Dizzying heights
Dear Tom,
What is the origin of the phrase, “dizzying heights”? A friend believes it refers to the
sensation you can get when you are at the edge of a precipice. I think it has to do with
the atmosphere.
William Johnson
Dear William,
Manned, hot-air ballooning got its start on Nov. 21, 1783, when brothers Joseph and
Etienne Montgolfier launched a balloon in Paris and were airborne for 20 minutes.
Technological advances followed quickly and by the early 1800s balloon pioneers were
able to ascend high enough that the amount of oxygen in the air was dangerously thin,
giving rise to the phrase“dizzying heights.” The atmospheric content of oxygen—21
percent of dry air by volume—does not change as we go higher, but the amount of
oxygen that we can inhale diminishes because the density of air decreases with
increasing height.