We're Becoming Invisible

When young, I enjoyed science writing (Asimov) and science fiction (Asimov and Heinlein). The Drake equation computes the probability that there are other civilizations in the universe. An article in yesterday's Times revisits the equation and concludes that it stands up well. But the kicker at the end is that we, i.e., Earth, as a civilization are becoming invisible.

But the trend might be in the opposite direction, if humans are any indication, he noted. Earth first became detectable in the 1950s, he said, when the planet was full of powerful television and radar transmitters beaming and leaking gigawatts of power into space.

“We assumed that was the way it was always going to be,” both for us and, by extension, for extraterrestrials, he said. But now the big transmitters are being phased out in favor of cable and satellites that leak hardly anything at all out to space. It’s very economical and it’s the wave of the future. Earth is gradually going radio quiet.

“That’s big change nobody anticipated,” he said. Once the big powerful transmitters go off the air, he said, “We will still exist but we will be hard to detect.”