With the Sun at its Center

For 14 centuries, the prevailing view of the workings of the Earth, the Sun, the planets and the stars was the one articulated by the Greek astronomer Ptolemy: that the Earth was a stationary object, and that all other planetary bodies revolved around it in a uniform circular motion. The Ptolemaic model was happily embraced by the Roman Catholic Church as it sought to portray the Creation of Man on Earth as God's masterpiece, the center of God's universe. By the 15th century, European scientists and mathematicians -- who were generally not atheists, but aesthetes who yearned for glimpses of beauty at the nexus of time and space -- grew curious about the troublesome phenomena that the Ptolemaic model seemed to gloss over without easy explanation, such as the fact that the Big Dipper, for example, at certain times looked further away from the Earth than at other times. Over the years, scientists added a plethora of minor amendments to the Ptolemaic model to attempt to explain the observable eccentricities, but Ptolemy's simple, elegant model was beginning to look like a Rube Goldberg invention.

Mikolaj Kopernik (later known by his latinized name, Copernicus) grew up during this time of unresolved skepticism, the son of a merchant. Born on this day in 1473 in Torun, Poland, Copernicus' father died when he was 10, and he was sent to be raised by his maternal uncle, Lucas Watzenrode, the bishop of Ermeland. The bishop set young Mikolaj on a course to become a church canon. He studied liberal arts (including astronomy and astrology) at Cracow before setting off to his uncle's alma mater, the University of Bologna, at 23. There he lived for a time in the household of Bologna's foremost astronomer, Domenico Maria de Novara, who introduced Copernicus to the curative and skeptical literature, including Regiomontanus' Epitome of Ptolemy's Almagest (1496) and Pico della Mirandola's scathing Disputations Against Divinatory Astrology (1496), which argues that one of the flaws with astrology was that no one could agree on the order of the planets floating around the Earth.

With dissent already in the air, the exploration of the new hemisphere of the Earth incidentally discovered by Columbus began to call into question all sorts of fundamental assumptions about the order and primacy of things, and encouraged scientists to consider anew the incompleteness of their knowledge. Meanwhile, Copernicus kept busy: he received a doctorate in canon law at Ferrara in 1503; studied medicine at Padua; served as a scholar in absentia at Wroclaw while assuming the duties of canon at Frauenberg (which involved general administration and occasionally practicing medicine); prepared a Latin translation of the aphorisms of the Byzantine poet Theophylactus Simocattes (published in 1509); and still managed to pursue his astronomical observations in his spare time, building a small tower at Frauenberg from which to observe the sky.

His reputation as an amateur astronomer was great enough, however, for Copernicus to be invited in 1514 to the Fifth Lateran Council to make recommendations on the reform of the calendar. By this time he had begun to articulate a theoretical critique of the Ptolemaic model, quietly showing a summary of his views to a few friends. As a good canon lawyer, he must have predicted that the Church would not be happy with his theories; but after his 25-year old admirer Georg Rheticus published a summary of Copernicus' summary without provoking the Church's anger (in all likelihood they were a bit busy with Martin Luther at the time), Copernicus turned to completing a full dissertation on the heliocentric ("Sun-centered") model.

In what would come to be known as On the Revolution of the Heavenly Bodies, Copernicus argued that the Ptolemaic model, as amended, was like a Mr. Potathead in which the arms, legs, nose, eyes, ears and mouth were all placed in the wrong holes (to paraphrase his paraphrase of Horace's Ars poetica). By contrast, Copernicus wrote, if one assumes that the Sun is a stationary midpoint and the Earth is in motion, by a relatively simple set of calculations the remaining planets fall into orderly orbits around the Sun -- orbits whose length of time increase with a planet's relative distance from the Sun. Thus, Mercury would circumnavigate the Sun in 88 days; Venus, in 225 days; Earth, in one year; Mars, 1.9 years; Jupiter, 12 years; and Saturn, 30 years.

While he admitted that he could not rule out other potential alternative models to the Ptolemaic model -- it would take later mathematicians to uncover solutions for the problems of falling bodies, acceleration and force and ultimately prove that Copernicus was correct -- at least he had constructed one handsome Potatohead, in which all of the pieces fit together into a balanced, harmonious whole.

Copernicus avoided the potential wrath of the Church by waiting 36 years to publish Revolution; legend has it that on his deathbed he was able to hold the freshly minted first edition in his hands before passing away on May 24, 1543 in Frauenberg, East Prussia (now Poland). The cause and its implications would be taken up, in turn, by Galileo, Kepler, Descartes and Newton, among others. To Galileo goes the prize for making Copernicus a posthumously dangerous thinker; after Galileo's Discourse on Floating Bodies (1612), the Church banned Copernicus' Revolution. The Church would finally lift its ban in 1835.

Categories: Astronomy, Physicists, Mathematics

Ada

Ada Byron -- born on this day in 1815 in Piccadilly Terrace, Middlesex -- was the daughter of poet Lord Byron and his wife Annabella. Shortly after Ada was born, however, Annabella had had enough of the poet's excesses and threw him out. Byron, who left England for the rest of his relatively short life, never knew his daughter, but pined after her -- at least mimetically -- in his lines from Child Harolde: "'Is thy face like thy mother's, my fair child!/ Ada! sole daughter of my house and of my heart?/ When I last saw thy young blue eyes they smiled/ And then we parted -- not as now we part, but with a hope.'"

Ada's mother, knowing all too well Byron's capacity for b.s. and thus a little skeptical of her daughter's bloodlines, recommended an intensive course in mathematics for her daughter, unusual for a woman then sadly as now, to ward against the "heedlessness, imprudence, vanity, prevarication and conceit"she might otherwise inherit from the old man. When she was still a teen, while attending a women's literary meeting at the home of Mary Somerville, Ada first heard of Charles Babbage and his design for a calculating machine, the Difference Engine, which could be used to determine the polynomial equation for a table of data, and she was inspired by his notion that a machine might be made, not only to foresee, but to conduct some activity based on that foresight.

She put her inspiration on hold temporarily, marrying Lord William King in 1835 and having 3 children, but she maintained her acquaintance with Babbage, and became fascinated by the possibilities of Babbage's new proposal for a more sophisticated calculating machine that could perform any kind of calculation, the Analytic Engine, understanding much more quickly than many of Babbage's male contemporaries how it could work and what it could do.

After Babbage delivered a talk on the Analytic Engine in Italy in 1841, Luigi Menabrea published a paper about the machine. Attempting to channel her passionate interest in Babbage's work into something meaningful, Ada translated Menabrea's paper from French into English, and at Babbage's suggestion, added her own extensive commentary. Published in 1843, Ada's translation was in fact almost a completely new book on Babbage's proposed machine, 3 times the length of Menabrea's article, in which she outlined the fundamental concepts by which the machine could be "programmed" to complete certain tasks (observing that a working Engine could "weave[ ]. . . algebraic patterns, just as the Jacquard-loom weaves flowers and leaves"), the main elements required in any mechanical "language" used to program the machine (including a discussion of the machine might be programmed to compute Bernoulli numbers, a discussion which some have cited as perhaps the ealiest articulation of a computer program), and her predicitions that such a machine might be used to compose music, produce drawings and handle other practical and scientific tasks.

The article was not simply the best description of the Analytic Engine and its capabilties to date, but a work of some vision, as unappreciated until the 20th century as Babbage's plans ultimately were by his contemporaries. After the article was published, the charming, vivacious countess of Lovelace (who also numbered David Brewster, Charles Dickens and Michael Faraday among her parlor guests) fell ill with uteran cancer, and treated herself with alcohol, opium and morphine, leading no doubt to the instability which inspired her to become, in her final days, a compulsive gambler (albeit a mathematically talented one) and going into debt before her death at age 36.

A Pascal-based software language developed by the U.S. Department of Defense in 1979 was named "ADA" in her honor, and Tilda Swinton played her in an unusual fantasy film, Conceiving Ada (1997).