Scotland’s forgotten Einstein?
An intrepid camera man ventured down George St in Edinburgh and asked 100 passers by who the man in this statue was.
Most of them had no idea.
Graham Bell? Carlisle? Fleming? Stevenson? Lord Kelvin?
Nope, none of them.
So the universe is full of invisible signals. There is a lot of noise out there.
Radio telescopes listening out into the far reaches of space to try and work out the origins of the universe, to hear the noises made at the time of the big bang.
MRI Scanners and mobile phones?
The all use electromagnetic radiation… which was discovered by….
Well in 1865 Scotland’s greatest physicist, James Clerk Maxwell put down his pencil after working out a huge set of equations that had proved electromagnetic radiation. Then he slipped quietly through the cracks of history.
The man was a geek. He saw all things in terms of pure mathematics. Einstein kept a picture of him in his study, saying that ‘he stood on Maxwell’s shoulders’ Maxwell was to electromagnetics what Newton was to gravity.
James was born in Edinburgh in 1841, the only child of a land owning family with an estate in Dumfries. He was a bright kid. We all, as kids, made a series of small drawings, each slightly different so that we could flick them together and see the drawing move. But Maxwell worked out just how fast that optimal flicker had to be.
At 14 years of age he published his first mathematical paper.
He then went to Cambridge, publishing three further mathematical papers. The University held a competition to see if anybody could explain how Saturn’s rings were held in place. The two vast concentric circles, 250 000 km in diameter, could be either rock, fluid or individual particles. Maxwell didn’t look at the planet- he looked at the maths. He worked out that the rings could be solid, but only on one side of the planet. If they were fluid, the forces that held them there would also destroy them. Then he worked out that the theory of small of particles orbiting on their own could be correct. And then went on to work out the number of particles that it might be.
He won the competition of course. Years later, it was proved the number of particles was correct, and that led to the Higgs boson and all the craft that have voyaged out into the galaxy since. The voyager probe proved him right about the rings. The gap between the rings is called the Maxwell gap. And now, when astronomers see a star being born, the start of a new solar system, it’s Maxwell’s maths that are still used.
After Cambridge, Maxwell became one of Britain’s first theoretical physicists. He became professor at Aberdeen University at the age of 25. His mum had died when he was 8, his dad when he was 24 and that early experience shaped him as a very humane man. Always wary of being a machine, his science had to do good.
All his colleagues were twice his age but he was befriended by Daniel Dewar, the principal of Aberdeen university and married Dewar’s daughter after proposing to her with a poem he had written. The marriage was very happy, they shared a sense of humour and a passion for poetry. And dogs. Maxwell’s had many dogs. All called Toby.
He was fascinated by colour. Newton had already split sunlight into the colours of the rainbow and it was known that white light is all colours, whereas black is no a colour at all. Artists knew that with three primary colours, they could mix any other colour. But nobody knew why that was.
Thomas Young thought that it was something to do with biology and that the human eye might have three receptors for each colour and the human eyes blended them together. Maxwell wanted to test this so he mixed the colours with mathematical precision, and then asked people what colour they actually saw – by using a simple colour wheel with different amounts of red, yellow and blue and then spun the wheel 20th of a second per revolution which is what the eye can see. Red and blue gave magenta as expected. But it needed red, green and blue to give white.
So there are primary lights, and primary colours. As paint absorbs light, the circle emanates light. Maxwell worked out exactly what combination was sensitive to our eyes and demonstrated the range of colours the human eye could see. He did that in 1861 with a colour demo. Three photographs of the same tartan ribbon- one filtered with red, one with blue, one green. If all three pictures were projected onto the wall at the same time – the coloured ribbon appeared. And the screen you are reading this on, is formed in exactly the same way.
Being smart, he then explained red green colour blindness. At 29 he was inducted into the Royal Society!
He then went to Kings College Cambridge, and started working with Faraday to try and unravel the greatest mystery of the age - electricity
Faraday thought there was a connection between magnetism ( as in a compass) and electricity ( as lightening). Maxwell went on to prove that there are invisible electric fields all over space. Static charge generates an electric field. He proved that electric poles always come in pairs. Then changing a magnetic field generates an electric field. And then that an electric current surrounds itself with an electric field.
I have no idea what this is but I am impressed.
The theories of Faraday and Maxwell were inextricably linked, and it was all proved by pure maths.
But Maxwell wasn’t finished. He investigated Faraday's idea that electro magnetic field lines can be disturbed by waves travelling along them (like ripples on water). He noticed that the fields fluctuated in time with each other, and then he measured the speed. Deep in that equation was the exact speed the wave form travels at. 300 000 km a second. The speed of light.
What an Eureka moment.
He theorized that light was an electromagnetic wave, but it was a few more years before he was proved right by Mr Hertz. But Mr Hertz didn’t think it had any practical application.
He was wrong about that.
There is now a movement to get James Clerk Maxwell onto a new banknote. And not before time.
Caro Ramsay 04 02 2016