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Yeah, the SETI Institute's site says we wouldn't be able to pick up signals from an earth like civilization in the system closest to us[1]: > If an extraterres

by bnralt 3y ago

Yeah, the SETI Institute's site says we wouldn't be able to pick up signals from an earth like civilization in the system closest to us[1]: > If an extraterrestrial civilization has a SETI project similar to our own, could they detect signals from Earth? > In general, no. Most earthly transmissions are too weak to be found by equipment similar to ours at the distance of even the nearest star. But there are some important exceptions. High-powered radars and the Arecibo broadcast of 1974 (which lasted for only three minutes) could be detected at distances of tens to hundreds of light-years with a setup similar to our best SETI experiments. It's not really a surprise why we aren't finding things. It's a surprise that we're still acting like this is a good way to look. [1] https://www.seti.org/faq#obs12 https://www.seti.org/faq#obs12

andyjohnson0 3y ago
> the SETI Institute's site says we wouldn't be able to pick up signals from an earth like civilization in the system closest to us[1] TO be clear, the signals it is referring to are those that would be similar the unintended leakage of normal broadcast and military radar systems used on earth. So detecting ETIs from their passive emissions is certainly unfeasible that the moment. Signals broadcast by a hypothetical extraterrestrial civilisation as part of an intentional seti signalling effort would (presumably) use much higher power, narrower bandwidth, and frequencies chosen to reduce attenuation by the interstellar medium. These would be detectable using our current technology, and is largely what seti is looking for.
cgriswald 3y ago
I don’t see that as being much of a problem. Although we would not be able to detect regular Earth signals, we are relatively near the point where we would be able to detect Earth, including its atmospheric composition. Given we’ve already sent the Arecibo message, we might be likely to send such a signal to Earth. If so, other beings may as well. I think the real problem is the timing. It seems unlikely that anyone will be looking at the same time anyone else is sending a message.

by bnralt 3y ago

andyjohnson0 3y ago

> the SETI Institute's site says we wouldn't be able to pick up signals from an earth like civilization in the system closest to us[1] TO be clear, the signals it is referring to are those that would be similar the unintended leakage of normal broadcast and military radar systems used on earth. So detecting ETIs from their passive emissions is certainly unfeasible that the moment. Signals broadcast by a hypothetical extraterrestrial civilisation as part of an intentional seti signalling effort would (presumably) use much higher power, narrower bandwidth, and frequencies chosen to reduce attenuation by the interstellar medium. These would be detectable using our current technology, and is largely what seti is looking for.

cgriswald 3y ago

I don’t see that as being much of a problem. Although we would not be able to detect regular Earth signals, we are relatively near the point where we would be able to detect Earth, including its atmospheric composition. Given we’ve already sent the Arecibo message, we might be likely to send such a signal to Earth. If so, other beings may as well. I think the real problem is the timing. It seems unlikely that anyone will be looking at the same time anyone else is sending a message.