I’ll Difference Your Engine

Appropriately, the world’s largest computer history is here in Silicon Valley, in Mountain View to be exact, pretty much across the street from the Google campus. Nick and I paid it a visit and to be honest, while I was expecting to be kind of bored (I’m a geek, but I’m not THAT geeky) I very much enjoyed our visit, ESPECIALLY:

The Babbage Difference Engine – Holy Cow. Let me tell you about the Babbage Difference Engine. The Babbage Difference Engine is first of all very fun to say. Second of all, it is a machine that was designed in 1822 – yes 1822 – and weighs 5 tons, and is used like a giant steampunk calculator to figure out polynomials.

Polynomials, for those of you who (like me) prefer not to remember their 10th grade math class, are these bad boys:  4x² + 3x – 5 

Back in the day, in the early 1800’s, they were using polynomials & their solutions for things like astronomy and navigation. However, because they didn’t have calculators or y’know, Microsoft Excel, the solutions to the polynomials (which were way more complicated than the simple one I’ve put up above – they were more like logarithmic or trigonometric functions) were printed in tables in big books, which were often full of errors since the typesetting/printing process was that typesetters would take the (initially correct) tables and hand-typeset them (just think of how difficult it is to keep your place in a giant table of meaningless numbers…and now think of keeping your place while having to typeset a mirror image (so it looks the right way when printed) of the table of meaningless numbers…eek!).

Babbage had the great idea to automate the calculation & printing process entirely, removing the possibility for human error, and so he pitched the idea of this “Difference Engine” to the government, who agreed it was a fantastic idea and promptly gave him £1,700, or the equivalent of about $300,000 in today’s USD, to build it.

Sadly, by 1843, 20 years later, the British government had given Babbage £17,000 (equivalent to USD $3 million today), and still did not have a Difference Engine. The government cut Babbage off and his Difference Engine was actually never built…until 2000, when the London Science Museum completed the construction of two Difference Engines. Wait, why two? Well, one was for them, and one was for Nathan Myhrvold, former CTO of Microsoft, who said he’d help fund the London Science Museum to finish theirs, if they built him one too! His copy is on loan to the Mountain View Computer History Museum.

If you’d like to learn/read more about the Babbage Difference Engine (forgive me but my eyes glazed over at the actual mathy “how does it work??” part), you can read the Wikipedia article, or watch this video, which is 24 minutes long but fascinating and definitely worth watching (they use it to solve a 5th order polynomial).

Other Cool Things At The Museum: 

OLD SEARCH ENGINES: and just for fun, they had a computer showing what search engines used to look like – see if this brings back any memories: