teh_pwn said:
Mathematically, the probability that you are alive at any point in time is basically 0. Time is infinite, your life span is finite.
ACTUALLY...
Time is infinite as a linear concept, it's basically just a sequence of moments, with no other rules opposed on that.
It is unclear though whether or not time as an actual physics phenomenon is really finite or infinite.
It's exactly the same with space, and that should be no surprise. Because what you did is take an abstract concept for realz, which is a rather common jump into crazyville.
--
Furthermore, you state that our life span is finite. YOU CANNOT POSSIBLY KNOW THAT.
Of course, the things you hear about everyone dying are rather convincing, but it may very well happen that we humans find a way to recycle body parts or whatever would be necessary to make us live forever.
Or even more drastic, as someone else said: Why not detach our consciousness from the actual body?
As long as we don't really know how all that stuff works, you can safely say that it's not set in stone that humans will die forever.
--
You're stating that the probability that we're alive at any point in time is basically 0.
But however you came to that conclusion, it is in fact false. The probability that we're alive at any point in time is 1 because it is factually true. You are alive, I am alive, there's basically no diceroll to be made.
It's like saying "The probability RIGHT NOW that I would have thrown a 3 A MINUTE AGO although it actually was a 5 is non-zero". That is false. The error you made is attaching probability to an already unprobabilistic fact because it's happened.
Making statements about the past in a probabilistic way is not a good idea simply because the past only contains fixed events. Referring to probability makes sense when you take things you've observed in the past, came to conclusions that indicate some probabilistic behavior as time passed, and then make GENERAL statements about the HYPOTHETICAL case that this and that may occur while referring to your observations.
So you say "Okay, I threw the dice 1,000 times, each number came roughly equal times, so they seem to be equally probable, the dice has 6 sides, well, then the probability for a number to occur if I throw this thing again is 1/6".
--
Now I know that you wanted to say "The probability for ANYONE to have lived at any point in time is 0". And that's also false. It is simply unknown. It could very well be 1.