Sir Isaac Newton Biography

Most of us only know one of the things that Sir Isaac Newton is known for, his laws of motion which have yet to be proven false. Most don't know that he built the first reflecting telescope, was the first to develop the theory of visible light, and created calculus in his spare time. Even though Newton is known for his advances in mathematics, he is also credited with many significant theories and discoveries in astronomy. His biggest contribution to the astronomical world was certainly his law of universal gravitation. Newton was confronted by his colleague Sir Edmund Halley in the year of 1684, with the problem of explaining orbital motion. After being confronted by Halley, Newton spent the next two and a half years formulating his three laws of motion. The first law states that an object that's in motion or at rest, stays in motion or at rest until acted on by an outside force. The second law states that force (F) is proportional to mass (m) multiplied by acceleration (a). The third and final law states that for every action there is an equal and opposite re-action. These laws did explain phenomena that were puzzling astronomers and mathematicians at the time, but they failed to explain orbital motion. One day while Newton was drinking tea in his garden, he saw an apple fall from a tree. By the time the apple had hit the ground, Newton had realized that the same force that attracted the apple toward the Earth is also what keeps the Moon in orbit. Applying this "eureka" moment and his three laws of motion to Kepler's laws of orbit motion, he was able to come up with the law of universal gravitation. Using this law, he debunked former beliefs in a geocentric universe. He was not the first to suggest a heliocentric universe, but he was the first to give significant scientific evidence of it being valid. Newton then published all of his findings in his book Principia in 1687. After this major contribution his later accomplishments do not get close to surpassing it, but they are still ever so important. With the help of a prism, Newton found that white light was actually a mixture of many different colors ranging from red to purple. He took his knowledge of light and developed a new kind of telescope that was yet to be used. Instead of using a series of lenses, it used a mirror to reflect the images. This reflecting property increased the magnification property even though the first model was only six inches long.

All of Sir Isaac Newton's contributions are still used/believed today. After Principia was published, it marked a major turning point in the history of science because the model of the heliocentric universe would have enough evidence to not to be challenged and overturned. Also with his advances in optics, he would give later astronomers a perfect guideline for new astronomical discoveries. Including being able to find the chemical composition, temperature, and speed of movement of distant material in space.

Sources:
Newton, Isaac (1642–1727). The Principia: a new Translation, Guide by I. Bernard Cohen, University of California (1999)

Westfall, Richard S. (2007). Isaac Newton. Cambridge University Press.

Westfall, Richard S. (1983) [1980]. Never at Rest: A Biography of Isaac Newton. Cambridge: Cambridge University Press. pp. 530–1.