The Beginning of Digital Computing

Today, computers are integrated into many aspects in our lives, but I noticed that the origin of computers has been quite a mystery to most people including myself. And I only started to learn about how computer was made because of the movie, The Imitation Game. I'd like to share what I have learned about

During World War II, the British were under siege from German battleships, submarines, and bombers. Although it was easy to intercept radio messages sent between the German fleets, no one could understand the meaning of the messages because they were encrypted. In addition, the encryption method slightly changed every day so that the pattern stays random. Cracking the code with human brain seemed impossible. Alan Turing realized that and started to make an automated machine to do the work in quicker time. He and his group of cryptographers finished building the machine in 1936, and it was able to crack every German encrypted message. This is the first time in history that we used machines to solve logical and mathematical problems.

So why is this machine powerful? First of all, it can understand numbers and process them quickly and automatically once the instructions are given. And because it is a machine with a determined setup, there is no way for it to make mistakes without any mechanical failure. Lastly, it has an infinitely long tape to read input from and write output to, so it will never run out of memory space. None of these can be done by human brain.

A more modern implementation of Turing machine

Most of the modern programming languages are Turing-Complete, meaning they can be simulated on a single taped Turing machine. The CPU in modern digital computers is essentially an advanced Turing machine unit. Such model has been studied and used for almost a century and this paradigm is not likely to be shifted in the near future.