Mathematics hero, James Grime, visited The Grange to speak to Year II students, bringing with him a genuine WWII Enigma machine.
First, James gave us a fascinating history of codes and secret messages. We discovered that Spartan generals preferred secrecy over urgency; they would tattoo a message onto a slave’s head, and wait for the hair to grow back before sending the message! Along the way, we learnt a couple of simple codes and ciphers to write ourselves, such as the Caesar shift cipher (A=D, B=E, C=F etc.) or the general substitution cipher (A=F, B=Y, C=K or anything you choose). We found that the second one would take millions of years to crack even if every person on Earth tested one possibility every second! Soon we got to the 1930s, where the Enigma machine was being developed. It followed the general shift cipher but was programmed to change every time a letter was typed, making it even harder to crack. We had a chance to see how the machine worked, and how messages were transmitted and decoded by someone on the receiving end. The best bit was that we could see this on one of the few remaining Enigma machines, which would have been used by the Nazis to code secret messages!
After this, we enjoyed code-breaking workshops, with a chance to try for ourselves breaking some new codes using our own intellect. Each broken code revealed a clue to someone or something we had learnt about in the morning, and we had to remember all we had learnt. It felt a little bit competitive, trying to get as many codes cracked as possible in the time we had, but we had lots of fun at the same time!
Abi Knox - IIALJ