Maxwell Flashcards
Overview
James Clerk Maxwell is one of the giants of physics. Unfortunately, his work is less famous than that of the other greats – possibly because his crowning glory – Maxwell’s Equations – are so hard to understand.
In producing these equations, he was the first scientist ever to unify any of nature’s fundamental forces. He discovered that electricity and magnetism are actually, at the deepest level, the same force – the electromagnetic force.
In doing so, Maxwell proved that light is an electromagnetic wave and so linked electricity, magnetism, and optics.
As if this achievement were not enough, his kinetic theory of gases accurately explained the origin of temperature. He introduced probability into the physics of the very small, laying the foundation for quantum theory.
He was the first person ever to produce a color photograph; and he used mathematics to explain Saturn’s rings over 100 years before the Voyager spacecraft confirmed that he was absolutely right.
In addition to his great discoveries, in his personal life, he was known for his capacity for hard work, his friendliness, personal kindness and generosity.
James Clerk Maxwell Lived 1831 – 1879.
Scotsman.
When Einstein was asked if he had stood on the shoulders of Newton, he replied: “No, I stand on Maxwell’s shoulders.”
And Richard Feynman, another of the 20th century’s greatest physicists said:huu “…the great transformations of ideas come very infrequently… we might think of Newton’s discovery of the laws of mechanics and gravitation, Maxwell’s theory of electricity and magnetism, Einstein’s theory of relativity, and… the theory of quantum mechanics.”
Bio
Born 1831 Edinburgh.
Paper at 14YOA. On ovals.
Nicknamed Dafty. Edinburgh U. Then to Cambridge.
Fellow of Trinity College. Studied mathematics.
Age 25: Straiton Gold Medal Mathematics.
Chair of natural philosophy University of Aberdeen.
Married Katherine Mayr Dewar, daughter of Dean.
Age 29: professor at King’s College London.
Age 40: professor at Cambridge.
Died 1879 at 48 YOA. Abdominal cancer.
Discoveries
1850’s: Mathematical analysis of the structure and long-term stability of Saturn’s ring system.
- With spinning color wheels, deduced light receptors in the human eye are capable of seeing just three colors of light. He had photographs taken of tartan; through a red, then a green, then a blue filter. Projecting the three images simultaneously produced the world’s first color photo.
Electromagnetism. Unification.
Studied André-Marie Ampère, Hans Christian Oersted, and, especially, Michael Faraday.
Produced “Beautiful Equations “.
Maxwell proved that there must be electromagnetic waves, whose speed he calculated would be identical to the speed of light, already known.
Maxwell then knew that light must be an electromagnetic wave. He also pointed out that infrared and other, as yet undiscovered electromagnetic rays, would travel at the speed of light. We now know that indeed there are other rays, such as radio waves, microwaves, UV rays, and x-rays, and they all do travel at the speed of light.
Hard to Understand, they are the Key to our Modern World Although we now recognize the genius, and indeed beauty of Maxwell’s work, it was controversial when he first published it in 1864.
Not many people realized that Maxwell’s Equations accurately and completely described electromagnetism.
In 1887, eight years after Maxwell’s death, Heinrich Hertz finally demonstrated by experiment that there truly are electromagnetic waves, which behave in exactly the way Maxwell predicted.
By 1901, Guglielmo Marconi was transmitting radio waves – the lowest energy form of electromagnetic waves – across the Atlantic Ocean, from Britain to Canada. The era of modern, wireless telecommunications had begun.
Kinetic Theory of Gas
Proved a central tenet of kinetic theory: that the viscosity of a gas does not vary with pressure ( at a constant temperature). His wife helped out in experiments.
