In 1609, an Italian mathematician named Galileo Galilee peered through an odd new device he had invented to look at the stars in the night sky. Suddenly, this well known and familiar place revealed itself as a barely exposed mystery. It was then that Galileo knew this was a ground breaking device.
The moon is a gray-white orb to the naked eye. Looking through this new instrument, Galileo was able to see shadows and bright spots on the surface of the moon. He could see that the moon also had mountains and valleys.
At the time, the planets were thought to be odd stars that “wandered” the sky. Through Galileo’s device, he could see that the planets were accompanied by moving pinpoints of lights which were moons of their own! Galileo quickly published his discoveries in a bulletin he titled “Message from the Stars”. His claims, at first, were met with wonder and excitement. He presented his new device to the leaders of the time including the Catholic Church in Rome. Eventually this device would be named “telescopio”. In Greek, telescopio means “to see at a distance”. This would eventually evolve into the word telescope, but it certainly was an apt name for this new invention. Galileo’s telescope was a simple instrument compared with the ones we use today. It was a tube with two lenses: the convex primary lens that curved outward and the concave eyepiece lens that curved inward. He built the device after hearing about the newly invented spyglass which was an instrument used by the military to peer into enemy camps.
This first telescope used the same principle that all telescopes would eventually rely on. That principle held that the combination of the two lenses gathered more light than the human eye could collect on its own. The lenses would focus that light and form an image. Because the image was formed by the bending of light, or refraction, these telescopes came to be known as refracting telescopes, or simply, refractors.
Galileo’s best telescope magnified objects about thirty times. Because of flaws in its design such as the shape of the lens, the images tended to be blurry and distorted. However, the early telescope was good enough for Galileo to explore the sky.
Even though the introduction of the telescope was met with excitement, as his investigations progressed, Galileo began to make enemies. Some people argued that the telescope made people see illusions. Others claimed that the planets’ details couldn’t be seen with the naked eye and therefore didn’t matter.
The hostility arose from a dispute about the way the universe worked. After all, this was a radical new concept that refuted the accepted norm of how people looked at the world. Remember at one time, people thought the world was flat until Christopher Columbus provided proof that it wasn’t! At the time, one belief about the universe was outlined by the astronomer Ptolemy a long time prior. His belief was that the Earth was the center of the universe and that everything revolved around it. Another astronomer, Copernicus, put the sun in the center of the universe.
The politically powerful Catholic Church promoted the belief that the Earth was the center of the universe. They also believed that the celestial bodies were perfect spheres – smooth and round devoid of any mountains or valleys. You can imagine the controversy the telescope generated with the new theories Galileo was putting forth.
In fact, Galileo was uncovering evidence supporting the Copernican theory. For instance, he saw that Venus has phases just like the moon which showed that the planet was moving around the sun and not the Earth. Also, he could see that Jupiter’s moons were clearly moving around Jupiter and not Earth.
Labels: Telescopes
