Paperbaby just sent us a beautifully colourful postcard. Here it is for you to enjoy. Please, write him back!

colourful squares

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Three friends, a mathematician, a physicist and an engineer, meet for dinner at a pizza place. The engineer arrives first and decides to order for everyone a 16″ stuffed crust pizza. The physicist arrives next and as the pizza is ready, states hating pizza crust and wishing to have as little as possible of that in his plate: but, he adds, I’ll pay 1/3 of the money, I want 1/3 of the area: that’s only fair. Right at this time the mathematician enters through the door. Discuss, in mathematical terms, the rest of the evening.

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It was remarked to me that this mathblog is too serious (perhaps it has to do with math being too serious to be left to physicists?) So, off to the start of our new column, Picture of the Week.


"An effective method of dealing with defects is to find a collection site."

Winner of “Bizarre” category of Micrograph 2005

Title: Chisai Benjo (Small Toilet)

Description: An effective method of dealing with defects is to find a collection site.

Magnification: ~15,000X

Instrument: SII NanoTechnology Inc. / SMI2050MS2

Submitted by: Takahashi Kaito (SII Nanotechnology Inc.)

Symmetry: the dynamical way

This week we present an awesome multilanguage software, written in Flash for Windows, Mac and Linux platforms. It is a modern presentation of symmetry aimed to students of all levels, including children.


As I am sure by now all readers have figured out, I am lazy. I don’t feel like writing reviews, especially as they would be enthusiastically monotous: the material I’m posting about is, obviously, what I have enjoyed and what my children have enjoyed (everything we post about, has been used and studied by us: this blog, in contrast to other websites out there, does what it says and says what it does). I am posting for two reasons: one is to save others the waste of time in locating quality material among oceans of cheap junk (I hope you appreciate my altruistic spirit). The second one is very selfish: I wish to hear your thoughts, and especially, if you try out the material, to know how you’ve been using it. Of course feel free to ask me similar questions, if you’d like.

Party cake

A classic USA math problem formulation involves sharing food fairly. Enjoy this problem with your lunch and the next one with your dinner 🙂

Five friends have ordered their favourite cake for a party. The cake is a parallelepiped and has icing on its top face and sides. Can you help our friends divide it fairly? Of course each friend needs to get equal amounts of cake, of top icing, and of side icing.

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Touching Soap Films

I am sorry to say that this week we present a not-so-uncommon occurrence, that is, a hard-to-find video, which is out of stock since years and has not been reprinted by the publisher. It is currently unavailable in DVD edition, but there are VHS copies out there. It’s a pity, no, it’s a crying shame, because it presents in a very fun and engaging cartoon, a huge amount of concepts in minimal surfaces. The movie can catch simultaneously the attention of a young child and of a differential geometer. In fact, it also discusses contemporary research topics, which makes it interesting even to minimal surface scholars and optimal geometers. Its only shortcoming is the amount of time and money it took me to get a copy: however, the video was well worth it.