Dear people that believe the picture is inaccurate / BS / propaganda / nonsense / etc.:
The analogies of an apple and its skin or a baseball covered by a layer of latex posted earlier are quite accurate. Don't take my word for it though -
take my picture instead:
The large grey circles are supposed to represent earth, the little blue spheres are the entire bodies of water. If the entire earth were covered by a
whopping 100km of water, you would end up with the situation on the left. The 'world sea' is just visible as a blue outline. A hundred km of water
covering the entire earth may seem like a lot, but even counting the 100km of water on both sides, it just takes up 200/12742 = 1.5% of the diameter
of the earth*. Volume-wise it would be 4.8% of the entire earth, and would all fit in a sphere of 4625km wide. If we take a more sane (yet still
completely ludicrous) mean depth of 10km, the 'world sea' isn't even visible anymore**. Thanks to the dimensional difference between cubic and square
scaling though, the sphere representing the body of water is - even though it is 10 times smaller (5.2*10^10 vs 5.1*10^9) - only 2.16 times as
The article describes the hypothetical sphere with a width of 860 miles. When spread out over the surface of the earth as depicted in the most right
situation, this still comes down to a mean depth of 2.7km! If anything, the sphere should look too large to us, rather than too small. I'm quite sure
there isn't 2.7km of water everywhere.. it is not hard at all to imagine that less obvious sources of water are accounted for.
So what's the reason it seems entirely too small? In my calculated opinion, it's simply due to our completely crappy sense of 'volume conservation'.
By 'default', we are horrible
in dealing with volume by intuition. We grow up gaining a grasp of most common volume manipulations, but we
really start from scratch - see this legendary experiment by psychologist Piaget: www.youtube.com...
If anyone is interested in the actual math, I'll gladly oblige a request - merely ommitted from this post to keep it readable.
* Keeping it easy here - the mean radius of earth probably includes the entiry body of water whereas I'm laying it 'on top' of the earth here. Should
be a minor difference.
** At this resolution anyway.. I have an enormous render of 3840x2160, but it only shows a faint outline for 10km.
*** If you have a hard time believing me; V=4/3*pi*r^3, so if r doubles - let's say x = r*2 - then the volume-wise scaling is
(4/3*pi*x^3)/(4/3*pi*r^3) = x^3 / r^3 = (2*r * 2*r * 2*r) / (r^2) = 8r^2 / r^2 = 8. The 'trick' is in the power of three / cubicialiciousness. Just
like in a cube of 1: width/length/height is 1=1, surface of one face is 1^2=1, and volume is 1^3=1; compare to a cube of 2: width = 2, surface = 2^2 =
4, and volume is 2^3 = 8. Basically, the scaling factor of one dimension is the square root of the scaling factor of a dimension lower, and vice
versa. This is actually a very important 'law', as it defines for example how large mammals can grow while keeping their surface/volume relation in
balance (which we need for things like breathing & digesting food - and is why those organs are so 'folded' on the inside; so that the surface area
can 'keep up' with the volume it relates too). Did.. did that help at all?
edit on 10-5-2012 by scraze because: wrong image
edit on 10-5-2012 by scraze because: An asterisk was missing.
edit on 10-5-2012 by scraze because: To != too. And