Pizza slicing the perfect way explained by mathematicians

Pizza slicing is a skill which two mathematicians say can be perfected if you follow their scientifically-studied formula. Joel Haddley and Stephen Worsley from the University of Liverpool in England believe their method works and will impress your friends the next time you slice up your takeaway (USA: takeout), especially if you are after identically shaped slices.

Most lay people use straight cuts that meet in the middle, the aim being to serve the pizza in nice equally-sized triangles. However, getting the centre right is not easy, and often there is some special topping there that we would rather avoid.

The mathematicians suggest that pizza-slicing has more to do with geometry than art.

Monohedral disc tiling

This is not the first time mathematicians have ventured into the culinary world and made suggestions on how to slice a pizza. Some previously suggested using a method called monohedral disc tiling, which results in 12 identically-shaped slices, six of which form a star-shape extending out from the middle, while the remaining six divide up the crusty part.

Pizza sliing 6 shields and 12 shields picThe mathematicians came up with a previous method for cutting perfect slices, known as monohedral disc tiling , which results in 12 identical slices. You start off by cutting the pie into six curved three side shapes across the pie. (Image: arxiv.org)

The slicer begins by cutting curved, three-sided slices across the pizza, and then cutting each piece in half – then you get the inside and outside groups.



Dr. Haddley, who teaches at the University’s Department of Mathematics, and Mr. Worsley, a postgraduate research student, have developed the technique further, giving us even more ways to slice.

They have shown that it is possible to create similar tilings from curved pieces with any odd number of sides. You then cut them in half as before. According to Dr. Haddley, mathematically, there is no limit to the number of sides.

Pizza smaller and smaller slicesYou can continue cutting each tile in half and getting more and more (smaller and smaller) slices. (Image: arxiv.org)

The two pizza-loving number crunchers went a step further by cutting wedges in the corners of their shapes, and created weird, spikey pieces that still form a circle. Dr. Haddley said to the New Scientist “It’s really surprising.”

As is often the case with mathematical formulas for straightforward procedures in the kitchen, it is unlikely that too many people will change the way they slice their pizza after trying Dr. Haddley’s and Mr. Worsley’s system.

Pizza chefHow many top pizza chefs would agree that it is more to do with geometry than art?

Dr. Haddley said:

“I’ve no idea whether there are any applications at all to our work outside of pizza-cutting.”

You do get some interesting pictures, he added.

Citation: Infinite families of monohedral disk tilings,” Joel Anthony Haddley and Stephen Worsley. Cornell University Library. Submitted 7 December, 2015. (arXiv:1512.03794)

Video – Pizza slicing trick

This video shows you how to slice up a pizza and keep some of it for yourself – without anybody noticing!