I would like to start a new column of mathematical puzzles. Scientific American has one; New Scientist has one; so I hope Science 2.0 will be happy to host one!

Preamble over, here's your "started for 10".



The diagram shows five circles, each with integer radius, all touching the base of the large triangle. The four smaller circles all touch their two neighbouring circles, with the large circle touching all four. The two sides of the triangle each touch two of the circles.

Let the radii of the circles be a, b and c, such that a > b > c.

Famous problem, famous solution, but is that the whole story?

How would you solve the problem of crossing the seven bridges of Konigsberg?

Spiked Math proposes a number of other solutions that never made it into print.

Original cartoon can be found here - including the pop-up punchline.



Further creative solutions gratefully received.

2013 will be the year of Mathematics of Planet Earth. This global initiative was spearheaded by Professor Christiane Rousseau of the University of Montreal, and it was fitting that the first national launch of MPE2013 was held in Canada on the 7th December 2012.

South Korea has agreed to send some 50 tons of boron from its reserves to Japan to help fight the nuclear disaster at the Fukushima reactor plant.

The scientists at TEPCO have been sent samples for analysis and a decision should be made pretty quickly. [Reuters, Korea Herald]

The UK Government's Chief Scientific Adviser, Professor Sir John Beddington, is in Tokyo trying to dampen expat fears that the Fukushima nuclear reactors could possibly ruin their lives.

I had actually received snippets of this meeting by email and was tempted to publish them yesterday. Luckily, Sir John's wisdom is now online for all to see. I just wish to copy some excerpts.