Plus Blog
December 23, 2012
Timothy Lanzone on the set. Travelling Salesman is an unusual movie: despite almost every character being a mathematician there's not a mad person in sight. Moreover, the plot centres on one of the greatest unsolved problems in mathematics, does P = NP? Last month we were lucky enough to host the UK premiere of this movie, here at the Centre for Mathematical Sciences , the home of Plus. We spoke to Jonathan Oppenheim from University College London about the maths behind the movie and to the film's writer and director, Timothy Lanzone about creating drama from mathematics. You can listen to these interviews in our podcast and read more about the P versus NP problem in this article. 
December 22, 2012
Today would have been the 125th birthday of the legendary Indian mathematician Srinivasa Ramanujan. This selftaught genius formed a remarkable working relationship with the mathematician G.H. Hardy which served as inspiration for the 2008 play A disappearing number by Complicite. Read our article on the play and some of the maths behind it, our interview with an actor/mathematician involved in the play, and an article featuring one of Ramanujan's contribution to number theory.
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December 21, 2012
Quick, quick, before the world ends get your head around Schrödinger's equation. This central equation of quantum mechanics is the origin of weird phenomena like quantum entanglement, also known as spooky action at a distance, and quantum superposition, being in several apparently mutually exclusive states at once. A possible consequence of the equation is the idea that the universe is constantly splitting into many parallel branches. So while one copy of you sitting in one of these branches might witness a spectacular end to the world today, another can rest assured that it will survive. Schrödinger's equation — what is it? In the 1920s the Austrian physicist Erwin Schrödinger came up with what has become the central equation of quantum mechanics. It tells you all there is to know about a quantum physical system and it also predicts famous quantum weirdnesses such as superposition and quantum entanglement. In this, the first article of a threepart series, we introduce Schrödinger's equation and put it in its historical context. Schrödinger's equation — in action Now it's time to see the equation in action, using a very simple physical system as an example. We'll also look at another weird phenomenon called quantum tunneling. Schrödinger's equation — what does it mean? Here comes the crazy bit. How should we interpret the solution to Schrödinger's equation, the wave function? What does it tell us about the physical world? Or indeed many worlds? You can also read other articles on quantum physics and quantum mechanics on Plus. 
December 20, 2012
On the 23rd of June this year Alan Turing would have celebrated his 100th birthday. During his short and tragic life he revolutionised the scientific world and so 2012 was declared Turing Year. We're sad to see that an official pardon for his 1952 conviction for homosexuality, which was then illegal, still hasn't been granted. But that hasn't stopped us from celebrating his life and scientific achievements. See all our articles related to his work below. If you're a secondary school student then you can join the Alan Turing Cryptography Competition run by the School of Mathematics at the University of Manchester. It involves a story of six chapters, following the exploits of two children, Mike and Ellie, who get involved in a cryptographic adventure involving a mysterious ancient artifact — the Egyptian Enigma! Every two weeks, starting on Monday 7th January, a new chapter of the story will be released on the website. Each of the six chapters contains a code to be solved. Teams of at most four students have to solve these codes as fast as they can and submit their answers on the competition website. There are some great prizes for the three topplaced teams at the end of the competition. There will also be a prize for the first team to solve each chapter and a number of spot prizes awarded throughout the competition. See the competition website for details. Alan Turing: ahead of his time Alan Turing is the father of computer science and contributed significantly to the WW2 effort, but his life came to a tragic end. This article explores his story. Another look at Turing's life and work. Find out what types of numbers we can't count and why there are limits on what can be achieved with Turing machines. How does the uniform ball of cells that make up an embryo differentiate to create the dramatic patterns of a zebra or leopard? How come there are spotty animals with stripy tails, but no stripy animals with spotty tails? The answer comes from an ingenious mathematical model developed by Alan Turing. Omega and why maths has no TOEs Is there a Theory of Everything for mathematics? Gregory Chaitin thinks there isn't and Turing's famous halting problem plays an important part in his work. Turing is most famous for his work as a WWII code breaker. This article looks at the efforts of all the code breakers at Bletchley Park, which historians believe shortened the war by two years. A version of Turing's famous test – the "Completely automated public Turing test to tell computers and humans apart", or CAPTCHA for short – helps in the fight against the everyday evil of spam email. Turing's scientific legacy is going stronger than ever. An example is an announcement from February this year that scientists have devised a biological computer, based on an idea first described by Turing in the 1930s. Did a philosopher kill WALLE? AI has become big business in Hollywood, but will we ever see the computers reliably pass the Turing test? Or is it philosophically impossible? 
December 19, 2012
Space is threedimensional ... or is it? When we spoke to theoretical physicist David Berman in October this year we found out that in fact, we are all used to living in a curved, multidimensional universe. And a mathematical argument might just explain how those higher dimensions are hidden from view. Kaluza, Klein and their story of a fifth dimension — David Berman explains the concept of dimension and how a mathematical idea suggests that we might well live in five of them. The ten dimensions of string theory — String theory has one very unique consequence that no other theory of physics before has had: it predicts the number of dimensions of spacetime. David Berman explains where these other dimensions might be hiding and how we might observe them. How many dimensions are there? – the podcast — You can listen to an interview with David Berman as he tells us how Kaluza, Klein and their fifth dimension might help us understand the ten dimensions of string theory. 
December 18, 2012
The maths of growth is one of the many topics explored on STEM NRICH. Want to stop your brain from rusting this Christmas? Then visit our sister project NRICH which received a major makeover this year and now has a beautiful new website. NRICH is aimed at students and teachers of maths of all ages and backgrounds. It offers challenging and engaging activities that develop mathematical thinking and problemsolving skills and show rich mathematics in meaningful contexts. To train your brain have a look at the NRICH advent calendar, which has an activity for every day up to Christmas, or the regular weekly challenge. If you're interested in reallife applications of maths, then visit STEM NRICH which explores the ways in which mathematics, science and technology are linked. And if you're stuck on a problem or have a general maths question you can ask the team at the Ask NRICH forum. Because life is too short for long division! 