Why Do We Believe That Catastrophes Come in Threes?

People Naturally Seek Patterns

A related third reason might be the fact that people are naturally pattern-seeking, and searching for and labeling triads, even if pointless, can give people a sense of control as only mumbo-jumbo, hocus-pocus, and flapdoodle can.

Michael Eck's Web page, The Book of Threes, is replete with countless examples of the ubiquity of threeness.

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To get back to Michael Jackson (with due acknowledgement that Buddy Holly, Ritchie Valens and the "Big Bopper" all died together in a plane crash in 1959, and that Jimmy Hendrix, Janice Joplin and Jim Morrison all died with weeks of each other in 1970, et cetera), the fact is that deaths (celebrity or otherwise) are like births, a random Poisson process that regularly gives rise to clumps of people being born together or dying together. It's well-known that in a group of only 23 people, there is a 50 percent probability that two of them will share a birthday (or a deathday), not necessarily in the same year.

If we stipulate the same year, then the probability falls, of course, but if we allow for birthdays in the same week of the year, the probability rises, and if we consider not 23 but thousands of celebrities of one sort or another, it rises much more. The bottom line is that these celebrity deaths in a relatively short time span are not unusual.

Three Puzzles Involving Number Three

Building on this triplebolic mood, I'll end this section by mentioning three puzzles involving the number three. They are among the oddly many such three-puzzles.

One is the Monty Hall 3 door problem, which I discussed in an earlier Who's Counting column.

The second is the 3 hat problem, which I also described in another earlier column.

And the third is the following: Approximately what percent of positive whole numbers contain the digit 3. Some numbers, like 24, 91 and 475, do not contain a 3, but many of them, like 13 and 783, do contain one. The answer is below.

Answer: Almost all whole numbers contain every digit because almost all are more than, say, 1,000 digits long. Any number that long or longer will almost certainly have 3's, 5's, 8's, and every other digit in it.