[ExI] how many of us can relate to this?

[spike]

> ...On Behalf Of Damien Broderick

> Subject: Re: [ExI] how many of us can relate to this?
> 
> On 11/12/2009 10:19 PM, spike wrote:
> > This brightened my day:
> > http://xkcd.com/597/
> 
> Well, then, get this, Mr. Ant Man:
> 
> http://xkcd.com/638/
> _______________________________________________

Thanks Damien, that one works on at least two different levels.

When we search for extraterrestrial intelligence, I sometimes fear we are
looking in the wrong frequencies, waaaay up too high.  Reasoning: any
interstellar communications would not be radial, but rather coherent beam
signals, as in laser.  Otherwise it takes too much energy.  So the sender
would need to know there is something or someone to receive the signal.  So
a transmitting civilization would need only a signal that means "We are
here, we have something to say, reply if you want to receive."  That signal
would likely be something as simple as "2,3,5,7,11,13" repeated once a year
would be plenty, in unary, as Sagan suggested in the movie version of
Contact.  Since you want the energy level to be as high as possible and
compete as little as possible with natural background, and the energy of a
photon is h(nu), then you get the most bang for the buck by sending a waaaay
low nu photons, giving you the most photons per Joule, the lowest frequency
you speculate the receiving civilization is likely to be able to hear.

So, it is possible that the reason we haven't detected the cosmic
we-are-heres is that we are searching way too high in the frequency band,
and that we need to build some super-inductors.

This is an attempted revival of a discussion we had here about ten years
ago.

spike