More planets than grains of sand

Let that sink in…

Because it’s worth repeating. There are estimated to be more Earth-like planets in the Universe than grains of sand on Earth.

Have you ever scooped up a handful of sand and let it run through your fingers, watching it fall to the ground below? I can’t even comprehend the number of grains of sand in one handful.

So, what does this mean for us earthly-beings?

It means we are really small. Like really small.

It means by all mathematical estimates we are not alone in this universe. Quite the contrary, actually — we most definitely are not alone.

The sheer size and complexity of the known universe can lead some to adopt nihilistic views. (It’s had that effect on me at times.)

But this understanding can also have a profound affect on your ability to make a positive impact on someone’s life, your company, your community, your world.

When you recognize the size of one’s self to the rest of the universe, your problems, your challenges, your constraints are really insignificant.

But your ability to control your one life, your one blip on the time continuum, is really all you have. So why not make the most of it?

Why not make as many freaking positive dents in the universe as you can?

Let’s go.

Zach

Here's an old, old, question, but this time with a surprise twist. The question is — and I bet you asked it when you were 8 years old and sitting on a beach: Which are there more of — grains of sand on the Earth or stars in the sky?

Obviously, grains and stars can't be counted, not literally. But you can guestimate.

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

More planets than grains of sand

They said, if you assume a grain of sand has an average size and you calculate how many grains are in a teaspoon and then multiply by all the beaches and deserts in the world, the Earth has roughly (and we're speaking very roughly here) 7.5 x 1018 grains of sand, or seven quintillion, five hundred quadrillion grains.

That's a lot of grains.

More planets than grains of sand

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

Our stargazer gets a Hubble telescope and a calculator, so now we can count distant galaxies, faint stars, red dwarfs, everything we've ever recorded in the sky, and boom! Now the population of stars jumps enormously, to 70 thousand million, million, million stars in the observable universe (a 2003 estimate), so that we've got multiple stars for every grain of sand — which means, sorry, grains, you are nowhere near as 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," but then, very matter-of-factly, he adds that you will find the same number of molecules "in just ten drops of water."

More planets than grains of sand

Say what?

Let me repeat: If you took 10 drops of water (not extra-big drops, just regular drops, I'm presuming) and counted the number of H2O molecules in those drops, you'd get a number equal to all the stars in the universe.

This is amazing to me. For some reason, when someone says million, billion or trillion, I see an enormous pile of something, a grand scene, great 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's wrong. Little things, if they're really little, can pile up just like big things, and yes, says Blatner, water molecules "really are that small."

So next time I look up at the sky at all those stars, I will be impressed, of course, by the great numbers that are out there. But 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.

We are surrounded by vastness, high and low, and either way, as Blatner's book says, we "can't handle the biggitude."

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

Are there more planets than there are grains of sand?

The result is about 10^24 planets in the universe. That's about 100,000 times as many as grains of sand. It's one septillion planets! The numbers are subject to huge estimation errors and are both “astronomical.” One estimate has us with 7.5*10^18 grains of sand on Earth.

Are there more galaxies than grains of sand?

Considering that, 300 billion galaxies with 100 billion stars each gives us 30,000,000,000,000,000,000,000, or 30 followed by 21 zeroes worth of stars in the universe. Now that is more than grains of sand on the Earth.

Are there more stars in the universe than grains of sand?

The numbers pretty much matched. There are about the same number of stars in the observable universe as there are sand grains in all of Earth's beaches.

How big is the universe compared to a grain of sand?

Simple internet search gives us 12.742 billion mm in diameter. A grain of sand, to make this easy, is 1mm in diameter. The observable universe is 93 billion ly in diameter. 93/12.742 = 6.67 light years.