Recently, the post-metal/ sludge outfit The Ocean released the first of a double album, entitled Heliocentric (Metal Blade Records). I recently reviewed the album here. Unfortunately, although I enjoyed the music, I couldn’t get past the lousy vocals; hence, the low score I awarded to the album. Be that as it may, though, the themes and lyrics of Heliocentric strike at the core of my philosophical outlook on life, and illuminate an important reason for my utter contempt of religion.
The word ‘heliocentric’ refers to the hypothesis developed by Nicholas Copernicus in the 16th century to explain the motions of the planets as viewed from Earth. A bit of history is in order. The Greek philosopher Aristotle (born 384 years prior to the zero point of our current dating system) published treatises on nearly every aspect of the natural world. As part of his views, Aristotle is primarily responsible for what is referred to as the Aristotelian Universe. The Aristotelian Universe describes the universe as a series of “crystal spheres” centered on a stationary Earth. All of the celestial objects exist on the inside surface of those spheres, and move in perfect circles about the Earth. This means of picturing the universe is called the Celestial Sphere, and was taken by Aristotle and his followers to be a literal understanding of the structure of the universe.
The Celestial Sphere is still useful today as a basis for navigation, for example, but is completely wrong as a literal understanding of the structure of the universe. This inaccuracy still reverberates today, and resides at the heart of the conflict between religion and rational thought (to call this conflict anything else is absurd). The Celestial Sphere, however, does provide an explanation for celestial motion that is seen in the sky. For example, the daily, or diurnal, motion of the Sun and stars (referenced by The Ocean in “The First Commandment of the Luminaries”), the seasons, the phases of the Moon, all can be explained by the Celestial Sphere. However, the Achilles’ Heel of the Celestial Sphere lies in explaining the motion of the planets.
The Aristotelians pictured the planets as moving in a perfectly circular manner about the Earth. It was assumed that the closer a planet is to Earth, the faster it moved against the background stars. With these assumptions, the following picture of a geocentric universe emerges.
However, there are two major problems, both observational facts, which this model fails to explain. First, Mercury and Venus are only visible during twilight hours; that is, close to the Sun. Secondly, and perhaps most damning of all, the observed retrograde motion of the planets. All of the planets exhibit this type of motion, pictured below, but is most obvious with Mars (the picture shows Mars undergoing this motion). The Aristotelian model fails to explain these problems, which were noticeable to the ancients, even with primitive measuring tools. Essentially, the Aristotelians ignored the problems and hoped that they would go away. They did not.
In the second century after the zero point of our current dating system, the Roman astronomer Ptolemy devised a mathematical means of dealing with the problems; what is referred to as epicycle theory. The theory, illustrated below, consists of maintaining the Earth’s privileged place in the center of the universe, and the circular motion of the planets about the Earth. Essentially, a planet can be made to move on two circles. The larger circle, called the deferent, is, more or less, centered on the Earth, and a smaller circle, called an epicycle, is centered on the deferent. The combination of the two types of circular motion results in the following path about the Earth.
Although strange, and entirely incorrect (referenced by The Ocean in “Ptolemy Was Wrong”), epicycle theory can be made to fit the appearances by adjusting the mathematics of the model appropriately. The two aforementioned problems can be successfully explained away; that is, the mathematics can be made to fit the appearances. Ptolemy’s model was regarded as the correct model of the universe for over 1400 years. Over the centuries, further mathematical refinements were made to epicycle theory, mostly in non-European cultures, as measurements of planetary positions became increasingly precise.
In the 13th century, the catholic theologian Aquinas took the audacious step of incorporating the Aristotelian Universe (including the Ptolemaic system) into catholic theology (never mind that the geocentric universe predates christianity by several centuries). What this means, of course, is that by stating that Ptolemy was wrong, the rationalists of the time were risking their lives by committing heresy. This sets the stage for the conflict between the rational and irrational that reverberates to this day.
By the mid 16th century, Ptolemy’s model was so mathematically complicated that mathematicians began to seriously question its validity as a true picture of nature. A monk, a cathedral bureaucrat really, from Frombork, Poland, named Mikolai Kopernik (his name has since been Latinized to Nicholas Copernicus) hypothesized a simpler picture of the universe called the heliocentric model.
Copernicus places the Sun at the center of the universe, and assumes that the Earth is merely another planet orbiting the Sun. In a treatise called De Revolutionibus Orbium Coelestium, Copernicus works out the mathematics of the model, and is able to discern the basic layout of the Solar System. He is able to calculate, for example, the length of each planet’s year (as measured in Earth years), and the relative distance that each planet is from the Sun (as measured in astronomical units), to a high degree of accuracy.
Being educated by the catholics, Copernicus is well aware of his heresy, and wisely keeps his head down, withholding publication until he lay near death in 1543. However, he had made his point. The Copernican system, though it had flaws, has the basic idea correct and is a perfect example of Occam’s Razor. Occam’s Razor states that the simplest explanation is probably the correct one. Copernicus, by placing the Sun at the center of the universe, greatly simplifies the explanation for the motion of the planets, and largely does away with the torturous mathematics of Ptolemy’s model. In essence, the Copernican system is a much more elegant solution to the problem of planetary motion.
Hwever, as mentioned, Copernicus’ model does have some flaws, though, flaws that were done away with a few decades later when the Austrian mathematician Johannes Kepler finally unlocked the secret of planetary motion with his discovery of the Three Laws of Planetary Motion. Then, in 1687, Isaac Newton published a solution to the entire problem by providing a cause for planetary motion, and motion near the Earth’s surface, as well, with the discovery of the Law of Universal Gravitation.
Along the way, however, there were incidences of great importance. The Italian physicist Galileo Galilei played a large role. Soon after the invention of the refractor telescope (credited to a Dutch lens maker, Hans Lippershey), Galileo heard of the device and built a few primitive examples of his own. However, that was enough to bring the geocentric model crashing down, and with it the authority of religion in the natural world.
The telescope is a most heretical device. The two most important observations of the night sky made by Galileo occurred in 1610. Most famously, Galileo observed the motion of the four major moons of Jupiter, realizing immediately that the moons orbited the planet. Galileo had secured proof that not all motion in the sky was centered on the Earth.
However, of greater importance is the observed phases, and change in angular size, of Venus. As Venus orbits the Sun, we see the planet go through a set of phases similar to those of the Moon. In addition, the angular size of the planet changes as the phases progress. For example, we see Venus as small in its gibbous phase, larger as a quarter, and larger still as a crescent. The progression of the phases reverses as the planet shifts from being an “evening star” to being a “morning star.” This can only be explained if Venus orbits the Sun at a closer distance than the Earth does.
Galileo published his observations in two treatises. Sidereus Nuncius (The Starry Messenger), published in 1610, details the observed motion of Jupiter’s moons. Letters On Sunspots followed in 1613 with detailed descriptions of Venus. Soon enough, Galileo began to openly challenge the church’s official theology regarding the geocentric universe; however, luckily for him, he was a respected, admired, and faithful member of the church. He also had friends, and former patrons, in high places.
Even still, in 1634, Galileo was tried and convicted by the Inquisition for his challenge to scripture. He spent the remaining years of his life under house arrest until he died in 1642. The following episode of the physics based educational series The Mechanical Universe, produced at Cal Tech in the 1980s, beautifully summarizes the events. The entire episode is worth watching, but skip to 20:15 or so to hear the details of Galileo’s conflict with the church.
Galileo's Tomb (photographed by the author)
Unfortunately, the lapsed monk Giordano Bruno was not so lucky.
A dominican friar trained in mathematics and astronomy, Bruno also firmly believed that the Copernican system was correct. A philosophical scholar himself, Bruno published his support of the Copernican system, as well as speculation that the stars could be similar to the Sun, just very far away. Therefore, it is conceivable, according to Bruno, that stars could have orbiting planets that could support life. For his heresy, Bruno was hunted down by a catholic mob and burnt at the stake on the Campo dei Fiori in Rome on February 17, 1600. The lyrics of “Catharsis of a Heretic” could easily apply to both Galileo and Bruno.
A true martyr, Giordano Bruno deserves a place on my arm...
Tattooist: Terry Ribera of San Diego.
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