Galileo Galilei pointed the first optical telescope toward the Heavens in 1610, and he never claimed to have invented the telescope. Actually, it was a gentleman by the name of Lippershey, a simple spectacle-maker who was intrigued by the fact that when two lenses were held apart at a certain distance, objects far away could be magnified and resolved clearly. It was Galileo that built a small tube, arranged a focusing device into the tube, set the lenses in place at the proper distance, and held in his hands the world's first telescope. Although tiny by today's standards, it nonetheless magnified at eight times. Within a few days he improved the optics to x20 magnification. He wound up with a x30 magnification telescope after refining the tube and focusing device, and using better glass. Galileo’s telescope and curiosity about the universe gave birth to an immense science—modern-day astronomy.
In 1611, Galileo traveled to Rome to discuss his scientific findings with his new telescope. He claimed that the universe is in motion, Jupiter's moons orbited the parent planet, the Sun's was positioned in the center of the universe, and that the Earth orbited the Sun. He was accused of heresy and, in 1635, sentenced to house arrest until his death in 1642. His theory was of a heliocentric universe and not a geocentric universe. The Earth suddenly lost favor and was now one on thousands of objects in the heavens. As he knelt before the tribunal of priest at his sentencing and condemned for disobedience, he muttered under his breath, "And yet it moves.” Galileo was considered dangerous for his radical theories at the time.
Isaac Newton was born the year Galileo died. As a young student, he studied the works of Galileo and Copernicus. He was convinced that they were both correct. He designed his own style of telescope: the reflector. Galileo's was a refractor. Newton's telescope gathered more light and could see fainter objects in the universe. If you would observe Newton's telescope, you would marvel at its simplicity. Great intelligence always demands a simple approach to problem solving. Newton's inventions and discoveries are numerous, such as Calculus. He needed the correct mathematics to explain his theories.
At age 25, Newton purchased a prism in order to study the "phenomenon of colors.” The Sun's white light was broken into the visible color spectrum: the rainbow. He noticed that the spectrum was elongated, with the blue end of the spectrum more severely bent than the red one. These findings were to have far-reaching effects in the development of telescopes and eventually the science of Spectroscopy. Newton realized that if light could not be reflected, refracted or absorbed, we simply would live in a world of darkness. It is simply the chemicals in the universe that absorb, reflect, or refract light in order for us to see.
Of course, Newton's gravity is again a simple approach. If the apple fell to Earth, this invisible force might extend much farther into the universe—even to the Moon. Like the apple, the Moon is held within its orbit because it is constantly falling toward the Earth. Gravity holds it in check; otherwise, it would hurl in a straight line out into space. Newton realized that gravity is the mutual attraction of all things with mass. Therefore, gravity is a function of mass. The Earth controls us because it has more mass, and that is why we stick to our planet. The Sun controls Earth. Other stars control the Sun, and other galaxies control our galaxy. Mass and how much an object has determines its pecking order in the universe.
Albert Einstein was influence by Marie Curie's discovery of radium. At the time, scientists had calculated the distance to nearby stars, and many questions had been answered about the universe. The Sun's source of light and heat was still open for discussion and had not been correctly determined. What could possibly radiate this much light and heat? Again, the simple approach. Einstein wondered if the Sun was fueled by the theory behind Curie’s radium—an enormous amount of energy coming from a small amount of matter. Could matter and energy be interchangeable? His hunch was correct. E=mc2. Of course, it required great mathematical computations to solve the problem and to put his theory into terms so that other scientist could understand his theory. It was a simple idea to begin with.
One should take the time and reflect on this thought: if it were not for Galileo, Newton, and Einstein, we would still be practicing Astrology--not Astronomy. Our knowledge of the universe would be limited to forming animal figures with the stars and know nothing about the science of the universe as we do today.