4. The view from here
The End of a Universe of Crystal Spheres, Deferents, and Epicycles
The mathematician/astronomer Galileo Galilei rocked the scientific and religious world when
he discovered four moons orbiting the planet Jupiter in 1609 while using a small telescope
built by his own hand. He sketched these moons over several weeks as they shuttled to and
fro across and behind the giant planet with each observation providing a "snapshot" of the
ever-changing arrangement of the moons. For example, the arrangement of the moons and Jupiter as they would appear on three different dates:
In 1610 Galileo published his drawings of Jupiter and the Moon in his ground-breaking book Sidereus Nuncius (The Starry Messenger). His lunar drawings showed our moon as another world; not as a perfect sphere, but one with sun-washed plains, craters and craggy mountains. The observations of the shifting positions of Jupiter's moons were stark evidence against the age-old view placing earth at the center of the universe with all other celestial bodies revolving about it. Later still, he published drawings of the changing phases of Venus and details of sunspots which he sketched as they marched across the sun's disk.Despite his straightforward observations, old notions die hard. Galileo was brought before the Inquisition for "grave suspicion of heresy". He had few friends at the inquisition due to his stubbornness, acerbic tone, his contrary teachings supporting the Copernican view of the universe, and his recently-published book Dialogo which contained thinly-veiled criticisms of the pope and his detractors. By recanting his "errors", Galileo's life was spared. It is said that, at his trial, Galileo whispered, "Eppur si Muove" ("Yet it [the earth] does move"). For his daring to promote new thinking, Galileo was placed under house arrest for the remaining nine years of his life. However, as some have observed, the strongest force in the universe is an idea whose time has come. Working at about the same time, Johannes Kepler went farther than Galileo by codifying the three laws of planetary motion. Planetary motion was sharply defined in his third law; i.e.,
the square of a planet's period is proportional to the cube of the distance along its orbit's
semi-major axis. With this the 1,500-year-old Ptolemaic system of deferents and epicycles explaining the orbits of the planets was doomed and modern scientific inquiry was born.
- DS
Connections
GPS and surface-mount electronic circuits have brought comp
uterized telescopes and super-sensitive CCD cameras into the hands of the amateur astronomer at an affordable cost. This lends power and capability to the telescopic observer that was undreamt of only a few years ago. Couple this capability with the online accessibility of professional data and the ease of "data mining" on the worldwide web, the distinctions between professional work and the work of the serious amateur astronomer begin to blur. Does the work of the "serious" astronomer diminish the worth of the visual observer?The visual observer keeps in his or her bosom the joy of seeing the scintillating stars of the Pleiades, the ghostly glow of the Lagoon Nebula surrounding its offspring stars, the slow march of Jupiter's Great Red Spot - three times the size of the Earth - across the disk of the Giant Planet. This joy powers the urge to share the beauty of the stars with friends,
neighbors, and total strangers in backyards and public observatories. These Celestial Ambassadors allow citizens to enjoy the awesome beauty of the variety of celestial objects
and find inspiration to know more, to become more involved, to purchase their own
instruments, or to pursue coursework or even careers in astronomy. Yes, the serious amateur enriches the body of data available to be analyzed, but visual observing - like art - moves the soul and causes the observer to stop occasionally and contemplate what the eye just
examined through an eyepiece and to ponder creation.
The effort to touch the starry firmament with our own eyes creates a connection that lingers long after the telescope is retired for the night. These observers leave behind them an
excited wake of friends and guests who can't wait to tell others about their experiences under the night sky because an observer with a telescope was compelled to share the beauty of the night sky.
- DS