Compliments of me, here are two trivial typos on page 2: Somehow the commas in "(1905)," and "(1873)," ended up being transposed with the closing parentheses, resulting in "(1905,)" and "(1873,)".
Preceding the 2012 journal article in which Abbott, Abel, Charlton, Demaine, Demaine, and Kominers proved that for any two polygons of equal area there is always a swing-hinged dissection from one to the other, those authors had made that claim at the MAA Mathfest 2008 meeting, as reported in "Shapeshifting Made Easy", by Barry Cipra, Science, vol. 321, issue 5894. pp. 1282 (September 5, 2008). Cipra concluded his comments with 'The results are an encouraging first step toward applications, Demaine says: "Now the optimization begins." '
However, it is not so clear what Cipra meant by applications. Doesn't Dudeney's lovely hinging in 1907 of the triangle to the square count as a first step, or perhaps Philip Kelland's mention in 1846 of the hinged 3-piece dissection ot two attached squares to another square? If Cipra isn't satisfied with those as first steps, how about Figures 3.13, 3.14, 11.11, 11.31, 12.4, 12.5, 20.8, and 20.9, and Solutions 12.1 and 12.2 in my 1997 book, Dissections: Plane and Fancy? In that book I also claimed as hinged the results of Methods 11 and 12 and the dissection in Figure 10.21. It would certainly seem that by the end of my book, Demaine should admit that the optimization had already begun.
And a full six years before the MAA Mathfest about which Cipra makes his report, I had already published Hinged Dissections: Swinging and Twisting. So I had certainly done a lot of optimizing of hinged dissections already in that book, as well!
On page 9, the fourth line from the bottom, I wrote, for no apparent reason, an "of" rather than a "to". The text should read "due to their special geometry" rather than "due of their special geometry". Somehow that preposition got scrambled.
Copyright 2019, Greg N. Frederickson.
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Last updated February 5, 2019.