The Firefly and the Pulsar

Summary

We’ve now had humans in space for 25 continuous years, a feat that made the news last week and one that must have caused a few toasts to be made aboard the International Space Station. This is a marker of sorts, and we’ll have to see how long it will continue, but the notion of a human presence in orbit will gradually seem to be as normal as a permanent presence in, say, Antarctica. But what a short time 25 years is when weighed against our larger ambitions, which now take in Mars and will continue to expand as our technologies evolve. We’ve yet to claim even a century of space exploration, what with Gagarin’s flight occurring only 65 years ago, and all of this calls to mind how cautiously we should frame our assumptions about civilizations that may be far older than ourselves. We don’t know how such species would develop, but it’s chastening to realize that when SETI began, it was utterly natural to look for radio signals, given how fast they travel and how ubiquitous they were on Earth. Today, though, things have changed significantly since Frank Drake’s pioneering work at Green Bank. We’re putting out a lot less energy in the radio frequency bands, as technology gradually shifted toward cable television and Internet connectivity. The discovery paradigm needs to grow lest we become anthropocentric in our searches, and the hunt for technosignatures reflects the realization that we may not know what to expect from alien technologies, but if we see one in action, we may at least be able to realize that it is artificial. And if we receive a message, what then? We’ve spent a lot of time working on how information in a SETI signal could be decoded, and have coded messages of our own, as for example the famous Hercules message of 1974. Sent from Arecibo, the message targeted the Hercules cluster some 25,000 light years away, and was obviously intended as a demonstration of what might later develop with nearby stars if we ever tried to communicate with them. But whether w...