The signals which are emitted from earth would be extremely weak, that is true, but they are very narrow bandwidth and modulated in a manner you would not see from a natural source.

One thing would be to have an antenna which is simply physically extremely very very large to focus them. This could be done at quite a distance though.

The question is are there any ET civilizations who are really really interested to find other civilizations in the galaxy? Interested enough to build enormous receivers and scan all the frequencies?

I don't think there's any doubt it could be done if they're within a couple hundred light years. IF they are though, they would have to be putting a lot of effort into listening.

Just another speculation. Cause it's fun.

Premises: Rather benign aliens with psychology somewhat similar to our own.

If UFO:s really are about alien spaceships, and if I were an Alien onboard, I would be careful with that first contact with humans.

Probably General Ezxoophyth and his superiors have ordered all ships to remain in stealth mode for the time being.

I think they realize that humans will react in may different ways, some might be enthusiastic, other openly hostile (and maybe dangerous, even to little grey bodies) others will be covert enemies, organising underground, planning to use heavy weapons against the "foreigners". They know that humans will tend to be very suspicious, feel very unsafe and insecure, and thay might have had the same experiences as we have from disastrous meetings between very different cultures.

In other words: If they announce themselves very clear and unambiguosly - some kind of hell will break loose and that would be dangerous and contraproductive even for them.

Of course, they have fast vessels and maybe fantastic weapons, but what's the point of getting into a war with humans? If they'd be forced to kill one human, even in self-defense, humankind would never ever trust them and further contact will be almost impossible.

Maybe they, the aliens in their ships, show themselves once in a while, just to test us and/or to make us accustomed to the idea. Like a psycho-cultural priming.

I consider that a bit of an oxymoron.

__________________

But General Exooplyth would not be hanging around Earths upper atmosphere. If they did actually enter our solar system; all they'd have to do is radio ahead. "Hey guys we are on our way; we are 1 light year out; lets meet on Pluto." But we can't reach Pluto at the current time too easily.

As bad as the movie Contact was; Sagan nailed it; regarding the premise of how it might take place. Forget the "UFO's on the White House Lawn" thats just trashy comic book stuff.

First we'll get a radio signal. The signal will contain information; instructions, directives; blueprints, and procedures.

Don't think Star Wars. Think Scientific conference.

Another speculation, we get a large download of text and images, and it turns out to be a religious text! And the blue prints turn out to be a temple! That would rather funny in my opinion. Or here is an idea, they send us the genetic blueprint for them selves as well as instructions on proper care. The human genome could fit quite easily on a modern hard drive, so unless they use exponentially more, I don't see that as been impossible.

__________________

It could? Maybe I'm missing something here.. Or misunderstanding...

http://www.utheguru.com/fun-science-...the-human-body
That is for one human, mind you.

__________________

Of course, if you're going to start counting information, most of that is a copy, from cell to cell, minus any random mutations that may occur. And most of that information never gets activated.

__________________
http://amssolarempire.blogspot.com

But if cloning has proved anything, it is that one cells DNA is all you need. Of course, creating a completely unrelated life form that may not even use DNA would be an impossible task with todays technology, but my point is, it is theoretically possible to send an organisms genome by telecommunication. It would require much more information then that of course for an alien life form,because there would have to be some kind of unambiguous representation of their equivalent of base pairs, or what ever they use. Still, information is information.
It would make a wonderful science fiction novel, a kind of reverse "Stranger in a strange land."

__________________

A for Andromeda, written by the excellent Fred Hoyle, included an entity sent by radio.
http://en.wikipedia.org/wiki/A_for_Andromeda

__________________
Orion's Arm . The Starlark . Voices: Future Tense . OA Flickr set

To reproduce humans or aliens, it's not as simple as "knowing the sequence in the genome". There seems to be a lot more to it than that - specific patterns of gene activation, and control over that etc. Still a lot of unknowns.

Admitted, but such things are information, which can be transmitted. It wouldn't be easy, even impossible for us at this point, but not impossible for any laws of physics reasons.

__________________

The Genesis Quest series was about aliens building human DNA from radio signals, to recreate our species millions of light-years away. People from a kit. As a side note, the transmitter humanity used to reach another galaxy was the size of a solar system, powered by a Dyson Sphere.

__________________
"If this were play'd upon a stage now, I could condemn it as an improbable fiction."
Shakespeare, Twelfth Night
Illuminati's Razor-The most complicatedly evil answer is usually the most correct answer. - Fazor
"Every book is a children's book if the kid can read." - Mitch Hedberg
"Distance doesn’t matter much in space, where if you just start a thing off with the right kind of shove, sooner or later it will get where you want it to go." -Frederik Pohl, Mining the Oort