The end of the Dark Ages and Invention of the Frozen Chicken

“I’ve told you a lot about science, now let me ask you a question.”

Okay, Albert fire away.

What is science?

“Science is the all the facts about how things work, space and all that kind of stuff.”

No it’s not.

“Yes it is.”

Science is not just about the facts it’s about the discovery of things. It’s a journey not a place.

“So how do you know when you’ve arrived?”

You never quite do, that’s the beauty of science. A lot of people think that all the important things have been discovered already.

“They haven’t?”

Not at all. A wise man knows how little he knows, only a fool thinks he knows everything. Science is like a travel across a vast ocean. You are happy for a while living on one island comfortable in how well you understand that island. Then someone comes along and decides to explore a little further and finds a bigger and better island just over the horizon. Facts and even reality are only what we currently think of as true.

“So you mean your theories are wrong too?”

Newton’s theories lasted over two hundred years and mine are only a little over a hundred years, so it’s too early to say. You can still fly a spaceship around the solar system using Newton’s theories or work out how the planets move pretty accurately. I really just extended his theories. If you start flying your space ship very fast or start circling a black hole then you’ll need to start thinking about my theories of gravity and general relativity but we’re getting ahead of ourselves Europe hasn’t even heard of me yet. They have barely started thinking about science properly at all.

“What date is it on Earth now then?”

We’re a little over 500 light years away so it’s the early 1500’s still on Earth. For a thousand years nothing much has happened in science in Europe. This is the end of the dark ages. Monks have been making beautiful copies of manuscripts from the ancient civilizations, keeping alive the knowledge that is over a thousand years old while most people couldn’t care less. As I told you last time, Arabic scholars were making advances in astronomy and mathematics but nothing much new was happening in Europe. The dark ages ended when Europe started thinking for itself.

“You mean no-one had any thoughts in Europe for a thousand years?”

Oh they were thinking about all sorts of things I’m sure, and fighting of course this was the age of the crusades, but not much science. Most of the ancient knowledge had been lost or forgotten in Europe. The first thing they had to do was find it all. The monasteries had some of the books from the ancient Greeks, but a lot were brought back with the Crusaders. Others were stolen back from the Arabic libraries in Spain when it was won back from the Moors.

“Why were there Arabic libraries in Spain?”

The Moors had taken over Spain for centuries and set up an Islamic culture and had brought thousands of ancient books with them. The library in Cordoba was the best in world back then, full of the best writings and ancient Greece and Arabic science.

“I thought you said the ancient Greeks got it all wrong?”

They didn’t get everything right and were certainly wrong about seeing but they had invented the art of thinking. Do you know what the word philosophy means?

“Thinking?”

It means the love of wisdom and that is what the ancient Greeks had and the Europeans had forgotten. Back then science was called natural philosophy, the love of wisdom about the natural world. When all these ancient books were recovered and read it opened their eyes to wisdom and the pursuit of knowledge. The advances made by Arabic scholars also showed them that new things could still be discovered. If you don’t believe that you’ll never discover anything new. So a few brave souls started to challenge the ancient ideas, people you’ve probably heard of like Leonardo da Vinci.

“He was just a painter. He did the Mona Lisa and the Last Supper.”

Oh he was more than that he was a brilliant architect, scientist and inventor, thinking of things that wouldn’t or couldn't be built for hundreds of years like helicopters and parachutes. This was the start of an explosion of thinking called the Renaissance or literally rebirth. Another of my heroes is Galileo, he came a little after Leonardo, and was the worlds first great scientist. He made huge discoveries in astronomy and physics. He was even the first person to talk about relativity in very simple terms.

“He invented relativity?”

No, but he introduced the concept to science. He compared the situation of someone standing on deck of a moving boat or inside a cabin on the same boat with no windows. On deck the person could tell they were moving forward, but inside the cabin apart from a little side to side sway they’d feel they weren’t moving forward at all. If you dropped a ball it would seem to fall straight down even though really it was also moving forward at the same speed as the ship as it falls. That is the simplest form of relativity, what you experience is only relative to what is around you. It just took a few hundred years more to work out the details.

“What took you so long?”

I had to be born first and that took hundreds of years. While I was waiting to be born Europeans were still busy working out what science was. Science was really given a kick start in the year 1605, when an Englishman called Francis Bacon published a book called The Proficience and Advancement of Learning. This gave birth to what would now think of science. Rather than just studying the writings of the great Greek philosophers, Bacon urged people to think for themselves and come up with new theories for how the universe worked. Bacon is now thought of as the father of modern science.

“What did Francis Bacon discover?”

Well he invented the scientific process, or at least a version of it. He thought that a theory would naturally come from examining the world. In his writings he didn’t talk much about experiments and sparks of creativity but in his last week alive he managed to invent the frozen chicken and die as a result.

“Francis Bacon died trying to create the first frozen chicken?”

In a snowy March in 1626 Bacon was visiting London with the King’s doctor when he had the spark of an idea that cold could stop meat from going off. They didn’t have refrigerators back then of course. So he got out of his warm carriage in Highgate to buy a chicken and have it stuffed with snow. Sadly the chicken probably stayed fresh as long as he did. He caught pneumonia and died a few days later.

A brief history of Light, from the daft Greeks to the brilliant Iraqi Al-Haytham

“Albert, what about us?”

What about us?

“Well, you’ve told me a lot about stars and the universe but not much about light. Aren’t we meant to be imagining this trip of yours across the universe on a beam of light?”

Of course, light is after all one of my favourite topics. A lot has happened in terms of light during the journey so far. When we started out starlight arriving on Earth was greeted by a truly appreciative audience that placed great importance on the twinkling lights in the sky. Mesmerised young faces would gaze up into the stars and ask their parents what stars were.

"So what did they tell them?"

They told them stars were little holes in the floorboards of heaven, where light shone through.

"Lovely idea."

A beautiful notion, but a little wide of the mark scientifically. Those ideas lasted for over a thousand years from the time of the ancient Greeks until the 1600's. That was when natural philosophers, which is what scientists were called back in the year 1605, started to realise that they could abandon the old ideas of the ancient Greeks and think for themselves.

"So what did these ancient Greeks think about light?"

The Greek philosophers had a good think about light and then most of them came up with all the wrong answers. Plato, born in 427 BC, was most famous for his writings on politics, but also dabbled in science and his idea was that light works by sending out 'feeling rays' from the eyes to whatever you happen to be looking. This sounds a bit odd today but as an idea it lasted for almost two thousand years.

"So if all humans went blind overnight, light would cease to exist."

True, but I suppose they thought cats and dogs saw things the same way. Another problem with this great theory is that if light comes from the eyes why can't people see in the dark?

"Of course, why didn’t I think of that?”

Don’t worry, neither did most of the Greek philosophers. More worrying is what this says about progress in politics, no-one takes any notice of Plato now on science but his writings on politics are still highly regarded – most famously Plato’s Republic. The other great greek philosophers weren't much better on light. Have you heard of Aristotle?

“I’ve heard the name but I’m not sure what he is famous for.”

Aristotle was perhaps the best philosopher of ancient Greece and was brilliant in developing logic and studying animals and biology. He wasn’t so good at light and thought that all colours were a mixture of black and white. Another ancient Greek, Epicurus, got the right idea in 300 BC with light coming from objects to the eye, but since he was a small second division philosopher no-one listened to him.

“Why didn’t anyone listen to him? It seems so obviously true.”

Not back then. The notion of light travelling from objects to the eye seemed nonsense to most people- how could the light coming from something big like an elephant fit through the tiny pupil of an eye?

"So how does it all fit?"

Very easily. Light isn't made up of atoms so it doesn't take up any space. You can fit more light than the eye could cope with through even the tiniest pupil.

"So did no-one have a clue about light back then?"

After the Greek and Roman empires collapsed Europe was stuck in the dark ages for a thousand years.

"I guess they weren't likely to work out much about light in the dark ages."

Very true, but it wasn't so bad everywhere. To find someone talking sense about light 1500 years ago, you would have to skip Europe and look towards the Middle East at a time when Arabic culture was leading the world in mathematics, astronomy and science. Iraq was the major science centre back then.

“Iraq?”

It may come as a surprise to many people but Baghdad and Basra a thousand years ago were some of the most cultured places on the planet rather than just another war-zone. Did you know the numbers 0 1 2 3 4 5 6 7 8 9 are called arabic numerals?

"I thought they were invented in Europe.”

Well you’re wrong. The numbers we now use around the world can be traced back even further to Hindu and Indian mathematicians. Imagine if we were still lumbered with Roman numbers, all those X's and V's. And it's not just the numbers, the foundation of modern mathematics was created by arabic mathematicians a thousand years ago. Think of the word algebra.

“That’s a type of mathematics. Equations and stuff.”

It certainly is, but the ‘al’ part also reveals its Arabic origins. The father of this type of mathematics, Muhammad bin Mūsā al-Khwārizimi, was from Persia which would now be part of Iran but he spent most of his life working in Baghdad. Algebra is work that comes his famous book on the subject that contained the word al-Jabr in the title. But the most important Arabic scientist for our story was Abu Ali Muhammad bin al-Hasan bin al-Haytham.

“Wow, long name.”

He’s often just called Ibn al-Haytham or even just Alhazen. He was born in the year 965 A.D. in Basra, in what is now Iraq. He knew all about the writings of the Greek philosophers and thought this ‘feeling ray from the eye idea’ just didn’t make sense. More than that he worked out things that we know take for granted like how light travels in straight lines and how light is reflected by mirrors.

“How did he get his inspiration?”

Al-Haytham had plenty of time to think about light since he spent years under house arrest pretending to be insane after giving up his attempts to stop the Nile flooding. At that time in Egypt the flooding of the river Nile was the most important event in the year. He was invited to Egypt after claiming he could stop this annual flood. The plan involved a dam on the Nile at Aswan. Overwhelmed at the scale of the task he admitted defeat and pretended to go mad as a result. The ruler of Egypt at the time, Fatimid caliph al-Hakim, was pretty upset at this. Since al-Haytham appeared mad it seemed a little unfair to kill him for failing in his mission, so he let him off and simply placed him under house arrest for life. Unfortunately the Caliph had a long memory so al-Haytham had to pretend to be mad until the Caliph finally died years later. Al-Haytham has the consolation that his plan would have worked if he had completed it. A dam was built at Aswan almost a thousand years later and it did stop the Nile flooding.

“So when did he have his great ideas on light?”

In all those years of house arrest he wrote 209 books on science, philosophy, mathematics and astronomy. The most famous and influential of these was his book on light Kitab Al Manazir or the Book of Optics. This amazing book started the science of light. Just about everything he said about light made more sense than the ideas of the ancient Greeks and so he overturned what was thought to be true for over a thousand years and no-one improved on his ideas for another 500 years. When Europe started to escape from the dark ages it was Alhazen’s book that helped to get people thinking sensibly about light.

"So Alhazen was the first ray of light to illuminate the gloom of the dark ages."

You're getting quite poetic in your old age.

"Why thank you, that's your first compliment in over two thousand years."