Biography of Isaac Newton (1642-1727)

Isaac Newton.

Mathematician, physicist, and British astronomer born on December 25, 1642 in Woolsthorpe, and died March 20, 1727 in London, whose genius to the formulation of the law of gravity, the invention of the differential calculus and the invention of the telescope for reflection among other scientific advances.

When he was still a child his father died, and to get his mother back marriage was raised by his grandmother. He studied at the King completo School in Grantham, where his uncle was Professor, studies that alternated with the work of farmer. The influence of his uncle, who was able to recognize the talent of the young, was decisive for you enter at the Trinity College of the University of Cambridge, where he graduated in 1665. As a result of an epidemic of plague, the University closed the same year, and Newton returned to the family home, where he made in the two years following discoveries such as the development of the power of a binomial (the so-called binomial of Newton), the mathematical method of the fluxions, primitive form of differential calculus, the inverse method, germ of integral calculusdecomposition of white light through a Prism (spectrum) and the first investigations about the force of gravity.

Isaac Newton by Godfrey Kneller.

The famous episode of the Apple was told Voltaire by Catherine, the niece of the Sage, who was housekeeper from his residence in London. Whether or not certain that the observation of the fall of the fruit suggested you an analogy with the movement of the Moon, the manzano, who was in the garden of his residence, was a fervent pilgrimage until it was destroyed in the 19th century by a storm. The Royal Society retains a fragment of it at its headquarters in London.

Returning to the University in 1667 he was awarded the title of Master of Arts, and two years later he was elected Professor. Took the Chair Lucasiana - name that boasts the physics of this University, where he gave lessons of Optics (1670-1672), algebra and arithmetic (1673-1683) and explained his own works. In 1672 he was elected member of the Royal Society, which named him its member in the Parliament in 1689 and its director in 1703.

In 1696 earned a position in the House of the currency through the intercession of his friend Charles Montague, and three years later his appointed its director, the position of which was used to relentlessly pursue counterfeiters of currency. He presented a draft reform of the currency that earned him in reward for the granting of the title of sir in 1705.

Sour character, disputes with other scientists were very violent. Among those who argued heatedly with him are Hooke, with whom he maintained an intense correspondence and thanks to which took interest in the dynamics, Leibniz, who discovered simultaneously and independently the differential calculus - and whose notation, significantly simpler than the Newton, eventually prevail in short time - and Flamsteed, who played several astronomical discoveries. His difficult character made him suffer two quite acute depressive crisis in 1678 and 1693. He contracted the disease called bad stone, for as a result of which died in 1727. His buried remains are found in Westminster Abbey.

Death mask of Isaac Newton.

Scientific work

The importance of Newton to the Western scientific thought is considerable. He is considered, perhaps overly, the father of classical physics, and not in vain its two main works, Philosophiae naturalis principia mathematica (1687) and Opticks (1707) are held by Kuhn as examples of scientific paradigms, because they make up complete systems that interpreted the work of later scientists.

Notably, the introduction of a method as his greatest contribution: laws are obtained by generalization, induction and mathematical analysis, phenomena or systematic experiments, and constitute the only reliable basis for knowledge. Thus, the mechanics of Newton is the birth of modern physics, the apotheosis of the cause-effect relationship, looking perfectly expressed with the phrase non Hypothesis fingo (not built hypothesis). The definition of space and time as absolutes, which are not deducted or are defined by any physical process, which occupied an important part of his discussions with Leibniz, conception which prevailed until the arrival of the theory of relativity in physics is also remarkable.

Isaac Newton by David Eugene Smith.

In the Principia, published by insistence - and financing - of his great friend and astronomer Edmond Halley, is based on three axioms of the movement, which are inferred from the experiences of Galileo by the movement of projectiles: inertia, the composition of velocities, and the conservation of momentum, and making use of infinitesimal calculus gets his famous three laws dynamic:

Law of inertia: A body is at rest, or in uniform rectilinear movement of indefinitely if no force does not act on it.

Basic Dynamics law: the acceleration that produces a force on a body is directly proportional to the magnitude of the force and inversely proportional to its mass, which mathematically take the expression F = m·a.

Law of action and reaction: If body an exerts one force on another (action), the other is exactly the same force, but in the opposite direction, on the first (reaction).

With the second law, assuming that dynamic calculations it would simplify considerably if it meant as equivalent to all the mass concentrated in the geometric center of the bodies, and with the third Law of Kepler, deduced the law of gravitation, whose statement said that "any two bodies attract each other with a force that is directly proportional to their masses and inversely proportional to the square of the distance between them". This law is subject to experimental verification, and this managed to prove the other two laws of Kepler.

It is also noteworthy that in the work of Newton space and time are defined as absolute entities, unrelated to any external object, because the dynamic defines a unique reference system for rest and movement that is not subject to any body, and the time is irreducible to any physical process (not defined by any physical process)still and always similar, concept that prevailed in modern scientific thought, until the arrival of the theory of relativity by Einstein. This was one of the arguments employed by Newton against Leibniz.

Isaac Newton. Roubiliac's statue at Trinity College (Cambridge).

Regarding optics, Newton tried to first reduce the chromatic aberration of lenses for telescopes, attempt that failed, but which nevertheless allowed him to discover that white light was a mixture of pure colors, what he called the spectrum. He explained that they appeared since each of them was characterized by a different index of refraction with the glass. He discovered Newton rings, interference figures that appear when put in contact with flat glass and the other convex. All these phenomena, and some wave nature as the phenomenon of diffraction, were explained with more or less success on a corpuscular theory, which explains that particles of light travels in rays in straight lines determined by forces acting to distance, and find a solid lead a kind of internal vibration.

Also the astronomical observation owes much to Newton to consider that the chromatic aberration of the lens could not be removed, he had the idea of replacing the purpose of telescopes with a mirror. So he built the telescope of reflection, one of the most important astronomical instruments. Optics works, published under the title of Opticks in 1704, enjoyed over thirty years of uncontested authority, even in spite of the errors that contained (for example the relative to the alleged impossibility of correcting chromatic aberrations of lenses).

In the mathematical field, they deserve to be mentioned the works Arithmethica Universalis (1707) and Tractatus de quadratura curvarum, in which English genius explained the rules of the method of the fluxions, where the concept of infinitesimal makes its appearance and it derived the differential and integral calculus. The notation of Newton was considerably more complicated than Leibniz's, which is that finally imposed.

In hydrodynamics, he developed a theory of flow, and discovered transverse minimum of a current that flows through a hole in a tank section is reached on the outside. His honor those whose viscosity is independent of the speed gradient are known as Newtonian fluids.

More unknown is his passion for Alchemy, which spent nearly thirty years of his life, and whose work remained hidden for a long time. Newton, who knew the difference between Alchemy and chemistry, considered secrets these "esoteric" works, and hid them to their peers, as well as that their Arian, since have been known thought had cost him his chair at Cambridge. Subsequent to his death, the Earl of Portsmouth, heir to his writings, equally refused to its publication.