What @TheMiddleWay said with some reservations. I am 99.9999...9% sure there is life elsewhere in the Universe, perhaps in our solar system. I won't go the full distance because of the same reasoning he brought up.

(Sorry, I'm definitely violating the keep it short rule. The short answer is I don't honestly know.)

I am educated as a scientist. Sometimes, I would respond: Definitely! But lately I've been questioning this assumption. The problem I have is the Anthropic principle (https://en.wikipedia.org/wiki/Anthropic_principle).

Because we exist, we report that we exist. Unfortunately, our data on the question of life beyond Earth is limited statistics. Our statistics on life in the universe are exactly unity. You can't do any meaningful statistical analysis on that little data.

From my knowledge of biology (I'm not a biologist, I'm educated as a physicist) I find it extremely unlikely, like .000000000000000000000000000000000000000000001 chance that self reproducing RNA spontaneously develop. That means, it is possible that life exists ONLY on the Earth and we "think therefore we are" only because of the Anthropic principle. I want to believe that there is life elsewhere but there exists no evidence.

Yes, the number of possible planets is exceptionally large, still that doesn't mean that life has developed separately from us. It isn't a matter of probability BECAUSE of the Anthropic principle... It is possible that we exist in one of the few universes that we could exist in despite that there are 10^450 other universes. Then it remains possible that we are the unlikely ONLY life form in our universe and perhaps all of the others as well.

This is a depressing thought for me but I can't dismiss it. Has anyone ever seen the movie Melancholia? When the world is facing annihilation, her sister says "certainly there is life on other planets?" the anti-heroin, Justine, who has had prescience throughout the movie, so we have no reason to doubt her, says: "Life is only on the Earth - and not for long." That statement scares the hell out of me but it may be true.

[imdb.com]

The probabilities of life elsewhere in the universe is undeniable. That being said, It's unlikely we'll ever meet life on other planets, let alone intelligent life. Comes down to distance.

I'm not so arrogant as to imagine that we're the only ones floatin' around !

Fiction mimics reality. The movie, Avator, takes place on a moon of a gas giant planet in the Apha Centauri system. Moons of gas giants in our home system possibly harbor life. The question about life anywhere other than earth may be answered within the next couple of decades, not to mention other planets in other star systems. So what will happen is we'll discover life and Christian missionaries will be the first to go there and try to convert the inhabitants.

While the probabilities are superficially good, until we actually find life elsewhere, we can't say for sure. If the odds of life arising are low enough, we may be unique. Like the odds of a monkey typing Hamlet by chance. Doesn't matter how many monkeys you have, it's odds are so low as to be effectively zero.

It would SHEER, Unadulterated Human Religious fed Arrogance to think/believe that only this 1 single planet amid possibly millions in the Universe would have some sort of life on it.
As to whether that life-form may be intelligent or not is another question since We humans see ourselves as being the 'Pinnacle of Intelligence and Evolution' then I ask Who are we to actually judge since WE can't even manage to get along with members of our OWN species.

The Fermi Paradox suggests there is a high probability of extraterrestrial life. So, I think keeping an open mind about the existence of ETs rather than denying the possibility is the better way to think. When proof presents itself maybe I'll feel a little better inside.

of course but how far away it is will be the difficulty

Why not.... Do I want to go there ? NO!

Yes, I would expect life to crop up elsewhere. It might be foreign enough for us to not even notice if we define it based on life here.

It's only a matter of time before we get confirmation. But it will not be in the UFOs field that it will be confirmed, but after our civilization leaves the boundaries of our solar system. So centuries from now.

Given the sheer unimaginable vastness of the universe there is surely a high probability of life in a variety of forms on other planets within our galaxy and beyond in other galaxies. I think it exceedingly unlikely that we are the only life form in the universe.

As you say, it's just a matter of probability. It's a given in my mind, but even finding the most rudimentary microbe on another world in our solar system would raise that probability astronomically (no pun intended) to the extent that we could start talking about sentience.

There has to be something living out there.

There is likely life on other planers. But, without any evidence, certainty is not possible.

There is not a doubt in my mind given how unfathomably big the universe is. I find it highly unlikely that we are the only sentient life in our galaxy much less the universe.

hey why not, its a big universe

If you're talking about life in general then yes, we know of microbes but if you're talking about intelligent life with communication technology then that is unknown at the moment.

I've mentioned the Drake equation (whichever incarnation you want to choose) and the Fermi paradox elsewhere on Agnostic.com. The numbers make very compelling arguments.

Now the question seems to be Why is there no evidence of ET life yet?. It is becoming apparent that believing we are alone is a step beyond arrogance.

Life in the single cellular sense? Probably, but I'm doubtful that we'll ever see it.
Intelligent life? Really no idea, but I'd be seriously surprised if it was in our galaxy.

"It's life Jim, but not as we know it..."

It's just a matter of time before we find evidence of it.

Scientist's estimate there are more than 10 thousand billion billion stars in the universe, and even if a fraction of them had planets that are suitable for any kind of life, I don't see how there COULDN'T be life out there.

No reason not.