How many grains of sand are there on Earth?

[Johnny L.A.]

±3. Just kidding.

Approximately how many grains of sand are there on Earth?

[Elendil's Heir]

To quote The Life of Brian: "A lot."

[Squink]

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.

[Fake Tales of San Francisco]

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

[Xema]

Originally Posted by Squink

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.

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.

[njtt]

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

[enipla]

14,273, 14,274, 14,275

What? Chicken would be fine.

Shit....

1,2,3,4

[Squink]

Originally Posted by Xema

But sand grains can be a lot smaller than 1mm on a side.

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.

[ftg]

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.

[mhendo]

Originally Posted by Xema

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.

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.

[Xema]

Originally Posted by mhendo

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.

[Rhythmdvl]

I just did some basic calculations, and I got:

[(number of roads a man must walk)^{number of licks it takes to get to the center of a Tootsipop}]*(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.

[Wendell Wagner]

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

[Colophon]

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?

[Chronos]

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.

Classic.

[kanicbird]

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

[Johnny L.A.]

Originally Posted by kanicbird

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.

[wolf_meister]

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

As the term is used by geologists, sand particles range in diameter from 0.0625 (or 1⁄16 mm, or 62.5 micrometers) to 2 millimeters. An individual particle in this range size is termed a sand grain. The next smaller size class in geology is silt: particles smaller than 0.0625 mm down to 0.004 mm in diameter. The next larger size class above sand is gravel, with particles ranging from 2 mm up to 64 mm (see particle size for standards in use). Sand feels gritty when rubbed between the fingers (silt, by comparison, feels like flour).

ISO 14688 grades sands as fine, medium and coarse with ranges 0.063 mm to 0.2 mm to 0.63 mm to 2.0 mm. In USA, sand is commonly divided into five sub-categories based on size: very fine sand (1⁄16 - 1⁄8 mm diameter), fine sand (1⁄8 mm - 1⁄4 mm), medium sand (1⁄4 mm - 1⁄2 mm), coarse sand (1⁄2 mm - 1 mm), and very coarse sand (1 mm - 2 mm).

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".

[Interconnected Series of Tubes]

Originally Posted by wolf_meister

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...

[beowulff]

Originally Posted by Johnny L.A.

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

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

[Labtrash]

Originally Posted by Interconnected Series of Tubes

God, here it comes...

you know, once, for 20 min...


Oh, forget it....

[CalMeacham]

Interesting to note that Archimedes addressed the question of haw many grains of sand it would take to fill the universe (as he knew it), wau back in the third century BCE. It's usually translated as "The Sand Reckoner". In the course of his investigations, to make the problem tractable, Archimedes invented a sort of scientific notation. Fascinating Stuff:

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

[ftg]

Originally Posted by CalMeacham

Interesting to note that Archimedes addressed the question of haw many grains of sand it would take to fill the universe (as he knew it), wau back in the third century BCE. ...

Psst.

[The Second Stone]

6,934,385,563,654,372,249,762,123,847,935,882

My post is my cite

[Giles]

Originally Posted by The Second Stone

6,934,385,563,654,372,249,762,123,847,935,882

My post is my cite

Yes, but while you were counting, a few quintillion lost some of their mass and became grains of silt. Go back and count faster next time.

[CC]

Ok, I'll bite - How can anyone say how many stars there are in the universe? Do we have an idea of how large this infinite thing is?

[Giles]

Originally Posted by CC

Ok, I'll bite - How can anyone say how many stars there are in the universe? Do we have an idea of how large this infinite thing is?

My guess is: we know the volume of the visible universe (i.e., the sphere with radius of the most distant visible object); we know the density of galaxies in our neighbourhood; and we know roughly the number of stars in an average galaxy. Multiply those three numbers together, and you have an estimate of the number of stars.

[CalMeacham]

PSST

Dammit -- I looked that time. If you don't put "Archimedes" in your post, it ain't my fault....

[Smeghead]

Actually, it's a little-known fact that there are really only seven. The rest are impostors.

[Chronos]

Fool: The reason why the seven stars are no more than seven is a pretty reason
Lear: Because they are not eight?
Fool: Precisely. You'd make a fine fool.

[panache45]

Originally Posted by kanicbird

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

According to the Science Channel, there are more stars than grains of sand. I just learned that today.

[panache45]

Are we including cat litter?

[Elendil's Heir]

A picture really is worth a thousand words....

http://www.rense.com/general72/size.htm