Night Sky: Your number’s up

Here’s what a million looks like, although many of this globular cluster’s million suns appear to blur together near the center. Still, if you can count five stars a second, you could point out all one million stars in about two days. (Matt Francis, Prescott Observatory)

August is when the sky transitions from its least number of faint stars (in the spring) to its greatest number, from September through December.

Although there are 30 trillion cells in the human body, far more than the combined number of stars and planets in our galaxy, we nonetheless associate vastness with astronomy, not biology. In any event, enormous numbers grab our attention. It’s a fairly recent development, since the word “million” didn’t come into general use until the 13th century. Before then, the largest number was a myriad, equal to ten thousand.

A million seemed huge when we were kids and became less intimidating only when we realized it was possible to count to a million. It’s really not so big: A million steps would take you from Woodstock to Brooklyn. A vacation lasting a million seconds would give you only an eleven-day reprieve from office misadventures.

In astronomy, we use “million” mainly in relation to the sun, which is nearly a million miles wide and sits 93 million miles away. We also use “million” when contemplating our neighbor planets, which are a few dozen million miles from us.

Like Peter the Great, who had his wife’s lover beheaded and kept that head in a bottle of alcohol in her bedroom for her to contemplate, nature can also be perverse. There’s no rhyme or reason for the numbers that biology or astronomy spring on us. Why do each of our body’s cells have 90 trillion atoms, roughly matching the stars in our local galaxy group? There’s the same number of atoms of air in each breath as there are breaths of air in Earth’s atmosphere. Such numerical coincidences are always interesting.

Anyway, even a trillion is tiny compared with the largest number of things in the universe — a one followed by 87 zeroes. That’s the sum total of all subatomic particles such as electrons. Yet even all the universe’s material is infinitesimally tiny compared with its size, since the cosmos is mostly empty space. If you let a football stadium represent an atom, its nucleus would be a fly on the 50-yard line. If the universe were a cube 20 miles wide on each side, all the matter it contained would be a single grain of sand.

Basically, there’s nothing here at all.

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