Philosophy
Augustin-Jean Fresnel
May 10th, 1788 to July 14th, 1827
Bill Ashworth in the Linda Hall Library Newsletter wrote...
Augustin-Jean Fresnel, a French physicist and mathematician, was born May 10, 1788. Fresnel's name is well-known to physicists because of his theoretical work in optics (he was an ardent proponent of Young’s wave-theory of light), but his greatest impact may have come from a practical device he invented, the Fresnel lens. Fresnel was asked by the French government if he couldn't find some way to make lighthouses more efficient. A typical lighthouse of the day would have a kerosene flame and some sort of lens and reflector system to direct the light out to sea, but most of the light was lost, and beams were very faint. So Fresnel came up with a lens that looks like a multi-sided crystal barrel, surmounted with an elaborate crown of prisms. It was so designed that nearly every ray of light from the source is re-directed out on a horizontal path. The first Fresnel lens was installed in France in 1823, and by the 1850s they were in use everywhere. Fresnel lenses are ranked in "orders" of first through sixth; a first-order lens, the largest in ordinary use, is about 12 feet high and 7 feet wide, and sends out a beam that can be seen for over twenty miles. There are only about a dozen first-order Fresnel lenses left in the United States; each is worth millions of dollars. In my opinion, they are the most beautiful cut-glass objects ever made. Fresnel did not live to see the popularity of his invention; he died of tuberculosis in 1827, at the age of 39.
Fresnel optics were also employed in large format photography by making the corners so much brighter with no detrimental effect on the ability to fine focus.
Without Fresnel screen
Fresnel lenses
Augustin-Jean Fresnel [Wikipedia]
- Hans Lippershey...dutch Lens Grinder
Hans Lippershey 1570 to September 1619 Hans Lippershey is part of the debate concerning the one who introduced the telescope...some say Galileo and some say Lippershey. Hans Lippershey was a lens grinder and one anecdote goes: Lippershey was "observing...
- William Rowan Hamilton's "theory Of Systems Of Rays"
William Rowan Hamilton August 4th, 1805 to September 2nd, 1865 In 1827, William Rowan Hamilton presented his Theory of Systems of Rays at the Royal Irish Academy in Dublin. Although he was still an undergraduate, only 21 years old, his work is one of...
- "oscar" Science
Oscar will be here soon [February 22nd] and it is interesting to note the huge anount of physics and chemistry involved in the production of motion pictures. Probably 99% of the movie goers could care less about the technical side of making movies but...
- Einstein Was Not Poor
Einstein wasn't a poor man for he garnered a few bucks from the Nobel Prize [which was shared or given to Mileva], lectures, teaching, and "patents"--yes, good ole "patents". Some were shared with his old colleague Leo Szilard. Switzerland: 1930:...
- Newton's Rings
Long before sitting at the computer and manipulating images, the realm of the darkroom ruled and when making prints via contact of glass plate negative with sensitized paper using a contact print frame this issue may occur. The phenomenon will also occur...
Philosophy
Augustin-Jean Fresnel and optics
Augustin-Jean Fresnel
May 10th, 1788 to July 14th, 1827
Bill Ashworth in the Linda Hall Library Newsletter wrote...
Augustin-Jean Fresnel, a French physicist and mathematician, was born May 10, 1788. Fresnel's name is well-known to physicists because of his theoretical work in optics (he was an ardent proponent of Young’s wave-theory of light), but his greatest impact may have come from a practical device he invented, the Fresnel lens. Fresnel was asked by the French government if he couldn't find some way to make lighthouses more efficient. A typical lighthouse of the day would have a kerosene flame and some sort of lens and reflector system to direct the light out to sea, but most of the light was lost, and beams were very faint. So Fresnel came up with a lens that looks like a multi-sided crystal barrel, surmounted with an elaborate crown of prisms. It was so designed that nearly every ray of light from the source is re-directed out on a horizontal path. The first Fresnel lens was installed in France in 1823, and by the 1850s they were in use everywhere. Fresnel lenses are ranked in "orders" of first through sixth; a first-order lens, the largest in ordinary use, is about 12 feet high and 7 feet wide, and sends out a beam that can be seen for over twenty miles. There are only about a dozen first-order Fresnel lenses left in the United States; each is worth millions of dollars. In my opinion, they are the most beautiful cut-glass objects ever made. Fresnel did not live to see the popularity of his invention; he died of tuberculosis in 1827, at the age of 39.
Fresnel optics were also employed in large format photography by making the corners so much brighter with no detrimental effect on the ability to fine focus.
Without Fresnel screen
With Fresnel screen
Fresnel lenses
Augustin-Jean Fresnel [Wikipedia]
- Hans Lippershey...dutch Lens Grinder
Hans Lippershey 1570 to September 1619 Hans Lippershey is part of the debate concerning the one who introduced the telescope...some say Galileo and some say Lippershey. Hans Lippershey was a lens grinder and one anecdote goes: Lippershey was "observing...
- William Rowan Hamilton's "theory Of Systems Of Rays"
William Rowan Hamilton August 4th, 1805 to September 2nd, 1865 In 1827, William Rowan Hamilton presented his Theory of Systems of Rays at the Royal Irish Academy in Dublin. Although he was still an undergraduate, only 21 years old, his work is one of...
- "oscar" Science
Oscar will be here soon [February 22nd] and it is interesting to note the huge anount of physics and chemistry involved in the production of motion pictures. Probably 99% of the movie goers could care less about the technical side of making movies but...
- Einstein Was Not Poor
Einstein wasn't a poor man for he garnered a few bucks from the Nobel Prize [which was shared or given to Mileva], lectures, teaching, and "patents"--yes, good ole "patents". Some were shared with his old colleague Leo Szilard. Switzerland: 1930:...
- Newton's Rings
Long before sitting at the computer and manipulating images, the realm of the darkroom ruled and when making prints via contact of glass plate negative with sensitized paper using a contact print frame this issue may occur. The phenomenon will also occur...