For example, say a map of Massachusetts is hanging on
a wall. Its scale is something like 1 inch for 10 miles.
Now one factoid of interest is that most all weather lies below
an altitude of 7 miles. 7 miles is a bit less than 1 inch. All
weather is within an inch of the map! All clouds, storms, etc are in
that shallow area above the map.
A perhaps surprising result.
Similarly:
90% of all air is within that inch, with the rest of it
dribbling off for a foot or so.
FAA regulations require pilots to use oxygen above a quarter of
an inch.
Humans cannot survive unaided above 3/4 inch.
Low earth orbit, and the space shuttle, are around 1.5 feet from
map.
More generally, when using a map, one can envision the third dimension. With a street map, the buildings. With a subway map, the city above. And more generally still, when using any representation, it can be interesting to envision some of the dimensions which have been sacrificed.
For another example (rather crufty), there is the map below. Its scale is about an inch for 10 miles. I've sortof tilted the map down, and added some altitude stuff to scale on the side.
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I still haven't found a good online orbital picture of clouds and
their shaddows. Here are some approximations...
Possible improvements for this page:
Clean up boston example numbers.
Get good cloud numbers, rather than the current _base_ of clouds.
Add a narrower scale map example. Metro boston for instance.
Flesh out a list of interesting heights...
| thing | km | miles | feet |
| FAA requires pilots use suplementary oxygen above 14,000 ft. | 4.2 km | 2.7 mi | 14 kft |
| Earth's moon | 190,000 km | 120,000 mi | 630 Mft |
| ... | km | mi | kft |
History: 1997.Jul.19 Added `clouds and their shaddows' images. 1996.Dec.05 Light dusting. 1996.Nov.17 Some work. 1996.Nov.15 Begun.