The Return of SETI | Hacker News Reader

The Return of SETI

theatlantic.com

55 pointsHooke13 comments

If you like hearing science from "the horses mouth" (vs/ TV), you may enjoy their YouTube channel with weekly lectures on a variety of topics and generally very cutting-edge: https://www.youtube.com/channel/UCzQdkHKOTVT_chwgDcau4sg

I've been wondering, what procedures are used by SETI researchers to avoid announcing false positives? Since there would seem to be ample opportunity for generating media hype surrounding what they find, I am surprised we don't hear about more possible discoveries.

That suggests to me a detailed description of their protocols may help researchers in other areas. For example, I doubt they use p<0.05 to decide a discovery has occurred.

Yes, there's an agreed procedure.[1]

[1] http://www.seti.org/post-detection.html

Thanks. Some is specific to SETI and most of the rest looks like good scientific common sense (independent verification, share all the data). The first step is still rather vague though:

>"(the discoverer) should seek to verify that the most plausible explanation for the evidence is the existence of extraterrestrial intelligence rather than some other natural phenomenon or anthropogenic phenomenon before making any public announcement."

What goes into "seek[ing] to verify that the most plausible explanation for the evidence is the existence of extraterrestrial intelligence"?

http://www.seti.org/faq

How would we know that the signal is from ET?

Virtually all radio SETI experiments have looked for what are called “narrow-band signals.” These are radio emissions that extend over only a small part of the radio spectrum. Imagine tuning your car radio late at night … There’s static everywhere on the dial, but suddenly you hear a squeal – a signal at a particular frequency – and you know you’ve found a station.

Narrow-band signals – perhaps only a few Hertz wide or less – are the mark of a purposely built transmitter. Natural cosmic noisemakers, such as pulsars, quasars, and the turbulent, thin interstellar gas of our own Milky Way, do not make radio signals that are this narrow. The static from these objects is spread all across the dial.

In terrestrial radio practice, narrow-band signals are often called “carriers.” They pack a lot of energy into a small amount of spectral space, and consequently are the easiest type of signal to find for any given power level. If E.T. intentionally sends us a signal, those signals may well have at least one narrow-band component to get our attention.

Well, as the above quote says, they have to rule out terrestrial sources as well. Also, how narrow is narrow enough? How was that decided?

What if ET discovered UWB before us and that is their primary means of communication?

If ET is looking to talk to someone, they're going to talk down to our level (in my opinion), hence the targeting of narrowband communications.

I have a vague recollection of this coming from the discovery of pulsars. One of the candidate theories about the regular pulses was extraterrestrial life. Seems like it would be hard to rule out ET if you're encountering something genuinely new. New theories would take weeks or years to cook up.

There are forms of SETI besides the listening-for-interesting-signals kind. Looking for large-scale artifacts also exists:

http://home.fnal.gov/~carrigan/infrared_astronomy/Fermilab_s...

http://www.space.com/24269-how-to-search-for-alien-civilizat...

I find these fascinating: let's consider the branching tree of ways civilizations might grow and then look for evidence for leaves on that tree.

This may be more effective. I really doubt we will find ET unless it specifically wants to be found with radio signals.

The Breakthrough Initiatives project was announced earlier this year, and was accompanied by a neat video created by Seth McFarlane: https://www.youtube.com/watch?v=rrXeRK2B6z8

"In June, the Russian billionaire Yuri Milner pledged $100 million"

Interestingly, this is also the same amount he spent on his California home.

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