Seems related to the fact that you can draw a surprisingly-small circle over part of Asia and have more people inside the circle, than out. Human geography is very uneven.
Yep, that's the one. Ballpark 7% of the Earth's surface, or 15% of the land-surface area (guesstimate based on the whole circle being about 22% of the land surface area—but much of the circle is over water). Over 50% of the population.
I think you should specify the northern border of the contiguous states. Otherwise, I bet 99% of Canada’s population lives south of Alaska northern border.
I hesitated to be more specific, but figured (probably wrongly so, should always be explicit when stating things like this) that it's implicitly obvious it's about the ~49th parallel border. In fact you can draw the line well below that border[0].
Another way to put it is that half of Canadian's population lives ~between Toronto and Montréal.
Quite probably only if we're ignoring the z-axis (depth), at least when talking over minerals. I think it will be a game-changer if a few km of rock won't be a hindrance anymore. If that ever comes, that is.
There’s a huge amount of gold (and other stuff) dissolved in seawater. Something like 20 million tons of it. The trouble is that it’s too evenly distributed.
Well, right, it's the intuition/viewpoint that takes it to "huh, neat and a little surprising, but believable" rather than "no fucking way!" that's similar, I'd say. If you're familiar with one of these (or other, similar) bits of trivia, the other one's probably more believable on your first encounter with it, because you've already been exposed to the underlying insight that makes it possible.
