How many grains of sand are there on Earth?

±3. Just kidding.

Approximately how many grains of sand are there on Earth?

To quote The Life of Brian: “A lot.”

Well, if you take the entire volume of the earth (1,083,207,317,374 km^3) and divide it up into sand size bits, 1mm on a side, you’ll have 1.08320732 × 10^30 of them. That’ll serve as an upper limit for the answer to your question.

I wonder if we actually have a name for the number. If it’s possible to guess.

Well, the lithosphere (crust) is about 1% of the Earth’s volume and nothing below that can reasonably be considered granular sand. Further, it seems unlikely that even 1% of the lithosphere properly qualifies as sand (assuming sandstone does not). You can thus reduce that exponent to 26.

But sand grains can be a lot smaller than 1mm on a side. If we accept something around 0.2mm as average, you can bump the exponent back up to 28.

It is going to take me quite a while to finish counting, I’m afraid.

14,273, 14,274, 14,275

What? Chicken would be fine.

Shit…

1,2,3,4

I intentionally restricted the size to that of nice sand. As far as I’m concerned, that crappy stuff you have go up and down the beach with a plow just to make it powdery, does not count as sand!

Your other points are well taken though.

Note: when you get up to how many grains of sand would fill the Universe, then you’d have caught up to 3rd century BC Mathematics.

Also, sand grains are not little boxes neatly stacked upon one another, with no space in between. Their various shapes means that, in every cubic foot of sand, there is a considerable percentage of the volume that is empty space.

True, but when you’re trying for a rough estimate, a packing density of 90% vs. 75% hardly matters.

I just did some basic calculations, and I got:

[(number of roads a man must walk)[sup]number of licks it takes to get to the center of a Tootsipop[/sup]]*(number of ways I love thee)!

That’s just a rough guess, of course. I think I may have forgotten to carry a two somewhere, so please mind your small, flightless waterfowl.

Fake Tales of San Francisco writes:

> I wonder if we actually have a name for the number. If it’s possible to guess.

Yes, we have a name for the number. The largest number mentioned so far is 10 to the 30th power. That is a nonillion:

http://en.wikipedia.org/wiki/Names_of_large_numbers

There’s a big problem of definition. At what point does a grain of sand become a particle of mud? Or a piece of gravel? Or a speck of soil?

Classic.

I believe scripture equates the # of grains of sand to the # of stars. I don’t know if that helps.

I’ve heard there are more stars than the Earth’s grains of sand.

Okay it’s time to get some standardization here.
Wikipedia states:

Interesting to know that sand falls in a granularity category between silt and gravel.

Have we considered the grains of sand that might reside on the ocean floor? After all, over 60% of the world is covered by water and how little we know of that underwater world. See you next week for “Sea Hunt”.

God, here it comes…

If Squink’s 10^30 estimate is off by a factor of a Billion, then yes, there are:
http://imagine.gsfc.nasa.gov/docs/ask_astro/answers/970115.html