another civilization is eavesdropping on us, they may actually get a better idea about what is going on with Earth. There is more to Earth, as a planet, than what we could send on the gold record that travelled on the Voyager spacecraft. We, as a planet, are not just about listening to Chuck Berry."
It is, according to Sullivan, easy to miss whether TV coverage of the Olympics can serve as an effective SETI message. Particularly when the picture itself, the moving color image, is the least of what an advanced civilization might want to watch, the physics of TV is more important than the actual content carried. Sullivan notes "the input is not actual TV programs in the broadcast signal. But I was talking first about the video carrier, which is a single frequency carrier. Your TV locks onto it. You can't get the whole program information. From another planet, you could get alot or dozens of those carriers, about a rotating planet with doppler shifts. That communicates alot of information to a receiver."
|Carbon-based bipeds appear to walk using two limbs while balancing precariously in a semi-upright posture but may be evolving rudimentary transportation systems based on the wheel. Credit: Australian Broadcasting Corp.
Whether the 1936 or 2004 Olympics represents a global signal that we leak apparently has less to do with the event itself and more to do with the electromagnetic spectrum. Sullivan considers "what signals we Earthlings are optimally leaking to our neighbors...should be broadly spread, strong, and possibly discernable as an intelligent signal... So for a good signal for reception, you want to balance a trade-off between both powerful and broad-area beaming."
Sitting down to watch the Olympics from 10 to 100 light-years away may not reveal much of interest about a race of carbon-based bipeds. We will leak the 2004 Games to travel into deep space, just like we did with the 1936 Games. Most of what qualifies as signals of sufficient persistence and strength have a small probability of reaching just the right antenna. But chances are better that another civilization will not be caught watching our TV. Sullivan concludes TV is only one way we declare ourselves outside our solar system: "Military radar, called the Ballistic Military Early Warning System or BMEWS, is a very powerful broadcast, but carries no real information. There are a couple other strong radars on the planet. The strongest radar is Arecibo, but it covers a very tiny bit of sky. The odds that you were in that patch, or broadcast path, is unlikely."
Whatever the source of our leaked signals, there is a timeliness to considering how we decorate our own local solar neighborhood. As the SETI Institute's Jill Tarter, often cited as the inspiration for the lead scientist in the movie "Contact" describes: "When you realize that you live in the first generation of humans with access to a technology that might answer the age-old question, 'Are we alone?' all other scientific questions fade in importance."
Related Web Pages
The Earth as Seen by Galileo
Blue Dot, Red Planet
Life in the Clouds
Commitment to Life on This Earth