I allow the possibility that "somewhere, out there" is existing some living form (or more specifically - intelligent form, because to find "any" living form (e.g. bacterias) outside earth we don't even need to leave solar system).

And that's it. I'm generally against using forms of "believe in" to things, which are possible (and what is more - necessary) to prove. I can "believe in..." in case of religion, philosophical "belief" etc. That's totally adequate and fine, since in faith we're not expecting, not need nor can "prove" (in manner of empiristic science) existance of God or such values as truth, good etc. Which doesn't mean that they don't exist.

In case of any life form though... I simply don't feel it's right to "believe" in it. Allowing for possibility - yeah, that sounds good. It sounds good due to the fact that we're facing "great unknown" - universe beyond our capabilities to observe it (due to technical limits). But it's as safe as assumption that we're totally "alone" in universe.

Moser's number is huge (and that is a huge understatement; it's way larger than the numbers we call "astronomical"), but that doesn't make it infinite. It isn't even close to the highest finite number that can be easily defined.

https://en.wikipedia.org/wiki/Steinhaus%E2%80%93Moser_notation


Lots of things that exist are not mentioned in the bible; in fact, there are more things that exist that aren't mentioned in the bible than there are things (both existing or not) that are.

In other words, that argument fails.

Don't know, i've only had a GF with the libido of a dead fish...

I could point out a principle in mathematics called the "pigenhole principle". Basically, if there are X items, and Y types of item, and Y > X, then at least 2 items must be in the same state.

(Example from where this statement got its name: If you have 13 pigeons and 12 holes, if every pigeon goes into a hole, at least one hole must have at least 2 pigeons; there is no distribution that would prevent that.)

(Of course, that principle isn't applicable to the particular question at hand; this is just the sort of thing to be aware of, what it says, and, also importantly, what it does *not* say.)

I see...

Also, many people don't understand probability, and some things are counter-intuitive.

For example, the birthday paradox: If 23 people are in a room, there is a 50% chance that at least two of them share the same birthday. Doesn't that number seem rather small? (I believe this calculation assumes that nobody is born on February 29, and that all birthdays are equally likely; two assumptions that aren't correct, but which serve to make the calculation simpler.) This chance increases to 99.9% at 75 people, and 100% at 366 (or 367 if you count 2/29) people (thanks to the pigenhole principle).

There's also, of course, the monty hall problem, which many people get wrong and insist their wrong answer is the correct one. (Apparently, at least one study has shown that at least one type of bird is better than humans at this sort of thing.)

I love math, and I wouldn't mind discussing it with anybody who is interested.

I wouldn't be so sure about that. It is possible that, billions of years ago, some life forms might have arrived via comet or meteor.

There is, I believe, evidence that life existed on Mars.

It's possible that the apparent nuclear war might have been the result of natural fission reactions. Yes, such a thing exists.
https://en.wikipedia.org/wiki/Natural_nuclear_fission_reactor

I'm not sure. I don't have the information to say what it was or what it meant.

Though i am aware of the natural nuclear fission, which explains why one such source of uranium was depleted because it was naturally reacting and being contained/regulated by the ocean. Quite an interesting event as i recall.

"If it bleeds, we can kill it."

Perhaps they carried some carbon compounds but I doubt they carried actual lifeforms.

I am not aware of any current evidence that life ever existed on Mars.

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A cliche, but a good one. XD +1

Classic, not cliché.

Yes, I'm sure aliens exist. About half the stars in existence have planetary systems and a significant number of those (about a percent of or a few percent of all stars) contain planets in the habitable zone. That means even life that is comparable to ours in that it depends on liquid water will exist. We know that the probability of life evolving on a suitable planet is non-zero. We also know that there are billions of suitable planets in our galaxy alone and that there are trillions of galaxies in the known universe (and who knows how far the unknown universe extends?) Statistics basically dictates that we are not alone in the universe. But the distances involved dictate that we will probably never establish contact unless super-luminal communication over arbitrary distances is invented. Super-luminal travel would be one step more. I don't know if it will ever be possible. But even if it is and if some civilization somewhere in the universe has mastered it, the chances of them being in our neighborhood and coming to us are very, very small. So I am equally sure that no alien visitors exist on this earth.

Depends what exactly is meant by the question.

Do I believe there either is or has been, or will be, some form of life, even as little as bacteria or other micro-organisms?
- Yes, it is quite possible, maybe even probable.

Do I believe there are aliens with superior technology who know about us and have visited Earth?
- Very unlikely, I'd flat out say no.

First of all we are talking about so long timespans. So it might be possible that already six billion years ago there was some intelligent life form (or micro-organism) two billion light years from us... but it would be very unlikely they'd still be around. They would have perished long before Earth was even formed, let alone first forms of life appearing here.

Or, it might be some planet or moon far far away from here "creates" some form of life ten billion years from now, long after humans and any forms of life on Earth have ceased to exist, after the sun has engulfed Earth and the colonies we tried to create on Mars failed too.

It is also possible there are lifeforms somewhere right now, but they are probably so far away from us that they will never know about us, and never have technology to come here. Billion light years is just as hard for them to travel, as it if for us. This is no Star Trek.