Joseph Mazur began thinking about the probability of life events when a stone blinded him in one eye at age 12. Now a professor emeritus of mathematics at Marlboro College and author of Fluke: The Math and Myth of Coincidence, Mazur has examined how probability impacts our daily lives.

Until recently, Mazur’s fascination with coincidence was just a hobby. But a chance friendship during a residency in Italy helped transform his hobby into a full-blown book.

Each morning, another resident came down to breakfast with a fantastic story about a chance encounter. And each evening, Mazur appeared at dinner with the odds of that coincidence occurring. He would tell her, “Well yes, it’s a coincidence to you, but let me explain why it might have happened.”

After a week of this, Mazur’s new friend urged him to write a book about the possibilities of coincidences. Mazur is careful to remind us, though, that his math should never “take away from the magic” of coincidence.

Mazur distinguishes between coincidences and flukes: “A coincidence is two events, or maybe more than two events sometimes, colliding in space and time … with no apparent cause and with a surprise.” A fluke, on the other hand, is “somewhat of a coincidence but on a lower scale,” and its cause is more apparent.

Misunderstanding probability can cause real problems. When we see frightening events such as terrorist attacks happen -- and see them covered extensively in media -- we also tend to misjudge their likelihood. Because they are so widely covered, we tend to think we’re in greater danger than we often are.

But Mazur has some words of caution for us. “[The world is] so vast, it’s so unlikely that any of these particular, nasty events are going to actually happen to us,” he says. “It’s very, very unlikely, and yet we rationalize them as if the world is smaller than it actually is.”