Saturday, December 04, 2010

Counting stars

The story made the top of the first page of the National section of the New York Times. It was on the nightly news. Half-a-dozen people asked me about it.

The universe contains three times more stars than previously thought!

300,000,000,000,000,000,000,000 stars in the visible universe. Not 100,000,000,000,000,000,000,000.

Now that's news!

I'm being facetious, of course.

A few comments. The result is tentative. It's significance has to do with the relative distribution of stars of various sizes in elliptical versus spiral galaxies, which may -- if true -- help in understanding how the different types of galaxies formed. A not insignificant development.

But all of that about elliptical versus spiral galaxies got lost in the fine print. It wasn't even mentioned by Diane Sawyer. The big news! Three times more stars that previously thought!

So what.

One big, incomprehensible number replaced by another big incomprehensible number. Not even an order of magnitude different.

When in the winter of 1609-10 Galileo turned his new telescope on the faint blur called "the Beehive" in Cancer, he counted 36 stars, invisible to the unaided eye. To the three stars of Orion's belt his instrument added 50. When he examined the Milky Way the stars he saw defied enumeration. Now that was newsworthy! The news? The universe wasn't made for us.

"He tells the numbers of the stars, He calls each by name," sings the psalmist. With Galileo's telescope the stars became too numerous to be namable, even by a deity. One hundred sextillion or three hundred sextillion. The change in the number is not important to anyone but the professional cosmologist with an interest in galaxy formation. For the rest of us, it is the number itself we should set about accommodating. A universe whose aching vastness Galileo glimpsed through his wonderful tube.