Reading Passage

Isaac Newton

Isaac Newton (1643–1727) was an English mathematician, physicist, and astronomer who is widely regarded as one of the greatest scientists of all time. Born prematurely on Christmas Day 1642 (by the old Julian calendar) in Woolsthorpe, Lincolnshire, England, Newton was a frail child whose father had died before his birth. His mother remarried when he was three and left him in the care of his grandmother. Despite an unremarkable early education, Newton blossomed at Cambridge University, where he studied mathematics and natural philosophy. The years 1665–1666, when Cambridge was closed due to the plague and Newton returned home to Woolsthorpe, proved to be the most productive period in the history of science — Newton himself called them his ‘annus mirabilis’ (year of wonders).

During his time at Woolsthorpe, Newton made a series of extraordinary discoveries. He developed the mathematical framework now called calculus (independently also developed by the German mathematician Gottfried Leibniz), which provides tools for dealing with rates of change and areas under curves — foundational tools for all of modern science and engineering. He conducted experiments with prisms that showed white light is made up of all the colors of the spectrum. And he began developing his ideas about gravity. The famous story of Newton seeing an apple fall from a tree and being inspired to think about gravity is probably apocryphal in its details, but it captures something true: Newton was thinking deeply about what force could make objects fall toward the Earth.

Newton’s three laws of motion, published in his masterwork Principia Mathematica (1687), transformed physics. The First Law (the law of inertia) states that an object at rest stays at rest, and an object in motion stays in motion, unless acted upon by an external force. The Second Law states that force equals mass times acceleration (F = ma) — a relationship that allows the motion of objects to be calculated precisely. The Third Law states that for every action, there is an equal and opposite reaction. These three laws provided the mathematical framework for understanding the motion of virtually everything, from falling apples to cannonballs to planets.

Newton’s greatest triumph was his law of universal gravitation. He proposed that every object in the universe attracts every other object with a force that depends on their masses and the distance between them — the greater the masses, the stronger the attraction; the greater the distance, the weaker it is. This single idea, expressed in a simple mathematical formula, explained why objects fall to Earth, why the Moon orbits the Earth, why the Earth and other planets orbit the Sun, and why the tides rise and fall. For the first time, the same laws of physics could explain both earthly and celestial phenomena. Newton showed that the universe operates according to mathematical laws that the human mind can discover and understand.

Newton’s influence on science and intellectual history is almost impossible to overstate. His Principia Mathematica is considered one of the most important books ever written. He was the first scientist to be knighted (by Queen Anne in 1705). He served as president of the Royal Society and as Master of the Royal Mint, where he worked to combat counterfeiting. Newton famously wrote: ‘If I have seen further, it is by standing on the shoulders of giants’ — acknowledging his debt to earlier scientists like Galileo and Kepler. His framework of ‘Newtonian mechanics’ governed physics for over two centuries, until Einstein’s theory of relativity showed that Newton’s laws were a special case of a deeper reality. Yet even today, Newton’s laws are sufficient for most engineering and everyday calculations — they are how NASA plans rocket trajectories.

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