Famous quotes containing the words optical and/or sound:
“There is an optical illusion about every person we meet.”
—Ralph Waldo Emerson (1803–1882)
“There have been many stories told about the bottom, or rather no bottom, of this pond, which certainly had no foundation for themselves. It is remarkable how long men will believe in the bottomlessness of a pond without taking the trouble to sound it.”
—Henry David Thoreau (1817–1862)