3.3 Isaac Newton

1. 3.3 Isaac Newton

2. Isaac Newton (1642-1727) • Born in the same year of Galileo’s death. • Orphan since birth. Newton was born three months after the death of his father • Grew up with his grandmother. • he was a small child; his said that he could have fit inside a quart mug (≈ 1.1 litres). • he never married, being highly engrossed in his studies and work.

3. Bio • At the age of 18, his mother attempted to make a farmer of him. • In 1661, he was admitted in Trinity College, Cambridge as a sizar. • He read the books of Copernicus, Kepler & Galileo. • 1669, he became a professor of mathematics. • (1670-1672) he taught Optics. • 1687, he returned back to mechanics. • 1704, back to calculus.

4. Bio • Newton was also a member of the Parliament of England from 1689 to 1690 and in 1701, but according to some accounts his only comments were to complain about a cold draught in the chamber and request that the window be closed. • In 1696, Newton moved to London to take up the post of warden of the Royal Mint. • 1701, retired from Cambridge. • Newton was made President of the Royal Society in 1703 and an associate of the French Academy of Sciences.

5. Bio • n April 1705, Queen Anne knighted Newton during a royal visit to Trinity College, Cambridge. • 1717, Newton moved the Pound Sterling de facto from the silver standard to the gold standard. • Newton died in his sleep in London on 31 March 1727. • After his death, Newton's body was discovered to have had massive amounts of mercury in it. • Mercury poisoning could explain Newton's eccentricity in late life.

6. Mathematics • In 1704, developed infinitesimal calculus. (Leibniz 1684) • Newton is generally credited with: • the generalised binomial theorem, valid for any exponent. • He discovered Newton's identities, Newton's method • classified cubic plane curves (polynomials of degree three in two variables) • made substantial contributions to the theory of finite differences • was the first to use fractional indices • He approximated partial sums of the harmonic series by logarithms  • was the first to use power series with confidence and to revert power series.

7. Optics (1670-1672) • he observed that color is the result of objects interacting with already-colored light rather than objects generating the color themselves. This is known as Newton's theory of color.

8. Components of visible light • Isaac Newton showed that by shining white light through a glass prism it could be separated back into its different wavelengths. • and that a lens and a second prism could recompose the multicolored spectrum into white light. • Newton’s color disk

9. Reflection Telescope • In 1668, he was able to produce the first reflecting telescope. • It is known as Newtonian Telescope. • It has many advantages compared to the refracting telescope.

10. Universality of gravity • In 1687, returned back to work on Mechanics. • What makes an apple falls down, is responsible for keeping the moon in orbit. • The moon is always falling toward Earth. • The moon moves forward in space, at the same time. • It constantly, misses the Earth.

11. Weightlessness • More than 200 years later, his ideas were put in action.

12. Universal Law of Gravity • This law works all over the universe. • G was determined experimentally by Cavendish in 1797-1798

13. Newton’s Laws of Motion (1687) The Law of Inertia: • In the absence of external forces, when viewed from an inertial reference frame, an object at rest remains at rest and an object in motion continues in motion with a constant velocity (that is, with a constant speed in a straight line).

14. Newton’s 2nd Law • the acceleration of an object is directly proportional to the net force acting on it and inversely proportional to its mass.

15. Newton’s 3rd Law • If two objects interact, the force F12 exerted by object 1 on object 2 is equal in magnitude and opposite in direction to the force F21 exerted by object 2 on object 1.