One might mean either of two things by "infinitely divisible time." One might mean merely that (1) any nonzero interval of time can in principle be divided into smaller and smaller units indefinitely: what's sometimes called a "potentially infinite" collection of units of time each of which has nonzero duration. Or one might mean that (2) any nonzero interval of time actually consists of infinitely many -- indeed, continuum many -- instants of time each of which has literally zero duration: what's sometimes called an "actually infinite" collection of instants. I myself favor (2), and I see no good reason not to favor (2) over (1). Both views of time are controversial among philosophers, and some physicists conjecture that both views are false (they conjecture that an indivisible but nonzero unit of time exists: the "chronon"). But let's apply (2) to the time of a person's death. Classical logic implies that if anyone goes from being alive to no longer being alive, then there's either (L) a last time at...

It's wonderful to hear that at the age of 12 you've already read a lot, and I'm impressed by your submission. Many people twice your age wouldn't be able to submit something so thoughtful. I would recommend that you take a look at the essays in John Martin Fischer's edited volume on the metaphysics of death . I found it helpful when I read it many years ago; it contains both tough-minded philosophy and also bits of comic relief. You may find it a challenging read, but I don't think it's beyond you. Nowadays there may be more up-to-date collections on the topic, but Fischer's volume is an excellent place to start.

If the probability of death is 100%, and the probability of being alive tomorrow is uncertain, does that mean the probability of dying tomorrow is greater than the probability of being alive? No. Let death be represented by a fair coin's landing heads-up. The probability that the coin will land heads-up at least once in the next thousand tosses is essentially 1 out of 1 (it differs from 1 only beyond the 300th decimal place). It's also uncertain that the next toss will land tails-up. Yet those facts don't imply that the probability of heads on the next toss is greater than the probability of tails: it's a fair coin, we're assuming. Or imagine a lottery with one thousand tickets, exactly one of which is the winning ticket. You have all the tickets gathered in front of you but don't know the winning ticket. There's a 100% chance that the winning ticket is gathered in front of you but only a 0.1% chance that the next ticket you touch is the winner. Nevertheless, responsible people do plan for...