How Many Grains Of Sand

Here'due south an erstwhile, sometime, question, merely this time with a surprise twist. The question is — and I bet you asked it when yous were 8 years old and sitting on a beach: Which are in that location more than of — grains of sand on the World or stars in the sky?

Plain, grains and stars can't be counted, non literally. But you can guestimate.

Science author David Blatner, in his new volume Spectrums, says a group of researchers at the University of Hawaii, existence well-versed in all things beachy, tried to calculate the number of grains of sand.

They said, if y'all assume a grain of sand has an average size and you summate how many grains are in a teaspoon so multiply by all the beaches and deserts in the world, the World has roughly (and we're speaking very roughly hither) vii.5 ten ten^xviii grains of sand, or vii quintillion, five hundred quadrillion grains.

That's a lot of grains.

OK, so how most stars? Well, to my amazement, it turns out that when you look up, even on a clear and starry dark, you won't run into very many stars. Blatner says the number is a depression, low "several thousand," which gives the sand grain folks a landslide victory. Just we're not limiting ourselves to what an ordinary stargazer tin see.

Our stargazer gets a Hubble telescope and a calculator, and so now we can count distant galaxies, faint stars, crimson dwarfs, everything we've ever recorded in the heaven, and nail! Now the population of stars jumps enormously, to 70 m million, million, million stars in the observable universe (a 2003 approximate), and then that nosotros've got multiple stars for every grain of sand — which means, lamentable, grains, you are nowhere most every bit numerous as the stars.

So that makes stars the champions of numerosity, no?

Ummm, no. This is when Blatner hits us with his sucker punch. Yes, he says, the number of stars in the heavens is "an unbelievably large number," only and then, very matter-of-factly, he adds that you will observe the same number of molecules "in merely ten drops of water."

Say what?

Let me repeat: If you took ten drops of water (not actress-big drops, merely regular drops, I'grand presuming) and counted the number of H_iiO molecules in those drops, yous'd get a number equal to all the stars in the universe.

This is amazing to me. For some reason, when someone says one thousand thousand, billion or trillion, I see an enormous pile of something, a grand scene, keen sweeps of desert sand, twirling masses of stars. Big things come from lots of stuff; little things from less stuff. That seems intuitive.

But that'southward wrong. Little things, if they're really petty, can pile up just like large things, and aye, says Blatner, water molecules "really are that small."

Then next fourth dimension I look up at the sky at all those stars, I will be impressed, of course, by the great numbers that are out there. Just I will remind myself that at the other end of the scale, in the nooks and crannies of the physical world, in the teeniest of places, there are equally vast numbers of teenier things.

Nosotros are surrounded by vastness, high and depression, and either fashion, equally Blatner'southward volume says, nosotros "can't handle the biggitude."

David Blatner'south forthcoming book is called Spectrums: Our Mind-Boggling Universe, from Infinitesmal to Infinity.