A Galactic Internet

``Wiring up'' the Milky Way

IN 1974, when Frank Drake sent a radio signal to the globular cluster M13 to any aliens who might live among its half million or so very old stars, people lamented that, because of the great distance of the cluster, it would be at least 50,000 years before we got an answer. It is a pity because Drake's signal was most ingenious, consisting of 1,679 on-off pulses. Why this number? Because as any numerate alien would know, it is the product of the two prime numbers 23 and 73. He then drew a 23 by 73 pictogram with pictures in binary code showing what humans look like, the structure of our DNA, the location of Earth, and so on.

To enjoy a two-way conversation with the aliens of M13 would be splendid (provided they were friendly), but is there any way to speed it up? Surprisingly there might be. Timothy Ferris, in his 1988 book Coming of Age in the Milky Way, proposed what could be called a ``Galactic Internet.'' Without involving faster-than-light signalling, it would vastly decrease the time it took to communicate across tens of thousands of light-years, either between ourselves and aliens - or, in the far future, between isolated human communities. It would work like this. Each civilisation sends out into interstellar space an automated transmitting/receiving station. This station is like humanity's website. It carries all information about ourselves that we wish the rest of the galaxy to know. It continuously broadcasts this information in the direction of likely sites of alien life while, at the same time, listening for and recording all alien data. ``Within a few dozen millennia or so," said Ferris, ``everyone is receiving and sending data to and from all the other worlds through these local junction terminals, which may be in their own star system or the one next door." Conversations could be speeded up still further. Each station could be made to replicate itself several times until there was a huge hub of them spanning the galaxy. With this network and countless similar alien ones in position, Ferris estimates, we might wait no more than a century to get answers to our messages instead of a typical 100,000 years in an unnetworked galaxy. And all this because we started talking before we knew if there was anyone to talk to. Run by intelligent computers, the network would be immortal. It would continue to exist and grow long after the civilisations that created it had become extinct. In the long run, Ferris added, ``It might evolve into the single most knowledgeable entity in the galaxy. Growing in sophistication and complexity with the passage of aeons, for ever articulating itself among the stars, it would come to resemble nothing so much as the central nervous system of the Milky Way." On Earth, the Internet has become one of the most successful of all human enterprises, promising to change the world profoundly. It could be the precursor of a much vaster network that ranged across the cosmos. Growing in sophistication and complexity with the passage of aeons, for ever articulating itself among the stars, it would come to resemble nothing so much as the central nervous system of the Milky way.