Life in the space, other than the Earth?

Question

I noticed a simillar question was posted 3 days ago, but mine is bit different. I am asking for the possibility of the life in the "whole universe", not just our solar system.

I have very little knowledge on the space study, so I may misuse some words. But I am sure you understand what I try to mean.

As you know, there are many, many galexies out there, which could take some billion light years or more to just get to there. We simply can not travel that far, because our technology has not been developed sophisticated enough.

Based on this fact, I think it is natural to imagine that there must be some lives (not the primitive ones like the becteria, etc.), close to the human. They may not have been evolved good enough just like us right now, but who knows if they are having the middle ages of their own right now.

This is what I think. Do you think, or can you give me a fact that there may be a high leved livings like us out there?

Where do you think they possibly be?

Answer 1

So far we've seen no verifiable evidence of other sentient species. That said, I believe with some certainty that somewhere in our galaxy at some past, present, or future time, a sentient species did/does/will exist.

Why haven't we heard from them?

Perhaps they are not technologically advanced enough to be heard. They may be mastering stone knives right now, or experiencing their own Rennaisance.

Perhaps they are here right now. Any species sufficiently advanced to travel interstellar distances would be able to hide or masquerade with ease. That Boeing 737 that just flew by may be a surveillance craft.

Perhaps they are so far away they will never notice us and vice versa.

Perhaps they existed a million years ago and died out.

Perhaps they will exist a million years from now.

It is really impossible to know for sure.

The Drake Equation suggests that there is sentient life out there. The Fermi Paradox casts doubt. Play around with the calculation form at the second link and see what you think.

Answer 2

What's weirder to think...that in all the vastness of space, in the billions of galaxies and trillions of stars, we're alone? Or that we're not?

Personally, I think there is intelligent life out there. We'll probably never find it, though. Our closest neighboring galaxy - Andromeda - is about 2 billion light years away. Traveling at the fastest speed possible (the speed of light, theoretically) it would take 2 billion years just to get there.

As for life within our solar system...it's possible that life will be discovered on moons we have yet to explore. Europa, for example.

Answer 3

There is a famous equation concerning this whose name eludes me. It computes the likely number of intelligent civilizations which might be thriving currently and able to communicate with us. The values for each parameter are assumptions, but even with fairly conservative numbers the likely number is quite large. It goes something like #of galaxies x #of planetary systems x #of planets x %of planets which might support life similar to ours x %of those which might actually develop life....etc.