Originally Posted by jimenato

Gis a clue!

Originally Posted by Dick Dasterdly

Interesting, thirty years into space on a five year mission and still transmitting and receiving.
Radio signals generated by other planets and solar systems have been picked up for many years.
A radio signal does not neccessarily have to be directed to and from one specific point or planet and can cover a wide spectum of the universe.
Also once out into space there is nothing to attenuate the signal until contact is made with another atmosphere or planet.

Originally Posted by bil

There certainly hasn't been anything detected that has intelligent origens.

Originally Posted by whitelinen

Originally Posted by bil

I'm glad you find that amusing. It's a simple factual statement. Care to share the joke?

Originally Posted by whitelinen

no you wouldnt get it

Originally Posted by bil

I can see a possible joke, but it's puerile and tedious.

Ooooppps. Of course, I was forgetting who you were.

Originally Posted by whitelinen

Miaow

Originally Posted by HBG

On my short journey through life I’ve been constantly surprised by new discoveries, from Dolly the sheep though to successfully transporting particles through time, even though it was just across the Danube.

It turned me into a believer. I believe in aliens, ghosts, a parallel universe, anything at all. If one turns up on my doorstep, I can only hope it’s a female, preferably with a nice bum.

Originally Posted by bil

OK, look at what I wrote. I am prepared to say it might happen, BUT, and it's a massive BUT, I see it as so unfeasible that it really doesn't need much planning for. Anyway, if they came, what's the odds of our planning being valid? Our planning for the flu virus is pretty sketchy, and that's a real thing that is very much a potential threat.

Do you really think that they will be that different?

Consider this. (Not wishing to sound patronising, but if you don't have the science, some of this may not be clear.)

First off, unless they are some weird form of plasma derived life, my money is on them looking and behaving much like us. Why? well, let's look.

1. They will be a carbon based life form.
2. They will operate at similar temps to us.
3. They will be bipedal with two legs.
4. They will be of a similar build to us with variations wrto the mass of
their home planet.

Reasons.

1. Carbon is the ONLY element that can make weak branching bonds.
2. The chemical reactions that sustain life need a liquid medium to work in
that has a very wide ability to dissolve materials.
3. It is improbably that they will not evolve from a water based life form.
Anything that evolves in water has to evolve to look similar because the
forces acting on them will be the same everywhere in the universe.
Aquatic reptiles, fish and mammals ALL look much the same. Legs evolve from fins, fins are placed on the curves of a sine wave for maximum push, and a fish is essentially a sine wave. Bend it thus and you will see that the pelvic and pectoral fins fall on the outer curves, and there are two in a sine wave. Make a fish that needs three pairs of fins and the curve becomes too long and cumbersome. This isn't proof, but it just places the probabilities waaaay over to the likelihood of fish developing as they have here.

Had dinosaurs not been wiped out, they would almost certainly evolved into a small bipedal form that would have filled the niche now occupied by apes.

They would probably have looked like us but with reptilian traces and ancestry.

4. Evolution is the survival of the fittest, and the human build is what worked best.


There are, in the history of evolution many routes by which things might have travelled, but at the end, our way of doing things works. To me the odds are that they would be bipedal, stand upright, have their sensory apparatus on a 'head', drink water and breathe air, because what else is there to breathe or drink?

Extreme environments are far less likely to spawn life as the initial stages are very fragile. In addition, if we accept the theory of panspermia, then all life has a common origen, no matter on which planet it evolves.

Originally Posted by bil

Ahhhhh, I fear we have made a slight error.

The difference between a laser and a spotlight is that the laser is coherent and parallel. That means it travels further, but can only be aimed at a pinpoint in the sky. The spot light covers more, but attenuates far faster, and every grain of dust reduces its power.

Radio fires out in all directions, but attenuates. It actually 'covers' the entire universe, so gets almost infinitely attenuated, ie undetectable fairly quickly.

I presume the transmitter you refer to is the one on the probe heading out of the solar system. We are a fraction, a tiny fraction of a lightyear from it. We can only just pick it up, and by the time that the expanding signal wavefront reaches A Centauri, just 4 light years away, thjere will be next to nothing to detect. What price detecting it 1,000 lightyears away?

Oh yes. One more point please? I'd love to know where we have been receiving signals in radio from other planets and solar systems?

I'm pretty sure that the only such signals are generated by particular solar masses, quasars etc. There certainly hasn't been anything detected that has intelligent origens.

Originally Posted by HBG

It turned me into a believer. I believe in aliens, ghosts, a parallel universe, anything at all. If one turns up on my doorstep, I can only hope it’s a female, preferably with a nice bum.