Could there be extra-terrestrial life?

[Lavender1627]

I would like to hear all your arguments on extra-terrestrial life.
What they might look like?
What they might be made of?
Where they might be?
How advanced (Technology, evolution, etc.)?

[canalon]

Very probably, There are enough planets out there, that there is no reason for us to be alone. Beyond that, I have absolutely no clue what they might look like, what kind of chemistry they might be based on or anything else.
But they probably have evolved from some very simple life forms and would provide an interesting test for the theory of evolution

[JackBean]

I believe yes. The Earth life can survive lots of conditions, and the extra-terrestrial life can be even different. New candidate planets are discovered almost every month, so in my opinion probability of some simple life is very high. However, it quickly decreases with complexity of the life.

[JorgeLobo]

There could be but "very probably" is not a defensible statement. Just becasue there are lots of planets doesn'lt mean their number alone satisfies probability. Since we dont know the events that led to life's initiation and maintenance, we can't estimate that probability.

[Cat]

Actually I think if you “predict” our future you will probably discover our past…

If conditions on Earth will become harsh and inhospitable, I predict that at least one government will create and lunch some space program sending people to other planets assumed to be hospitable to us. Let’s say it takes several generations to get there. Once there, newly arrived people never have seen earth – past is nothing but a legend. In a few generations people move apart, start new societies, create new history and forget the past. Instruments/technology wears out and become rare and “magical” to population. As time goes on, appearances change and they completely forget the past. After several thousand years, they reach technological level equivalent of our today’s society and start wondering if they are the only ones in the universe…

[JackBean]

why should they forget the technology?

[Cat]

why should they forget the technology?

Because we always forget what we don't use (unless we write it down). Do you know how to make a sword? Not unless you look it up.

Let's try another one. Common equipment for a biologist - microscope. What do you need to know to make one?

1. Biologist that knows how to set it up (basic structure/function).
2. Glass maker to make lenses.
3. Geologist to find materials.
4. Miner.
5. A blacksmith.
6. Mechanical Engineer
7. Whomever I forgot...

Now, say it takes 500 years to reach new planet. To make a microscope on the new planet all those specialties must be maintained, thus you teach then to each new generation. Here is the problem: to be a miner (more than any other specialty listed here) a person needs hands-on knowledge impossible to pass on while in flight. This skill will have to be re-developed when they arrive on the new planet. However, I would predict that there would be sufficient material that could be obtained by disassembling the ship to postpone re-developing this skill in favor of hands-on agriculture.
Now, how long do you think it would take for the language to change sufficiently so that written information becomes difficult to translate? Keep in mind that Shakespeare's work is about 400 years old and needs to be translated.

[JackBean]

I guess if they were to colonise other planet, they will probably take the knowledge with them. However, these issues (population size etc.) is probably one of the things, why we are not in space yet.
(besides others, of course)

[animartco]

It would be most surprising if there was no life on other planets. In our solar system there are several places where there could be life, including Venus. Research into extremophiles, is growing day by day. We now know that even quite sophisticated organisms can survive in amazingly acidic conditions. And this is on Earth! Imagine what could have evolved on a whole planet with those conditions in the same timescale as it took life on Earth to evolve. I think we are far to insular in our thinking about alien life forms. Bilaterally symetrical life is probably quite rare. Almost equally rare would be oxygen breathers. Or creatures evolved to live in 1G or in sunlight which is really quite harmful to organisms. The other factor which few have considered is that it is doubtful whether alien life would have eyes or ears. They probably have a completely different set of senses to any found on Earth, and this is why they don't use radios.

[JorgeLobo]

They don;t use radios?

[animartco]

No,Jorgelobo, no radios. Surprising isn't it? As well as thinking that they'd look like us we assume that alien technology would be along the same lines as ours. There are probably races which do their computing by using subatomic particles making quantum leeps up down and around in a feeler held 4inch square Hadron collider.

[JorgeLobo]

Sorry the irony went by you. Guess no thong underwear either?