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Given any Delta, there exists Epsilon


At the end of an overnight flight from San Francisco to New York is hardly the ideal time to play “I Spy Mathematics” on a packed airplane. We were all grumpy and groggy from four scant hours of sleep. It seemed that nobody had watched any films en route and, like most of the other passengers, I didn’t have headphones or earplugs to hand.

Clearly there was no point in scanning the entertainment offerings with just 15 minutes to landing. But then I remembered spotting an ad on screen for The Great Courses as I’d settled into my seat in San Francisco. Was it possible that I’d blown a chance to watch Art Benjamin, David Bressoud, Judith Grabiner, David Kung, James Sellers or Mike Starbird in action? I decided to try to find out.

MacTutor History of Mathematics website creators honoured by LMS

Edmund Robertson & John O’Connor of the University of St. Andrews have been honoured by the London Mathematical Society for their pioneering MacTutor History of Mathematics website hosted at St. Andrews.

mactutor dudes

On 3rd July it was announced that both men have received the Hirst Prize, and Edmund Robertson has been been invited to give the associated Hirst Lectureship, all part of LMS 150th Anniversary celebrations.

Eight Easy Pieces (you can touch but don’t look)

Here’s a bar bet you can’t lose. Actually, it’s more of a kitchen bet, being a quiche cutting conundrum.

You’ve just bought a lovely fresh haggis quiche at your local Minus 4 shop and are planning to eat it in one sitting, in your kitchen with a friend. You’ve agreed to share it in the fairest possible way: one of you cuts and the other choses. The quiche is in the usual circular shape.


A coin is tossed—rather unnecessarily, it must be said—and it is determined that your friend gets to cut. You step out of the kitchen for a moment and upon your return discover to your horror that your friend has already done the cutting, but not as you had expected. Instead of making one simple straight cut as close to a diameter as possible, the big oaf has made four straight cuts.

All Squared, Number 8: Martin Gardner (Colm Mulcahy part 2)

Martin Gardner "standing by every word he ever wrote"

This is the second and final part of our interview with Colm Mulcahy. Last week we talked about card magic; in this part we moved on to the subject of Martin Gardner and the gatherings of interesting people associated with his name.

We’ve tacked on some blather we recorded about the British Science Festival in Newcastle to the end of this podcast. Listen in to hear what we think about maths! (We’re broadly in favour of it.)


All Squared, Number 7: Card Magic (Colm Mulcahy part 1)

colm book

Colm Mulcahy is an original Aperiodical contributor (Aperiodicontributor?) and friend of the site. He’s spent the last year and a bit writing his new book, Mathematical Card Magic: Fifty-Two New Effects. It came out a few weeks ago, so we thought it was a good opportunity to talk to him and find out just what’s so great about mathematical magic tricks.

Actually, we had that thought quite a while ago and if we’d been the least bit organised this podcast would’ve come out the same day as the book. As it happened, we first arranged to talk to Colm back in May, and then it took literally three months before we actually managed to record the interview.

… And then it took us three weeks to edit it up and upload it. Sorry!

Because Colm had so much interesting stuff to say, we’ve split the interview into two parts. In this first half we talk about the book and mathematical card magic; in the second part, out next week, we talk about Martin Gardner and the Celebration of Mind.

Mathematical Card Magic: Fifty-Two New Effects is published by CRC Press, priced £19.99/$29.95.


Who wants to host a Celebration of Mind? There’s still time

This Sunday, 21st October 2012, marks what would have been the 98th birthday of Martin Gardner, American man of letters and numbers, as well as logic, puzzles, magic and scepticism. I had the good fortune to know Martin in the last decade of his life, and a more gentle and modest man you could not find, completely disproportionate to the forceful and wide influence he wielded for over 50 years as a science and mathematics journalist of the highest calibre.

The first time I met Martin he fooled me by showing me a tall thin glass and getting me to agree that its height exceeded its circumference, when in fact it didn’t.