History of Science - 4
History of Science - 4.
Rene Descartes.
Pierre Gassendi.
Christiaan Huygens.
Robert Boyle.
Giovanni Borelli.
Edward Tyson.
Science is written the language of mathematics, as Galileo realised.
This language was far from being fully developed in Galileo’s time.
The symbols plus and minus were introduced to mathematics only in 1540, by Recorde.
Recorde studied in Oxford and Cambridge, and qualified in mathematics and medicine.
He was a polymath.
He later introduced the symbol ‘equal to’.
Unfortunately he died in a debtor’s prison, in 1558.
The invention of logarithms in the early 17th century, enormously simplified and speeded up,
the laborious process of arithmetic calculations.
This meant that all multiplications and division could be reduced to addition and subtraction.
Till 1970’s logarithms and associated slide rule,
were the only tools that made complex calculations possible.
One of the key figures of that time was Descartes.
He was born in 1596, to a moderately wealthy family.
He had an inheritance which allowed him to do what he liked, without worrying about money.
Descartes was a sickly child.
He graduated in law in 1616, at the age of 20.
He was something of a dreamer, who loved creature comforts.
His education convinced him of his own ignorance, and the ignorance of his teachers.
He decided to ignore textbooks and study by himself.
He moved to Holland, and signed up for military service, with the prince of Orange.
Comfort living Descartes, found his niche in engineering with his mathematical skills in military school.
He met the mathematician Isaac who introduced him to higher aspects of mathematics,
and also became a longterm friend.
He published a book ’The method’ in 1637.
Descartes, one day was watching a fly buzzing around.
He realised that the position of the flies could be represented by three numbers,
by giving its distance from the three walls, in the corner of the room.
He instantly saw this in three dimensional terms.
These are known as Cartesian co-ordinates after Descartes.
This meant that apart from geometrical shapes like triangles,
a curved line could be in principle represented by a series of numbers, in a mathematical equation.
This transformed mathematics by making geometry susceptible to analysis using algebra.
This had repercussions right upto theory of relativity, and quantum theory in the 20th century.
Descartes introduced the convention of using letters in the beginning of the alphabet like a, b, c,
to represent specified quantities, and letters in the end of the alphabet,
like x, y, z to represent unknown quantities .
He introduced the concept of exponential notation like x cubed.
He moved to France in 1622, to continue his independent studies.
He travelled across Europe, but curiously he did not attempt to meet Galileo.
He eventually returned to Holland in 1628, where he spent the next 20 years.
The 30 year religious war still kept central Europe in turmoil.
Holland was a country where there was religious tolerance.
Like Galileo, Descartes never married.
He kept a woman called Helene, with whom he had a daughter, Francine, in 1633.
He doted on Francine, who unfortunately died in 1640.
Descartes wrote a book putting forward all his ideas about physics.
When he was about to publish it, the news of Galileo’s conviction for Copernican ideas, reached him.
He stopped publication of his book, because it supported Copernican ideas.
His friends persuaded him to publish his works.
Eventually he published the book, ‘The method’ in 1637.
It was accompanied by 3 essays on meteorology, optics, and geometry.
He explained the weather in terms of rational science, not by the whims of some gods.
The essay on optics, described the workings of the eye.
Essay on geometry reflected his findings on cartesian coordinates.
His second great work on philosophy was published in 1641.
The famous line ‘I think and therefore I am’ is from this book.
In 1644, he published another book on philosophy, which was essentially about physics.
He correctly interpreted inertia, and said that moving objects tend to keep moving in a straight line.
Galileo thought they moved in a circle.
In 1647, he went to France, where he met mathematician Pascal.
He suggested to him that taking a barometer up a mountain,
would show whether pressure varied with altitude.
They found it does, suggesting that there is only a thin layer of air, around the Earth,
and the atmosphere does not extend forever.
In 1659, he was invited by queen Christine of Sweden to join her intellectual circle.
He was horrified to learn that he had to visit the queen at 5 a.m. everyday.
The northern winter, and the early rising to meet the queen, resulted in him developing pneumonia.
This resulted in his death in 1650, just before his 54th birthday.
Though Descartes believed in God, he insisted that the world will live in,
can be understood in terms of basic physical entities.
These entities he said, obey laws which we can determine by experiment and observations.
Descartes did not get everything right in his thinking.
He rejected the idea of a vacuum.
He also rejected the idea of atoms, proposed by Gassendi.
The idea of atoms went back to Democritus and Epicurus, around 5th century BC.
But Aristotle rejected the idea.
Aristotle was more influential in western ideas, before the scientific revolution.
Gassendi was born in 1592.
He became a doctor of theology and was teaching at the university of Aix in 1624.
He published a book criticising the Aristotelian world view.
Gassendi’s most important contribution to science, was the revival of atomism.
He thought the properties of atom, like their taste, was dependent on their shape.
He had an idea that atoms might join together to form molecules.
He believed atoms moved about in a void, and there was literally nothing in the gaps between atoms.
Though he was right about this, but he rejected Harvey’s idea about circulation of blood.
Nobody got everything right in the scientific world.
Torricelli was an Italian scientist who got to know Galileo.
Galileo introduced Torricelli to the problem that water in a well,
could not be forced up by a pump for more than 30 feet.
Torricelli reasoned that this was due to the atmospheric pressure pressing down.
He tested the idea in 1643, using a tube of mercury sealed at the top,
inverted over a shallow dish of liquid metal.
He predicted that the column of mercury would settle down at around 2 feet.
His experiment confirmed this.
The gap between the top of the mercury column and the sealed end was a vacuum.
In this process he invented the barometer and the concept of a vacuum.
Descartes did not accept that the gap above the mercury was a vacuum.
He believed that every day substances like air, water or mercury mingled with a finer fluid substance,
which filled all the gaps.
The experiments done for Pascal, by his brother-in-law, with a barometer and altitude,
suggested that the atmosphere thins out as we go higher.
So there must be a vacuum about.
Descartes said that his universal fluid extended beyond the atmosphere, across the universe.
He proposed a convoluted theory, where the Earth does not move, but the Copernican model holds.
Basically he hated the idea of a vacuum.
Descartes’s influence was so great, that it delayed the acceptance of Newton’s ideas about gravity.
His ideas on light were better, though it was also wrong.
According to atomists like Gassendi, light was a stream of tiny particles emerging from a bright object,
like the sun.
According to Descartes vision was caused by pressure on the universal fluid on the eye.
Descartes had some good ideas, but he got stuck with many wrong ideas.
The scientist Huygens was born in 1629, to a wealthy family in Holland.
He was educated at home till the age of 16.
He met Descartes, who was a frequent visitor to his house.
Descartes aroused his interest in science.
Huygens studied mathematics and law.
At the age of 20 he decided to devote himself to the study of science.
His father was broadminded enough, to provide him an allowance,
and let him free to study what he pleased.
Huygens early work was in mathematics.
He then moved on to mechanics, where he did important work on momentum,
and the nature of centrifugal force.
Huygens became widely known for his invention of the pendulum clock, independently of Galileo.
He was mainly interested in a good time keeping device for his astronomical work.
He patented the pendulum clock in 1657.
Unlike Galileo’s design, Huygens design was rugged and practical.
From 1658 onwards, thanks to Huygens, ordinary people could have accurate timepieces,
instead of estimating the time by the position of the sun.
He worked out the theory of the behaviour of oscillating systems in general.
In 1655, Huygens began working with his brother,
on the design and construction of astronomical telescopes.
All refracting telescopes suffered from a problem of chromatic aberration.
This occurs because the lenses in the telescope bend light with different colours,
by slightly different amounts.
This was a major problem for astronomical observations.
The Huygens brothers reduced chromatic aberration by using,
two thin lenses in the eyepiece of a telescope, instead of one fat lens.
The brothers were also good at grinding lenses.
The telescopes became the best instruments of their time.
In 1655 with the first telescope, with the new design, Huygens discovered Titan,
the largest moon of Saturn.
He found that Saturn is surrounded by a thin flat ring of material.
Huygens was invited to work the French royal academy of sciences.
In 1662, a royal society was formed in London.
Scientific minded people in England got together to discuss new ideas, and communicate new discoveries,
in the royal society.
It had no official sources of funding.
Huygens became the first foreign member.
The French equivalent society had the patronage of King Louis XIV.
It provided financial support and practical facilities for eminent scientists like Huygens.
The success of these two societies spawned many imitations in Europe.
Huygens completed his work on optics in 1678, but published it only in 1690.
His theory was able to explain how light is reflected by a mirror,
and how it is refracted when passing from air to glass or water.
He explained it in terms of a pressure wave known as aether.
He made an important prediction that light should travel more slowly in a dense medium,
such as glass, compared to air.
Descartes assumed that light travels at infinite speed.
Huygens proposed that light has a finite speed.
His idea came from the Danish scientist Romer.
Romer was born in 1644.
He worked as an assistant to the astronomer Bartholin.
He assisted in locating the exact position of Tycho’s observatory,
which was important for precise astronomical analysis of his observations.
Romer’s greatest work was the observation of the moons of Jupiter.
He did this along with Cassini.
Cassini is best known for discovering the gap in the rings of Saturn.
Each moon of Jupiter needs to be eclipsed behind Jupiter at regular intervals.
Romer observed that the interval between these eclipses were not the same.
It varied with the position of Earth, relative to the position of Jupiter.
He interpreted this as being the result of the finite speed of light.
He predicted that the eclipse of Io, a moon of Jupiter, would occur 10 minutes later than expected,
on 9th November 1679.
He was sensationally proved right.
Using the available best estimate of the diameter of the Earth’s orbit,
he calculated from the delay of the eclipse, the speed of light to be 225,000 km per second.
This is stunningly close to the modern value for the speed of light of 299,792 km per second.
Given this was the first measurement of the speed of light,
it was a great achievement in the history of science.
Romer travelled to England, where he met Newton, Halley and Flamsteed.
He became the director of the royal observatory in Copenhagen in 1681.
He died in 1710.
Huygens’s work on light, along with Romer, was the crowning achievement of his career.
He met Newton in 1689.
Huygens returned to Holland in 1691.
He died in 1695.
Huygens’s life was mostly without incident outside his scientific work.
But the same could not be said of his contemporary Robert Boyle,
who almost singlehandedly made chemistry respectable.
Boyle promoted the idea of atoms, and he also studied behaviour of gases.
Robert Boyle was born in 1566, to the Earl of Cork, Richard Boyle.
Richard Boyle was a self-made man, driven by a burning desire,
to make his fortune and find a respectable place in society.
He made it big, through a combination of skill and luck.
He attended King’s school at the same time as Marlowe.
He then studied at Cambridge.
He started to study law, but ran out of money.
He worked as a clerk in London.
He then went to Ireland, which was a colony of England, in 1588 in search of a fortune.
He found the job with a government department, in-charge of dealing with the land,
that had been seized by England, during the reconquest of Ireland.
Bribes and gifts to officials like Boyle were routine at that time.
Boyle failed to make a fortune for 7 years.
In 1595 he married a wealthy widow.
She owned land, which fetched a rent of 500 pounds a year.
He set about using this money for further investments.
These eventually prospered beyond his wildest dreams.
His wife died while giving birth to a still born son, in 1599.
He suffered a set back in 1598, during the Munster rebellion, where he lost much of his property.
He was arrested for embezzlement, but was acquitted, in a trail presided by queen Elizabeth.
He was probably guilty, but clever enough to cover his tracks.
The queen was impressed by his defence of his case.
She appointed him to a key position, in the administration of Ireland.
He made an important purchase of derelict estates from Walter Raleigh.
The estates were losing money when he bought it.
By good management he turned it around, made a healthy profit.
He built schools, roads, bridges, and new towns.
He established himself as one of the most enlightened English landlords in Ireland.
In 1603, he had risen so high, that he married Catherine, the 17 year old daughter,
of the secretary of state for Ireland.
He received a knighthood on the same day.
Catherine produced 15 children.
When they grew old enough, they were married off to influential families.
In 1620, he became the Earl of Cork, thanks to a gift of 4000 pounds to the right people.
His youngest son Robert Boyle escaped the arranged marriage,
because his father died before the wedding could be organised.
He never married.
Life as the son of Richard Boyle was never easy.
Richard Boyle believed that his sons should not have a soft upbringing.
He sent them off to live with some country family, to toughen them up.
Robert Boyle had to live home as a baby, and never saw his mother again,
who died when he was 4 years old.
From the age of 5 to 8, he lived with his father.
He was taught Latin and French.
He was then sent to study at Eton.
Robert Boyle took readily to academic life.
He had to be forced to play games, which was very much part of Eton.
His studies were interrupted by illness, which was to plague him all his life.
Robert Boyle was sent to Europe with a tutor to study.
He was in Florence when Galileo died.
He began reading widely about Galileo and his work, and started to develop an interest in science.
At this time there was a rebellion in Ireland, and his father lost all his Irish properties.
His father died just before his 77th birthday.
Robert returned to England at the age of 17.
He was penniless, and he also had to return debts to his tutor.
There was also some political developments.
A civil war broke out in England.
King Charles 1 was at loggerheads with parliament.
The king’s forces were fighting with the parliamentary forces headed by Oliver Cromwell.
The parliamentary forces won eventually, and King Charles 1 was executed in 1649.
From 1649 to 1660 England had no King.
Cromwell was lord protector till 1658.
Richard Cromwell son of Oliver Cromwell became the lord protector.
He was ousted by the army.
Charles 2 who was exiled in France was restored to the throne in 1660.
Robert Boyle, who was identified with the king’s side, found refuge in his sister Katherine’s house.
Here he met John Milton.
His father had left him a house.
In 1645 he moved into this house, and kept a low profile in politics.
He had a modest income from his estate.
He read widely and wrote on different topics.
He carried out many experiments, which were mainly alchemical.
His sister Katherine was an intelligent woman, and her house was a meeting place for many intellectuals.
They called themselves the ‘invisible college’.
This was the forerunner of the royal society.
Robert Boyle became acquainted these intellectuals, while visiting his sister.
The group often met at Gresham college in London.
It was a seat of advanced learning like Oxford and Cambridge.
Boyle visited Ireland to look into the family estates there.
A physician called Petty, taught him anatomy, physiology and how to dissect.
On his return to England, he was able to get an income of 3000 pounds a year, from his father’s estate.
This was enough for him to do anything he pleased.
At the age of 27, he moved to Oxford, which was the centre of scientific activity.
Over the next fourteen years he carried out scientific work which made him famous.
Boyle employed assistants to carry out his experiments.
One of them was Robert Hooke.
Boyle was one of the pioneers in the application of his scientific method.
He followed the methods of practical men like Galileo and Gilbert.
He also drew inspiration from Francis Bacon, who wrote about the scientific method.
Bacon had a great influence on scientists that followed him.
Bacon spelt out the need to collect as much data as possible, and explain the observations.
This was in contrast with dreaming up a wonderful idea, and looking for facts to support it.
Bacon system can be summarised that science should be built on the foundation of facts.
His first significant contribution to science was on compressibility of air.
He used a J shaped tube, with the top open, and the short end closed.
Mercury was poured into the tube to fill the U bend at the bottom.
When the mercury was at the same level on both the sides,
the air in the closed end was at atmospheric pressure.
When the pressure was doubled by pouring more mercury, the volume of the trapped air halved.
If the pressure was tripled, the volume was reduced to a third, and so on.
Significantly the process was reversible.
He published this in a book, ’The spring of the air’ in 1660.
The second edition of this book, had what is now known as Boyle’s law,
which states that the volume occupied by a gas is inversely proportional to the pressure on it.
He built an air pump with the help of Hooke to study vacuum.
He demonstrated that water boiled at a lower temperature when the air pressure was lower.
He came close to discovering oxygen, showing that a flame required the presence of air to sustain it.
He specifically pointed out the similarities between respiration and combustion.
This book was written in English and available to the common man.
Unlike Galileo he did not have to fear about the church.
In 1661 Boyle published his famous book ’The Sceptical Chymist’.
He was trying to make alchemy scientific.
Later scientists believed that this helped transition from alchemy to chemistry.
It changed the belief that there was a philosopher’s stone which could turn a base metal into gold.
Boyle was a leading light in establishing the scientific method in England.
Boyle disproved the Aristotelian idea, that the world comprised of 4 elements,
air, Earth, fire, and water, mixed in different proportions.
He espoused a form of atomic hypothesis, that all matter is composed of tiny particles.
He published his idea in a book ‘Origin of forms and qualities’ in 1666.
He suggested that atoms move freely in fluids, but are at rest in solids.
He coined the term chemical analysis.
Apart from these major findings, Boyle also worked on many other things.
He invented the match.
He proved by experiment that water expands on freezing.
He was also a major literary figure, writing on many subjects including fiction.
He had a modest nature and declined many prestigious offers,
including president of the royal society, in 1680.
He made many charitable donations, and left most of his property for charity, when he died.
The royal society received its charter in 1662.
Boyle was one of the first members.
Boyle moved to London in 1668, and stayed with his sister Katherine.
In 1691 his sister Katherine died.
Boyle died a week later, short of his 65th birthday.
Boyle’s experiments showed that both fire and life dependent on something in the air.
Scientists continued the biological investigation of human beings, after Harvey and Descartes.
Just as the telescope revolutionised the way people thought about the universe,
the microscope revolutionised, the way people thought about themselves.
The first great pioneer of microscopy was Italian physician Malpighi.
He studied philosophy and medicine at the university of Bologna.
He graduated in 1653, and became a lecturer in logic at Bologna university.
He moved to the university of Pisa in 1656, and became professor of theoretical medicine.
In 1659, he returned to Bologna to teach medicine, where he became professor of medicine in 1666.
In 1691, he became the personnel physician to pope Innocent 12.
He died in 1694.
From 1667 onwards his work was published by the royal society of London.
His work was mostly concerned with microscopy.
It dealt with the variety of subjects, including the circulation of blood in bats,
the structure of insects, the development of chick embryos,
and the structure of stomata in the leaves of plants.
Through his microscopic studies of the lungs of frogs, Malpighi found that the inner surface of the lungs,
is covered by tiny capillaries, through which the arteries on one side,
are directly connected to the veins on the other side.
He found the missing link in Harvey’s description of blood circulation.
Few years later, the same discovery was independently made by dutch microscopist Antoni.
Richard Lower demonstrated in an experiment, by shaking a glass vessel containing venous blood.
The dark purplish blood changed colour to bright red as it mixed with air.
It showed that the red colour of blood flowing through the body is produced by something in the air.
Boyle and Hooks carried out similar experiments.
Now scientists began to realise that blood carried particles of food, and something from the air,
around the body.
This was in line with the Cartesian image of the body as a machine.
The theme of the body as a machine was developed in the 17th century, by the Italian scientist Borelli.
Borelli was a friend of Malpighi.
He was born in 1608.
He became a professor of mathematics around 1640.
He met Galileo in the early 1640’s.
He became professor of mathematics at the university of Pisa, in 1656.
This was the post held by Galileo earlier.
Borelli studied anatomy around this time.
For political reasons, he was exiled to Rome.
He became associated with ex-queen Christina of Sweden.
This was the same queen who had made Descartes get out of bed at an unearthly hour.
She was forced to abdicate in 1654, and lived in exile in Rome.
Borelli died in 1679.
He was the first person to suggest that the trajectory of a comet is parabolic.
He explained that Jupiter exerts an influence on its moons,
similar to the influence of the sun on the planets.
His work on anatomy, called ’On the movement of animals’, was published after he died.
Borelli treated the body as a system of levers, acted upon by forces, exerted by muscles.
He analysed how muscles acted in walking and running.
He described the flight of birds, and the swimming motion of fish in mathematical terms.
The crucial point in his work was he did not have a special treatment for humans,
distinct from animals.
He had a role for God, as the designer of the machine of humans and animals.
This was different from the idea, of the human body being operated by a guiding spirit,
which controlled the activities of the body from minute to minute.
The relationship between humans and animals, was spelt out by a remarkable piece of dissection,
carried out by Edward Tyson.
Tyson was born in England in 1650.
He was educated in Oxford and Cambridge.
He got his medical degree in 1677.
He practised as a doctor in London.
He did anatomical dissections, which was published by the Royal society.
He became a fellow of the Royal college of physicians.
In 1684, Tyson was appointed as Governor of the Bethlehem Hospital in London.
This was a mental institution.
The word ‘bedlam’ came from the common pronunciation of the name of this institution.
This was the first asylum for the insane in Briton.
The mentally ill were abused in every possible way, and were treated as a kind of entertainment.
Bedlam was a place for fashionable people to go and view the curiosities, like a zoo.
Tyson changed all that, by introducing many reforms.
He died in 1708.
One of his memorable dissections took place in 1680.
He dissected a porpoise with Robert Hooke on hand, to make drawings.
He was surprised to discover that the porpoise was a mammal.
This discovery was published to an astonished world.
One of his famous dissections was that of a chimpanzee.
This was published as a heavily illustrated book,’Anatomy of a Pygmie compared with that of a monkey,
a ape and a man’.
The book presented incontrovertible evidence that humans and chimpanzees,
were built to the same body plan.
He established that the chimpanzee resembled a human being more than a monkey.
He was particularly impressed by the way in which the brain of the chimpanzee,
resembled the brain of a human being.
By an element of luck the dissected chimpanzee was a young one.
Human beings resemble infant chimpanzees more than adult ones.
Humans develop much more slowly than chimpanzees and other apes.
We are born in a relatively undeveloped state.
This is the reason why human infants are so helpless.
This is also the reason why they are capable of learning different kinds of things,
instead of entering the world in preprogrammed way, like apes.
In 1699, with the publication of Tyson’s book, it was clearly established,
that human beings were a part of the animal kingdom.