Famous Astronomers: The Great Sir Isaac Newton

Isaac Newton is known as the philosopher who expounded the true theory of the universe. Born a year after the death of Galileo in 1642, Newton was a sickly child from the start, but the tender care from his mother ensured that he would go on to live a healthy life.

 

Newton began to show flashes of his brilliance from an early age, as he took an interest in the mechanical aspects of everyday objects such as a windmill or clock. Newton enjoyed replicating these objects, even going so far as to building a carriage in which the occupant controlled the wheels. He constructed a clock that was actuated by water.

 

This brilliance almost became short-lived when Newton's mother became a widow for the second time. Now faced with financial uncertainty, the 14-year-old was destined to spend the rest of his days working on the family farm, but even his mother knew that this would be a fruitless endeavor, so she allowed Newton to go back to school, where excelled mightily and became the head of his class.

 

Like so many great scholars and natural philosophers before him, Newton focused his studies in the area of mathematics while at Cambridge, employing math as an instrument for discovering the laws of nature. By the time he was 27-years-old, like Galileo, Newton became a professor of math at Cambridge. But his natural ability of discovery remained with him.

 

For example, it was Newton who discovered the composite characters of light, that a beam of ordinary sunlight is comprised of different-colored lights. It was through his continued study of light refraction and reflection that Newton was able to improve the telescope for the sake of astronomy. But perhaps Newton's greatest claim to fame was his discovery of the law of universal gravitation.

While Kepler's laws on planetary movement around the sun were the accepted truths of the day, it was Newton who mathematically provided the proof. Taking the simple act of an apple falling from a tree to the ground, Newton was able to calculate from the known laws of mechanics, which he had himself been mainly instrumental in discovering, what the attractive power of the Earth must be, so that the moon shall move precisely as we find it to move. It then appeared that the very power that makes an apple fall at the Earth's surface is the power that guides the moon in its orbit.

 

Newton showed by a most superb effort of mathematical reasoning, that if the orbit of a planet were an ellipse and if the sun were at one of the foci of that ellipse, the intensity of the attractive force must vary inversely as the square of the planet's distance. If the law had any other expression than the inverse square of the distance, then the orbit that the planet must follow would not be an ellipse; or if an ellipse, it would, at all events, not have the sun in the focus.

 

Newton was able to show from Kepler's laws alone that the force which guided the planets was an attractive power emanating from the sun and that the intensity of this attractive power varied with the inverse square of the distance between the two bodies.

 

 

Ball, R.S. (2000).Avoid Great Astronomers. Retrieved March 14, 2008, from the Gutenburg Project Web site: http://www.gutenberg.org/dirs/etext00/grast11.txt.