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![]() "Joe" wrote in message ps.com... We had a very, very cold front that came thru last week. Sailed with a friend on his Star a day after the front blew thru. It was crystal clear sky and I noticed the Bolivar Lighthouse about 10 mi. north of where you normaly see her. The cap of the lighthouse top seemed raised much more than the rusty bottom. 1.) For 3.3 ASA points what is the proper term for what we saw, and what caused it? As we sailed south is seemed as the bottom of the lighthouse was taller than the top. This is a gravitational lensing phenomena as predicted by Einstein. The cold air is denser and has more gravity so light travels slower through it. The image of the bottom of the light house travelled through colder air so the image took longer to get to you than the top image. Since you were traveling toward the light house it was getting bigger with time and the delayed image is shorter because when that image was initially propagated you were further from the light house. Hence the bottom of the light house appears smaller. The phenomena is known as transient specular image gradient delay. 2.) For 3.3 ASA points what is the proper term for this effect? Then when just on the horizon the lighthouse stretched out tall and 3 appeared, and they appeared to be floating above a shimmering horizon. 3.) For 3.4 ASA points what is the proper term for what we saw? A lighthouse. For 2 bonus asa points describe an optical illusion you have seen as sea. Atmospheric ducting in the microwave, optic and acoustic regimes. Voices heard clearly from over 10 miles away, images of foriegn cities in the sky and over the horizon radar images. http://mintaka.sdsu.edu/GF/explain/s...uct_intro.html http://en.wikipedia.org/wiki/Fata_Morgana_(mirage) http://www.icogitate.com/~ergosum/es...thehorizon.htm http://www.resologist.net/art06.htm http://epod.usra.edu/archive/epodviewer.php3?oid=38560 http://www.crazy****.com/site/pics/i..._fat_chick.jpg |
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