1: Without direct observation you can't say anything with certainty (and with quantum states, even observation can tamper with evidence to the point where there can be doubt as to the validity of your result.
2: But that's not relevant in this discussion and is a whole can of worms anyhow), but we can say something is "probable to the point of being certain", which basically means if it's exceedingly unlikely something isn't the case, it probably is the case. Occam's razor and all that. The simplest and most likely result is most often the case; in this case the mathematics favor the existence of alien lifeforms somewhere (although at this stage in our progression as a species most likely unobservable) to the point where it's so probable it might as well be 100% (see 0.00000000001% chance that we're alone in just our galaxy, let alone the billions upon billions of other galaxies. Even if we assume only 1 in 100 billion planets can sustain life, that still means there's roughly one planet per galaxy, which means there would be billions upon billions of planets with life on them in our universe).
3: It's unproven, and unobserved (thus far), but the chance of non-terrestrial lifeforms is ~100% in our universe. We might never come in contact with them, and they might not be intelligent to the point of being able to communicate, but the odds are so much in favor of there being life somewhere that it's just illogical to think otherwise.
I'll break down my response as follows:
1: Which goes back to my point - There is nothing that indicates in any way there is something aside from us out there.
2: You are correct about one thing here -
The worms.
Probrably this morning I'm going out to grab an early morning bite but there are sooooo many variables between me (Personally) and me actually having it (The breakfast) in my hand, each variable either adding up to or against me having it in that way.
By it's definition even Occam's Razor isn't an absolute, it says "Most Likely" based on condition(s) of
established simplicity.
In the case of simplicity, it's a condition of all variables possible to be removed have been to simplify the information which, in turn will hopefully point to a specific thing or direction.....
However in this case, since we are still FAR from having all the data/evidence there is no way it can be broken down to such simplicity, at least we can't do it with the data we currently have to work with.
Occam's Razor can probrably answer an issue that's direct such as a "Yes" or "No" kind of thing but there are times and things you just cannot boil down to something so simple, aside from the final "Yes" or "No" answer in the end.
3: That's the point - Until
it's proven one cannot honestly say it as a certainty. Even if it seems logical to do, say or even believe one thing, how many times has the universe made just the opposite reality?
Used to be for example a Black Hole's gravity well was so powerful nothing; As in N.O.T.H.I.N.G. would or could ever escape it's gravity well and that was the thing we knew about them.... Or we thought we did.
Not too long ago lines of magnetic force were observed, researched and proven as fact to be emanating from them, generated by them and these were expanding and contracting in AND out.
Our knowledge was once again tripped up and that goes back to our knowledge being incomplete.
You can't rule out a variable if you don't know it even exists in the first place and logically (To me) I cannot and will not say it in such terms or assign a percentage value to it. Until we have something that's actual concrete evidence like an overloaded Vegas Casino sign pointing to it I'm not.
I can only say that's is possible...... But at the same time it's certainly not fact...
Yet.
