The Great Silence...

[AGXStarseed]

(This video keeps getting recommended to me so I gave in and watched it. Liking what I saw, I decided to share it to see what you guys thought).

Video Description:
"For the past half-century, humanity has been listening for alien radio transmissions but so far we appear to be the only ones broadcasting into the void. Astrobiologists now seek to narrow down the search by looking for other technological and biological signatures. In this video, I explore some of the methods by which they hope to do so and why the great silence of the universe is such a mystery."

 

[oregano]

There are plenty of reasons, the main one being that a civilization could be quite advanced yet still not have developed radio, at least in the sense we know it. Humanity's radio capabilities are largely the results of the work of one man, Nikola Tesla, although the credit tends to go to others, mainly Marconi. Victorian civilization was pretty advanced-it had developed steel and concrete-but it still lacked the ability to broadcast via radio. And then there's other advanced human civilizations, like the Roman Empire, that never developed electronics.

We know that our planetary alignment is far from universal, meaning that sentient life on other worlds may well be drastically different from ourselves, and live on planets that have a vastly different mineral composition than Earth, thus making their civilizations greatly different from us. A sentient lifeform on a planet that has no copper, for example, is unlikely to invent radio. A popular theory right now is that there could be sentient beings who communicate via telepathy, and thus would not have any need for radio.

A civilization could have a form of wired communication system similar to humanity's cable television. The Hungarians tried to use telephone technology as a form of wired broadcast system in the 1920s, and Nazi Germany had a limited coverage wired broadcast network by the time WW2 broke out.

There are any number of possibilities, including that radio signals could simply fade away long before they reach us. We know that signals below 60 Mhz or so do not penetrate the atmosphere, but simply bounce off it until they disappear. There is no reason that radio signals that escape the atmosphere, either accidentally or deliberately, would do the same thing-simply fade away in the vastness of space. The idea that extraterrestrials could be watching TV shows from the 1950s was originally put forth in science fiction of that era, but we have no proof of it, and the behavior of HF radio signals on Earth suggests the exact opposite-that radio signals simply "die" in space.

 

[Theta.G]

They tuned in to the wrong approach and should be looking into the visual aspect. Long range imaging devices that can capture some of the 99% of the light spectrum we cannot see and transmute it into something we can see.

Long distance auditory reconnaissance is a dead end, however it makes some people wealthy so will continue.