Coincidences attract our attention because they seem weird, odd, or unlikely. Their improbability stimulates wonder—“what are the odds of this happening?”
Probability theory, which is a branch of mathematics, promises to shed light on this defining aspect of meaningful coincidences.
Carrying this banner, I valiantly strode forward into probability’s thicket of mathematical concepts and formulas. My confidence was bolstered by having gotten a Double A in a probability theory seminar at Swarthmore College.
Here’s what I wrestled from the thicket.
Background on Probability
The purpose of probability theory is to understand randomness and uncertainty to enable us to more accurately predict the future.
Probability is the measure of the likeliness that an event will occur. It is quantified as a number between 0 and 1 (where 0 indicates impossibility and 1 indicates certainty). The higher the probability of an event, the more certain we are that the event will occur.
A simple example is the toss of a coin. The probability is 1/2 (or a 50 percent chance) of either “heads” or “tails.”
