17th CENTURY TIMELINE IN ENGLAND

1603 In March Queen Elizabeth dies. James I becomes king.

1605 A Catholic conspiracy to blow up parliament, is discovered.

1611 The King James Bible is published

1618 The Thirty years was begin

1625 James I dies. Charles I becomes king.

1628 The Petition of Right is presented to the king by parliament

1629 Christian Huygens was born in The Hague, Holland

1629-1640 The Eleven Years Tyranny. Charles I rules without parliament.

1635  Robert Hook is born in Freshwater, Isle of Wight

1642 Civil war between king and parliament begins. Isaac Newton is born in Woolsthorpe-by-Colsterworth , England

1646 Leibniz is Born in Leipzig, Germany 

1648. The Thirty years war ends. The battle of Preston ends hopes of restoring Charles I to power

1649 King Charles I is beheaded

1652-1654 The first Anglo-Dutch war

1653 Oliver Cromwell becomes Lord Protector of England

1656  Halley is born in Haggerston , England

1658 Oliver Cromwell dies. His son Richard takes over.

1659 Richard Cromwell resigns.

1660 Charles II becomes king

1666 The great fire of London

1687 Newton publishes his great work, “The Principia”

Robert Hooke

Robert Hooke (1635 – 1703) was an English natural philosopher, architect and mathematician  who played an important role in the scientific revolution, through

both experimental and theoretical work.

• Yes, he was also an important architect of his time, though few of his buildings now survive and some of those are generally misattributed; he was instrumental in devising a set of planning controls for London whose influence remains today. Historians have characterized him as "England's Leonardo".

• His adult life comprised three distinct periods: 1) as a brilliant scientific inquirer lacking money; 2) achieving great wealth and standing through his reputation for hard work and scrupulous honesty following the great fire of 1666  3) but eventually becoming ill and party to jealous intellectual disputes.

• Robert Hook was the last of four children, two boys and two girls. He grew up in the isle of Wright. His father was a minister, and Robert was expected to join the Church. Robert’s father was also in charge of a local school, and so was able to teach Robert, partly at home perhaps due to the boy's frail health. Robert’s father was a Royalist , and his son grew up to be a staunch monarchists.

R. Hooke drawings

• As a youth, Robert Hooke was fascinated by observation, mechanical works, and drawing, interests that he would pursue in various ways

throughout his life.

• On his father's death in 1648, Robert was left a sum of forty pounds, a small fortune  that enabled him to buy an apprenticeship; he had poor health all his life, but evident mechanical facility; his father had it in mind that he might become a watchmaker, though Hooke was also interested in painting.

• At Wadham College (Oxford) during the Protectorate of Oliver Cromwell, he became one of a tightly knit group of ardent Royalists. He built some of the earliest Gregorian telescopes, observed the rotations of Mars and Jupiter and, based on his observations of fossils, was an early proponent of biological evolution. In 1662 he became the curator of Experiments to the Royal Society, a post that he held all his life.

This beautiful microscope was made for Robert Hooke in the late 1600s, and was one of the most elegant microscopes built during the period. Hooke illustrated the microscope in his Micrographia,

one of the first detailed treatises on microscopy and imaging.

• He was also interested in the nature of light, and investigated the phenomenon of refraction, deducing the wave theory of light, and was the first to suggest that matter expands when heated and that air is made of small particles separated by relatively large distances.

But Hooke is a relatively obscure scientist. His reputation suffered after his death and this is popularly attributed to a dispute with Newton

 over credit for his work on gravitation

• http://www.flickr.com/photos/ashleymcc/2888355680/

• Between 1679 and 1680 Robert Hooke exchanged a series of letters with Isaac Newton. The letters covered a wide variety of scientific topics. In one of the letters, Hooke mentioned a hypothesis that the Sun exerted “an inverse square force”, i.e.: the Sun pulls on the planets, and this force gets stronger the closer you are to the Sun.

• Hooke also claimed the force caused the elliptical orbits of the planets. Newton replied he never heard of such a hypothesis… but he thought about the problem and soon proved that the elliptical orbits of the planets can result from an inverse square force…

• Newton apparently saw no need to tell anyone that he had produced such a proof, especially Hooke. He was a very secretive man and began to view Hooke as a rival. Newton, as President of the Royal Society, did much to obscure Hooke, including, it is said, destroying (or failing to preserve) the only known portrait of the man.

• Hooke was irascible, at least in later life, proud, and prone to take umbrage with intellectual competitors. He had dispute also with other scientists and started using  ciphered codes to guard his ideas. But … As curator of Experiments to the Royal Society he was responsible for demonstrating many ideas sent in to the Society, and there is evidence that he would subsequently assume some credit for these ideas. He died in 1703.

Christiaan Huygens ( 1629 –1695)

• Christiaan Huygens, (14 April 1629 – 8 July 1695) was a prominent Dutch mathematician, astronomer, physicist. He was born at The Hague, in Holland. Christiaan studied law and mathematics at the University of Leiden and the College of Orange in Breda. After a stint as a diplomat, Huygens turned to science.

Huygens’ pendulum clock was regulated by a mechanism with a "natural" period of oscillation and had an error of less than 1 minute a day, the first time such accuracy had been achieved. His later

refinements reduced his clock's errors to less than 10 seconds a day.

• His work included early telescopic studies elucidating the nature of the rings of Saturn and the discovery of its moon Titan, the invention of the pendulum clock and other investigations in timekeeping, and studies of both optics and the centrifugal force.

• Huygens believed in extraterrestrial life and was of the opinion that life on other planets is pretty much similar to that on Earth. He thought that availability of water in liquid form was essential for existence of life and therefore the properties of water should vary from planet to planet, since the kind of water that is found on Earth would instantly freeze on Jupiter and vaporize on Venus.

• He though that there is water, and hence life, on Mars and other planets. He even reported observing dark and bright spots on the surface of planet Mars and Jupiter. This he explained could only be justified by existence of water and ice on those planets. Unfortunately the recent space explorations proved him wrong.

• Huygens is remembered especially for his  theory of light, expounded in his Treatise on light, 1678. In his book he postulated that the light is made of electromagnetic waves, thus contradicting Newton, who believed that Huygens' wave theory was proved only in 1801, with an experiment could no longer be explained with light particles (more on this later…)

Huygens studied the centripetal force and produced the correct formula:

Where m is the mass, r is the radius and v is the velocity.

Example. A 60 kg Olympic figure skater skates at a constant 5 m/s during one section of a routine. During that section, the skater goes in a perfect 10 m radius circle.

• What is the centripetal force acting on the skater?• Right after the first circle, the skater turns in a tighter, 4

m radius circle at the same speed. How does the centripetal force acting on the skater change ?

• What is the acceleration of the skater as she completes the circles?

Sol. We apply the formula: F= 60 (5)^2/10=150 N for i) and For ii), F= 60 (5)^2/4 =375 N. When she skates on a tighter circle she is

subject to a higher centripetal force. iii) The force is the produce of mass ands

acceleration, and so A= F/60= (5)^2/10= 2.5 m/sec^2 for i) and

A= (5)^2/4= 6.25 m/sec^2 for ii)

Born 8 November 1656Haggerston, Shoreditch, London, England

Died 14 January 1742  Greenwich, London, England

Fields Astronomy, geophysics, mathematics, meteorology, physics

Institutions

University of OxfordRoyal Observatory, Greenwich

Known for

Halley's comet

Edmond Halley

• Halley was born in Haggerston,  England, from a wealthy family. He studied at St Paul's School, and then, from 1673, at The Queen's College, Oxford. While an undergraduate, Halley published papers on the solar system and sunspots.

• On leaving Oxford, in 1676, Halley visited the south Atlantic island of Saint Helena and set up an observatory with a 24-foot-long (7.3 m)  aerial telescope with the intention of studying stars from the Southern Hemisphere. 

• In 1686 Halley published the second part of the results from his   expedition, being a paper and chart on trade winds and monsoons. In this he identified solar heating as the cause of atmospheric motions. He also established the relationship between barometric pressure and height above sea level. His charts were an important contribution to the emerging field of information visualization.

• But Halley also solved other great problems in nautical navigation: the determination of longitude.

We are now used to see maps with meridians and parallels clearly marked

One of Halley’s charts

• . Latitude was fairly easy to determine, but without accurate longitude, one could never be sure where one was on the ocean. Errors in longitude led to considerable loss of life and ships.

• The governments of all the maritime powers offered substantial prizes to anyone who could solve the longitude problem. In addition to money, the solution of longitude also promised great honor and prestige. Halley’s greatest contribution was the invention of the isogonic map, that is, maps with lines of constant variation over the Earth’s surface.

• Halley spent most of his time on lunar observations, but was also interested in the problems of gravity. One problem that attracted his attention was the laws of planetary motion. In August 1684 he went to Cambridge to discuss this with Sir Isaac Newton, only to find that Newton had solved the problem, but published nothing. Halley convinced him to write the Principia Mathematica Philosophiae Naturalis (1687), which was published at Halley's expense

• .

Halley study the 3 body problem, that is, the motion of 3 or more planets subject to Newton’s universal gravity law.

• Producing an exact solution for Newton’s equations with more than two objects became known as the three body problem. Newton didn’t know how to solve the three body problem, he realized it was difficult (in fact he claimed it was too difficult for humans to solve). From the time of Newton up to the present, many people have studied it; some progress was made and a few specialized solutions were discovered.

• See http://www.scholarpedia.org/article/File:3body_problem_figure2.gif

• In 1691 Halley sought the post of Savilian Professor of Astronomy at Oxford, but, due to his well-known atheism, was opposed by the Archbishop of Canterbury. The post went instead to David Gregory, who had the support of Isaac Newton.

Halley helped to solve a dispute between Hook and

Hevelius.

• In 1679 he went to Danzig (now Poland) on behalf of the Royal Society to help resolve a dispute.

• Because astronomer Johannes Hevelius did not use a telescope, his observations had been questioned by Robert Hooke. Halley stayed with Hevelius and he observed and verified the quality of Hevelius' observations.

Halley published a catalog of the stars in the Southern hemisphere . He was awarded

his M.A. degree at Oxford and elected as a Fellow of the Royal Society.

• In the meantime, Edmond Halley started examining historical records of comets. Comets have been seen for hundreds of years and previous astronomers had made many observations. Halley had collected his comet observations since when 1682, when he observed a bright comet.

He was the first to evaluate the orbit of one of the brightest comets that now bears its name. It is one of the few comets that is visible with naked eyes. He understood that said comet appears in the solar system every 76 years and correctly predicted its return in 1758

Halley’s comet orbit

The comet appearance in 1986 was observed by the space shuttle. It

will return to the inner solar system in the year 2061.