Stephen Hawking Wants To Find Aliens Before They Find Us (cnet.com)

Stephen Hawking is again reminding people that perhaps shouting about our existence to aliens is not the right way to go about it, especially if those aliens are more technologically advanced. In his new half-hour program dubbed, Stephen Hawking's Favorite Places, the theoretical physicist and cosmologist said (via CNET):"If intelligent life has evolved (on Gliese 832c), we should be able to hear it," he says while hovering over the exoplanet in the animated "U.S.S. Hawking." "One day we might receive a signal from a planet like this, but we should be wary of answering back. Meeting an advanced civilization could be like Native Americans encountering Columbus. That didn't turn out so well." Hawking manages to be both worried about exposing our civilization to aliens and excited about finding them. He supports not only Breakthrough: Listen, but also Breakthrough: Starshot, another initiative that aims to send tiny nanocraft to our closest neighboring star system, which was recently found to have an Earth-like planet.

Comments

Re:With all due respect to Mr. Hawking and us...

[110010001000]

Uh, FTL travel is not possible. Ever. This is known already. Because, you know, physics. What you are describing is pure fantasy.

Re:What a dumb-ass

[kuzb]

He was the guy who basically married general relativity to quantum mechanics, and catapulted our understanding of stellar phenomenon forward by a substantial amount. Long after your bones are dust, people are going to remember him for his important contributions to science.

Re:You'd think someone as smart as Hawking ...

[Immerman]

I seem to recall hearing that, if an identical society to our own were currently orbitting Alpha Centauri, our current radio telescopes would probably be able to detect any high-power military radar sweeps that pass their horizon in our direction, but not much else. So for now at least it seems unlikely that we'll be able to detect planetary "radio leakage", regardless of vertical attenuation.

And the radar point raises another good one: vertical attenuation probably wouldn't make a huge amount of difference for detection. Even if they somehow transmitted a signal perfectly horizontally, it would still head into space as the planet's surface curved away from it, and transmission frequencies would almost certainly be tuned to the most transparent bands in the atmosphere, so atmospheric attenuation probably wouldn't make a huge difference. We'd only get relatively brief, regular bursts of signal as the the transmitter's horizon aligned with Earth each day, but for detection that's all you need.