SIR ISAAC NEWTON

~ a brief biographical sketch by ~

Carl J. Wenning

Sir Isaac Newton

• English scientist and mathematician

• Born: Woolsthorpe, Lincolnshire, December 25, 1642 (Julian Calendar)

• Died: London, March 20, 1727

Most notable accomplishments

• “Invention” of the reflecting telescope

• Laws of motion• Law of universal gravitation

• Principia Mathematica

Additional Background

• Un-notable childhood• Graduated Cambridge 1665 without distinction

• Went to mother’s farm due to plagues and began to wonder about gravity

• Wondered about acceleration due to gravity for both moon and apple

Cogitation

• How does acceleration of the relate to the acceleration of the ?

• a = v2/d and a = 9.8m/s2

• But v = 2d/t = where d = 60r• Now, a /a = 3,600 = 602!• Therefore, a is proportional to d2 !

€

F =ma =GMm

d 2

Cogitation

Verification

• From Kepler’s observation, • Now if law of gravitation is correct, then

• Which reduces to Kepler’s third law!

• That is, KIII holds simply because:

€

P2 = ka3

€

F =mv 2

r=G

mM

r 2

€

F =GmM

r 2

Newton…

• Announced law of gravitation only 15 years later due to uncertainty of equivalency.

• Study of light (spectra) and optics (lenses)

• Invents telescope to avoid chromatic abber.• Developed calculus to see if gravity like pt.

• Enunciated three laws of motion• Mathematical Principles of Natural Philos.

Because of criticism…

• Began to live the life of a recluse

• Worked on transmutation of lead

• Appointed warden of Royal mint• Calculated insurance tables• Elected president of Royal Society in 1703 (after the death of Hooke, the so-called universal claimant)

• Now buried in London’s Westminster Abbey

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