Yes. At the Royal Society recently, we had a panel to discuss the METI [Messages to Extraterrestrial Intelligence] issue. It splits the community down the center. It’s not a mild discussion, either. You can get some very heated opinions. One camp says “Don’t let them know we’re here.” And the other camp, which I’m in, says, “Hold on a minute, if they’re that advanced, they already know we’re here from our [radio and TV signal] leakage. So don’t get too wound up about it.” They’d only travel distances like that, take all the time and trouble to come here, if it were a matter of survival.
Having said that, you get people who are transmitting messages regardless. One member of the SETI community who is director of a Ukrainian telescope now and again decides to send out a message. We sent out the Arecibo message in 1974 with a digital representation of where we are in the solar system, plus the human shape and DNA structure. And of course, on Voyager, there was a disk. But this split opinion has created a situation where not much has happened lately.
If they asked you to send a message out, what would you send?
I wouldn’t do it all in one chunk. The first bit would be very small: “Hello.” The typical greeting you would give if you found a tribe in the Amazon. You’d point to yourself and give your name, something very concise, and you’d include a crib. After that, I’d send an Encyclopedia Galactica—a lot of information they could process after they got the original primer. I came to that conclusion from thinking “what would I want to receive?”