We have been distracted from our blogging duties of late by the smell of a fresh ocean breeze and the sound of waves lapping against the shore -- not to mention the spectacular sunset views from the beach house my folks rented in Ocean Shores (Washington state) for the last few days to celebrate their 50th wedding anniversary. Yeah, you heard me: 50 years! Plus three kids and five grandkids, all of whom crammed into the beach house for four days for fun, relaxation, a veritable gorge-fest of food, and the odd sensation of suddenly realizing from whence one's most annoying personality traits derive. (My habitual use of profanity while putting together Ikea furniture? I totally get that from my dad, except he sometimes swears in French.)
Anyway, congrats to the folks on this impressive marital milestone. I missed quite a bit of news in the meantime, but fortunately, Jen-Luc Piquant gave me a selective rundown of the highlights, based on her peculiar tastes. For instance, we are hugely relieved to learn that pop singer Amy Winehouse has finally landed in rehab (yes, yes, yes). The always entertaining Blogs 4 Brownback hit a humor-home-run (unintentionally, or satirically? you decide!) with a post on why flutes and woodwind instruments are inherently Satanic, tastefully alluding to the infamous scene from American Pie ("This one time, at band camp..."). And The Loom's Carl Zimmer's collection of science-themed tattoos on Flickr has made me long for a sci-tat of my very own; I suspect Jen-Luc has been frequenting a virtual tattoo parlor already, although her preference is for a nose ring or something that would actually show up on her avatar image.
But today's post isn't about any of that. I happened upon an article by the BBC on a new nano-chip device inspired by 19th century English mathematician and engineer Charles Babbage's famed difference engine. Via Brass Goggles, Scientists at the University of Wisconsin-Madison are surmounting the heat and power limitations of conventional silicon IC technology by using parts made of diamond or piezoelectric materials -- substances that can change shape when an electric current is applied, like crystals and certain ceramics. Because it will run cooler and use less power, and also be very, very small (on the nanoscale) a whole bunch of them should be able to fit on a single chip -- even more than on today's ultra-small chips, which could finally be approaching the fundamental physical limits of scaling down to increasingly smaller sizes. The new nanochips, in turn, while unable to compete with high-speed silicon chips, could nonetheless prove extremely useful in more mundane applications: automotive electronics, for instance, or toys and domestic appliances -- all of which are becoming more high-tech with each passing year.
Babbage is another of those historical scientists for whom I have a soft spot. (My all-time favorite is Eilmer of Malmesbury, a plucky 11th century monk who built his own set of "wings" and jumped off the roof of the local abbey. He glided several hundred feet before crash-landing and breaking both his legs.) He was one of those kids who felt compelled to take apart his toys just to see how they worked -- and, I'd wager, probably experienced mixed success actually putting them back together again, just like kids with similar inclinations today. Mathematically, he learned quite a bit on his own, so much so that he was quite advanced by the time he entered Trinity College at Cambridge, even founding an Analytical Society while a Cambridge -- possibly the first math club. He collected jokes into his own series of "jest books" as part of an attempt to scientifically analyze "the causes of wit" -- despite the fact that everyone knows that any attempt to explain a joke invariably sucks the wit right out of it.
But he had a creative, rebellious side, too. Babbage invented an early speedometer and a “cowcatcher,” a device that could be affixed to steam locomotives to clear cattle from the tracks. And he defied his family to marry for love, without his father's permission, thereby finding himself disinherited. Fortunately, he had a tidy income aside from that inheritance, which enabled him to pursue his other great love: the design and construction of elaborate “thinking machines." The passion sprang from frustration at all the errors in the mathematical tables used in the 19th century. Those tables were vital for calculations in astronomy, engineering, and navigation of the nautical variety. But they were riddled with errors: Babbage found over a thousand errors in just one table, causing him to exclaim, "I wish to God these calculations had been executed by steam!" Since God seemed disinclined to grant his wish, Babbage took on the challenge of mechanizing the process himself.
He found further inspiration in a scheme employed by French mathematician Gaspard Riche de Prony: using out-of-work hairdressers to work in calculating "factories,"manufacturing new logarithms for the new metric system of measurement by rote, as if those calculations were the usual mercantile goods. (Why so many idle hairdressers in France during that time? The vast majority of their wealthy clientele had lost their impeccably coiffed heads during the French Revolution.) It was the world's first mathematical assembly line, and it convinced Babbage that similar tasks could easily be performed by a machine. In fact, a mechanical calculator for adding and subtracting numbers, called the arithmometer, had already been invented.
Babbage's first steam-powered “Difference Engine” created tables of values by finding the common difference between terms in a sequence. The prototype he built and proudly demonstrated in his Dorset Street home was one of the most complex machines ever built in the 19th century. At heart, though, it was pretty much an unwieldy calculator. So he abandoned it after 10 years and designed his Analytical Engine, now recognized as the forerunner to the modern computer. This new, improved machine wouldn't’t just calculate a specific set of tables; it would solve a variety of math problems based on the instructions it was given, and would exhibit a rudimentary decision-making capability.
As is often the case with pioneering visions, Babbage had his skeptics and naysayers. Robert Peel, the head of England’s Tory administration at the time, denounced it as a “worthless device, its only conceivable use being to work out exactly how little benefit it would be to science.” It didn't help that his projects were way over budget and long past their deadline, and, apart from the small prototype, never actually built. It's hard to find any proof of principle if one never gets past the blueprint stage.
A working Difference Engine, based on Babbage's designs, wasn't built until the 1990s, by a team of scientists at London’s Science Museum. One of their members, Doron Swade, wrote an excellent popular science book about the history of Babbage's calculating machines and their project to bring the long-dead engineer's vision to fruition. They used only the materials and tools that would have been available in Babbage’s day. And it worked. The machine is now prominently displayed in the museum.
Babbage didn't have the advantage of knowing about piezoelectricity. It's related to the pyroelectric effect, in which a material generates an electrical charge in response to a change in temperature. This effect was first noted in 314 BC, in the writings of Theophrastus, who observed that tourmaline (a crystal) attracted bits of straw and ash when it was heated. It remained a curiosity to scientists for centuries, but nobody is recorded as having seriously studied it until the mid-18th century, when Carolus Linnaeus and Franz Aepnius cited it as evidence of a close relationship between mechanical stress and electric charge.
The discovery of piezoelectricity occurred in 1880, thanks to Pierre Curie (prior to his celebrated marriage to Marie) and his brother Jacques. They demonstrated the effect using crystals of tourmaline, quartz, topaz, cane sugar, and a type of salt. Mostly, it was just a pretty cool effect, until the development of sonar during World War I, when scientists realized that it might actually be useful. Quartz crystal has an especially strong piezoelectric effect, making it an idea material for a transducer in sonar systems. There are now piezoceramic filters in most radios, TVs, and buzzers, and some gas grill lights have a piezoelectric igniter to generate sparks.
The UWM scientists who developed the Babbage-style nanomachine have replaced moving mechanical parts and steam with piezoelectric materials and ultra-hard materials like diamond. Modern computers might be based on the movement of electrons around circuits, but the UMW machine would use each tiny part to push and pull in order to perform calculations. At the moment, the machine is mostly proof of principle. The team is now working on building the first transistors based in their new design, before moving on to constructing working circuits.
It's just... so... cool when we rediscover intriguing insights and ideas from the past, that were too far ahead of their time to be of much use. Until now. I mean, in 1902, archaeologists unearthed the remains of a 2000-year-old analog computer known as the Antikythera mechanism. There were those rudimentary calculators in France, and Babbage's ingenious engines, not to mention the very first computers in the 1940s and 1950s, before the silicon revolution succeeded, finally, in revolutionizing not only how we perform complex calculations, but how we live. I think Babbage would be pretty chuffed to learn his Difference Engine inspired scientists 150 years or more in the future to take an innovative approach to their little "scaling problem."