Astronomy in the Renaissance

Few subjects catch the spirit of the Renaissance so much as astronomy, an area where physics overlapped with metaphysics and asked both how and why the universe existed. It witnessed the greatest conflict between science and the church and allegations of murder and wrongdoing befitting a Greek tragedy more than a history of science, in a display of academic jealousy taken to its extremes.

But it also ushered in a revolution that changed the way humans see their place within the cosmos. The Copernican revolution is named after Nicolaus Copernicus, who proposed that the Sun, not Earth, was at the center of the solar system.

While the idea of a sun-centered system was new to Copernicus, it had been an ancient concept first advanced by Aristarchus of Samos in the 300s B.C. But Aristarchus had been unable to prove his hypothesis and was disregarded in favor of Ptolemy’s geocentric model.

Astronomers in the Middle Ages and renaissance made further developments in their models. But, in general, their models were complicated. They accounted for the movements of celestial bodies with a series of circles and epicycles — one circle carrying around another, which in turn carried around a planet. These models did not fit the observations as well as a simpler model suggested by a medieval philosopher named William of Occam. The guiding principle of Occam’s razor is that the best model is the one that requires the fewest assumptions and modifications to match the data. Guided by Occam’s razor, many scientists began to doubt Ptolemy’s geocentric model.

The idea that the sky was a place of awe and mystery had long inspired poetry, music and visual art. It was only natural that, at the end of medieval times and beginning of the renaissance, the night sky would start appearing in great works of art.

In the 14th and 15th centuries, artists including Leonardo Da Vinci and Galileo painted detailed moons and celestial bodies. The interest in astronomy grew even more as modern technologies developed and allowed people to view the cosmos in ways never before seen.

Using telescopes, satellites and computers, today’s astronomers can gather a wealth of information on the nature of the universe. In addition to studying light visible to the human eye — which includes ultraviolet, infrared and radio waves — scientists are now able to look at other forms of radiation that are invisible to us, such as X-rays and gamma rays.

The discoveries of these different wavelengths have opened up a whole new area of research, known as astrophysics. While this is still an emerging field, it has already sparked the development of such areas as nuclear and particle physics and cosmology. This exciting area of study will only continue to grow. But, it is important to remember that, just like the ancients, we must keep looking up. We must not lose sight of our place in the universe, even as the cosmos evolves around us.