Wikipedia:Featured picture candidates/Image:Missing square edit 2.gif

Missing Square Puzzle

Original - The Missing square puzzle. This is an alternative of the well-known "missing square paradox", popularized by Sam Loyd in the beginning of the 20th century. When the four quadrilaterals rotate about their centres, they fill the space occupied by the small red square. However the total area of the figure remains apparently unchanged during the process. Look better!

Reason: highly pedagogic and funny geometrical illusion which doesn't call for any special mathematical or geometrical skills and motivates the reader to go through the detailed explanation in the article.
Articles this image appears in: Missing square puzzle
Creator: Joaquim Alves Gaspar

Info - Also a second try (see here), with some minor improvements. I made this puzzle more than twenty years ago (in wood) and haven't found yet any written reference to it. However, and because its principle is quite simple, it might be hidden is some old puzzle book. The aim of the animation is to puzzle the reader and defy him to find the explanation, which is quite simple and doesn't call for any special mathematical or geometrical skills. For a full description see the article.
Support as nominator --Alvesgaspar (talk) 23:06, 27 September 2008 (UTC)[reply]
Question According to the article, the apparent paradox is resolved because the 4 quadrilaterals + square combination is slightly larger than the four quadrilaterals alone. But the animation makes them the same size. Should the larger square be a pixel larger or something? Or does the documentation in the article need to be expanded and made more comprehensive? (I'm pretty sure it does.)--HereToHelp ^{(talk to me)} 00:34, 28 September 2008 (UTC)[reply]
- The size of the big square in the animation does change slightly between the two arrangements.--ragesoss (talk) 00:51, 28 September 2008 (UTC)[reply]
  - By golly it does! It's just undetectable in the thumbnail.--HereToHelp ^{(talk to me)} 01:31, 28 September 2008 (UTC)[reply]
    - I can see it in the thumbnail. Pick a corner, stare for a moment, and it'll move a couple of pixels. Durova^Charge! 10:14, 28 September 2008 (UTC)[reply]
      - Oh yes...I must have been blind when I wrote the first comment.--HereToHelp ^{(talk to me)} 13:14, 28 September 2008 (UTC)[reply]
Support. Interesting. I fixed a small spelling error in the caption. Amphy (talk) 02:24, 28 September 2008 (UTC)[reply]
Support it appeals to my inner geek. Durova^Charge! 03:06, 28 September 2008 (UTC)[reply]
Support, but is the graphic demonstrating the problem, or answering it. I think that if lines showing the size change are included, it would increase the image's value, especially because the size difference appears so minimal in the thumbnail. Spencer^T♦^C 03:33, 28 September 2008 (UTC)[reply]
- Good idea, but the lines would be so close together they'd be hard to discern. By increasing the size of the orange square, we increase (exaggerate) the disparity between the two figure allowing the difference to be wider (clearer).--HereToHelp ^{(talk to me)} 21:04, 30 September 2008 (UTC)[reply]
Info -- Three small mistakes were corrected in frames 2, 11 and 12. Now I think it is pretty clear, in the transition from one frame to the next, that the area in being increased (or decreased) -- Alvesgaspar (talk) 12:11, 1 October 2008 (UTC)[reply]
Support - I like the sense of questionability and mathematics behind this image. Matthuxtable (talk) 20:52, 7 October 2008 (UTC)[reply]
Support. Excellent work. Spinach Dip 22:41, 7 October 2008 (UTC)[reply]

Promoted Image:Missing square edit.gif MER-C 10:35, 9 October 2008 (UTC)[reply]