James Clerk Maxwell

Scottish physicist James Clerk Maxwell may not be very well known, but lots of the technology we use today depends on his ideas.

Who was he?

  • James was born in Edinburgh on June 13th, 1831 and brought up in Kirkcudbrightshire

  • He was inquisitive and often asked "What's the go' o' that?" ("How does that work?")

  • He loved geometry (the maths of shapes) and published his first scientific paper on oval curves at the age of 14

  • Most of his work was done on electricity, light and electromagnetism (a force that explains how magnetic and electric fields are connected, and how anything with a + or - charge reacts to them)

  • He died in England on November 5th, 1879

In physics, Maxwell is considered as important as Isaac Newton and Albert Einstein

James Clerk Maxwell and colour

James Clerk Maxwell made lots of discoveries about how we see light and colour.

He worked out that any colour of light could be made by mixing different amounts of blue, green and red light. (A bit like mixing blue, yellow and red paints to make different colours),

He showed this on a colour triangle (1855). Maxwell's theory is the idea behind how colour screens on computers and mobiles work.

Maxwell invented colour photography (1861). He took photos using red, green and blue filters and then put the images together to make a colour image of a tartan ribbon.

The first colour photograph, taken by Maxwell in 1861 - courtesy of National Media Museum/SSPL

Maxwell's colour wheel

Maxwell made his colour wheel to experiment with mixing colours. He could change the amount of each colour on the wheel and then spin it fast to mix the colours. Different amounts of red, green and blue would result in different colours.

Watch this video and see what happens when you spin Maxwell's wheel.

Maxwell's colour wheel

What is electromagnetism?

Maxwell's most important work was showing that electricity and magnets are linked.

  • In the past people thought that electricity and magnets were completely different things.
  • Michael Faraday discovered that they were linked. He worked out that a moving magnet could make electricity flow through a wire. This is the basis for how all the electricity we use every day is generated.
  • James Clerk Maxwell showed that electricity and magnetism create waves of electromagnetic energy. This includes light, x-rays, radio waves, microwaves and other types of energy we rely on.
  • Maxwell figured out the maths behind electromagnetism (creating its theory in 1865) - other people then used his ideas to invent a wide range of things we use today, including mobile phones!

We depend on electromagnetism every day

Mobile phones send and receive data using radio waves - a type of electromagnetic wave, just like light, microwaves or x-rays.

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