The UK's Alan Turing £50 bank note is a love letter to coding

The UK has finally unveiled its Alan Turing bank note, and it's a fitting tribute to the pioneering computer scientist in both what it represents and the technology behind it. To start, the durable polymer £50 bill completes the Bank of England's "most secure" set of notes to date with anti-counterfeiting features appropriate for the legendary WWII codebreaker, including a metallic hologram as well as windows themed around Bletchley Park and a microchip. The imagery is a nod to Turing's many achievements, including some deep cuts that you might not immediately recognize. The mathematical formula you see comes from Turing's influential 1936 paper "On Computable Numbers," a foundational work for computer science. You'll also see pictures of the Automatic Computing Engine Pilot Machine (the trial model for a very early computer) and schematics for the British Bombe codebreaking machine Turing specified.