Albert Einstein

Imagine completely changing the way in which people see the world. What an amazing achievement that would be. How famous you would become! That is what happened to Albert Einstein.

ALBERT EINSTEIN’S CHILDHOOD

Albert Einstein was born in Ulm, in southern Germany, on March 14, 1879. He was the eldest child of Hermann and Pauline Einstein.


When Albert was still a baby, the family moved to nearby Munich. Hermann set up an engineering business there with his brother, Jakob. Albert was an unusual child who did not start to talk until he was three years old. But he seemed fascinated by the natural world, and he loved music. He began learning to play the violin at the age of five and became a fine musician.

At school, Albert did not like the strict timetables and he found the lessons boring. His teachers thought him lazy and a dreamer.

Things did not go well for the Einstein family. Their business was failing and Albert’s parents decided to leave Germany and move to Milan in Italy. Albert left school in Munich to join them there. He was now a young man.

EINSTEIN IN SWITZERLAND

After a year in Milan, Einstein went to Switzerland to study. There he trained to teach physics and mathematics at the Swiss National Polytechnic in Zurich. Einstein did not enjoy formal studies. He missed classes, preferring to study physics on his own. He only managed to pass his exams by borrowing the notes of a classmate.

The professors at the polytechnic were not impressed. Einstein could not become a university teacher, so he worked as a tutor until 1902 when he got a job as a technical assistant in the Swiss Patent Office in Bern.

During the day, Einstein worked at the Patent Office, but in his spare time he was developing his ideas in physics. In 1905 Einstein received a doctorate from the University of Zurich. He also published three very important scientific papers.

One paper was about the movement of atoms. The second was about the nature of light. For many years, scientists thought that light was a wave. Einstein showed that it sometimes acted as a particle. Isaac Newton had suggested that light was a stream of particles in the 17th century. Now, Einstein showed that he was right, at least in some situations.

The third paper challenged the way that Newton had looked at the world. It introduced the first of Einstein’s famous theories of relativity. In his Special Theory of Relativity, Einstein started to think about space and time in a new way. He looked at things moving in relation to each other, such as a train overtaking a car. From these studies he found that there was something special about the speed of light. The speed of light (measured in a vacuum, or empty space) is always the same. And nothing can travel faster than the speed of light.

Strange things happen to objects moving close to the speed of light. If we watched a spaceship going faster and faster, until it was travelling close to the speed of light, we would see the clocks on the spaceship going slower. As the spaceship reached the speed of light, the clocks would look to us as though they had stopped!

Another idea that Einstein introduced was that energy and matter can be changed from one to the other. He wrote an equation to show how the two are connected: E = mc2. It is probably the most famous equation in the world.

These ideas were startling at the time. Very few people understood Einstein’s work. But some scientists did, and they realized its importance. The universities started to take a serious interest in this Patent Office clerk.

GERMANY AND FAME

For a few more years, Einstein continued to work at the Patent Office. He then moved into a university teaching post. He taught at Prague and Zurich, and ended up teaching in his old polytechnic. In 1913 he returned to Germany. He was made director of the Kaiser Wilhelm Institute for Physics in Berlin. He was also a professor at the University of Berlin. Einstein had left the Patent Office far behind.

He continued to work on his new view of space and time. Then in 1916 he published the General Theory of Relativity. It caused a sensation.

For over 200 years, Newton’s theory of gravity had been used to describe how things fall to Earth and how planets orbit the Sun. But it did not always give the orbits exactly. There was a particular problem with Mercury’s orbit, which did not quite fit. And there was another problem: Newton did not really explain gravity. He just said that things attract each other.

Einstein’s General Relativity showed that space and time are very closely linked. We should really think of them together, as space-time. Einstein showed how any object with mass changes the space-time around it, rather like a ball creates a curve in a rubber sheet it is sitting on. This curving of space and time is felt as gravity.

The idea seemed incredible, but it solved all the problems with the planetary orbits. And like all good theories in science, General Relativity made predictions that could be tested. If Einstein’s ideas were right, then the light of a star appearing behind the Sun would be bent by the Sun’s mass. This could only be tested during a solar eclipse, when the Sun’s dazzling disc was hidden. There was an eclipse in 1919. Across the world, people waited eagerly as Einstein’s theory was put to the test. His prediction proved to be right.

Einstein became very famous. He was surrounded by photographers and newspaper reporters, and showered with honours. In 1921 he was awarded the Nobel Prize for Physics.

WAR AND AMERICA

Einstein had strong beliefs about politics. He spoke out against Germany’s role in World War I. At that time he was a pacifist—someone who is against all war.

Later, his beliefs changed. Einstein was Jewish. He was involved in the movement (called Zionism) to create a state of Israel where Jews from all over the world could settle. Even though he was now a celebrated scientist, he was hated by those who hated all Jewish people. When Adolf Hitler and the Nazis came to power in Germany in 1933, Einstein left for the United States.

Though he had been a pacifist in World War I, Einstein believed that Hitler had to be stopped. Like others, he was worried that Hitler might be developing a powerful new kind of bomb—the atomic bomb. But in the end it was the United States that used two atomic bombs against Japan in 1945. After World War II, Einstein took part in campaigns demanding that all atomic bombs, now known as nuclear weapons, should be removed.

In the United States, Einstein joined the Institute for Advanced Study in Princeton, New Jersey. He was by now the most famous scientist in the world. He still kept working to try to find an even grander theory than his relativity—one that would bring together all the forces we know about.

There were other developments in physics. New ideas were spreading about the way tiny particles far smaller than atoms behave. The world of the very small—the quantum world—was turning out to be amazing too. But Einstein could not accept these new thoughts, although he had suggested startling ideas himself. He tried to develop his theory without them. And in this he failed.

Albert Einstein died at Princeton on April 18, 1955. His work had changed the way we understand the universe.

Charles Darwin

Charles Darwin was quiet and shy and disliked crowds. He did not want fame, but became one of the most famous scientists of all time. He suggested a theory explaining how living things gradually change, or evolve, over great periods of time. Those animals with features better matched to their surroundings are more likely to survive. These features will then be passed on to the animal’s children. Over very long periods of time, this process gradually means the animals change to suit their environment. New kinds of living things appear as older ones die out. This idea, the theory of evolution by natural selection, caused huge arguments in Darwin’s time. But it is now one of the most important ideas in all of science.

SCHOOL AND STUDIES

Charles Robert Darwin was born in Shrewsbury, Shropshire, on February 12, 1809. His family was wealthy, and his grandfather and father were well-known doctors. His mother died when Charles was eight, so his elder sisters looked after him.

Charles was not especially clever at school, but he was keen on nature and used to collect insects and worms in boxes. In 1825 he went to the University of Edinburgh to study medicine. Unfortunately, he felt sick at the sight of blood, so he moved to Cambridge University, to prepare for joining the Church. What Charles really wanted to do was to be a naturalist and study animals and plants.

OFF AROUND THE WORLD

In 1831, at the age of 22, Darwin joined the ship HMS Beagle, as the naturalist on a round-the-world scientific expedition. The expedition set off under the command of Captain Robert Fitzroy to make maps of South America’s coastline. Darwin went ashore at several places to study wildlife and collect specimens of plants, animals, rocks and fossils. He was amazed by an earthquake in Chile that raised the shoreline by over one metre. Darwin began to think about how the Earth’s surface is always changing, an idea he read in Principles of Geology (1830-1833) by British scientist Charles Lyell.

IMPORTANT ISLANDS

If the land and sea gradually changed, then Darwin wondered whether the same thing happened to animals and plants? His visit to the Galapágos Islands in the Pacific Ocean was especially important. Darwin saw how animals were very similar from one island to the next, yet slightly different. He imagined how giant tortoises, mockingbirds and finches gradually changed or evolved due to the slightly different food and other living conditions on each island.

BACK AT HOME

The Beagle returned after five years and Darwin set to work in London, studying all the specimens that he had collected. His book of the voyage, Journal of Researches (1839), sold very well. Darwin read An Essay on the Principle of Population (1798) by Thomas Robert Malthus. Malthus showed how humans and other living things produced far more offspring than could survive. Darwin realized that there must be reasons why some offspring lived but others died. Perhaps nature chose, or selected, the survivors? In the 1840s he developed this idea, but kept it private. It would offend many people who believed in the Bible and that animals and plants, created by God, were unchanging.

AN INSTANT BEST-SELLER

In 1839 Charles Darwin married Emma Wedgwood and moved to Down House in Downe, Kent. They had ten children, but three died when they were babies. Darwin began to suffer long illnesses, perhaps due to a disease caught in South America. In 1858 he received a letter from Alfred Russel Wallace, a naturalist travelling in Malaysia. Wallace described ideas on evolution very similar to Darwin’s own. Darwin was persuaded to give a talk on the topic in London, to the Linnean Society, and to finish his own book. This he did in 1859. On the Origin of Species by Means of Natural Selection sold out on its first day, and has been a best-seller ever since.

A HUGE ARGUMENT

As Darwin had expected, his book caused a storm of arguments. Many people saw that the idea of evolution could be applied to humans, and made fun of the idea that we are related to apes. Darwin was very upset by this. Many others soon saw the scientific sense in Darwin’s work. In particular, he was supported by Thomas Henry Huxley, who became known as ”Darwin’s Bulldog”.

A QUIET LIFE

In his later life Darwin stayed at home, quietly studying nature. He wrote several more books on breeding new garden plants, animal pets and how earthworms are “nature’s gardeners” and enrich the soil. In 1871 he tackled human evolution from apes, in The Descent of Man. Gradually, he was given many honours and awards, including a fellowship of the Royal Society. When he died on April 19, 1882, he was a world-famous scientist and was buried with great ceremony in London’s Westminster Abbey.

Did you know?

• Charles Darwin left medical school because he was squeamish and did not like dissection or surgery.
• In 2000, Charles Darwin's picture replaced that of Charles Dickens on the Bank of England's new £10 notes.
• After leaving medical school, Charles Darwin went to Cambridge University to study theology. However, he spent a lot of time collecting beetles instead of studying.

John Dalton

In the early 19th century John Dalton, a British schoolteacher and chemist, was fascinated by the patchwork puzzle of chemical elements. His understanding of atoms and how they combined to form different elements led to a revolution in scientific thought and helped create the modern world.

JOHN’S EARLY LIFE

John Dalton was born on September 6, 1766, in the village of Eaglesfield, in Cumberland (now Cumbria). His parents belonged to the fundamentalist Christian movement known as the Quakers and he was educated at the Quaker village school. Young John was so good at his studies that when he was 12 he became a teacher there. In 1781 he became a teaching assistant at the Quaker school in Kendal, and four years later became joint principal with his brother. While there he came under the influence of the wealthy, blind scientist John Gough, who taught him mathematics, meteorology and botany.

In 1793, Dalton was appointed professor of mathematics and natural philosophy at New College, Manchester. This college was established by followers of the Presbyterian Church movement. Before this, only members of the Church of England could attend university. In 1800 he became secretary of the Manchester Literary and Philosophical Society. It was at this time that Dalton became interested in chemistry, and in how the various chemical elements combine with one another to form chemical compounds.

DALTON’S DISCOVERIES

In 1803, Dalton suggested that the tiniest particles of a chemical element are atoms of that element. This had been suspected by many thinkers since the time of the Ancient Greeks, but Dalton was the first to use science to show that it could be true. He realized that atoms of different chemical elements join together in fixed numbers based on their weights to make chemical compounds. This achievement was known as his atomic theory.

At first, some scientists did not agree with his atomic theory, but by the end of the 19th century lots of evidence showed that he was largely right. Dalton also believed that atoms could not be divided up, but we now know that this is not true. There is a whole world of particles, such as electrons, smaller than atoms. This did not matter at the time though. Dalton had shown the world that atoms are the basic building blocks of the objects we see around us and that all our chemistry is about atoms.

FURTHER SCIENTIFIC RESEARCH

Dalton’s later work concentrated on atomic weights. He was the first scientist to understand that chemical elements could be classified according to their atomic weights. He realized the importance of atomic weights after studying how gases dissolved in water. He concluded that their mixing depended on the weight of the individual atoms of the gases. He devised a system of chemical symbols and formulae and drew up a table of the atomic weights of all the elements then known.

His theory of atomic weights contained errors. At first, he had not realized that atoms group together to form molecules. In 1811 this idea was shown by Italian physicist Amedeo Avogadro to be true. But Dalton’s general idea was right, and a precise value could then be given to the mass of each atom.

His studies of the Earth’s atmosphere contributed a great deal to meteorology. He was the first person to confirm that rain is caused by a drop in temperature and not a change in atmospheric pressure, as previously thought. He also studied aurora, the dancing “lights” seen at the north and south poles, as well as the Earth’s magnetism and wind system. His studies of gases led to Dalton’s Law, which states that the total pressure of a mixture of gases equals the sum of each of the pressures of the gases in the mixture. This was a very important law in chemistry.

Dalton also became the first scientist to describe the medical condition known as colour blindness. This is a defect of vision affecting the ability to distinguish between colours. He had the condition (and so did his brother), and the first of his many readings to the Manchester Literary and Philosophical Society in 1794 was devoted to it.

MODEST MAN OF SCIENCE

Dalton’s ideas brought him great fame and changed the study and use of science everywhere. He gave many scientific lectures throughout Britain. In 1817 he became president of the Manchester Literary and Philosophical Society, a post that he held until his death. The French Académie des Sciences elected him as one of their eight foreign associates in 1830. He also helped found the British Association for the Advancement of Science in 1831.

In private he lived a simple and quiet life as a Quaker. He had few friends and never married. He was deeply dedicated to the search for answers to scientific problems.

Following a stroke in 1837, Dalton became an invalid. He died in Manchester on July 27, 1844, and was given a funeral by the city that was attended by 40,000 mourners. Since 1884 there has been a statue to him in the entrance to Manchester Town Hall.

Galileo Galilei

Galileo Galilei was one of the first modern scientists, and made exciting discoveries about stars and planets using his telescope. He also found out about how things move as they fall to Earth. He was important because of the way he did his work. He observed carefully how things behaved and took notes. He then set up experiments to test his theories.

Galileo knew how to focus on what really mattered in a problem. And he did not just use words to describe how things move. He used mathematics. That meant he could say things very precisely.

Galileo was an important figure in the Scientific Revolution. This brought a new way of thinking to Europe in the 16th and 17th centuries.

GALILEO’S EARLY LIFE

Galileo was born near Pisa, in Italy, in 1564. He lived in Italy all his life. His father was a music teacher. When he was a child, Galileo studied in a monastery. He liked the quiet way of life there and wanted to become a monk. But his father sent him to the University of Pisa to study medicine. Galileo did not find medicine interesting and preferred mathematics. He eventually gave up his medical studies and taught mathematics instead. Soon, important mathematicians started to take notice of him. He became a professor of mathematics and taught at the universities of Pisa and Padua. His work made him famous. The powerful Grand Duke of Tuscany, Cosimo de’ Medici, made him his court mathematician.

GALILEO’S FIRST EXPERIMENTS

In Galileo’s time, people’s ideas about the world came mainly from the famous Greek philosopher Aristotle. Aristotle had said that heavy objects fall more quickly than light ones. Galileo found that Aristotle was wrong. He showed that if you drop a light object and a heavy object from the same height, they will speed up at the same rate and reach the ground at the same time. This was a surprise. It went against Aristotle’s ideas and common sense. But Galileo’s experiments showed that it was true.

Galileo also looked at pendulums. He found that they take the same time to complete a swing, however far they swing.

WHAT DID GALILEO DISCOVER?

In 1609, Galileo heard of an amazing Dutch spyglass that could make faraway things seem close at hand. He was fascinated. Soon he was making his own telescopes. They were much better than the early Dutch ones. Then one day he turned his telescope to the night sky. What he saw astonished him. Galileo found that the Moon had mountains, valleys and craters. He discovered that Jupiter had four little stars of its own going round it (he was seeing Jupiter’s four biggest moons). He found that the pale glow of the Milky Way was in fact the light of many thousands of faint stars. He watched sunspots. And he saw that the planet Venus showed phases, appearing as waxing and waning crescents just like the Moon.

These discoveries did not fit in with people’s ideas about the universe. Aristotle had taught that the heavenly bodies were smooth and perfect spheres. Yet the Moon clearly was not like that.

Aristotle and the Greek astronomer Ptolemy had believed the Sun and planets went round the Earth. In 1543 a book by Nicolaus Copernicus, a Polish astronomer, suggested that the Earth and planets went round the Sun instead. By Galileo’s time, many people thought it was true that the planets went round the Sun, but they still believed the Sun went round the Earth. Galileo could see that his work supported Copernicus. But Copernican theory went against the teaching of the Catholic Church. The Bible said that the Earth did not move, and was at the centre of the universe.

GALILEO AND THE CHURCH

In Galileo’s day, people could be tried and even killed as heretics if they wrote books that went against the Church’s teaching. The Inquisition was responsible for trying heretics. Galileo hoped he would be safe because the Pope liked his work. So he wrote a book showing that he believed that Copernican theory was probably true. But the book was banned and Galileo was tried by the Inquisition. He was forced to say he had been wrong, and was sentenced to life imprisonment, although he was allowed to live at home. He carried on working on moving objects, and wrote his most important book in these last years. Galileo died in Arcetri, near Florence, in 1642.


Galileo’s trial became famous. He had not wanted to go against the Church. He was a religious man. But he felt that people should accept what science had shown to be true when they interpreted the Bible. He thought you should not believe it blindly word for word.

Galileo only had simple telescopes. And not all of his arguments were correct. But now we have plenty of evidence that the Earth is just another planet going round the Sun. We have even found planets orbiting other stars.

Did you know?

• When Galileo left the University of Pisa in 1585 he did so without having passed his degree, although it had been medicine that he was studying and not the astronomy or physics that he would later be acclaimed for.
• In 1992 the Roman Catholic Church officially apologized for condemning Galileo to life imprisonment for going against their teachings in claiming that the Earth revolved around the Sun and not the other way round. After almost five centuries the Church had finally admitted that it was wrong and that Galileo was right.
• Legend has it that Galileo dropped two objects from the Leaning Tower of Pisa to show that if you drop a light object and a heavy object from the same height, they will speed up at the same rate and reach the ground at the same time. This story was first told by his last pupil and first biographer, Vincenzo Viviani, although many believe that at best it is more probably an exaggerated version of an actual event.

Leonardo da Vinci

Leonardo da Vinci is one of the greatest artists who has ever lived. He is also among the greatest scientists. He experimented with unusual ways to mix paint and use colours. He created new painting techniques and original ways to compose pictures. He studied everything he saw—from living things to machines, using his incredible drawing skills to record them in detail. Then he used his observations to think up plans for inventions that were not built until hundreds of years later, such as a telescope, a tank and a helicopter!

LEONARDO’S CHILDHOOD

Leonardo was born on April 15, 1452, in the small town of Vinci, near Florence, in Italy. (His name means in Italian, “Leonardo of Vinci”.) His father was a wealthy Florentine official who did not marry his mother, a simple peasant woman.
Leonardo was brought up by his mother’s family in the beautiful Tuscan countryside. As a small boy, he spent hours exploring the woods, fields and streams. He loved to watch insects, animals and birds, and to examine different plants and flowers, then make sketches of them. His restless curiosity, interest in nature and keen eye for observation shaped the whole course of his life.

LEONARDO BECOMES A CRAFTSMAN

At the age of about 12, Leonardo went to live with his father in Florence. The great city was then a bustling centre for training master artists and for brilliant students of literature and science. Leonardo was sent to school to learn reading, writing and maths, and he became a fine musician. However, he showed such a talent for drawing that he was taken on as an apprentice by one of the leading artists in the city, Andrea del Verrocchio.

In Verrocchio’s workshop, Leonardo began to learn how to mix different types of paint, make brushes and prepare canvases for painting. He studied the art of fresco (painting using watercolours on wet plaster) and learnt how to sculpt. Artists in those days knew many other skills. Wealthy people paid Verrocchio to create bronze church bells, musical instruments and furniture, to make compasses for ships and to cast objects in gold and silver.

Leonardo studied all the crafts in the workshop, and became fascinated by the variety of tools and machines used there. He examined how each of the pieces of technical equipment worked and made careful drawings of them. Leonardo carried a sketchpad with him at all times, so he could make accurate drawings of anything around Florence that interested him. He began to think about how everyday machines worked, such as the waterwheels that turned millstones to grind corn. And he studied the specialist machines being used on an enormous construction site where the city cathedral was being built.

AN ARTIST IN FLORENCE

By 1472, Leonardo had finished his apprenticeship with Verrocchio. However, he stayed working in the great craftsman’s workshop as his assistant. Verrocchio thought the 21-year-old was so skilled that he allowed Leonardo to help with a masterpiece he was working on called The Baptism of Christ. Leonardo painted an angel kneeling in the left of the picture, and some of the background. He used delicate colours to show feelings on the angel’s face, and tried a new idea for painting haziness in the landscape to try to show distance. In those days, artists could only paint flat pictures; they did not know how to show perspective.
By 1478, Leonardo had set up a workshop of his own. Two of his first paintings were gentle, touching portraits of Mary with baby Jesus, called Madonnas. Between 1480 and 1481 he also created a lovely, small painting called the Annunciation, showing the Bible story of how Mary was once visited by an angel. Leonardo brilliantly captured the meeting of the human and the spiritual worlds by setting the figures in a deep, misty, magical landscape, with exquisitely detailed, lifelike wildflowers and plants around the angel’s feet.

Many wealthy people in Florence began to ask Leonardo to create works of art for them—in particular the ruler of the city himself, the great Lorenzo de’ Medici. Strangely, Leonardo never carried out work on one big order, which was for a painting in the chapel of a palace, the Palazzo Vecchio. He also left several other works unfinished. One of these was a portrait of St Jerome. Another was an order from a monastery for his first large-scale painting, The Adoration of the Magi, showing the visit of the Three Wise Men to baby Jesus. Perhaps Leonardo did not finish the paintings because he was engrossed with other work he was doing in private. Leonardo was not only still studying and sketching machines, such as pumps and army equipment. He was also planning new machines of his own.

WORK AT THE COURT OF MILAN

In 1482, Lorenzo de’ Medici sent Leonardo on an important mission. He asked him to take a silver musical instrument called a lute as a peace offering to the warlike ruler of Milan, Duke Lodovico Sforza. Leonardo wrote a daring personal letter to deliver to the duke at the same time. In it, he described the amazing ideas he had for incredible new machines, which would be perfect for the Duke’s army. These included armoured vehicles, moveable bridges and original designs for catapults, cannons and other weapons. At the end of the letter, Leonardo added that he also happened to be a skilled painter, sculptor and musician. He offered to create a bronze horse statue to honour the Duke’s father.

The Duke was highly impressed and invited Leonardo to work for him as an engineer and painter. Leonardo set up a studio with pupils and assistants helping him on many different projects. From 1483 to 1485 he worked on two versions of a wonderful picture called The Virgin of the Rocks. Then he was asked to paint a massive fresco on the wall of a dining room in a monastery. For the next two years, Leonardo created a masterpiece called The Last Supper, which showed the final meal Jesus Christ shared with his close followers.

However, much of Leonardo’s time was taken up with scientific studies. He was employed on the duke’s many war campaigns, advising on new ideas for weapons and building defences. He also produced models for the building of a magnificent dome for Milan cathedral, drew up plans for other great buildings, and designed theatre sets and costumes. He studied how humans and animals moved, explored possibilities for inventing flying machines, and thought deeply about the moon, stars and planets. He also became firm friends with a mathematician called Luca Pacioli, who was working on the relationship between distances. Leonardo made a series of drawings to illustrate Pacioli’s ideas, and studied how he could use mathematical rules to create paintings that looked solid, deep and lifelike.

FOUR YEARS IN FLORENCE

Leonardo stayed in Milan for 18 years. Then at the end of 1499, French soldiers attacked the city and conquered it. The 48-year-old artist returned to Florence once more. Not long afterwards Florence was caught up in its own war against the city of Pisa. In 1502, Duke Cesare Borgia asked Leonardo to become his chief architect and engineer. He worked hard, designing and building forts. He also drew up plans to cut off Pisa’s water supply and force the city to surrender. His brilliant ideas involved changing the direction of a river and also building canals, but these were not carried out.

Leonardo saw horrors during the war, which inspired him to plan an enormous painting called the Battle of Anghiari for the great hall of the Palazzo Vecchio. However, he only got as far as making detailed sketches and a full-size drawing. Instead, Leonardo turned to studying the flight of birds and experimenting further with his designs for flying machines. He also painted several famous portraits. The only one that still survives is a captivating picture of a woman with a mysterious smile, called the Mona Lisa. It is probably the most famous painting in all the world today.

LEONARDO’S LATER YEARS

In 1506, Leonardo returned to Milan, at the request of the French governor there. The King of France himself, Louis XII, was living in Milan at the time, and just a year later he appointed Leonardo to be his court painter. However, Leonardo continued to devote lots of time to engineering projects and scientific investigations, such as examining fossils to work out what they were.

After the governor of Milan died, Leonardo went to Rome in 1514 to work for the brother of the pope. Although he completed one magnificent painting, a portrait of St John the Baptist, he spent most of his time studying and experimenting. By examining animal parts from a butcher’s shop, he produced brilliant models of how the heart works. He tried making giant, rounded mirrors because he wanted to see the moon and stars close-up. And by studying he plants he discovered that the same patterns exist in many natural things.

Shortly after the pope’s brother died, in 1516, Leonardo went to live and work in France. He was 64 years old. King Francis I gave Leonardo the title of “First painter, architect and mechanic of the king”, and set him up in a house near his own palace in Amboise. He paid Leonardo well and left him to do as he pleased, visiting him now and again to enjoy fascinating conversations. Leonardo began the huge job of sorting out all the scientific papers he had produced during his lifetime. He died before he was able to finish, on May 2, 1519.

Did you know ?

• Leonardo never finished the horse statue he offered to make for the Duke of Milan. He got as far as creating an enormous clay model, but when the French armies invaded the city, they destroyed it by using it for archery practice!
• When Leonardo wrote in his notebooks, he wrote backwards (from right to left) using 'mirror writing'. No one is sure why. Some people think that he wanted to make it hard for others to read his studies and steal his ideas. Other people think that it was just easier for him, because he was left-handed. Whatever the reason, when Leonardo wrote documents for other people to read, he wrote in the usual way.
• In Leonardo's day, very few people grew up left-handed like him. Everyone was very supersitious and many believed that the left side of the body was evil and unlucky. Children who showed signs of being left-handed were usually forced to using their right hand instead. Leonardo was also a vegetarian, which was equally unusual in those times.
• Leonardo was buried in the palace church at Amboise in France. However, the building was destroyed three hundred years later, during the French Revolution, so his grave can no longer be found.

Michael Faraday

Whenever you turn on a light, listen to a CD or watch the television, you will probably not think about it, but you are doing something that owes a great deal to the life and work of the English scientist Michael Faraday.

In the 19th century he worked on electricity and magnetism. His work helped others understand the science of electricity and magnetism. This eventually led to the development of everyday conveniences and luxuries that we take for granted today. Faraday was one of the greatest and most important scientists in history.

WHAT WAS HIS EARLY LIFE LIKE?

Michael Faraday was born in Newington Butts, Surrey, on September 22, 1791. His father was a blacksmith. The Faradays were a deeply religious family and belonged to a small sect of Christianity called the Sandemanians. Michael was committed to this sect for the whole of his life. In 1821 he married a fellow Sandemanian, Sarah Barnard, and was later both a deacon and an elder in the Church.

A DEVELOPING INTEREST IN SCIENCE

Michael attended a day school in London before being apprenticed as a bookbinder between 1805 and 1812. During his apprenticeship he developed a great love of reading. He also developed an interest in science after attending various scientific lectures, especially meetings of the City Philosophical Society in Fleet Street. In 1812 he attended the Royal Institution to hear the final four lectures of the great English chemist Sir Humphry Davy. He made detailed notes of the lectures and sent them to Davy asking for a job. The following year, Davy appointed Faraday as his assistant at the Royal Institution.

Between 1813 and 1815 he and Davy toured many of the great chemistry laboratories of Europe. Back at the Royal Institution, Faraday continued working on chemistry and helped Davy invent the miner’s safety lamp. By the age of 30 Faraday had become a very senior person at the Royal Institution and was becoming increasingly interested in physics.

WHAT DID FARADAY DISCOVER?

Faraday believed that there was a relationship between electricity and magnetism. In 1819 the Danish physicist Hans Christian Oersted discovered the idea of electromagnetism. He found that a wire carrying an electric current deflects a magnetic needle at right angles to the wire. This showed that an electric current can create a magnetic field. In 1821 Faraday began experimenting with electromagnetism. He demonstrated how electrical energy can be converted into mechanical energy—and thus invented the world’s first electric motor.

Another great idea came in 1831. Oersted had earlier shown that an electric current can create a magnetic field, but Faraday now discovered that a magnetic field could be used to create an electric current. This was known as “electromagnetic induction”. He showed it by moving coils of copper wire inside a magnetic field, causing an electric current to flow in the wire. The discovery helped him to create the world’s first electric dynamo—a machine that converts mechanical energy into electrical energy.

With his inventions of both the electric motor and the electric dynamo, Faraday showed that electricity could be produced and controlled by man. As we know now, one day it would be used to provide the power for our homes, factories, hospitals, streets and much more.

MORE SCIENCE

Faraday also investigated an area of science known as electrochemistry, which deals with the relationship between electric currents and chemical reactions. In 1834 he established the basic laws of electrolysis when he discovered that acids, bases and salts are electrolytes. This means that when acids, bases and salts are dissolved in water they produce a liquid solution that contains charged particles or ions that can conduct an electric current. Faraday also developed a liquid version of the gas chlorine and identified the gas called benzene. He also invented the words anode, cathode, electrode and ion. As well as all this he made great contributions to the studies of light and gravity.

In 1826 Faraday started the Royal Institution Christmas lectures for children. These continue today and have been televised each year since 1966. Faraday delivered many lectures himself and became one of the most popular scientific speakers of the day. In 1833 he became professor of chemistry at the Royal Institution.

Faraday also worked for the British government. From 1830 until 1851 he was professor of chemistry at the Royal Military Academy, Woolwich. There he worked on improving explosives. Between 1836 and 1865 he was scientific adviser to Trinity House, which meant that he oversaw the programme to electrify all the lighthouses around the British Isles. The government was very pleased with Faraday’s work and granted him a generous pension, although he refused the offer of a knighthood.



Faraday had become very famous. His portrait was often painted and he was one of the most photographed men in the country. In 1858 Queen Victoria and Prince Albert gave him a home for free at Hampton Court Palace. It was there that he died on August 25, 1867.

Faraday’s work greatly advanced our understanding of science and made it of practical use to us all. He helped change the world.

Isaac Newton

On Christmas Day, 1642, a boy was born in the manor house of Woolsthorpe, near Grantham, in Lincolnshire. He was born prematurely and was tiny, but he survived to become one of the greatest scientists the world has ever known.

NEWTON’S CHILDHOOD

Isaac Newton was named after his father, a farmer who had died a few months before Isaac was born. When Isaac was two years old, his mother Hannah married again. Isaac was brought up at Woolsthorpe by his grandmother. He did not like his mother’s remarriage and hated his stepfather, the Reverend Barnabus Smith.

His mother had three children by her second husband. When Isaac was 11, his stepfather died, and his mother, stepbrothers and sisters moved to live with him and his grandmother.

Isaac was sent to the Free Grammar School in Grantham. It was 8 kilometres from home, and he stayed with a family in the town. Isaac’s school reports were not very good and his mother thought he might be better off managing the farm. But Isaac did not get on too well with that either. Luckily, an uncle noticed his cleverness and love of learning. He persuaded Isaac’s mother to send him back to school. He also encouraged Isaac to go to university.

NEWTON GOES TO UNIVERSITY

In 1661 Newton entered Trinity College, at the University of Cambridge. He studied law, but he had a lot of freedom in his studies and he became interested in mathematics and astronomy. He read about the work of the astronomers Nicolaus Copernicus and Johannes Kepler, and worked through many mathematics books by himself. His mind was buzzing with ideas.

In 1665 the university was closed because of the Great Plague, which swept through southern England, killing thousands. Newton went home and for a year worked on mathematics and physics and developed his theory of gravity. This was probably the most creative time in his life.

NEWTON BECOMES A SCIENTIST

Back at the University of Cambridge, people began to recognize his ability. In 1669, at the age of just 27, he became a professor of mathematics there. For nearly 20 years, as well as giving lectures, Isaac Newton worked on his ideas in mathematics and physics. Many scientists admired his work. One was Edmond Halley, an important astronomer. Halley encouraged Newton to write up his work and publish it.

Newton needed the encouragement. He was a shy man, but could become angry if his work was criticized. He held long-lasting grudges. He did not publish his work for years because he was afraid it might be attacked.

In 1671 Newton was made a Fellow of the Royal Society—a society in London that only very important scientists are invited to join. He had been experimenting with light and told the Royal Society about his discoveries. Another important scientist belonging to the society, called Robert Hooke, did not agree with his ideas. Nor did the Dutch scientist Christiaan Huygens. Newton and Hooke became enemies, though they were polite in public.

In 1687 his friend Halley published Newton’s most famous work. It was written in Latin. It was called Philosophiae Naturalis Principia Mathematica, or Mathematical Principles of Natural Philosophy (science was called “natural philosophy” in those days). It is usually known as the Principia.

In this work, Newton described his theories about liquids and gases, and presented his theory of gravity. It was widely admired. But Hooke said that Newton had taken some of his ideas. Newton and Hooke continued their quarrel for years. Newton waited until Hooke died in 1703 before publishing his work on light.

Newton’s work on mathematics involved him in another argument. During the year he spent at home because of the plague, he had started to work on the mathematics of things that change. We now call this branch of mathematics calculus. Another famous scientist, Gottfried Leibniz, had come up with the same ideas a little later than Newton. They argued about who invented calculus first. The argument lasted until Leibniz died in 1716, and even after that.

All this anger and resentment led Newton to a nervous breakdown in 1678, and another in 1693. He turned away from people and shut himself away for long periods. Newton was deeply religious. Alongside his work in science, he pored over the Bible. He thought there were deep meanings hidden in its words. He was also fascinated by alchemy—the attempt to change different substances into gold.

MASTER OF THE MINT

Newton joined the Royal Mint in London in 1696. The Royal Mint makes the coins used as money. Three years later he became Master of the Mint and a rich man, but he never married, and he lived simply.

Newton was now 57 years old. For the rest of his life he was in charge of the Royal Mint. He also kept up his argument with Leibniz. In 1703 Newton became president of the Royal Society. Two years later he was knighted Sir Isaac Newton by Queen Anne.
Isaac Newton died in London on March 20, 1727, at the age of 85. He was the first scientist to be buried in Westminster Abbey.

WHAT WERE NEWTON’S ACHIEVEMENTS?

Isaac Newton is most famous for his theory of gravity. The story goes that he was sitting in the garden one day when he saw an apple fall from a tree. He wondered why it did not just float in the air instead of falling.

He realized that the force that made the apple fall to the ground was the same as the force that kept the Moon going round the Earth. He was able to describe the orbits of all the planets using this force—the force of gravity. But there were problems with his theory too. One basic problem was that Newton never really explained gravity. He just said that any two masses pull each other.
The problems were only solved many years later, in the 20th century, when Albert Einstein worked out his Theory of General Relativity. But Newton’s theory was good at describing the way objects fall and how planets orbit the Sun. We still use it for many things.

Newton also showed that white light is a mixture of all the colours of the rainbow. He used a prism to split white light into its separate colours. He made many other studies of light. Newton believed that light is a stream of particles. Other scientists agreed with Christiaan Huygens that light must be a wave. Now we know that Newton was not wrong—light acts as both a particle and a wave.
Newton’s interest in light came from his efforts to make a good telescope. He invented a reflecting telescope, which used mirrors instead of lenses, in 1668. We call them Newtonian telescopes.

He also invented the mathematical method of calculus. Though Leibniz invented the same method, Newton had thought of it earlier. We now use calculus as a basic tool in many problems in science and mathematics.

Newton’s Principia is often described as the greatest scientific work ever written. It seems hard to believe that one person could achieve so much. Newton could be difficult, and sometimes unpleasant, but he devoted his life to searching for truth and he knew that there was a great deal more to learn. He wrote:

“To myself, I seem to have been only like a boy playing on the seashore, and diverting myself in now and then finding a smoother pebble or a prettier shell than ordinary, whilst the great ocean of truth lay all undiscovered before me.”

Did you know?

• In addition to being a great scientist, Isaac Newton was also a Member of Parliament. He tried to prevent King James II from turning the universities into Catholic institutions and was elected Member of Parliament for the University of Cambridge in 1689 to make sure that this did not happen.
• Isaac Newton was a deeply religious man and he devoted a great deal of his time to investigating religion. In fact he owned more books on that subject than he did on science. He also sought to find evidence in the Bible for much of the mythology of Ancient Greece.
• Some people today have accused Isaac Newton of trying to destroy the reputation of the scientist Robert Hooke, with whom he had lots of arguments. Although no real evidence supports this, many believe that some of Newton's great scientific ideas were actually those of Hooke.