Why is tomorrow promised to no one?

In the New Testament, the letter from James 4:13-15 — who was not one of the two disciples names James — says the following:

Come now, you who say, “Today or tomorrow we will go into such and such a town and spend a year there and trade and get gain” whereas you do not know about tomorrow. What is your life? For you are a mist that appears for a little time and then vanishes. Instead you ought to say, “If the Lord wills, we shall live and we shall do this or that.”

There is also a mathematical formulation for more secularized mindsets about why tomorrow is promised to no one:

P(t) \approx e^{-0.003 e^{(t-25)/10}}

Fortunately, the blog Gravity and Levity also puts the formula into a readable format.

What do you think are the odds that you will die during the next year? Try to put a number to it — 1 in 100? 1 in 10,000? Whatever it is, it will be twice as large 8 years from now.

This startling fact was first noticed by the British actuary Benjamin Gompertz in 1825 and is now called the “Gompertz Law of human mortality.” Your probability of dying during a given year doubles every 8 years. For me, a 25-year-old American, the probability of dying during the next year is a fairly minuscule 0.03% — about 1 in 3,000. When I’m 33 it will be about 1 in 1,500, when I’m 42 it will be about 1 in 750, and so on. By the time I reach age 100 (and I do plan on it) the probability of living to 101 will only be about 50%. This is seriously fast growth — my mortality rate is increasing exponentially with age.

And if my mortality rate (the probability of dying during the next year, or during the next second, however you want to phrase it) is rising exponentially, that means that the probability of me surviving to a particular age is falling super-exponentially.

Currently, I’m at 1 in 375.

Next blog post, we will explore the phrase, ‘better you than me.’