I took a plane from Campo Grande to Brasília and it was a very nice flight. There were few clouds so that I could see all the roads and lakes on the ground.
It kept me wondering: looking down from 36.000 feet was like seeing the map at which zoom level?
It depends how many pixels your eyeballs have
… and on your field of view. Well, in fact, only on your field of view. Once you know which angle you can see you can easily[sup]TM[/sup] calculate the viewed area size on the ground, which easily translates into a degree of longitude of the mercator projection and this into a zoom level. Hmm, that would give the zoom level if we assume you would have viewed just one tile. What a stupid question! Nah, not really, just my answer attempt is.
Or with google earth cruise around at 36,000ft and with your favorite slippy map that displays zoom level notice that zoom level 14 matches pretty well
-RickBrown in Reno, NV
RickBrown, that is a very interesting answer!