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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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