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Isaac Newton was born on Christmas Day 1642 in the manor house
in Woolsthorpe, three months after his father's death. He was
so tiny that no one expected him to survive. When Newton was
three years old, his mother remarried, an event which improved
her situation, and lead to 3 more children, but which deprived
Newton of a mother. His stepfather, the Reverend Mr Smith, would
not take the three year old Newton along with his mother, and
he was left at Woolsthorpe with his grandparents.
We know little about Newton's pre-teen years other than that
he attended day schools in the neighbouring villages of Skillington
and Stoke. In August 1653, when Newton was 10, Reverend Smith
died and Newton's mother returned to Woolsthorpe. At the age
of 12, Newton was sent to grammar school in Grantham. Here
he got a standard education of the time - Latin and Greek,
and some Bible studies, which was taught at the time to reinforce
the Protestant faith in England. He was placed in the bottom
class at Grantham, but a playground fight which he won due
to sheer spirit began a rise to the top of the school.
He mostly kept his own company, as he was a 'sober, silent,
thinking lad', and when he did associate with others, it was
nearly always with girls. He is remembered from that time
in Grantham for 'his strange inventions and extraordinary
inclination for mechanical works'. For example, a windmill
powered by a treadmill run by a mouse, which was urged on
by tugs on a string tied to its tail, doll furniture for the
girls at his school, and a little 4 wheeled vehicle for himself
which ran by crank, which he could turn while sitting in it.
When he turned 17 his mother called him home to Woolsthorpe,
and appointed a trusty servant to teach him about real life
- running the farm. Newton did not take well to this. Set
to watch the sheep, he would instead build model waterwheels,
and other gadgets, and the sheep would often escape. His uncle
and his school master watched all this from a distance, and
strongly recommended that Newton's mother send him back to
school to prepare for university. She conceded when the school
master agreed to drop the fee for school attendance.
Newton set out for Cambridge early in June 1661, matriculating
to Trinity College. He entered Trinity as a subsizar, a poor
student who earned his keep by performing menial tasks for
the fellows, fellow commoners (very rich students), and pensioners
(the merely affluent). It seems that his mother was not prepared
to pay for any more of his education. At Cambridge he was
exposed to many philosophical texts and ideas, especially
those of Descartes, who was very popular at the time. After
studying Descartes he was attracted to mechanical philosophy,
and began to question the environment around him, including
the nature of matter, cosmic order, light, colours, and sensations.
To test a question about colours, he stared at the sun with
one eye until all the colours changed. As a result he had
to shut himself up in the dark for several days before he
could rid himself of the spots now floating before his eyes.
He had found a new passion. In order to pursue these mathematical
studies, Newton needed to secure a permanent position at Cambridge.
He had not distinguished himself during his three years and
failed to secure a fellowship. His only chance was to be elected
to a scholarship in 1664. It seems that his genius was recognised,
and he was sent to be assessed by the only person at Cambridge
who could judge his competence in the unorthodox studies he
had chosen to pursue. Dr Barrow examined him and Newton was
made a scholar of the house, a position guaranteed for at
least 4 years. Newton surrendered himself to his mathematics,
forgetting to eat, and sometimes forgetting to sleep.
He was not solely interested in mathematics, but embraced
the whole of natural philosophy, which he explored from a
range of viewpoints, ranging all the way from mathematics
to alchemy. Within natural philosophy he gave new direction
to optics, mechanics, and celestial dynamics. His studies
on mathematics were perhaps the most important, as the discipline
the subject imposed on his imagination marked the difference
between wild tacks of fancy and fruitful discovery.
In the summer of 1665, a disaster descended on many parts
of England. The plague hit Cambridge, and the university closed
down on October 10th, although many of the students had left
long before that. The plague was to stay in Cambridge for
two years, and the university only opened again in the spring
of 1667. Newton decided to return to Woolsthorpe. It was here
in 1666 during his enforced hiatus that he had his annus mirabilis.
This is at least partly legend, as he was in fact working
on many of his ideas during 1664 and 1665, but 1666 was indeed
a fruitful year for Newton.
Working on mathematics, Newton applied himself to drawing
tangents beneath curves (differentiation) and finding areas
under curves (integration). He took these 'new analyses' and
expanded upon them, computing logarithms to calculate the
area under a hyperbola, and eventually finding a method by
which to find the area under virtually every algebraic curve
then known to mathematicians. Newton began to treat the areas
under curves kinetically, as areas swept out by a moving line.
From the idea of motion he derived the term fluxional, to
describe this method, something we now call calculus. Newton
produced 3 papers on calculus in 1666, the resulting body
of work leaving other mathematicians in awe. In one act, Newton
had become the leading mathematician in Europe. Before then
nobody knew who Isaac Newton was, and had no idea that the
work of this young man of 24 had left the acknowledged masters
for dead.
Newton then moved to the science of mechanics. Descartes'
conception of motion had analysed impact in terms of the force
of the moving body impinging on others. Newton treated the
moving body as the passive subject of external forces acting
upon it, and this new approach to impact dynamics remains
the basis for the analysis of impact today. The question of
the mechanics of circular motion was more complex, and Newton
agreed with Descartes that a body in circular motion strives
to constantly recede from the centre. This seemed to add weight
to the idea that bodies in motion had their own force. Newton
took his studies on impact a step further, and used them to
show that the earth's rotation does not fling bodies into
the air because the force of gravity, measured by the rate
of falling bodies, is greater than the centrifugal force arising
from the rotation.
At Woolsthorpe, Newton read a book by Galileo called Dialogue
Concerning the Two Chief World Systems and it set him thinking.
Newton knew all about Johannes Kepler's work on how planets
circle the sun and in the book, Galileo was talking about
how things fell to the earth.
Newton wondered if he couldn't think of a way to join up
the two ideas. Could the same force that kept the moon from
being thrown away from the earth apply to gravity at the earth's
surface? Newton made the link, and called his findings the
law of 'Universal Gravitation'. While his connection between
the two was famously 'occasioned by the fall of an apple'
from a tree in the orchard at Woolsthorpe, the idea did not
come to Newton in a flash of inspiration, but was developed
over time.
Newton then started experimenting with the 'celebrated phenomenon
of colours'. The view held at the time was that colour was
a mixture of light and darkness. Hooke was a proponent of
this theory of colour, and had a scale which went from brilliant
red, which was pure white light with the least amount of darkness
added, to dull blue, the last step before black, which was
the complete extinction of light by darkness. Newton realised
that this was not the case - a white page with black writing
did not appear coloured when viewed from a distance and the
two blended, it was grey.
People were using prisms to experiment with colour, and thought
that somehow the prism coloured the light. Newton obtained
a prism, and set up his so that a spot of sunlight fell onto
it. In their experiments, Descartes, Robert Hooke and Edward
Boyle had put a screen close to the other side of the prism
and seen that the spot of light came out as a mixture of colour.
Newton realised that to get a proper spectrum you needed to
move the screen a lot further away. In the study upstairs
at Woolsthorpe, he used the 22 feet from the window to the
far wall to project a beautiful spectrum. The white light
split into different colours and each colour had been bent
a different amount by the prism. But to prove that the prism
was not colouring the light, he did an Experimentum Crucis
- his crucial experiment. He put a screen in the way of his
spectrum that had a slit cut in it, and only let the green
light go through.
Then he put a second prism in the green light. If it was
the prism that was colouring the light, the green should come
out a different colour. The pure green light remained green,
unaffected by the prism. Newton had proved that white light
was made up of colours mixed together, and the prism merely
separated them - he was the first person to understand the
rainbow.
While his two year hiatus at Woolsthorpe was a time of intense
concentration on his work, his results were not of divine
revelation, but rather the culmination of years of thought.
'I keep the subject constantly before me' he said 'and wait
'till the first dawnings open slowly, by little and little,
into a full and clear light.'
Back at Cambridge, Newton faced another election. This time
for a fellowship which would cement his place in the scientific
establishment, giving him the freedom to continue the studies
he had begun. In October 1667, Newton was elected a fellow
of the College of the Holy and Undivided Trinity. From then
he lived in Trinity for twenty eight years. While he did not
get the academic fellowship he expected at Cambridge during
this time, it was partly his own fault as he isolated himself
from other fellows, not speaking to anyone at dinner time,
and not joining colleagues on the bowling green.
In October 1669, Newton became the 2nd Lucasian professor
of mathematics, essentially appointed by Barrow when he stood
down. For the first year of his tenure, he devoted much of
his time to continuing his optics research. After this, encouraged
by Barrow, and John Collins, he focused again on mathematics.
Collins tried in vain to push Newton forward into the scientific
community, Newton preferring anonymity, and eventually he
pulled away even from Collins.
It was Newton's reflecting telescope, made in 1668, which
finally brought him into full view of the scientific community.
His work with colours led him to believe that refracting telescopes,
which were subject to colour interference, were outdated.
He made his reflecting telescope entirely on his own, some
parts of it with tools that he made specifically for the purpose.
His invention made telescopes much smaller - his was only
six inches long, and one inch in diameter, yet it magnified
over 30 times. It was especially useful when looking at distant
bodies such as Jupiter, which only reflected small amounts
of light, and to this day, the most powerful telescopes continue
to use reflecting dishes according to Newton's principle.
Newton was so proud of his telescope, that he couldn't resist
showing it off. Word went around Cambridge, and then the Royal
Society got wind of the invention, and asked to see it. When
the telescope arrived, it caused a sensation. Newton was ecstatic,
despite his pretence of indifference, and in return sent them
his theory of colours in a letter.
The letter Newton sent contained nothing new, but it was
the first time that his work had been made available for discussion
by other scientists. Hooke refuted much of what Newton said.
Hooke was a leading power at the Royal Society, and he considered
optics to be his domain. The critique of Newton's work was
to be the beginning of a long and spiteful rivalry between
the two men, with Newton taking an arrogant stance, and Hooke
often accusing Newton of plagiarism. Newton also received
some criticism of his optics experiments from some Jesuits,
who claimed that they could not replicate Newton's prism experiment,
and therefore it was wrong. Newton erupted in anger at this,
and at Hooke. He convinced himself of a conspiracy against
him, and gave up the study of optics, refusing to correspond
with anyone about it.
Newton moved to chemistry, and more specifically alchemy.
He laboured day and night in his chemical laboratory and immersed
himself in mathematical and mystical calculations. In the
late 1670s theological studies occupied most of his time.
He began a history of the church, starting in the 4th and
5th centuries. In 1686 he presented his single greatest work,
the Philosophiae Naturalis Principia Mathematica (Mathematical
Principles of Natural Philosophy). In it, Newton revealed
his laws of motion, and the law of universal gravitation.
The Royal Society were going to publish Newton's book, but
withdrew due to lack of funds. The astronomer Edmund Halley,
who was wealthy and thought highly of Newton eventually paid
for its publication. The Principia redirected Newton's intellectual
life, away from theology and alchemy and back into 'real'
science.
After the Principia appeared, Newton became somewhat bored
with Cambridge. In 1689, he was elected a member for Parliament
for the University, and he moved to London. While he only
lasted a year as an MP, not seeking re-election in 1690, he
very much enjoyed his time in London. He began to see people
socially, notably Christiaan Huygens. In 1696 Newton was appointed
Warden of the London Mint, becoming Master in 1699. He took
these duties very seriously, revising the coinage and taking
severe measures against forgers.
He was elected President of the Royal Society in 1703, but
only just - very few members seemed to want this cantankerous
genius as their president. However, he held this office until
his death - perhaps because the members were too afraid to
vote him out. Less than two years after his election, Queen
Anne knighted Newton in Cambridge. His presidency led Newton
to resume relations with Astronomer Royal John Flamsteed.
For more than 10 years, Newton interfered with Flamsteed's
affairs, exercising his authority as president.
He also fortified his position, appointing supporters in
positions of authority within the Society - Halley succeeded
a secretary, and another Newton supporter, Brook Taylor, was
made the other secretary.
In 1709, Newton began work on a second edition of Principia,
and he also published a second edition of Opticks, however
after he moved to London, he did nothing but reshuffle ideas
that he had had in Cambridge. As he became older, he seemed
concerned with leaving his image behind - he had many portraits
painted. As his health began to deteriorate he began to distribute
his wealth amongst his family. After a series of painful and
debilitating illnesses he died on March 19, 1727. |