Posted Feb. 10, 2009 – It’s easy to be confused about coincidences. If lightning strikes the church just as aunt Betty dies, most of us would connect the two events. Some folks even claim that everything is intimately linked. But this morning while you brushed your teeth, and a tree crashed to the ground in Yellowstone Park, would you really say the two events are connected?
Coincidences are bothersome to scientists. Take the Andromeda galaxy, straight overhead at midnight. That this nearest of all spiral galaxies is also the biggest and brightest within 35 million lightyears is strange. But there Andromeda sits, and that’s how it is.
Or consider that our sky has just two disks, sun and moon, that both appear the same size. This alone brings about those amazing total eclipses. And we have a north star that just happens to be the brightest and most precisely aligned of the past 26,000 years.
Far more typical than such true coincidences are the logical match-ups. People are often amazed that the moon spins in the same period in which it revolves around Earth, keeping the same hemisphere forever pointed our way. But tidal stresses always slow a satellite’s rotation until it’s locked in place. Every moon of every planet has this same synchronous spin. What about the fact that the strong nuclear force, gravity, and 20 other parameters are just perfect for the formation of life? Another coincidence?
Here the Anthropic Principle is invoked: Only in our kind of universe would stars, planets and sentient beings have had time to form. If things weren’t this way, we wouldn’t be around to wonder about it, but since we do and here we are, then the universe had to be this way. Yogi Berra would be proud of this reasoning, but it’s now generally accepted.
It’s sometimes hard to separate coincidence from correspondence. Take the 11-year sunspot cycle. Powerful solar storms must do something to us. But only some two dozen sun-cycles have been observed, against which we can hunt for thousands of potential rhythms from political events to climate changes to earthquakes. Which are related and which are merely the mischief wrought by the law of averages?
Checking back we find that the solar cycle swings in harmony with the fashionable length of women’s skirts, the rabbit population of Australia, the party that controls Congress, the position of the Gulf Stream, and the thickness of Earth’s atmosphere. Only those last two are probably related to the sun.
But you see the problem. Or do you?