The History and Tools of Astronomy

Astronomy is one of the oldest fields of science ever. People have been looking to the stars for ages. We look up to the stars and cosmos for the answer to how life originated. Some say life is a huge mistake. Others believe that something supernatural must have happened, such as god creating the universe.

A popular theory in the first days of astronomy was the geocentric theory. This meant that the Earth was in the center of the universe, and that all the other stars and planets, including the sun and moon, revolved in circular orbits around Earth. This theory was believed throughout the middle ages until a man named Nicolaus Copernicus published a book describing his new theory, called the heliocentric theory. Copernicus’s theory stated that the earth and all the other planets revolved in circular orbits around the sun. Galileo also supported the new heliocentric theory and observed the phases of Venus to further prove Copernicus’s ideas. The Catholic Church was very displeased, mainly because the geocentric theory was doctrine. Copernicus’s theory wasn’t a hundred percent perfect though, and a major problem in his theory was the circular orbits. That was found by the German mathematician Johannes Kepler. Kepler had found that the orbits of planets were ovular, not circular. Kepler, however, did not know why planets moved this way. In 1687, Isaac Newton came up with his famous theory about gravity. Newton’s theory applied greatly to planetary motion. Newton said that a larger mass would attract a smaller mass. The mass of the objects and the distance between them were two factors determining the orbit of the smaller object. This theory revolutionized science, not just astronomy, and Newton had gotten his name written in the history books for sure.

Telescopes are an important tool for astronomers. Telescopes were invented by many people around the same time, but most agree that Hans Lipperhey was probably the first to invent the telescope. The term telescope was actually coined by Giovanni Demisiani. The word means ‘far-see’. The first type of telescope was a refracting telescope. Refracting telescopes utilized lenses, usually there were two lenses. The objective lens is a convex lens near the front of the telescope. The other lens is called the eyepiece lens, and was usually concave. When Galileo had heard about the telescope, and decided to build one of his own. Each time he built a telescope, he would increase the magnification rate. There was a problem with early refracting telescopes, which was called chromatic aberration, or a rainbow halo effect that blocked a lot of view. Isaac Newton, knowing the problem, built his own telescope, but his used mirrors instead of lenses. Newton believed that chromatic aberration could be fixed by using a refracting telescope, but he was wrong and the right combination of lenses was eventually found. Telescopes kept improving and they still do so today after Newton’s telescope. The first modern research telescope, the Hale telescope, had used mirrors with silver finishes to prevent mirrors from deforming and was built in the early twentieth century. One of the best telescopes, or group of telescopes, is the VLT in Chile. The VLT, or Very Large Telescope, is four huge telescopes. The VLT has collected more information than any other telescope except for the Hubble.

In conclusion, astronomy has developed greatly in its history, and is now a major field of science with amazing discoveries becoming headlines almost instantly, whereas back in its first days, astronomy was barely known, with the exception of Galileo, he had visitors look at his telescopes in his lifetime. Astronomy will continue to grow and grow, and we will eventually make more discoveries and answer the question, are we alone?