is in the lasting love
its water gives to those
who drink from it.
The heart is a holy place
stained by parched lips
in the shape of halos.
the heart is a holy place — || Maza-Dohta
If there are millions of technical civilizations in the milky way, each capable of radio astronomy, how far away is the nearest one? If they’re distributed more or less randomly through space, then the nearest one will be some two-hundred light-years away, but within two-hundred light years, there are hundreds of thousands of stars. To find the needle in this haystack requires a dedicated and systematic search.
There are many cosmic radio sources having nothing to do with intelligent life, so how would we know that we were receiving a message? The transmitting civilization could make it very easy for us if they wished. Imagine we’re in the course of a systematic search, or in the midst of some more conventional radio observations, and suppose one day we find a strong signal slowly emerging. Not just some background hiss, but a methodical series of pulses. The numbers: 1, 2, 3, 5, 7, 11, 13. A signal made of prime numbers; numbers divisible only by one and themselves. There is no natural astrophysical process that generates prime numbers. We would have to conclude that someone fond of elementary mathematics was saying, “Hello.” This would be no more than a beacon to attract our attention. The main message would be subtler, more hidden, far richer. We may have to work hard to find it.
But the beacon’s signal alone would be profoundly significant. It would mean that someone had learned to survive technological adolescence, that self-destruction is not inevitable, that we also may have a future. Such knowledge, it seems to me, might be worth a great price.