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progress is noise
Friday, July 8 2005
If we're a typical case of intelligent life in the Universe, here's why we're never going to find signs of extraterrestrial life by scanning the heavens for characteristic radio signals: the more advanced a civilization, the more their info-bearing radio signals amd artifacts come to resemble pure white noise.
When Marconi sent his first radio signals across the Atlantic in 1901, they were full of simple patterns that changed over the course of milliseconds, standing out sharply from the background noise. An unfamiliar observer tuning in on these signals could identify them as some sort of communication in the radio spectrum, something that requires a certain level of technological sophistication. This achievement implies everything us humans think of as special: civilization, agriculture, religion, and written language. Once we'd mastered the transmission of radio signals, we'd found a way to bridge the enormous gaps not just between the continents, but between the planets and stars. At last we could interact with the universe (within onerous Einsteinian limits, but that's the price of admission to this universe).
But the period of time during which our signals can be readily understood by unfamiliar observers as being something other than noise is rapidly drawing to a close. Analog signals are systematically being replaced with digital ones, and the digital signals aren't just digitized, they're also compressed and encrypted. As compression and encryption technology progress, the signals they leave us with become less and less distinguishable from noise. In order to read them one has to know certain complicated facts and secrets, the sorts of things distant interstellar civilizations aren't going to have. So to them, our cell tower transmissions and even our deep space probe communications can't be distinguished from the hiss of random space noise.
How long will this process take, from the discovery of analog radio communication until the time after which nearly all of that communication will resemble background noise? Well, the process isn't over, but after the plugs are pulled on analog television and radio, I'd venture to say it will have been less than 130 years. That's the size of the window of opportunity provided to other galactic civilizations to tune into some of the din of our everyday communications. After that, the only signals they'll be able to get will come from vintage equipment or explicit attempts to reach out to them. And those signals, by their very nature, will be sporadic, relatively brief, and dwindling in number.
Mind you, it's not just our ongoing radio transmissions that are quickly becoming indistinguishable from noise. It's also our historical artifacts. Much of our civilization's output is ending up not on paper or engraved in stone, but as increasingly tiny magnetic domains on hard drives or as dimples in the foil on optical disks, both forms of data subject (like transmissions) to the dual obscuring forces of compression and encryption. Millions of years after we wipe ourselves out in some anachronistic self-fulfilling nuclear-powered religious frenzy, space aliens landing on our planet won't have any way to read that stuff, even assuming they somehow figure out how our languages work.
and now for a couple scenes from my laboratory
Julius comes in from the laboratory deck.
Sally (foreground) and Eleanor in the laboratory today.
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http://asecular.com/blog.php?050708 feedback
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