Wednesday, February 5, 2014

The Speed of Light

It was the evening of April 21st, 1820, when Hans Christian Ørsted was preparing for a lecture, that, as he switched a battery on, he noticed his compass deflected from the magnetic north. When he switched it off, the compass went back. He had discovered, as had Newton, one of the four forces of physics. The first had been gravity, the second was to be electromagnetism.
Michal Faraday was a bookbinder, and in a time when science was a hobby mostly for the rich, he was not a likely candidate for an eminent scientist. But he taught himself much, and in his early adulthood obtained tickets to the lectures of Humphrey Davies, a popular scientist of the time.
Faraday eventually got a job working for Davy. And although Davy was a good scientist, the greatest thing, according to some, that he discovered in his life was Michal Faraday.
Faraday, after seeing Ørsted’s experiment, theorized that as electricity moved along a wire, it created a little piece of magnetism, and this in turn created a little piece of electricity, and thus they were connected in a never ending braid.
Instead of trying to get a wire to move a compass, he decided to see if he could get a compass to move a wire. The experiment worked. They were connected.
Sir Humphrey Davy, Faraday’s old mentor, was the new president of The Royal Society. When he saw his old student’s work, he at once accused Faraday of plagiarism from another scientist, although that scientist had denied it was. Davy opposed Faraday joining the Royal Society, which was the elite body of science at the time. But at the election, Faraday even had the vote of the man Davy claimed Faraday had stolen from.
Years later, in 1865, James Clerk Maxwell, after doing his equations, discovered that Faraday had been right all along. The two forces were connected. But electricity could only create magnetism, and magnetism could only create electricity at a very particular speed. A speed at which only one thing could go. Faraday was exonerated. Light was connected to electromagnetism. The speed at which this could happen was  670,000,000 miles per hour. Or 186,00 miles per second. It was the speed of light.
To be continued.

Andrew C. Abbott

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