Saturday, December 13, 2008

December 2008 Moon Illusion...

Did you notice the near full moon rise on the 11th of this month? If so you may have witnessed a "moon illusion"(see links below). I did! Where the moon seemed twice as big in the sky as it normally does. I've noted this phenomena before and many years ago had been told it occurred from looking at an object on the horizon magnified through the breath of the atmosphere. A little recent inter-net research and the answer seems more vague than ever. And maybe that's a good thing. Simple answers oft times lead us to simple solutions and often simple solutions aren't really what we need to solve problems, gain knowledge or accomplish other tasks in this world. In fact simple solutions often lead us down the wrong road as the problems multiply themselves. Hmm, thinking about the moon can be a lofty thing.

In any case here's a photograph of that moon illusion I mentioned above. The image was captured near Wauconda, Washington. The ridge in the middle ground of the photo is approximately 4,500 feet above sea level and the time is 1530:hours (3:30:pm) Thursday, 12.11.08. This mountain slope is now, two days later, under a foot of snow. And somewhere behind the cold, dark clouds sitting over this river home is a near full moon shining, but we won't see it tonight.


Hope your December is going well. Remember to get out there, look up in the sky and if your lucky enough to see that full moon you might even get the urge to howl...
Foster

Regardless of its elevation, the distance between an observer (at the center of the horizontal line) and the moon remains constant (unfilled circles)






Kaufman L., Kaufman J. H. PNAS 2000;97:500-505

As a late edition to this posting; a note from friend Arthur Emery: "It may not have been a complete illusion either..."http://www.timesonline.co.uk/tol/news/environment/article5332018.ece

Other links...

http://en.wikipedia.org/wiki/Moon_illusion

http://www.pnas.org/content/97/1/500.full

http://www.lhup.edu/~dsimanek/3D/moonillu.htm

http://facstaff.uww.edu/mccreadd/

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