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  • (4/3): We saw a presentation on the Golden Spiral and built our own approximations. We also learned that the Golden Spiral has appeared (both deliberately and accidentally) in art for a long time! For some examples, see this link.

  • Here is the paper I referenced about knight tours. And here is a slide presentation that gives a perhaps more intuitive explanation for some of the results.

  • 2/27: We saw a presentation on "Math Beyond Infinity" today, and discussed different "sizes" of infinity. Check out Hilbert's Hotel for an intuition-building follow-up. (Tip: as mentioned in class, this would be a very good in-class presentation for someone, so if you're looking for ideas, check this out!)

    You could also start by looking at this short video:

  • Here is a step-by-step write-up of the Ken-Ken creation tutorial we went through in class on 2/27. It might be helpful as you think about how to create your own puzzles!

  • 2/25: We learned a bit in today's presentation about the history of the number system we use today! If you'd like to know more, the Wikipedia entry is a good place to start.

  • 2/20: Here is a follow-up to the presentation we saw in class about Benjamin Franklin's (semi)magic squares which includes a bit of background about how he constructed them. Complete with a diss at recreational mathematicians!
    "Being one day in the country at the house of our common friend, the late learned Mr. Logan, he showed me a folio French book filled with magic squares, wrote, if I forget not, by one M. Frenicle [Bernard Frenicle de Bessy], in which, he said, the author had discovered great ingenuity and dexterity in the management of numbers; and, though several other foreigners had distinguished themselves in the same way, he did not recollect that any one Englishman had done anything of the kind remarkable. I said it was perhaps a mark of the good sense of our English mathematicians that they would not spend their time in things that were merely 'difficiles nugae', incapable of any useful application."
    -- Benjamin Franklin, The Autobiography of Benjamin Franklin
    Click on this picture to see a colorful version of the page that was passed around in class, and stare at this animation for a little while.

  • 2/18: We saw a presentation about Leage of Legends and the role that linear optimization plays in determining how to spend one's resources.

  • Here is a very nice write-up that gives some intuition into how to think about puzzles like the Liar & Truth-teller. This also applies to a large number of logic problems, and is in general a good introduction to a more logical mode of thinking.

  • 2/11: We had a presentation and discussion on the backdoor that the NSA may have put into RSA's cryptography. Here is an article that gives a sort of primer on the technical aspects of what that means and how it works. No advance knowledge of cryptography is required.

  • 2/4: Here's a nice follow-up video to what we saw in the class presentation of the Twelve Tone Series.

  • 1/30: We saw a really cool presentation on the Missing Square Puzzle. Check out the Wikipedia article for a few other examples. My personal favorite:

  • 1/21: We saw a presentation on the golden ratio, which appears all over math as well as in nature. Here is a page that has an applet you can use to draw nice patterns, and which describes how the golden ratio relates to sunflowers (as mentioned in class).

  • 1/16: Here is the full solution to the puzzle discussed in class about evening out marbles, which gives the full explanation for why the process terminates. Check out the CMU shout-out in the solutions! (source: Mathematical Mind-Benders by P. Winkler)