Monthly Archives: April 2014

Golygons and golyhedra

A most delightful way to procrastinate is to attempt the unsolved problems on MathOverflow. Especially rewarding is when you actually end up solving such a problem, or when you learn something in the process, or both. Last night I learnt … Continue reading

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Orchestral biography of Turing

Whilst submerged beneath several blankets in my morning hypnopompia, I was awakened by the Today programme on Radio 4. Specifically, I heard news that the Pet Shop Boys are due to perform an orchestral biography of the mathematician and cryptanalyst … Continue reading

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Cipher 66: Hash inversion

Yes, this is designed to be deliberately difficult: 15fbaa066a407be6ca5d86838b756d3d Enjoy…

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Poncelet’s porism: the Socratic dialogue

In the 1994 proceedings of the Mathematical Association of America, there is a truly wonderful article by Jonathan King. Entitled Three Problems in Search of a Measure, it provides three very different examples of problems that can be solved using elementary … Continue reading

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Cipher 65: Melencolia

Firstly, congratulations to the British EGMO team (Olivia, Kasia, Katya and Eloise) for their impressive performance, coming eighth out of 29 competing teams. Apparently the competition was held in the same five-star hotel in Antalya enjoyed by a previous Balkan … Continue reading

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Lifting the exponent

I overheard mention of a particular problem on a recent British Mathematical Olympiad, namely the following: A number written in base 10 is a string of 3^2013 digit 3s. No other digit appears. Find the highest power of 3 which … Continue reading

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Cipher 64: Sic transit gloria Monday

Firstly, I have a few late items of news to discuss: Maria Holdcroft (former UK EGMO team member) and I survived our skydive on Wednesday, and have so far raised in excess of £886.77 (a large portion of which is from … Continue reading

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Cayley-Menger determinants

Niccolo Fontana Tartaglia, whom you may recognise from having discovered Cardano’s solution to the general cubic equation, also discovered a generalisation of Heron’s formula to compute the volume of a tetrahedron: As you may expect, this can be generalised to … Continue reading

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