A Mathematical History Tour: Charles Babbage: LONDON

Without computers I wouldn't be writing this blog post, and you wouldn't be reading it. Of course there are many other reasons why computers are important to us in this information age in which we live. But we wouldn't have the technology that we have today and all that it provides us had it not been for the bright, curious, inventive people who went before us - people who dreamed dreams and worked hard to make them come true. In the case of computers there is such a long line of dreamers from whom our technology sprung, people like John Napier, Blaise Pascal and Charles Babbage.

Mathematician Charles Babbage (1791-1871) is widely considered to be a father of the computer. As well as being a mathematician he was an inventor, an engineer, and a philosopher - so basically a polymath. The machine pictured above is his "Difference Engine," which was intended to automatically calculate values of polynomial functions using finite differences.

The model pictured at the top of this post and in the five pictures below is of his Difference Engine. This one was built in the 1990s at the Science Museum in London. Sadly it proved too costly to be built in Babbage's lifetime. He poured his own fortune into it and also petitioned money from parliament, but eventually they got fed up with giving him more and more money and not seeing results. Since it had not been built in his time, it was uncertain as to whether it would work, but this model and the other (which resides in Mountain View, California) do, indeed, work. It even includes a printer!

The picture below is not part of the Difference Engine but rather part of another of Babbage's inventions, the Analytical Engine. Whereas the Difference Engine was more of a calculating device, the idea behind the Analytical was that of more general computation, and that idea was a great leap forward. It was a machine that could be programmed using punch cards. What is displayed below is one small part of the machine that was completed by Babbage. As far as I know a full Analytical Engine has never been built.

While it was Babbage who had the vision for constructing these machines, it was his "colleague" (for lack of a better term) Ada Byron Lovelace who had a broader vision for the use of such a machine. Though it was not built, she wrote a program for it for calculating Bernoulli Numbers. This is considered to be the first computer code. It's quite something, given the views about women in math and science in the 19th century that it is a woman who wrote the first computer code! I have a post on Ada from my previous sabbatical at this link.

Ada saw even beyond using this device for numerical calculation, however and wrote that the Analytical Engine " . . . might act upon other things besides number, were objects found whose mutual fundamental relations could be expressed by those of the abstract science of operations, and which should be also susceptible of adaptations to the action of the operating notation and mechanism of the engine . . . Supposing, for instance, that the fundamental relations of pitched sounds in the science of harmony and of musical composition were susceptible of such expression and adaptations, the engine might compose elaborate and scientific pieces of music of any degree of complexity or extent."

Ada died young, only 36, and Babbage grew old and crotchety. He continued working on his plans until the end of his life, but after he died his work was mostly forgotten. When programming began to be understood in the 1940s their work was rediscovered. One of those who rediscovered them through their writings was Alan Turing, he of the Turing Test, Bletchley Park, and the Enigma Code - all of which you can read about at this link.

Though I did see the Difference Engine during my last sabbatical, I chose to focus exclusively on Ada in writing about it. This was in part because I had hoped to get to his grave-site in London at Kensal Green Cemetery, but I was running around so fast and furiously that this one site escaped me at that time (whereas I did get to see Ada's grave in Hucknall - next to that of her father Lord Byron). This second sabbatical has given me a second chance, and I headed straight for Kensal Green Cemetery on the day I arrived in London in order to pay homage to this great and visionary man. Here is the entrance to Kensal Green:

As I learned on my last sabbatical, it is very hard to find one specific grave in a large (old) cemetery - even when one has done her research about its location and its features.