Register Log In Wordsmith Talk Forums (Old) Weekly themes. (have been consolidated into a single forum above) Eponyms or words derived from people's names. Fresnel lens Search Advanced Forum Search Forums Calendar Active Threads

Previous Thread Next Thread Print Thread Fresnel lens #79290 08/31/2002 1:25 PM Joined: Jan 2001 Posts: 13,858 wwh Carpal Tunnel wwh Carpal Tunnel Joined: Jan 2001 Posts: 13,858 Fresnel, Augustin Jean (1788-1827), French physicist, an adherent of the wave theory of light. Born in Broglie, Eure-et-Loir, and educated at Caen and at the École Polytechnique in Paris, he made numerous experiments in the interference of light. Fresnel was the first to demonstrate that two beams of light polarized in different planes do not exhibit interference effects. From this experiment he correctly deduced that the wave motion of light is transverse, rather than longitudinal (like that of sound) as had been previously believed. Fresnel was the first to produce circularly polarized light. He also worked out a number of basic optical formulas, including those for reflection, refraction, double refraction, and the polarization of light reflected from a transparent substance. Fresnel's work on optical effects caused by the motion of objects was important in the later development of the theory of relativity. In the field of applied optics, Fresnel designed the type of compound lens, often called a Fresnel lens, that is used to produce parallel beams of light from lighthouses and in a type of spotlight frequently used in theatrical lighting. Fresnel's scientific work was known only to a small group of scientists during his lifetime, and some of his papers were not published until after his death. He was a member of the French Academy of Sciences and of the Royal Society of London. You can buy a Fresnel lense from Edmund Scientific. In early days of television they were sold to enlarge image on TV screen. I still have one. "Fresnel, Augustin Jean," Microsoft(R) Encarta(R) 98 Encyclopedia. (c) 1993-1997 Microsoft Corporation. All rights reserved. Copy Link to Clipboard Share Post on Facebook Share Post on Twitter Re: Fresnel lens #79291 10/18/2002 9:31 PM Joined: Jun 2002 Posts: 7,210 Vermont Buffalo Shrdlu Carpal Tunnel Buffalo Shrdlu Carpal Tunnel Joined: Jun 2002 Posts: 7,210 Vermont I have many fond memories of hanging and aiming "fresnels" in my college theatre days... and the lekos and scoops... formerly known as etaoin... Copy Link to Clipboard Share Post on Facebook Share Post on Twitter Re: Fresnel lens #79292 10/18/2002 10:07 PM Joined: Oct 2000 Posts: 5,400 rego park of troy Carpal Tunnel of troy Carpal Tunnel Joined: Oct 2000 Posts: 5,400 rego park i too, have large (12 inch square-- 30 cm or so) fresnel lens. it is very flat, and useful. it's also a wonderful toy, that family children love. its plastic, so its safe for children to use with care. my other obsession Copy Link to Clipboard Share Post on Facebook Share Post on Twitter Re: Fresnel lens #79293 10/18/2002 10:26 PM Joined: Jan 2001 Posts: 13,858 wwh Carpal Tunnel wwh Carpal Tunnel Joined: Jan 2001 Posts: 13,858 Jackie sent me a URL where you can buy a clear plastic Fresnel magnier for about ten bucks. Said to be very helpful for reading fine print. I plan to get one. http://www.vikingop.com/shop/catalog/sku.asp?SKS=6&ID=SP304&LEVEL=SK&PR=Q10& Copy Link to Clipboard Share Post on Facebook Share Post on Twitter Re: Fresnel lens #79294 10/19/2002 1:00 AM Joined: Sep 2001 Posts: 6,296 Piedmont Region of Virginia, U... Wordwind Carpal Tunnel Wordwind Carpal Tunnel Joined: Sep 2001 Posts: 6,296 Piedmont Region of Virginia, U... And Fresnel only lived till he was about 39 years old, if my math's right. The ASp is my checker. She'll let me know whether I missed it by a decade or not... Copy Link to Clipboard Share Post on Facebook Share Post on Twitter Re: Fresnel lens #79295 10/31/2002 6:26 PM Joined: Oct 2002 Posts: 2 Occasional Idiot stranger Occasional Idiot stranger Joined: Oct 2002 Posts: 2 Alliance Tool and Die Corp. had a Fresnel Optics division in Rochester, NY. They used to cut the metal dies and mold the plastic lenses mainly for overhead projectors. I remember seeing a 3-4 ft diameter die being continuously cut over a period of a few days. The copper "hair" spun off like cotton candy into huge piles. Copy Link to Clipboard Share Post on Facebook Share Post on Twitter Re: Fresnel lens #79296 10/31/2002 6:57 PM Joined: Jan 2001 Posts: 13,858 wwh Carpal Tunnel wwh Carpal Tunnel Joined: Jan 2001 Posts: 13,858 If you use Netscape 4.7, you will see that Netscape has a far advanced Fresnel lens that can make a beam of light bend into an arc. Quite revolutionary. Dear Occasional Idiot. Welcome to the laughing academy. Copy Link to Clipboard Share Post on Facebook Share Post on Twitter Moderated by  Jackie  Hop To General Topics ------  Information and announcements  Q&A about words  Wordplay and fun  Words and languages in schools  Miscellany  Weekly Themes  Looking for (writers, speakers,... (Old) Weekly themes. (have been... ------  Words from medicine  Beheading words  Meta-words  Words from classical mythology  Animal Safari  Words with unusual etymologies  Eponyms or words derived from p...  Loanwords from German  English as a global language Print Thread Switch to Threaded Mode Show Likes Link Copied to Clipboard View Profile Private Message Follow User Forum Posts Like Summary View Profile Private Message Website Follow User Forum Posts Like Summary View Profile Private Message Website Follow User Forum Posts Like Summary View Profile Private Message Follow User Forum Posts Like Summary View Profile Private Message Follow User Forum Posts Like Summary View Profile Private Message Follow User Forum Posts Like Summary View Profile Private Message Follow User Forum Posts Like Summary

Default Style BlackNTan Drab eBay GooG v2 infopop new dark new light original dark original stock rounded corners Slate snow sunny dropshadow theblues Touch Of Grey UBB.threads UBB.threads - Dark UBB.threads - Light UBBCentral UBBCentral - Crimson UBBCentral - Lime UBBCentral - Marshmallow UBBCentral - Mocha UBBCentral - Zen UBBT77 UBBT77 - Dark ubbthreads ubbthreads-dark Forum Rules · Mark All Read Contact Us · Forum Help · Wordsmith Talk