It was very sad to hear that Benoit Mandelbrot has died aged 85.

He is one of very few mathematicians who has both changed the subject and captured the public imagination.  His high idea, that there is a symmetry across scales, is easy to understand especially if you have walked the coast of Britain. 

However it is the images that have really caught the imagination.  This one was iconic in the eighties.  Everyone knew this image, whatever age they were.  

It was also inspirational for a teenager interested in mathematics.

And most people understood the basic idea.  They could see the symmetries, how the main shape was repeated throughout the image on different scales.

This image was already iconic then.  But now we have so much more.  I was struck by this 3D fly-through:

I’m looking forward to putting on my virtual reality helmet and flying through these things, changing scales as I go.

Let’s leave the last word to Benoit Mandelbrot recorded at TED this year.

In Golden Earring – Radar Love I had a big problem.

This the solution so please read the problem first and have a go at solving it yourself.

My wife has lost a golden earring, I can buy a bunch of similar earrings but I know one is a fake.

I can weigh two groups of earrings, each weighing can give one of three results: they weigh the same; the left group is heavier, the right group is heavier.

The question is – how many earrings can be in the bunch I buy and leave me confident that I can find the fake with just three weighings?

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Smart shows have smart writers, and none are smarter than the writers of Futurama.  We’ve seen a number of clever math references in Futurama and the Simpsons.  Now a fully fledged theorem is written up on screen.

If I had a TV show that’s exactly what I would do.  As it is I just post on Math Factor.

The theorem is by staffer and Math PhD Ken Keeler.  In the show Harlem Globetrotter, and all-round genius, Sweet Clyde comes up with a theorem to solve an apparantly intractible problem.

To quote Professor Farsnworth ‘Who says pure maths isn’t useful in the real world!’

Professor Farnsworth invents a mind-switching machine.  A lot of plot later nine people have their minds in the wrong bodies.  Unfortunatley the machine has a limitation, it cannot process the same two bodies twice.

There seems to be no way out until Clyde and EthanTate enter.  Clyde comes up with ‘Sweet Clyde’s Inversion Theorem’ and saves the day.

He shows that however many people there are, and however mixed up their minds, it is always possible to get every mind back in the right body as long as you have two extra bodies to help, and you know your maths!

This is the mess they are in:

Fry’s mind is in Zoidberg’s body

Professor’s mind is in Bender’s body

Bucket’s mind is in Amy’s body

Leela’s mind is in Professor’s body

Emporer’s mind is in Bucket’s body

Hermies’ mind is in Leela’s body

Zoidberg’s body is in Fry’s body

Bender’s mind is in Emperor’s body

Amy’s mind is in Hermies’ body

Take a moment to solve this yourselves.  Remember you need to get each mind back in the right body by repeatedly switching the minds of two bodies.  No switch can be repeated.  You cannot switch two of the original nine bodies because we have lost track and assume those combinations have already been used.  So every switch must involve Clyde and/or Ethan.  

Read on for the solution.

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