Fermi's Paradox.

[Dauphin]

If there are inteliigent civilization's out there, why can't we detect them?

I figure everyone might just be whispering. You could have a million people on Earth, spread out every few miles, and they would not be heard, even if they shouted.

I hear a lot about radio and television signals being sent out in to space, and that aliens with 100 light years can now be watching and listening to our broadcasts. How true is this really? Firstly, can anyone tell me how powerful the first radio transmitters were and whether those signals were sent out into space (or just bounced straight back due to the ionosphere). Secondly, I can't even pick up radio or TV station transmission even when I get about 50 miles aways, let alone 50 light years away.

Anyone got any technical and historical knowledge on this stuff. For example, how far away can you pick up a fairly coherent (i.e you can tell what it is and maybe get a fuzzy picture) satellite TV signal assuming it is losing power intensity purely due to the inverse square law.

[Eli]

Bump.

[Solly]

Why do we need to detect them?

[BeBMan]

We are still busy searching intelligence here at our planet

[BeBMan]

Re: Fermi's Paradox.

Originally posted by Big Crunch
I hear a lot about radio and television signals being sent out in to space, and that aliens with 100 light years can now be watching and listening to our broadcasts.

I guess here lies the problem. After seeing our stuff the Aliens decided it is not worth to build a starship to meet us.

[Kuciwalker]

Truly, that is the answer.

[The diplomat]

Re: Fermi's Paradox.

Originally posted by Big Crunch
If there are inteliigent civilization's out there, why can't we detect them?

Perhaps because there is no extraterrestrial life out there to detect.

[FrustratedPoet]

Wrong. Read the first half of that sentence you quoted and try again.

[The diplomat]

Originally posted by FrustratedPoet
Wrong. Read the first half of that sentence you quoted and try again.

Well, there are many possible explanations. Maybe the extraterrestrial civilizations do not have the tech to transmit signals to us, maybe they received our signals but can't understand them, maybe they are too far away to communicate with us, maybe they don't care to communicate.

But there is also the possibility that the original "if" is wrong, and there is no life out there at all.

[Solly]

The question, and this discussion, is irrelevant.

[Hueij]

Re: Re: Fermi's Paradox.

Originally posted by BeBro


I guess here lies the problem. After seeing our stuff the Aliens decided it is not worth to build a starship to meet us.

Hehe... I guess Carl Sagan was right in Contact about what tv pictures the aliens would pick up first

[:) Smiley]

Though another extension of the paradox goes that since Earth is a young planet in the cosmic time scale, there ought to be at least one earlier civilization that would expand all over the place in the universe.

[The diplomat]

Maybe we should get to work on an interstellar propulsion system and go looking for ET.

[lord of the mark]

you guys familiar with the rare earth hypothesis?

Says that while life may be widespread, development to intelligence takes a long time. Which require relatively long period without life being wiped out. Which require certain stability in orbits, many other astronomical factors. Which are probably quite rare.

So theres probably intelligent life somewhere out there (there are, afterall billions and billions of stars) but probably not more than a handful of independent starts to intel life in the entire galaxy. Which would mean that not having met up with any isnt all that surprising.

[Odin]

Originally posted by lord of the mark
you guys familiar with the rare earth hypothesis?

Says that while life may be widespread, development to intelligence takes a long time. Which require relatively long period without life being wiped out. Which require certain stability in orbits, many other astronomical factors. Which are probably quite rare.

So theres probably intelligent life somewhere out there (there are, afterall billions and billions of stars) but probably not more than a handful of independent starts to intel life in the entire galaxy. Which would mean that not having met up with any isnt all that surprising.

Familliar with it? I've READ the book. I beilive there is at least one other world in our solar system with life, Europa. One thing I dissagree with about the Rare Earth Hypothosis is that Photosynthesis is needed for the evolution of Metazoans. I belive that Chemosynthesis is enough to liberate oxygen from CO2. It would be cool if we found complex animals in the seas of Europa.

I think the problem with finding ET is that sentient species are rare, and they don't all exist at the same time. I think there is less than 5 other sentients in the galaxy. I know those alien sightings are fake because the descripitions are too human-like. Who knows, Maybe the first ETs we find are actually quite small, imagine big-brained social insects.

I think most living things in the universe are made up of similar materials that we are, Nucleic Acids, Lipids, Proteins, and Carbohydrates. This is because the whole universe obeys the same chemical laws, and so one cam imagine the Primordial Soup drifting down into the deep sea and energized by black smokers to form life. The main differences will be in the Bases Of the Nucleic acids and some of the less common amino acids. The simple amino acids such as Alanine and Glycine, are universal.