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:
“The work of the political activist inevitably involves a certain tension between the requirement that positions be taken on current issues as they arise and the desire that one’s contributions will somehow survive the ravages of time.”
—Angela Davis (b. 1944)
“For the purpose of knowledge, one must know how to use that inner current that draws us to a thing, and then the one that, after a time, draws us away from it.”
—Friedrich Nietzsche (1844–1900)