Your answered your question with one word "believing". Sorry mate science isn't believe. Yes there is probability of aliens. We have equations like drake. But and this is big but - we haven't found one. Maybe it's as we want it to see. Maybe they have observed our solar system and are debating if Venus, earth or mars has life?

The number of planets and exoplanets does little for the chance of abiogenesis.

Not quite. There is no evidence that God or any gods exist, so it's purely faith. We have evidence that life exists on one planet (Earth), and there is an uncountable number of planets in the universe, so the probability that alien life exists is very real and not just belief/faith. Whether we'll ever find/interact with them is a different issue.

Having been contacted by aliens in the past, though, is still purely belief.

So you think that we sit at the absolute epicenter of the universe even though we don't sit at the center if our own galaxy?

It isn't unrealistic at all if the odds of abiogenesis are prohibitively small. We can imagine all sorts of events with vanishingly small possibilities. We might not be able to wrap our human minds around the numbers involved, but that's kind of the problem: we look at the size of the known universe and say, well surely, x must have happened at least once. But without a sense of the probabilities involved, we simply do not have any reason to say whether x has happened or not.

There are plenty of conceivable events that happen precisely zero times (things that would violate the laws of physics), and we can imagine possible events that never happen at all -- simply because they are so unlikely that not even trillions of years of interactions between gazillions of particles will bring them about. We might posit that somewhere a teacup from the 1972 Sears-Roebuck catalog is orbiting a planet made of leather. This is certainly possible -- in the sense of not contradicting physical laws -- but it is so unlikely that, no matter how vast the universe is, we cannot be certain that such an item exists. Abiogenesis might simply be one of these mathematically highly unlikely events.

I'm actually not as skeptical about extraterrestrial life as I sound. I do think that, given the tendency that compounds have of quite naturally bunching together into slightly more complex compounds, it does seem reasonable to think that life is fairly abundantly distributed around the universe. But we simply don't know enough about life or about the universe yet. For aught we know, life could exist in the cores of neutron stars and on every god-forsaken rock in the universe -- or just here on this little blue rock for the past few billion years or so. Nobody knows.

You have no way of knowing that there even exist a non-observable universe, and in the BB theory, we are indeed in the center of the universe (observable or not).

Not at all. We are the center of our observable universe and that's all. We are not the center of our universe

Actually, for intelligent life to occur (and not be destroyed) there may be even more conditions to be fulfilled than the amount of galaxies.

Besides, you are looking only at one dimension here - size of the universe. There is one, even more hard to comprehend - time. And I find it entirely possible that there may have been civilizations before but what can be almost impossible - is to have the right matching for time and place.

Anyways, not taking aliens as a matter of fact is the right scientific approach for now. And probability may go to hell with such a sample size, as someone pointed above.

I believe there is life in the universe other than our solar system. It’s just too big to think that’s not possible.

I just don’t believe aliens have visited our planet because I’m not deluded.

There is a difference between "life likely exists somewhere out there" and UFO anally probing some drunk dude.

There is no proof of aliens. I guess you think Enrico Fermi was insane.

[deleted]

> nor probably ever will

Actually, there are several possibilities within reach. Mars had water, so we might find signs of current (or, more likely, past) life. Several moons of Jupiter and Saturn also have water. So, maybe within our lifetimes.

Well I see the same distance into space no matter which way I look?? I must be in the center then

[removed]

Belief is faith. Believing in aliens is no different than believing in God. Until we get out there and find out more we could just as well be completely alone vs the universe being crowded. Doesn't mean we've always been alone or will be. But we very well could be living in a period where we are the only life in the galaxy.

I don't speak math (one of my few regrets in life), but I am pretty sure that it is a mathematical impossibility of us to be the only planet of sentient beings.

People who read and write math can correct me and I'll take it. Just seems you can't have gazillion stars and tetragazillion planets out there, it would take some serious calculations to "prove" we are as smart as it gets. . . because that really would be depressing . . .

I've never met anyone who says that there isn't life out there somewhere. What people deny is that we get visitors. And seeing the size of the universe, I doubt it too

Given the amount of galaxies, stars, and planets, it is unrealistic that the earth is the only planet where life has occurred. It is, however, very likely that the conditions on earth has happened elsewhere

"yet not believing in aliens"?

What does that even mean? No aliens have ever been documented to exist.

According to the current orthodoxy (Big Bang theory), we are in the center of the universe.

(As is everything else as well).

We literally just don't have sufficient information to make a most approximate educated guess, with a sample size of one.

Or probability.. it's more probable they exist than dont.. coming to visit earth is another story

We don't know how easy it is for life to start and I don't think there is a "centre of the universe" or is that everywhere could be the centre.

I can't remember.

What do you mean by “believe in aliens.”

“Believe in aliens” is generally shorthand for believing that aliens routinely visit Earth and possibly intervene to teach humans fire and how to build pyramids and occasionally probe the rectums of farmhands.

I think you mean, “believe life exists elsewhere in the universe.” That’s the scientific view that statistically there ought to be life elsewhere if only single celled life, but no contact has even been made nor probably ever will.