[sac-forum] Re: Puzzling Phenomenon
- From: "Howard C. Anderson" <handy13@xxxxxxxxxxxxxx>
- To: sac-forum@xxxxxxxxxxxxx
- Date: Fri, 05 Feb 2010 17:20:19 -0700
Hi Jeff,
Yes, took one-year optics course from Stones book "Radiation and Optics."
Sounds like you are describing a type of Fraunhofer Diffraction effect.
That
sounds like it might be close to the mark. Stone's book shows images for
single and multiple point sources but not for a point shadow. The shadow
effects can probably be calculated from the diffraction equations in
Stone's book.
Probably a one or two month exercise based on how long it took me to show
why dew forms on my corrector plate:
http://www.astroshow.com/dewtell/dewtell.htm.
Last two years of undergraduate work for me included 3 three-hour math
courses and
one six-hour physics course. I did get three-place accuracy for the
Cavendish
balance experiment (Gravitational constant), Foucault's rotating mirror
experiment (speed of light)
and Millikan's oil drop experiment (charge of an electron.) Did not do
any bench
work with optics however... Now I wish I had... Not sure where I would
have
fit it in although I was running out of math courses. Even took Tensor
Analysis
as an undergraduate.
--
Thanks,
Howard, in Tempe AZ
Http://www.astroshow.com
http://www.AZcendant.com
http://www.ShastaDaylight.com
Jeff Hopkins wrote:
Hi Howard,
I have a pilot's license and used have my own plane, a Mooney Mark 21.
I used to see that all the time. What you are seeing is the plane is
acting like a lines and the Sun is focused around it. If you are the
right distance from the surface the spot will be a bright spot. Closer
and it will be a shadow. Further and the spot dissipates. If you ever
took a Physical Optics course you might have done an experiment with
focusing using a point.
Jeff
Hopkins Phoenix Observatory
Counting Photons
Phoenix, Arizona USA
www.hposoft.com/Astro/astro.html <http://www.hposoft.com/Astro/astro.html>
International Epsilon Aurigae Campaign
http://www.hposoft.com/Campaign09.html
On Feb 5, 2010, at 12:09 PM, Howard C. Anderson wrote:
Hi,
I encountered a puzzling phenomenon on a flight from Phoenix to Atlanta
and recorded it on video: http://www.astroshow.com/Puzzle/Puzzle.html
Bright spot on the ground that moved as the plane moved. Spot,
aircraft,
and the sun were on the same straight line. Either a diffraction
effect caused
by aircraft's disturbance of the density of the air, simple specular
reflection, or something
else? Nothing I've thought of satisfies me regarding the cause.
Would appreciate thoughts from anyone who might know the cause
or is willing to speculate.
--
Thanks,
Howard, in Tempe AZ
Http://www.astroshow.com
http://www.AZcendant.com
http://www.ShastaDaylight.com
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