What is the common factor linking book-flips, solitaire, twelve-tone music and the solution of quartic equations? Answer: .

**Symmetries of a Book — or a Brick**

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Tags: Algebra, Group Theory

What is the common factor linking book-flips, solitaire, twelve-tone music and the solution of quartic equations? Answer: .

**Symmetries of a Book — or a Brick**

Tags: Algebra, Analysis, Arithmetic, Group Theory, Number Theory

An ambitious programme to unify disparate areas of mathematics was set out some fifty years ago by Robert Langlands of the Institute for Advanced Study in Princeton. The “Langlands Program” (LP) is a set of deep conjectures that attempt to build bridges between certain algebraic and analytical objects.

Tags: Algebra, Algorithms, Group Theory, Puzzles

The article in this week’s *That’s Maths* column in the* Irish Times* ( TM038 ) is about Rubik’s Cube and the Group Theory that underlies its solution.