# Happy 100th birthday Alan Turing!

On Saturday Alan Turing would have celebrated his 100th birthday. In his short life he revolutionised the scientific world and so 2012 has been declared Turing Year to celebrate his life and scientific achievements. You can join the celebrations by visiting the special exhibition at the Science Museum or attending the Turing Educational Day at Bletchley Park. Turing is also being honoured in this year's Manchester Pride Parade and the LGBT History Month. And here at *Plus*, apart from getting to work on building our own Turing machine out of LEGO, we're also celebrating with these favourites:

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 WALL-E?

AI has become big business in Hollywood, but will we ever see the computers reliably pass the Turing test? Or is it philosophically impossible?