History
In geometry, dihedral angle is the angle between two planes. Aviation usage differs slightly from usage in geometry. In aviation, the usage "dihedral" evolved to mean the positive, up angle between the left and right wings. While usage with the prefix "an-" (as in "anhedral") evolved to mean the negative, down angle between the wings.
The aerodynamic stabilizing qualities of dihedral angle were first described by Sir George Cayley in 1808–1809.
Read more about this topic: Dihedral (aircraft)
Famous quotes containing the word history:
“The history of the Victorian Age will never be written: we know too much about it.”
—Lytton Strachey (1880–1932)
“The disadvantage of men not knowing the past is that they do not know the present. History is a hill or high point of vantage, from which alone men see the town in which they live or the age in which they are living.”
—Gilbert Keith Chesterton (1874–1936)
“History ... is, indeed, little more than the register of the crimes, follies, and misfortunes of mankind.
But what experience and history teach is this—that peoples and governments have never learned anything from history, or acted on principles deduced from it.”
—Georg Wilhelm Friedrich Hegel (1770–1831)