“The past is a foreign country—they do things differently there.” It’s a saying that rings especially true in the world of technology. But while innovating requires us to focus on the future, there are times when it’s important to look back. Today—the 100th anniversary of Alan Turing’s birth—is one such moment.

Statue of Alan Turing at Bletchley Park

Turing’s life was one of astounding highs and devastating lows. While his wartime codebreaking saved thousands of lives, his own life was destroyed when he was convicted for homosexuality. But the tragedy of his story should not overshadow his legacy. Turing’s insight laid the foundations of the computer age. It’s no exaggeration to say he’s a founding father of every computer and Internet company today.

Turing’s breakthrough came in 1936 with the publication of his seminal paper “On Computable Numbers” (PDF).  This introduced two key concepts, “algorithms” and “computing machines”—commonplace terms today, but truly revolutionary in the 1930’s:
  • Algorithms are, in simplest terms, step-by-step instructions for carrying out a mathematical calculation. This is where it all started for programming since, at its core, all software is a collection of algorithms.
  • A computing machine—today better known as a Turing machine—was the hypothetical device that Turing dreamed up to run his algorithms. In the 1930’s, a “computer” was what you called a person who did calculations—it was a profession, not an object. Turing’s paper provided the blueprint for building a machine that could do any computation that a person could, marking the first step towards the modern notion of a computer.
Considering the role computers now play in everyday life, it’s clear Turing’s inventions rank among the most important intellectual breakthroughs of the 20th century. In the evolution of computing, all paths trace back to Turing. That’s why Turing is a hero to so many Google engineers, and why we’re so proud to help commemorate and preserve his legacy.

In 2010, Google helped Bletchley Park raise funds to purchase Turing’s papers so they could be preserved for public display in their museum. More recently, we’ve been working closely with curators at London’s Science Museum to help put on a stunning new exhibition “Codebreaker - Alan Turing’s Life and Legacy.” This tells the story of Turing’s vast achievements in a profoundly moving and personal way, through an amazing collection of artifacts—including items loaned by GCHQ, the U.K. government intelligence agency, never before on public display. Topics addressed include Turing’s early years, his code-breaking at Bletchley Park, his designs for the Pilot Ace computer, his later morphogenesis work, as well as his sexuality and death. The exhibition opened on June 21 and is well worth a visit if you’re passing through London in the next year.


And finally, we couldn’t let such a momentous occasion pass without a doodle. We thought the most fitting way of paying tribute to Turing’s incredible life and work would be to simulate the theoretical “Turing machine” he proposed in a mathematical paper. Visit the homepage today— we invite you to try your hand at programming it. If you get it the first time, try again... it gets harder!

Turing was born into a world that was very different, culturally and technologically, from ours—but his contribution has never been more significant. I hope you’ll join me today in paying tribute to Alan Turing, the forefather of modern computing.