Current Use
Large burning lens are sometimes made as Fresnel lenses, similar to lighthouse lenses, including for use in solar furnaces. Solar furnaces are used in industry to produce extremely high temperatures without the need for fuel or large supplies of electricity. They sometimes employ a large parabolic array of mirrors (some facilities are several stories high) to focus light to a high intensity.
The Olympic torch that is carried around the host country of the Olympic games is lit by means of a burning glass. The ceremony is organized at the site of ancient Olympia in Greece. The first use of this torch was for the 1936 Summer Olympics in Berlin.
Read more about this topic: Burning Glass
Famous quotes containing the word current:
“It is a quite remarkable fact that the great religions of the most civilized peoples are more deeply fraught with sadness than the simpler beliefs of earlier societies. This certainly does not mean that the current of pessimism is eventually to submerge the other, but it proves that it does not lose ground and that it does not seem destined to disappear.”
—Emile Durkheim (1858–1917)
“Absolutely speaking, Do unto others as you would that they should do unto you is by no means a golden rule, but the best of current silver. An honest man would have but little occasion for it. It is golden not to have any rule at all in such a case.”
—Henry David Thoreau (1817–1862)