<p>A quick google gave me these (approximate) figures:</p>

<ul>
<li><p>7.5 x 10<sup>18</sup> grains of sand in all the beaches and deserts of the world</p></li>
<li><p>7 x 10<sup>22</sup> stars in the observable universe</p></li>
</ul>

<p>If these are reasonable estimates, then there are approximately nine thousand stars in the observable universe for each grain of sand on Earth. (By observable universe, I mean in all the galaxies that we can detect with our most powerful telescopes.)</p>

<p><a href="https://www.npr.org/sections/krulwich/2012/09/17/161096233/which-is-greater-the-number-of-sand-grains-on-earth-or-stars-in-the-sky" rel="noreferrer">Robert Krulwich: Which Is Greater, The Number Of Sand Grains On Earth Or Stars In The Sky?</a></p>

CC BY-SA 3.0
2017-11-13T00:28:27.410Z
How much sand is there in all the other places? ;-)
Dronz
CC BY-SA 3.0
2017-11-13T03:30:13.717Z
Nitpick: the observable universe has nothing to do with telescopes. Merely whether EMR emitted from the source after the recombination epoch has had sufficient time to reach Earth. Whether or not we can detect it is irrelevant (ironically enough.)
corsiKa
CC BY-SA 3.0
2017-11-13T03:39:51.227Z
@corsiKa Good point. I was a little unsure myself about that.
Mick
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2017-11-13T07:25:02.193Z
The number you've quoted is all the grains of sand ***on beaches***. Presumably the number of grains of sand in all the world (including under the sea) would be *dramatically* larger given that beaches and deserts represent less than a tiny fraction of the area of the ocean.
Valorum
CC BY-SA 3.0
2017-11-13T09:09:02.630Z
@Valorum Beaches and *deserts*. And doing some Googling, it seems the ocean floor is mostly rocky, not sandy. Only coastlines are sandy, and they were hopefull included in the calculation.
Erwin Bolwidt
CC BY-SA 3.0
2017-11-13T12:16:35.930Z
Since the calculations only use *visible* beaches, I'd imagine that the number is out by at least 100% even if you only account for the sand a few miles offshore.
Valorum
CC BY-SA 3.0
2017-11-13T15:12:21.240Z
@Valorum does the "tiny fraction" mean 0,01% ? because anything bigger than this means the stars still win.
Mindwin Remember Monica
CC BY-SA 3.0
2017-11-13T15:59:54.813Z
@Mindwin - I don't know what methodology they've used to represent the area of all the beaches in the world. I do know that more than 71% of the entire globe is covered in water. Assuming that they've represented the beaches and deserts as 5% of the Earth's surface and assuming each cubic meter of water has 0.01% as much sand as a cubic meter of beach, it could easily be *hundreds of thousands of percents* out. I am, however no expert on sand suspension in sea water
Valorum
CC BY-SA 3.0
2017-11-13T17:53:37.547Z
Even if you double the number of grains of sand because of a 100% error it will still be much less than the 4 orders of magnitude more observable stars.
Matthew Whited
CC BY-SA 3.0
2017-11-13T19:00:53.013Z
Fortunately, if you want to give them all an ID number, there are enough GUIDs for all the stars, all the grains, and plenty spare :)
Caius Jard
CC BY-SA 3.0
2017-11-13T22:17:40.477Z
The area where I live (around Berlin, Germany) is mostly sand under a small soil cover. It doesn't look like a desert at all. I guess this was not included in the count?
Paŭlo Ebermann
CC BY-SA 3.0
2017-11-14T01:26:22.650Z
The statement in question has an implicit "common-man" assumption of only counting beaches and deserts. In a TV program, the presenter will hold up a handful of sand on a beach, not dig a hole in Berlin or dive to the bottom of a river or the ocean, for example. Plus there's a desire to not run into niggling issues of what the technical definition of "sand" is.
zibadawa timmy
CC BY-SA 3.0
2017-11-12T16:30:08.517Z
2017-11-12T16:46:19.570Z
2017-11-12T16:46:19.570Z
Mick
<p>My ten year old daughter asked me this question at breakfast and I initially said yes, but on second thought I was also puzzled.</p>

CC BY-SA 3.0
2017-11-13T04:05:02.343Z
On Skeptics.SE: https://skeptics.stackexchange.com/questions/9059/more-stars-than-grains-of-sand
Andrew Grimm
CC BY-SA 3.0
2017-11-13T08:48:05.060Z
From @AndrewGrimm 's link, 10^20 to 10^24 grains of sand, 7x10^22 stars. You can shrug and tell her "dunno" ;)
JollyJoker
CC BY-SA 3.0
2017-11-13T09:22:34.107Z
@JollyJoker about a mole of each.
Andrew Grimm
CC BY-SA 3.0
2017-11-13T14:18:39.100Z
According to [Neil deGrasse Tyson](https://youtu.be/TLObjMmM6nA?t=1m46s), there are indeed. And if it's good enough for Neil deGrasse Tyson, it's good enough for me.
roberto06
CC BY-SA 3.0
2017-11-13T15:57:39.147Z
The estimates of each quantity are so plentiful as to vie with the answers themselves in magnitude.
Carl Witthoft
<universe>
Are there more stars in the universe than grains of sand in the Earth?
Ruy
# Are there more stars in the universe than grains of sand in the Earth?

(Asked by: username_0 on 2017-11-12)

My ten year old daughter asked me this question at breakfast and I initially said yes, but on second thought I was also puzzled.

**Tags:** universe
> **Comments:**
> **username_1**: On Skeptics.SE: https://skeptics.stackexchange.com/questions/9059/more-stars-than-grains-of-sand  
> **username_2**: From @AndrewGrimm 's link, 10^20 to 10^24 grains of sand, 7x10^22 stars. You can shrug and tell her "dunno" ;)  
> **username_1**: @JollyJoker about a mole of each.  
> **username_3**: According to [Neil deGrasse Tyson](https://youtu.be/TLObjMmM6nA?t=1m46s), there are indeed. And if it's good enough for Neil deGrasse Tyson, it's good enough for me.  
> **username_4**: The estimates of each quantity are so plentiful as to vie with the answers themselves in magnitude.  

---

## 1 answers

### Answer by username_5 on 2017-11-12. Score: 33

A quick google gave me these (approximate) figures:

* 7.5 x 1018 grains of sand in all the beaches and deserts of the world
* 7 x 1022 stars in the observable universe

If these are reasonable estimates, then there are approximately nine thousand stars in the observable universe for each grain of sand on Earth. (By observable universe, I mean in all the galaxies that we can detect with our most powerful telescopes.)

[Robert Krulwich: Which Is Greater, The Number Of Sand Grains On Earth Or Stars In The Sky?](https://www.npr.org/sections/krulwich/2012/09/17/161096233/which-is-greater-the-number-of-sand-grains-on-earth-or-stars-in-the-sky)

> **Comments:**
> **username_6**: How much sand is there in all the other places? ;-)  
> **username_7**: Nitpick: the observable universe has nothing to do with telescopes. Merely whether EMR emitted from the source after the recombination epoch has had sufficient time to reach Earth. Whether or not we can detect it is irrelevant (ironically enough.)  
> **username_5**: @corsiKa Good point. I was a little unsure myself about that.  
> **username_8**: The number you've quoted is all the grains of sand ***on beaches***. Presumably the number of grains of sand in all the world (including under the sea) would be *dramatically* larger given that beaches and deserts represent less than a tiny fraction of the area of the ocean.  
> **username_9**: @Valorum Beaches and *deserts*. And doing some Googling, it seems the ocean floor is mostly rocky, not sandy. Only coastlines are sandy, and they were hopefull included in the calculation.  
> **username_8**: Since the calculations only use *visible* beaches, I'd imagine that the number is out by at least 100% even if you only account for the sand a few miles offshore.  
> **username_10**: @Valorum does the "tiny fraction" mean 0,01% ? because anything bigger than this means the stars still win.  
> **username_8**: @Mindwin - I don't know what methodology they've used to represent the area of all the beaches in the world. I do know that more than 71% of the entire globe is covered in water. Assuming that they've represented the beaches and deserts as 5% of the Earth's surface and assuming each cubic meter of water has 0.01% as much sand as a cubic meter of beach, it could easily be *hundreds of thousands of percents* out. I am, however no expert on sand suspension in sea water  
> **username_11**: Even if you double the number of grains of sand because of a 100% error it will still be much less than the 4 orders of magnitude more observable stars.  
> **username_12**: Fortunately, if you want to give them all an ID number, there are enough GUIDs for all the stars, all the grains, and plenty spare :)  
> **username_13**: The area where I live (around Berlin, Germany) is mostly sand under a small soil cover. It doesn't look like a desert at all. I guess this was not included in the count?  
> **username_14**: The statement in question has an implicit "common-man" assumption of only counting beaches and deserts. In a TV program, the presenter will hold up a handful of sand on a beach, not dig a hole in Berlin or dive to the bottom of a river or the ocean, for example. Plus there's a desire to not run into niggling issues of what the technical definition of "sand" is.  

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