May 1, 2016 08:03 PM
http://nautil.us/blog/why-its-hard-to-re...e-unlikely
EXCERPT: [...] The most unusual coincidence in my life took place when I flew from Boston, my home, to Chicago to meet Scott Isenberg, the new editor assigned to revise a statistics textbook I had authored a few years earlier. [...] Scott began to talk nostalgically about [...] his neighborhood [...] where he grew up. [...] Every remark he made about his childhood abode reminded me of something that my wife had told me. As we continued to notice more of these coincidences, I told him Debra’s name and he literally jumped out of his chair. It turned out that they had been friends in high school. You might think, what is the probability of such a rare event? It may be one in many millions.
The simple question might be “why do such unlikely coincidences occur in our lives?” But the real question is how to define the unlikely.
[...] In its essence, the idea of coincidences could be explained (somewhat simplistically) using a deck of cards. Drawing the ace of spades out of a well-shuffled deck of 52 cards is a relatively rare event: Its probability is only 1 in 52. We compute it using the mathematical rule that divides the size of the event, one card (if we’re talking about drawing any ace, this would be a size of four), by the size of the sample space for drawing a card out of a deck, which is 52, the total number of cards.
But if every day of your life you draw a card out of a deck, you can be sure to see the ace of spades sometimes. In fact, you expect this to happen roughly once in 52 draws. It is the fact that cards can be drawn repeatedly out of a deck (with reshuffling after every draw) that makes rare events show up.
This is essentially what happens in our lives. We are exposed to possible events all the time: some of them probable, but many of them highly improbable. Each rare event—by itself—is unlikely. But by the mere act of living, we constantly draw cards out of decks. Because something must happen when a card is drawn, so to speak, the highly improbable does appear from time to time.
It is the repetitiveness of the experiment that makes the improbable take place. The catch is that you can’t tell beforehand which of a very large set of improbable events will transpire. The fact that one out of many possible rare outcomes does happen should not surprise us because of the number of possibilities for extraordinary events to occur. The probabilities of these singly unlikely happenings compound statistically, so that the chance of at least one of many highly improbable events occurring becomes quite high....
EXCERPT: [...] The most unusual coincidence in my life took place when I flew from Boston, my home, to Chicago to meet Scott Isenberg, the new editor assigned to revise a statistics textbook I had authored a few years earlier. [...] Scott began to talk nostalgically about [...] his neighborhood [...] where he grew up. [...] Every remark he made about his childhood abode reminded me of something that my wife had told me. As we continued to notice more of these coincidences, I told him Debra’s name and he literally jumped out of his chair. It turned out that they had been friends in high school. You might think, what is the probability of such a rare event? It may be one in many millions.
The simple question might be “why do such unlikely coincidences occur in our lives?” But the real question is how to define the unlikely.
[...] In its essence, the idea of coincidences could be explained (somewhat simplistically) using a deck of cards. Drawing the ace of spades out of a well-shuffled deck of 52 cards is a relatively rare event: Its probability is only 1 in 52. We compute it using the mathematical rule that divides the size of the event, one card (if we’re talking about drawing any ace, this would be a size of four), by the size of the sample space for drawing a card out of a deck, which is 52, the total number of cards.
But if every day of your life you draw a card out of a deck, you can be sure to see the ace of spades sometimes. In fact, you expect this to happen roughly once in 52 draws. It is the fact that cards can be drawn repeatedly out of a deck (with reshuffling after every draw) that makes rare events show up.
This is essentially what happens in our lives. We are exposed to possible events all the time: some of them probable, but many of them highly improbable. Each rare event—by itself—is unlikely. But by the mere act of living, we constantly draw cards out of decks. Because something must happen when a card is drawn, so to speak, the highly improbable does appear from time to time.
It is the repetitiveness of the experiment that makes the improbable take place. The catch is that you can’t tell beforehand which of a very large set of improbable events will transpire. The fact that one out of many possible rare outcomes does happen should not surprise us because of the number of possibilities for extraordinary events to occur. The probabilities of these singly unlikely happenings compound statistically, so that the chance of at least one of many highly improbable events occurring becomes quite high....

