cool. ur website is the best personal website I've seen in terms of content and technology. How do I get the trackback url for this entry? I want to link it to my blog entry at: http://www.jroller.com/page/bioye/20031204#13th_man_optical_illusion_response

cheers

bioye

It took about 4 minutes to figure out where the extra guy comes from. That's need the way the body parts are "reusable" in different roles.

Dave Orchard

I must say the developer of this problem probably spent countless hours in embedding the idea of reusability of objects extending space and time illusion. A unique blend of representational artistry with shapes and figures and how easily we draw conclusions on what we perceive.

My reasoning is very simple, notice the person on the far left. He does not have hair in the second scene. Therefore he is not a complete person and should not be counted. Since there is so little of him missing we assume that it is a complete person, but if it was only a 1/2 of a person one would not count him. So, both scenes actually have only 12 folks.

How much missing is really missing in software ?

cheers ssircar

There's actually 2 men that you need to focus on. If you start with the picture of 12 men, concentrate on the lower far left man, call him man 1, and the second guy from the right in the top row, with the black tank top, we'll call him man 2. As they swap positions, you'll notice man 2 leaves behind a trace of his shoes and moves to the left but does not complete another body part, but rather becomes his own single entity. As man 1 moves to the right, only his hair moves which ends up on the head of another man. Notice that what remains of man 1 still looks somewhat complete but actually isn't. If the swap at this point was complete, man 2 should have combined with man 1, and you'd once again have 12 men. However, they remain separate, so you have 2 men instead of one, thus 13 total.

All 12 people in th 12 person photo lose a sliver of himself to build a thirteenth person. Most obvious is the top of the hair (fair left) and the bottom of the shoes (second from right on the top). But if you look closely, you will see face pieces missing on the 13 picture. Mouth, nose, eyes, neck. Then people torsos and legs also shrink.

Very impressive on how they lines everyone up with such precision to get the slivers of folk.

sainttx

I drew a grahical explanation of this puzzle and loaded it on-line at: http://www.lrbcg.com/pogo/puzzlemenexplain.jpg

I still don't get it.