During photosynthesis, plants emit light humans can’t see, but NASA can see that light from space - and they've even made maps of it!
21
The average temperature at 40,000 feet above sea level is -60 F.
56
The brain case [of Neanderthals] on the average was more than 13 percent larger than that of the average of modern man
61
In Arizona, a solar wind energy tower has been proposed that would generate as much energy as the Hoover Dam.
5
Pumice is the only rock that floats on water.
14
Airports that are at higher altitudes require a longer airstrip due to lower air density.
39
One ragweed plant can release as many as one billion grains of pollen!
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