Why Do I Feel Thirsty?

In: Environment/weather Science

8 May 2012

This visualization shows the size of a sphere that would contain all of the Earth’s water compared to the size of the Earth. Yikes! That’s a lot of dirt and rock!


Thanks to D. Cramer for emailing me the link!

15 Responses to Why Do I Feel Thirsty?



May 9th, 2012 at 1:53 am

i call BS. does this take into account water in the atmosphere, or within living things, or groundwater?



May 9th, 2012 at 9:15 am

Not BS, Just basic geometry. Volume of a sphere is 4/3 pi r^3. Radius of the earth is approx 6370 km. deepest part of the ocean is approx 11km. Now make a few assumptions and do the math before you call BS.



May 9th, 2012 at 12:56 pm

Also, if you click on the picture it leads you to the sources…



May 12th, 2012 at 6:38 pm

Would like to see a sphere representing the volume of biomass.



May 14th, 2012 at 9:22 am

And only 2.5% of the Earth’s water is freshwater.



May 15th, 2012 at 10:29 pm

@ Michael: apparently you live somewhere *within* the big, brown sphere. I live on the surface of the big, brown sphere — surrounded by the big, blue sphere. Try an honest comparison instead of “mathematical” obfuscation. You’re good at obfuscation, aren’t you?



May 16th, 2012 at 11:26 am

To answer que’s question: yes (12,900km3), yes (1,120km3), yes (23,400,000km3). But “Oceans, seas and bays” plus “Ice caps, Glaciers, & Permanent Snow” are over 98% of the world’s water so the difference these make would barely be visible.

Source: clicking the link then scrolling down…

(p.s. who is Frank, why does he live underwater, what’s his problem with “mathematics”, how does he know Michael, who is Michael, what does he think Michael is trying to obfuscate, what else does Frank think Michael obfuscates, and why did Frank write his comment in MS Word then copy it over, complete with curly quotes?)



May 16th, 2012 at 11:27 am

(I stand corrected – Dustin’s CMS converts quotes to curly quotes. Other questions still stand)



May 19th, 2012 at 11:52 am

Not basic geometry, the problem with this graphic is that nothing below the earth’s crust needs water, so the better comparison would be a sphere the size of the earth’s crust compared to a sphere of all the earth’s water.


Colin Moden

May 31st, 2012 at 11:22 am

I agree with Jeff. Most people don’t intuitively get the distinction between Volume & Surface area of a sphere, but mathematically they scale very differently. If I wanted to convince people that water is scarce I’d use volume calculations for the 2 spheres. But surface area is probably more meaningful, all water & life exists in a very thin skin layer on the planet.



June 4th, 2012 at 3:22 pm

It would be interesting to compare it to a sphere of the compacted flesh of all humans living on the planet. How big would we be? Am I standing next to a Dixie cup, a bathtub, or a lake?



September 9th, 2013 at 3:28 pm

One way to think about it is to imagine a 5 gallon bucket of water, doesn’t seem like much, tip it over though, and it covers a lot more area than you would expect.



February 2nd, 2014 at 11:52 pm

This is crap. The math is wromg an the physics is wrong.

Quit tryng to scare people



March 20th, 2014 at 6:06 pm

This is a fun representation but as with many guestimates and approximate science it will always be proven inaccurate at some point. Even now new possible hidden stores of the old H20 are being found that possibly lie deep underground:


Tom bertsch

June 24th, 2015 at 7:49 am

I would like to see a sphere representing all the Tootsie rolls ever eaten! Just the chocolate ones! I would also like to see a sphere representing the time wasted arguing stupid so called facts discussed here! Then perhaps some other nitwit ( sporting a large set of cobalt blue balls, no doubt ) could convert that to BTUs!

Comment Form