Originally Posted by DaveMatrix

If they are out there, they already know how screwy we are. Our TV & radio signals have been beamed out into space, at the speed of light, for over 60 years (see 'Contact',w/Jodi Foster, Great Intro). These signals are traveling much faster than voyager.......God only knows how some ET will interpret that eclectic mix of humanities thoughts & ideas.......I hope the ET's are friendly, or we're royally screwed.

Originally Posted by Crompsin

Listening is one thing, but holding a shiny flat round thing in your hand is another.

So is holding a slinky with your alien tentacle paws. Or an AK47 assault rifle.

...

'Sides, any intelligent life out there will eventually intercept rerun episodes of Friends and automatically determine that our entire planet is completely barren of intelligence.

Originally Posted by DaveMatrix

I can see the insight one might gain from personal contact with an ET object, but voyager is simply traveling to slow, it hasnt even reached the next system, Alpha Centauri. TV & radio signals seem more likely to really reach out, over 60 light years in all directions so far. Thats already past the 100 closest stars in this galaxy.

Originally Posted by albania

There's a definite limit to how well one can resolve a signal from background noise. My gut tells me that to get anything useful an alien species would have to be pretty damn close to Earth. That is not to say they wouldn't be able to detect signals that came from Earth, thus proving that we're an "intelligent" species, they just would never be able to make anything coherent out of them much less see a rerun of friends or what have you.

Originally Posted by DaveMatrix

I'd never say never, a highly advanced ET species may have technology that is capable of eliminating the background noise and the cleaning up the signals. We're pretty good at that right here on good ole mother earth.

Originally Posted by albania

I didn’t thing I said never. But there are a few issues at hand here, first is that the universe is full of stuff, including background radiation that is everywhere even in sectors of "empty space". As photons travel through space they interact with what’s around them. They deviate in course they lose energy and they get absorbed. Second, even assuming there was a sector of empty space and direct path from your light beam to whomever you were transmitting to you'd still never be able to get the full message across at any distance. This is so because it is impossible to create photons that will travel perfectly parallel to each other and there are practical size constraints to making a receiver. As the distance to your intended target increases you'll need a bigger and bigger receiver to pick up the complete message. If you could travel all the way out to infinity you'd need an infinitely large receiver. All these things make my intuitive physicist side tingle; my gut feeling is that no one will be seeing crappy reruns of any show here on earth sixty light years away.

At distances of the earth and solar system even it's not as bad, but we have help we know the approximate location of the receivers and transmitters and of the stuff in between them, and all sorts of clever tricks make it possible for us to share information effectively.

Originally Posted by DaveMatrix

Actually you did say "never".

Quote:
Originally Posted by albania
they just would "never" be able to make anything coherent out of them much less see a rerun of friends or what have you.

A quick look at wikepedia turned up this little fact,

http://en.wikipedia.org/wiki/SETI

Quote:
From 1995 through March 2004, Phoenix conducted observing campaigns at the 64-meter Parkes radio telescope in Australia, the 140 Foot Telescope of the National Radio Astronomy Observatory in West Virginia, USA, and the Arecibo Observatory in Puerto Rico. The project observed the equivalent of 800 stars over the available channels in the frequency range from 1200 to 3000 MHz. The search was sensitive enough to pick up transmitters with power output equivalent to airport radars to a distance of about 200 light years.

If we have the ability to pick up a signal equivalent to an airport radar, from 200 light years away, then an advanced ET species could surely do the same.

Originally Posted by albania

Quote:
Originally Posted by DaveMatrix
Actually you did say "never".

I should learn to read, yes you should have a problem when someone says never.

I talked to my Electricity and Magnetism professor. He said it was plausible to send a communication of some sort to places even a 100 light years away, we have dishes large enough on earth that could also pick up such a message assuming the power was sufficient. He said that since tv signals are not generally pointed into sectors of space that it wouldn't be likely for aliens to ever see any tv show.