Novus Mundus

Amerigo Vespucci -- explorer, geographer and merchant, the first to call the Americas "the New World" and the incidental inspiration for the naming of those continents -- was born on this day in 1451 in Florence.

Vespucci has long taken the rap for being a fraud who had never sailed anywhere special and who had misappropriated the naming rights to the continent discovered by his rough acquaintance, Christopher Columbus. As is usually the case, the real story is a little more interesting than that. Born of a noble family, the classically-educated Vespucci, who grew up with a love of literature, astronomy and geography, ingratiated himself with the powerful Medici family (who were easily impressed by intellectual types) and got himself hired as a sort of purchasing agent and sales rep for their ship-outfitting business in Spain.

A welcome visitor at the court of Isabella and Ferdinand, he watched Columbus' first 2 voyages with interest, and furrowed his brow each time Columbus returned to declare that he had discovered a Western sea route to India. He decided to get to know Columbus a little better, and through his salesmanship became Columbus' key supplier for his third voyage across the ocean in 1497.

Hearing nothing with his skeptical ears that suggested that the coarse Genoan had actually found India, Vespucci decided, as a scientist, that he needed to go and see for himself, so in 1499 he outfitted his own voyage West and set sail under the Spanish flag. Arriving at the northern coast of what would eventually be called South America, he explored the Amazon and promptly fell into the same trap that had snagged Columbus, in that Vespucci initially insisted on calling the Amazon "the Ganges." However, with his superior skills as an astronomer, he did develop a method for determining longitude which became the standard for 300 years, and was able to estimate the circumference of the Earth to within 50 miles.

On his second trip in 1501 (this time on behalf of Portugal rather than Spain), Vespucci made his breakthrough: tracing the coast of the continent down to within 400 miles of Tierra del Fuego, he charted his progress and came to the realization that the land was not India at all, but an entirely "New World" previously unheard of in the courts of Western Europe. With that also came the revolutionary realization that there were 2 great oceans rather than one separating Europe from Asia to the West -- one greater than the one that Columbus had crossed and which Columbus had never even reached because of the big continents that stood between them. Vespucci reported his findings to the Medicis in 2 brief but erudite letters, the first called Novus Mundus (or "New World"), which when published shortly thereafter caused a sensation. He died on February 22, 1512 in Seville, Spain.

Meanwhile, Vespucci himself never presumed to name the new continent for himself; the name came from a map published by a German preacher named Martin Waldseemuller in 1507, who mistakenly declared Vespucci the discoverer of the continent, and upon that claim quite naturally decided it should be named for him. Columbus, for his part, never gave up believing that he had found the route to India, and though he continues to get all the credit for having discovered the New World, it was Vespucci who figured out that it was "New."

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

Hubble's Universe

Edwin Hubble changed our understanding of the universe by showing, in 1929, that galaxies were moving away from Earth with a speed proportional to their distance or, in effect, that the universe itself was expanding.

Born on this day in 1889 in Marshfield, Missouri, Hubble took the long way around to becoming an astronomer -- although he had an interest in the stars from an early age (inspired in part by reading the novels of Jules Verne). A high school track star who broke the Illinois state high jump record, he attended the University of Chicago on a scholarship, lettering in track, basketball and boxing, and working as a lab assistant to famed physicist Robert Millikan. He went to Queens College Oxford as a Rhodes scholar in 1910 and studied Roman and English law, returning to the U.S. in 1913 to enter the bar. After a half-hearted year of practice in Louisville, Kentucky, he left the law to enter the University of Chicago again, this time as an astronomy graduate student. "I knew that even if I were second-rate or third-rate," he later recalled, "it was astronomy that mattered." After finishing his doctorate there, he turned down an invitation to join the staff of the prestigious Mt. Wilson Observatory to enter the Army in World War I.

After the War he did join Mt. Wilson, where he worked with the world's best telescope (100-inch) for almost the rest of his life. Before Hubble came onto the scene, there was no consensus as to the boundaries of our galaxy, the Milky Way, or with regard to whether certain spiral nebulae (far off, fuzzy patches of light) contained individual stars within our Milky Way or were separate "island universes." By accurately measuring the distance from Earth to the Andromeda nebula in 1924, Hubble not only showed that it was about 100,000 times further away from Earth as the nearest stars, but that the nebula was comparable in size to our own cluster of stars; the Andromeda nebula, it seemed, should be thought of as its own galaxy -- at least in light of the definition of the Milky Way previously proposed by Harlow Shapley. (When Hubble wrote to Shapley to report this, Shapley was heard to remark, "Here is the letter that has destroyed my universe.")

Hubble also used a spectograph to determine the Doppler shift of the light spectra coming from stars as they moved further away from the Earth, and plotted a formula showing that the "redshift" of light from distant galaxies (i.e. the evidence of their movement away from Earth) was proportional to their distance from Earth. "Hubble's law" turned out to be accurate based on additional observation, leading Hubble to the conclusion that the universe was expanding. This conclusion was consistent with Albert Einstein's theory of general relativity and one that lent credibility to Georges Lemaitre's Big Bang theory of the origin of the universe, the idea that the movement of bodies within the universe in part reflected its origin from the explosion of an atom. The result was an entirely new cosmology than the one astronomers had previously projected; Einstein himself, who had previously assumed that the universe was static, became convinced of Hubble's conclusion after visiting Hubble in California, a circumstance which catapulted Hubble into scientific stardom.

After World War II, Hubble assisted in the design of a 200-inch telescope and first operated it in 1948. He died in 1953 in San Marino, California. 37 years after his death, NASA launched the space-based Hubble Telescope, named in his honor, which after a series of repairs has opened entire new vistas to astronomical observation.