Peter Osman writes: > I once saw an electron micrograph of a CDRom, it was covered with > indentations tens of microns wide by 100's of microns long, so I guess its > acting something like a diffraction gating combined with a diffuse > reflector. > > Has anyone actually had any success using a CD Rom as a signalling mirror > over realistic distances? > One afternoon last summer I was playing with a CD-ROM, seeing how far I could reflect the image of the sun on a distant surface. I was very surprised to see that the reflected solar image 100' away still showed the image of the disk- round with a hole in it! This was completely unexpected, and suggested to me that perhaps these could be used as signaling mirrors. (This would be useful for the paddlers and campers in my office as a number of us have towers many feet high of discarded disks). I wonder if the diffraction grating surface has something to do with this? Perhaps a physicist in the group could reflect on this. -- mike ------------------------- Michael Edelman mje_at_spamcop.net http://www.foldingkayaks.org http://www.findascope.com *************************************************************************** PaddleWise Paddling Mailing List - Any opinions or suggestions expressed here are solely those of the writer(s). You must assume the entire responsibility for reliance upon them. All postings copyright the author. Submissions: PaddleWise_at_PaddleWise.net Subscriptions: PaddleWise-request_at_PaddleWise.net Website: http://www.paddlewise.net/ ***************************************************************************Received on Sun May 27 2001 - 18:06:36 PDT
This archive was generated by hypermail 2.4.0 : Thu Aug 21 2025 - 16:30:43 PDT