Optical Illusion....Explain This!

[scj7129]

Greetings All!

Here is an optical illusion I would like to hear some opinions about. The photo was taken by myself.

It is a picture of one of three legs of a clocktower. The legs are curved down and outwards.

The reflection that you are seeing in the leg, is a reflection of the top of the clocktower....twice!

Once facing towards the top and one facing downwards.

There appears to be a "joining" of the two images in the middle.

The question is...."WHY?"

Any takers?!

[WahoGT]

The shiny curved surface is acting like a concave mirror (googe concave mirror physics for a detailed explanation with photos).  It has to do with how the curved surface reflects light rays to a focal point, past which the reflected image becomes inverted.  I'm guessing you were near this focal point, and the varied curvature of the upper and lower portion of the reflective surface in relation to you (the lower portion is closer than the rear and at a steeper angle) caused the upper portion of the surface to be on one side of the focal point and appear upright, while the lower surface is on the other side of the focal point causing it to be inverted.

[WahoGT]

Here's a youtube demonstration showing how the image flips based on whether or not you're inside or outside the focal point.

Mirror video

http://www.youtube.com/watch?v=NuFjqPEXG_4

Mathematical Explanation

http://www.youtube.com/watch?v=BmHK25Mts3I

[Buddy1]

Nicely done, this gave me a physics flashback!!

[scj7129]

COOL!..... To really "see" this effect, I had to stand on the concrete base that the leg was mounted to, which was probably a good 24" off the ground!....Standing on the ground, the effect was not visible!