Isaac Newton

T J Osler

Sir Isaac Newton, FRS December 1642 – 20 March 1727 was an English physicist, mathematician, astronomer, natural philosopher, alchemist,

and theologian and one of the most influential men in human history

• In June 1661, he was admitted to Trinity College, Cambridge

• Soon after Newton had obtained his degree in August of 1665, the University closed down as a precaution against the Great Plague.

• Although he had been undistinguished as a Cambridge student,[10] Newton's private studies at his home in Woolsthorpe over the subsequent two years saw the development of his theories on calculus, optics and the law of gravitation

• In 1667 he returned to Cambridge as a fellow of Trinity.[11]

Newton showed that white light is composed of light of all colors. He used a glass prism to illustrate this.

Electromagnetic Spectrum

Binomial Theorem

Pascal’s Triangle

Newton’s discovery

k

knnnn

k

n )1(

3

)2(

2

)1(

1

Newton could now apply this formula to fractional exponents

k

k

k

12

1

4

32

1

3

22

1

2

12

1

12

1

2

1

He could now write binomials to fractional exponents

k

k

xk

xx

0

2/1 2/111

A replica of a Newton reflecting telescope that he presented to theRoyal Society in 1672[15].

Cassagrain Telescope

Image of a refracting telescope from the Cincinnati Observatory in 1848

Woodcut illustration of a 45 m (150 ft) focal length Keplerian astronomical refracting telescope built by Johannes Hevelius. From his

book Machina coelestis (first part), published in 1673.

Robert Hooke FRS (18 July 1635 – 3 March 1703)Hooke challenged Newton’s ideas. Newton had no stomach

for controversy, so he stopped showing his ideas.

Edmond Halley FRS  (8 November 1656 – 14 January 1742) was an English astronomer, geophysicist, mathematician, meteorologist,

and physicist.

Plaque in South Cloister of Westminster Abbey

• Halley told Newton that he and others were working on a problem:

• Find the Force of Attraction by the sun that will cause the planetary orbits to be elliptical

• Newton replied that he had solved this problem earlier. The solution is an inverse square law.

• Halley then urged Newton to publish this and other results.

Newton's own copy of his Principia, with hand-written corrections for the second edition

Although Newton had invented the calculus and used it to derive many of his results, he choose to write the Principia in geometric language.

This is because the modern algebraic form of analysis was not yet seen as a suitable form for writing mathematical ideas.

It would take another 50 years before analysis would finally end the tyranny that geometric thinking held over mathematics.

• Newton’s three Universal Laws of Motiopn were a giant first in the history of science.

• Nothing like them had been seen before.• Before Newton, men observed nature and

tried to describe nature in geometric (mathematical) terms.

• After Newton, we seek the fundamental laws. Then a particular problem is solved by using mathematics with the fundamental laws.

Application of Universal Laws

Find the vertical motion of a particle near the surface of the earth, neglecting air friction.

Initial Conditions: When t = 0,y = h and v = dy/dt = v0

Use Second Law:

mgdt

ydm

dt

dvm

2

2

gdtdv

dtgdv

cgtv

cgtv 0t 0vv

0vgtv

0vgtdt

dy

dtvgtdy 0

dtvgtdy 0

cgtv

Initial condition 1: When

,

dtvgtdy 0

ctvgty 02

2

1

0t hy Initial Condition 2: When

,

htvgty 02

2

1

Newton Derives Kepler’s Law of Areas

• Line from the sun to the planet sweeps out equal areas in equal times

Gottfried Wilhelm Leibniz 1 July 1646– 14 November 1716) was a German philosopher and mathematician

Controversy over who invented Calculus, Newton or Leibniz?

• Today we believe that both men should share the discovery

Isaac Newton in old age in 1712, portrait by Sir James Thornhill

• Newton enjoyed great fame in his final years

• He was recognized throughout Europe as the most outstanding mathematician – scientist of his time (or maybe all time)

Newton statue on display at the Oxford University Museum of Natural History

Newton's grave in Westminster Abbey Newton's grave in Westminster Abbey Newton's grave in Westminster Abbey

• "Threatening my [step-]father and mother Smith to burn them and the house over them." --From a list of his sins made by Isaac Newton at age 19.

• "Plato is my friend, Aristotle is my friend, but my best friend is truth." --Head of Newton's Quaestiones Quaedam Philosophicae (Certain Philosophical Questions), ca. 1664.

• "I know not what I appear to the world, but to myself I seem to have been only like a boy playing on the sea-shore, and diverting myself in now and then finding a smoother pebble or a prettier shell, whilest the great ocean of truth lay all undiscovered before me." --Quoted in D Brewster, Memoirs of Newton

• "Nature and Nature's laws lay hid in night; God said, Let Newton be! and all was light." --Alexander Pope (Quotation source: http://www.treasure-troves.com/bios/Newton.html