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The following is based on the 13th and last part of Jacob Bronowski’s BBC series on the history of science and invention, “The Ascent of Man” (1973):

The human brain is three times larger than it was two million years ago. But almost all that growth took place in just three parts of the brain, those that control:

  1. The hand
  2. The tongue
  3. Foresight

Which allows us to build, to talk and to imagine our future far more than any other animal.

In addition, our minds are very plastic: most animals are wired to act just in certain ways, humans are not. We depend on knowledge, not reflex. That means a long childhood. And, even after we are grown, we must think and prepare before we act, we must balance short-term and long-term, our needs and those of others.  That in turn leads to ideas of justice, of right and wrong.

Most civilizations, like those of China, India and even the Europe in the Middle Ages, as great as they were, limited the imagination of the young, of those with talent. The son did what the father did what the grandfather did and on and on. Only the talent of a few is ever used, the rest is wasted. The West does not do this.

One way is through a democracy of the intellect: its thought and knowledge is built by scientists and thinkers not by kings and priests. The lives of Erasmus and John von Neumann show this.

Erasmus was a monk in the 1500s. Against orders he read the Greek and Roman classics. It opened up the world to him. He became friends with Sir Thomas More, who, like him, cared more for truth than for power and authority – so much so that the king had More put to death.

John von Neumann, who came up with game theory in the 1950s and did important work in understanding computers, took the other road. Towards the end of his life he worked for companies and governments, drawn to the centres of power. Science for the sake of power and money, not for the sake of truth. He wasted his great talent.

Likewise the West is in danger of throwing away its great promise:

I am infinitely saddened to find myself suddenly surrounded in the west by a sense of terrible loss of nerve, a retreat from knowledge into – into what? Into Zen Buddhism; into falsely profound questions about, Are we not really just animals at bottom; into extra-sensory perception and mystery. They do not lie along the line of what we are now able to know if we devote ourselves to it: an understanding of man himself. We are nature’s unique experiment to make the rational intelligence prove itself sounder than the reflex. Knowledge is our destiny. Self-knowledge, at last bringing together the experience of the arts and the explanations of science, waits ahead of us.

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The following is based on part 12 of Jacob Bronowski’s BBC series on the history of science and invention, “The Ascent of Man” (1973). This one is about genetics:

Gregor Mendel was a farm boy who became monk. He joined the Augustinian order in Brno, the second largest city in what is now the Czech Republic. They sent him to the university of Vienna to get a teaching degree. The university said he “lacks insight and the requisite clarity of knowledge” and failed him in 1853.

A few years later he began to do experiments on pea plants. People assumed that if you cross a tall pea plant with a short one you get pea plants of middling height. Instead of assuming Mendel tried it: he found that you get nothing but tall pea plants! And if in turn you cross those tall pea plants you get 75% tall pea plants and 25% short ones.

Why? Mendel said it was because each plant gets a height particle – what we now call a gene – from each parent. In the first generation of his experiment, each plant had a tall gene and a short gene, so all of them were tall. But in the second generation one fourth received two short genes and so they were short.

He had discovered the gene, one of the greatest discoveries in the history of science. It sank like a rock. Mendel was a nobody: the important science journals in France and Britain did not print it. In 1866 he had it printed in a Brno science journal and there it sat unknown to the top people in science till 1900.

The next big discovery was printed in Nature in 1953, so it was known instantly worldwide: DNA and how it works. DNA is what genes are made of. James Watson and Francis Crick beat out Linus Pauling in discovering how it works.

DNA is a double molecule, each half the mirror image of the other half. When the molecule splits in two, each half can create its missing half. But there is more: it is a long molecule that contains smaller molecules called bases: adenine, guanine, cytosine and thymine. These become in effect the four letters – A, G, C and T – of the language that genes are written in, containing the instructions of how to build everything in the body.

But genes and DNA are not enough to account for life as we know it. You also need:

  1. Sex, which mixes genes in new ways. Till sex came along life did not progress beyond the level of pond scum.
  2. Human sexual selection, which speeds it up even faster: humans, compared to other animals, put far more thought into choosing who they have children with. They also have taboos against incest which prevents a few older males from getting all the females and lowering the rate at which genes mix.

As John Donne said:

Love’s mysteries in souls do grow
But yet the body is his book.

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The following is based on part eleven of Jacob Bronowski’s BBC series on the history of science and invention, “The Ascent of Man” (1973). This one is about quantum physics:

We used to think that science could give us a perfect picture of the material world. But we now know, because of quantum physics in the 1900s, that absolute knowledge is impossible. There is a limit to what we can know – even with the most perfect and most powerful instruments imaginable.

For example, with a high-powered electron microscope you can see atoms. Yet no matter how much you increase the power you will never get a sharp image.

Even something as simple and straightforward as the position of a star in the sky is not perfectly knowable: different human observers come up with different positions and even the same person repeating the observation does not come up with the very same answer each time.

Karl Gauss in 1795 noticed that the observations made a bell curve – the closer you get to the average position, the more observations there are. But you cannot even say that the star is at the average position – all you can say is that it is the most probable position, which is not quite the same thing as its true position.

Gauss lived in Gottingen, a small German university town. It was here, over a hundred years later, in the 1920s, that some of the leading minds of physics came on the train from Berlin to work out the physics of the atom and its parts: quantum physics.

The atom is made of moving parts, such as the electron, and yet there is something very strange about them. Werner Heisenberg in 1927 found that you can tell what the position of an electron is but not its speed and direction – or, if you nail down its speed and direction, then you cannot tell its position. It is one or the other but never both at the same time. This is Heisenberg’s Uncertainty Principle.

Gottingen had something else: a collection of skulls. These skulls were used to support a racist view of the world, a view of the world that dealt in inhuman certainties. It came to power in the person of Hitler. The skies darkened over Europe, as they had in the days of Galileo. The great minds of Europe fled – or fell silent:

It’s said that science will dehumanize people and turn them into numbers. That’s false, tragically false. Look for yourself. This is the concentration camp and crematorium at Auschwitz. This is where people were turned into numbers. Into this pond were flushed the ashes of some four million people. And that was not done by gas. It was done by arrogance, it was done by dogma, it was done by ignorance. When people believe that they have absolute knowledge, with no test in reality, this is how they behave. This is what men do when they aspire to the knowledge of gods.

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The following is based on part ten of Jacob Bronowski’s BBC series on the history of science and invention, “The Ascent of Man” (1973). This one is about the atom:

Dmitri Mendeleev played a game his friends called Patience: he wrote the chemical elements down on cards, one element on each card along with its atomic weight, and laid out the cards in different ways.

He found that if he laid the cards in order of atomic weight and yet put elements with like properties in the same rows, he could create a table – what we now call the periodic table of elements. He found that he could tell which elements had yet to be discovered and what their properties would be.

But what makes such a table possible? Why do properties repeat so that you can make rows in the first place? How can the different properties of an element, like density and colour, come from just a single property, atomic weight? The answer is: they cannot. Atoms must have more than just weight. Atoms must be made of parts.

In 1897 J.J. Thomson found the first part: the electron. In 1911 Ernest Rutherford said the atom is like a little solar system: the electrons go round the nucleus just like the planets go round the sun.

But Niels Bohr in 1913 saw that it could not be that simple: the planets are slowly running down and some day will fall into the sun. Not so with atoms. Bohr found the answer in Max Planck’s idea of quantum energy: just like matter comes in atoms, so energy comes in quanta. Therefore the electron can only be at certain energy levels or orbits. .

But what about the nucleus that the electrons were circling? That proved to be made of parts too: protons and neutrons, as James Chadwick found out in 1932.

All this, along with Einstein’s physics, made it possible in 1939 for Hans Bethe to work out how the sun shines. It does it by making two hydrogen atoms into one helium atom and, in the process, changing the left over  matter into heat and light. The sun is a young star, but older and larger stars, it was soon understood, turn helium into the other elements: carbon, oxygen, iron, gold and all the rest.

The stars evolve hydrogen into the elements while the earth evolves the elements into life. That is how nature works: one small step at a time.

That seems to go against entropy – the idea that the universe is running down, becoming more disordered over time. But entropy is a statistical observation. That means by and large it holds true, but it does not  always hold true.

Ludwig Boltzmann gave us our idea of entropy. He also championed the idea that matter is made of atoms. We take it for granted – partly because of him – but in 1906 there were still plenty of doubters. In despair, just before his side was about to win, he killed himself.

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The following is based on part nine of Jacob Bronowski’s BBC series on the history of science and invention, “The Ascent of Man” (1973). This one is about evolution:

The theory of evolution was discovered independently by two men: Charles Darwin and Alfred Russell Wallace.

Both loved the English countryside, both loved beetles and both in their twenties found a way to make a living as a naturalist. There was a ready market in England for specimens of plants and animals from parts foreign. Both went to South America to pursue their profession.

Darwin went in 1831. For five years he served as the ship’s naturalist on board the Beagle, a survey ship of the British navy.

Wallace went in 1848 to the Amazon and for four years lived among the natives gathering plants and animals rare or unknown back in Europe. He set foot in a part of the world that no white man had ever seen before. He found 40 different kinds of butterflies in 40 days. But then, on the way home, the ship caught fire and he lost everything, the 40 butterflies, all of it, except for his watch, some shirts and a few notebooks – and his life. But two years later he set out for the Malay archipelago (Indonesia) and started all over.

Darwin saw the natives in South America as beastly while Wallace could imagine himself  becoming one, living the rest of his days in the Amazon where his children would be “rich without wealth, and happy without gold!”. To him they were not just a little above apes but just a little below philosophers.

Both Darwin and Wallace came back from South America persuaded that the species change: that lions and tigers, for example, were once just cats way back in time. But neither knew how the change came about.

Then one day Darwin read “Principles of Population” (1798) by Robert Malthus. Malthus said that more people are born than can possibly be fed, so some must die. That was it: only the fittest live to give birth to the next generation. That is how the species change.

In 1844, at age 35, Darwin wrote it all down in a book and told his wife to print it should he die and left it at that.

But then 14 years later, when Wallace himself was 35, lying sick on the island of Ternate in the Spice Islands, he read the same book and had the same idea. He wrote it up and sent it to Darwin for advice. Darwin’s hand was forced. He came out with his book, “Origin of Species”, a year later in 1859.

Neither Darwin nor Wallace had any idea of genetics. That came later. But in their time Louis Pasteur did prove that life is based on chemistry.

No one knows how life began but we do know that the chemistry that life is made from forms easily under the early conditions of the earth – and even, to a degree, in outer space where you can find, of all things, formaldehyde.

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The following is based on part eight of Jacob Bronowski’s BBC series on the history of science and invention, “The Ascent of Man” (1973). This one is about the rise of industry:

In the late 1700s there were three revolutions: one in France, one in America and one in England. In France and America they overthrew their kings and said that all men are created equal and born with certain rights. In England they did not do that, they did something even better: through the rise of industry they gave the man in the street a degree of wealth and freedom that in the past belonged only to kings and other top people.

We are still in the middle of that Industrial Revolution – or we better be because there are still plenty of things to get right. But despite all of its evils, the old days were far worse: many died of the plague or childbirth, ordinary people did not have soap, cotton underwear or glass in their windows – things we take for granted. We feel we can make of our lives what we want of them – in the old days it was hard work from sunup to sundown. Where would most of us be if we were born before 1800?

The revolution was made by men who thought in just that way:

  • that life is what you make of it: we are not ruled by the stars or fate;
  • that inventions should be useful for the man in the street, not just playthings for the rich;
  • that science is not just about the truth, as it was for Newton and Galileo, but about making society better.

A man in America in those days who was just like that was Benjamin Franklin. The Industrial Revolution began in Britain and not, say, in France, because it had far more men who thought that way and acted on it. Men like Josiah Wedgwood, Charles Darwin’s grandfather, who made china sets for queens and then made the very same thing (without the patterns) for the British midde-class.

These men did not go to Oxford and Cambridge. Partly because most of them could not: they did not belong to the Church of England. But also because the kind of men that Oxford and Cambridge produced did not think like that and would have never made an Industrial Revolution.

But the Industrial Revolution was more than just a certain way of thinking or even a bag of inventions, as important as they were. There were also changes in how people worked. For example, before 1760 craftsmen worked at home in villages at their own pace; after 1820 the common practice was to bring workers into a factory to make things there, working with machines.

It also led to a new view of nature that the Romantic poets wrote about. Wordsworth put it this way in 1798 in “Tintern Abbey”:

For nature then…
To me was all in all – I cannot paint
What then I was. The sounding cataract
Haunted me like a passion

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The following is based on part seven of Jacob Bronowski’s BBC series on the history of science and invention, “The Ascent of Man” (1973). This part is about the physics of Newton and Einstein:

Newton was born on Christmas Day in the year that Galileo died, 1642.  He got his university degree at Trinity College, Cambridge  but then came the plague years: 1665 and 1666. He went to live with his mother in the country. There he made his great discoveries in physics and mathematics.

From his notebooks we know that he was badly taught: he had to work out mathematics for himself. But along the way he discovered a new form of mathematics: calculus. It became his secret weapon.

Copernicus and Kepler told us how the planets move but could not say why. Newton could: gravity. With his law of gravity he could work out how fast an apple fell from a tree and how many days it took the moon to go round the earth. Utterly amazing.

But none of it was made public till 20 years later. In the meantime Newton made his name in optics: he showed how white light is made out of coloured light. He became a professor at Cambridge and a leading light of science in Britain.

Then one day Edmund Halley came to Cambridge to ask Newton a question about physics. Halley loved his answer but then asked, “How do you know?” Newton said he would send him the proof. That proof took three years and was so long it became a book: the “Principia” (1687). It laid out his physics. Our idea that there are laws of nature comes from that book.

Newton’s physics was a wonder of the age, yet it assumed that time and space are absolute, that they are the same for all observers. Still it stood for 200 years. Then in 1881 Michaelson found the first hole in it: light always went at the same speed no matter what. No one knew what to make of it until Albert Einstein came up with his theory of special relativity in 1905.

Einstein would think about stuff like this: Suppose you get on the tram at the town clock to go to work and your tram went the speed of light. What would you see? If you looked back at the clock you would see that time had stopped – and yet for the people on the street the hands of the clock are still moving! Strange. That means the closer you get to the speed of light, the more time slows down. Time is not absolute. Nor is space: if you push the example further you find that the tops of the buildings will look like they are bending over the street and passers-by will look tall and thin.

Einstein worked out his physics along those lines and, while his conclusions were strange, he was proved right in the course of his life. Even the bit about the edge of a phonograph record ageing more slowly than the centre.

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The following is based on part six of Jacob Bronowski’s BBC series on the history of science and invention, “The Ascent of Man” (1973). It is about astronomy up to the time of Galileo (pictured):

Cultures all over the world have some knowledge of astronomy – if only to know when to plant. But often it never goes beyond that.

The Mayans, for example, had the number zero before Europe did and a much better calendar too, yet they did not study the motions of the stars.

Easter Island was the same: people came there by accident but had no way of leaving because they had no model of the heavens. They were stuck there as the stars passed overhead, their secrets unread.

It seems the New World lacked a model of the heavens because they lacked the wheel. The Greeks built their model on the wheel: wheels within wheels, forever turning. It was Ptolemy who wrote down that  model in all its glory in about the year 150. It stood for over a thousand years.

In 1543 Copernicus put the sun, not the earth, at the centre – for sound Renaissance reasons. To the man in the street it seemed unnatural.

Then in 1609, a lifetime later, all that changed when Galileo in Venice, Italy pointed a telescope at the stars. What he saw proved Copernicus right.

The Catholic Church at the time was battling against the Protestant heresy. Taking a hard line, it believed that faith should rule. Galileo believed that truth should persuade.

In 1611 the Vatican starts to keep a file on him. In 1616 they tell him he can no longer hold or defend the Copernican system as proven fact.

Galileo waits till a more intellectual pope came to power, Pope Urban VIII in 1623. He is the one who hired Bernini to work on St Peter’s. But he is also the one who had the birds in the Vatican gardens killed because he did not like the noise.

In 1624 Galileo came to those gardens and had six long talks with the pope. He asked the pope if he could teach Copernicus. The pope said no. But Galileo continued to believe the pope was on his side. He was profoundly mistaken.

Galileo returned  to Florence and wrote “The Dialogue on the Great World Systems” (1632). Because the book did not present Copernicus as fact but merely debated his ideas, Galileo thought he was safe. But just to make sure he got four imprimaturs from Church censors.

It did not work. The pope stopped the presses and tried to buy back all the copies. Then in 1633 he called Galileo before the Inquisition. They threatened him with torture, twice, and forced him to state that Copernicus was wrong. Silencing him, the Church banned his book for over 200 years.

That all but killed science in Catholic countries. Now the cutting edge of science moved to the Protestant north. Indeed, in the year that Galileo died, in 1642, on Christmas day was born Isaac Newton in England.

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The following is based on part five of Jacob Bronowski’s BBC series on the history of science and invention, “The Ascent of Man” (1973). It is about the rise of mathematics.

Mathematics is not the mere use of numbers, it is to reason about them.

With the Greeks, that begins with Pythagoras, born about -580.  He said that numbers are the language of nature. He showed that in two ways:

  1. He showed how music that sounds good is music that is played on strings that come in particular lengths – those that are whole numbers.
  2. In about -550 he took the mathematical discoveries of the Egyptians and Babylonians, which to them were just discoveries, and showed how they followed from the nature of simpler elements – the first known mathematical proofs. It showed how number is bound up with the nature of the world, how it is the secret language of nature.

Proofs in geometry reached their height 300 years later in Alexandria when Euclid wrote down all the main ones in a book, The Elements. It is one of the most copied and translated books in all history.

Greeks applied geometry to the stars, to the motion of the sun and the planets. In 150, Ptolemy wrote down that beautiful model of the heavens, of circles within circles,  in a book, which stood for over a thousand years. It came to the West from the Greeks not through the Romans, who cared little for mathematics and science, but through the Arabs.

The Arabs also brought to the West the astrolabe (pictured at the top of the post). It is an instrument that measures the height of a star or the sun that is laid over a star map. With it you can work out your latitude, sunrise, sunset, time for prayer and the direction of Mecca. It was a Greek invention that the Arabs made much more usable.

But more important than Ptolemy or the astrolabe were Arabic numbers, which by adding the number zero (an Arab word), made numbers far simpler to use than the old Roman (or even Greek) sort would allow. The Arabs brought the zero from India in 750, but it took another 500 years to catch on in the West.

Muhammad did not alow his followers to paint the human form, so Arab art becomes a wonderful play of forms. It was math as art. Bronowski shows us the beautiful palace of Alhambra as an example.

One thing the Greeks got completely wrong was how objects are seen in space: perspective. It was Alhazen, one of the great Arab minds, who got it right. That was in the 1000s. In the West Italian painters took to it first in the 1400s. It is what makes the Renaissance paintings so different than what came before.

But even with Alhazen something was still missing from the Greek and Arab picture of the world: time. That was added by the West in the 1600s with the work of Kepler, Newton and Leibniz.

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The following is based on part four of Jacob Bronowski’s BBC series on the history of science and invention, “The Ascent of Man” (1973). It is about metals, alchemy and the rise of chemistry.

Man first used fire 400,000 years ago. It kept him warm, cooked his food, kept away wild animals. But he did not learn to use it to get the metal hidden in stone till -5000 somewhere in Persia or Afghanistan: put a certain green stone in the fire and out came a red, liquid metal: copper

Copper was the plastic of its day, an almost universal material that you could shape into anything. But copper had one drawback: it was too soft. It could not keep an edge; it would wear out too quickly.

By -4000 someone made a surprising discovery: if you add tin, an even softer metal, it made a new metal that was much stronger than either one: bronze. An impure metal, an alloy, is stronger than a pure one.

By -1500 the Hittites in what is now Turkey knew how to make and work iron, which requires a much hotter fire.

By -1000 people in India knew how to make steel from iron and carbon. It was used in swords but it was so hard to make that it did not become common till the 1800s.

And then there was gold. It was not terribly useful, but in a world that is constantly changing and falling apart, it stayed the same: wind and rain could not make it rust and fire could not destroy it but only make it purer. In every age and every city it is prized above all the rest.

By 100 in China the alchemists tried to make gold out of more common materials. After hundreds of years of trial and error they failed. But along the way they learned quite a bit about the stuff that makes up the world: the chemical elements.

In the 1700s alchemy became a proper science, chemistry. That was the work of three men in the West: Priestley, Lavoisier and Dalton:

  • Priestley discovered oxygen. It was because people did not know about oxygen that they thought fire was material, like air or water. Fire is not material – it is a process that takes other materials apart and puts them back together in new ways.
  • Lavoisier ran Priestley’s experiments but carefully weighed everything before and after, even the air. He found that elements like mercury and oxygen always go together in certain proportions – it was not just a matter of chance. That was true for any substance that could be broken down into simpler substances.
  • Dalton took Lavoisier’s numbers and asked “Why?” That is the essence of science: ask an impertinent question and you are on the way to the pertinent answer. Dalton’s question led him, in 1803, to discover that everything is made of atoms.

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The following is based on part three of Jacob Bronowski’s BBC series on the history of science and invention, “The Ascent of Man” (1973). It is about architecture and the rise of cities:

One of the biggest steps in the ascent of man was the rise of the stone mason. Instead of living in caves or houses made of earth, man built his house out of wood and stone and brick. It might seem like a small change but in fact it was huge:

  1. It marks a new understanding of nature: that it is something you can take apart, understand and then put back together in new ways.
  2. It allowed the rise of cities: not just physically by providing the necessary buildings but also by giving a new understanding of human society as something made of parts working together.

A city is made up of people who work together in certain ways. In particular:

  • division of labour: a man doing one sort of work his whole life and becoming very good at it, perhaps even coming up with new inventions. Not just the masons but other craftsmen too like potters, coppersmiths and weavers.
  • chain of command: which allows a city or a people to act as one and achieve things for the greater good, like the control of water by irrigation. Information comes into a commander or ruler at the centre and comands flow out. For it to work you need roads, bridges and messages.

When the Incas fell to the Spanish in 1532 they were at just this stage. Their civilization was cut short before it came up with the wheel, the arch or even writing. They kept records on knotted strings called quipu, but it recorded only numbers not words.

The Greeks, despite their great love of geometry, never came up with the arch. That was a Roman invention. By spreading the load it allowed columns to hold up more weight or be spread farther apart. The Roman arch and later the Arab one were based on the circle.

A thousand years later in the 1100s came the Gothic arch, the oval or pointed arch of the Gothic cathedrals of northern Europe. By spreading the load even farther than the Roman arch, buildings could rise to 40 metres. And since the arches, not the walls, were holding up the building, it made possible huge stained glass windows.

The Gothic arch was the last big breakthrough in architecture till the 1800s with the rise of buildings made with steel frames.

Man built Gothic cathedrals not because he suddenly needed huge, beautiful churches, but because he could. Man loves to make things, so much so that he often makes them better than he has to. That in turn allows things to be used beyond their intended purpose, leading to new ways of doing things – technology.

Taking things apart and putting them back together laid the groundwork for more than just architecture and cities but also for a new understanding of nature – which in time became science.

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Altamira

“The Ascent of Man” (1973) was a BBC series, Jacob Bronowski’s take on the history of science and invention. I saw it in the 1980s on the cable channel of the City College of New York. I would love to see it again. In the meantime I will have to make do with the book, which I picked up the other day for two dollars at a used book sale. I will do a chapter a week:

Man is part animal, part angel. To call him just an animal or just an ape would be a misleading understatement. Unlike other animals, man has an imagination. He can imagine the future and create it:

Every animal leaves traces of what it was; man alone leaves traces of what he created.

The gazelles for all their beauty and grace can never leave the grasslands of Africa. Should the grasslands ever disappear one day, they will disappear along with it. They are custom-made for a particular place. Man is not. Man got his start in those very same grasslands but has spread across the world, even to the cold and ice of the far north.

Among the multitude of animals which scamper, fly, burrow and swim around us, man is the only one who is not locked into his environment. His imagination, his reason, his emotional subtlety and toughness, make it possible for him not to accept the environment but to change it.

Men in the far north have white skin, not black. But it was not white skin that allowed them to live there: it was fire. Man has spread over the earth too quickly for difference of race to matter much. Even more to the point, man is able to make up for his physical shortcomings faster than nature can. Instead of growing fur like a bear, for example, he makes clothes.

In fact, while man has changed faster than almost any other animal over the past two million years, the physical changes in his body were driven mainly by changes in his brain. For example, as he was able to make tools to kill and cut, his teeth got smaller.

Some milestones:

  • 2,000,000 years ago: Australopithecus africanus. He could walk upright. That freed his hands to make and use tools, which in turn allowed him to eat meat. Eating meat meant less time spent eating and more time for other things. They took care of not just their own children but even those whose parents had died. He stood 1.2 metres tall (four feet) and had a brain about half the size of ours.
  • 400,000 years ago: Homo erectus: discovers how to make and control fire. He probably had language too, which allowed for better hunting. Spreads as far as China, Europe and Java.
  • 180,000 year ago: Homo sapiens: way better tools, like harpoons. Art for the first time.

Only man creates art. It shows that man can imagine things that he does not see before him; it means he can think about the future.

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“I had not been long back from Hiroshima when I heard someone say, in Szilard’s presence, that it was the tragedy of scientists that their discoveries were used for destruction. Szilard replied, as he more than anyone else had the right to reply, that it was not the tragedy of scientists: it is the tragedy of mankind.

“There are two parts to the human dilemma. One is the belief that the end justifies the means. That push-button philosophy, that deliberate deafness to suffering, has become the monster in the war machine. The other is the betrayal of the human spirit: the assertion of dogma that closes the mind, and turns a nation, a civilization, into a regiment of ghosts – obedient ghosts, or tortured ghosts.

“It’s said that science will dehumanize people and turn them into numbers. That’s false, tragically false. Look for yourself. This is the concentration camp and crematorium at Auschwitz. This is where people were turned into numbers. Into this pond were flushed the ashes of some four million people. And that was not done by gas. It was done by arrogance, it was done by dogma, it was done by ignorance. When people believe that they have absolute knowledge, with no test in reality, this is how they behave. This is what men do when they aspire to the knowledge of gods.

“Science is a very human form of knowledge. We are always at the brink of the known; we always feel forward for what is to be hoped. Every judgement in science stands on the edge of error and is personal. Science is a tribute to what we can know although we are fallible. In the end, the words were said by Oliver Cromwell: “I beseech you in the bowels of Christ: Think it possible you may be mistaken.”

“I owe it as a scientist to my friend Leo Szilard, I owe it as a human being to the many members of my family who died here, to stand here as a survivor and a witness. We have to cure ourselves of the itch for absolute knowledge and power. We have to close the distance between the push-button order and the human act. We have to touch people.”

– Jacob Bronowski, 1973.

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Darwin

Charles Darwin (1809-1882) was a British scientist who discovered the theory of evolution by natural selection, explaining the history of life on earth. He wrote about it in the “Origin of Species” (1859) and the “Descent of Man” (1871).

The Bible says God created the species – all the kinds of plants and animals. Darwin said no: all life belongs to the one large family, each branch developing or “evolving” into different creatures. Over time fish came from worms and men from monkeys. His theory shook – and still shakes – the West.

The son of a rich family, Darwin went to Cambridge but he had no direction in life. The only thing he seemed to love was nature, especially beetles. Then he heard the HMS Beagle was about to sail round the world. Darwin signed up.

Along the way they came to the Galapagos islands. Each island had its own kind of finch. Yet they were all similar to the same bird found nearby in South America. How did this happen? Did God create a finch for each island? If not, how did they change or evolve for each island?

On the ship Darwin read Charles Lyell’s “Principles of Geology” (1830-33). Lyell said that the mountains, the rivers and so on were not created suddenly, either by God or some sudden natural calamity. Instead everything was created bit by bit, by slow, everyday change that is still going on.

This is called uniformitarianism. It makes for great science: Science is not about one-off changes like acts of God but about what can be observed to happen over and over again.

So Darwin thought that if the finches had changed for each island, it was a slow change that was going on all the time right under his nose. But what was it?

One night years later when Darwin was back from sea he read “Principles of Population” (1798) by Malthus. Malthus said that more children are born than can be fed, so some die, chiefly among the poor.

That was it: too many finches are born. Only those best suited for the island would live long enough to give birth to the next generation. Over time the fit would multiply and the unfit die out. That is how each island got its own finch. That is how evolution happened. No acts of God were required.

For over 20 years Darwin kept the theory to himself and some close friends. But then one day Darwin got a letter from Alfred Russell Wallace. Wallace had also sailed around the world, he had also read Malthus and he had also come up with the same theory. He asked Darwin what he thought of it.

This forced Darwin’s hand. In 1858 they jointly made the theory public. A year later Darwin explained the theory in his book, the “Origin of Species”.

The theory destroyed Darwin’s Christian faith, but not Wallace’s. Wallace did not see how evolution could explain man, especially his mind. Darwin thought it could and wrote about it in the “Descent of Man”.

Darwin died rich and famous but without hope of heaven.

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Einstein

Albert Einstein (1879-1955) was one of the top minds in physics in the 1900s, if not since Newton himself. He was widely regarded as the definition of genius. His theories in physics made possible the atom bomb, which can destroy a whole city in a moment. He was a kindly, humble man who rarely combed his hair and often had a sad look on his face.

Einstein discovered the theory of relativity. He came out with it in two parts: special relativity in 1905 and general relativity in 1915.

He came up with his theory while riding the train to work at the patent office in Berne, Switzerland. He looked at the town clock and wondered what would happen if he moved away from it on a beam of light. He asked the kind of simple questions a child would ask. But then he would tirelessly follow the physics and the numbers to the breaking point till he found the answer.

The most famous bit of his theory is this:

E=mc²

This means that matter (m) can be converted into energy (E). Energy is the force needed make something move faster or change its course. The c is for how fast light moves. In an atom bomb matter is converted into energy at an incredible rate. Which is how such a small thing can destroy a city. It is also how the sun and the stars shine.

The theory also says that nothing can move faster than light. And as you move faster time slows down. But for time to slow down by a lot, you need to be going almost as fast as light itself.

This leads to the Twin Paradox: one twin stays on Earth while the other goes to the stars in a ship that moves almost as fast as light. When he gets back from the stars he will find that his twin brother is much older than he is. Because what had seemed like months on the ship was years on Earth.

Just as matter and energy are two sides of the same coin, so are space and time. Gravity, which we know as the force that pulls things down to earth, is a fold in space. The gravity of the earth is like a deep well in the structure of space.

When the second world war broke out in 1939 Einstein knew the Germans could use his theories to build an atom bomb and win the war. He wrote a letter to President Roosevelt to tell him the horrible news. Taking no chances America built the bomb.

When Einstein died they burned his body but kept his brain. His genius had become a legend by then. But when they looked at his brain, it seemed completely ordinary. Years later, however, when they knew more about brains, they noticed that the part that thinks about space and number is larger than most people’s. He was probably born that way.

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