[ZenGum]

The water graph shows all the water and does it accurately, I am confident. The oceans seem deep to humans but they are a very thin layer compared to the earth. Yes, it is surprisingly little. That is the point.

Its similar to taking your rolled up freshly delivered newspaper and spreading it out one page at a time so it covers the entire yard. Or cutting up a playing card to make a stip of cardboard a couple of metres long. We're playing with dimensions here.


As for the population thing, consider the following.
An old style phone booth is somewhat less that one square metre in floor space.
Squeezed in a bit, we can fit 6 people per square metre - allowing for large well-built types as well as children and slim types.
There are 1 million square metres per square kilometre, so we can get 6 million people per square kilometre.

If we allow two vertical metres for each group of six people, we can get 500 layers of people per vertical kilometre.

Hence we can get 6 million x 500 = 3 billion people per cubic kilometre.

Given current global population of around 6.7 billion, the entire human population of the earth could be squeezed into slightly more than two cubic kilometres.

That is about one cubic mile, for you old fashioned types.

Remember, that is squished the hell in with no provision for air supply or movement or anything. Don't even think about the toilet situation!

I've also read that all the gold ever discovered on earth would make a cube 18 metres along each side.