An English physicist was lecturing before an audience
in London about 130 years ago about
some of the
tiicks that could be performed with magnets and wires.
He had a coil of wire connected to a galvanometer.
Since there was no current flowing through the wire,
the needle of the instrument was motionless. Then the
lecturer lowered a bar magnet into the coil. The needle
jerked to the right: an electric current had arisen. He
removed the magnet. The needle jerked again, this
time to the left.
The story is told that after the lecture a woman from
approached the lecturer and asked him:
"But, Mr. Faraday, of what use is the electricity
produced for just a split second
by that magnet?"
Very politely, Michael Faraday asked in return,. "Madame, of what
use is a new-born baby?"
Faraday's experiment was indeed the first step
towards the electric generator of today. From this experiment
it was but another step to inducing a continuous
electric current. In fact, Faraday
eleven days after his first experiment in induction.
blacksmith's son, Faraday was born near London
on September 22, 1791. His family was too poor to keep him in school
long. "My education," he wrote
later, "consisted of little more than the rudiments of reading,
writing, and arithmetic."
At the age of 13 he began working as an errand
boy in a
bookshop. A year later he became an apprentice to a bookbinder.
Both these jobs helped him to
develop a passionate interest in books. "While an
apprentice," he wrote afterwards, "I loved to read the
scientific books which were under
Faraday was also able to attend some public lectures
by the world-famous Sir Humphrey Davy. He
attended the lectures with great
enthusiasm and took extensive notes. Davy was
England's foremost chemist
at that time and a
very popular lecturer.
Shortly afterwards Faraday asked Davy to give him
work as an assistant, and he submitted his lecture
notes as proof of his earnestness. Davy, who liked
flattery, employed Faraday first as a secretary and
then as a laboratory assistant. Faraday's salary was
smaller that the one he had earned as a bookbinder,
but he was very pleased to be working in a scientific
Humphrey Davy invented the miner's safety lamp
carbon arc. He discovered many chemical
substances. But it is often said
that his greatest discovery
was Michael Faraday!
From now on Faraday was able to devote practically
all his time to research in science. He did experiments
in chemistry, electrochemistry, and metallurgy that
alone would have been sufficient to establish his reputation
as a scientist. He discovered benzene, produced
the first "stainless steel", was the first to
many gases, discovered the laws of electrolysis,
and the magnetic rotation of the plane of polarized
light. But his main interest was in electricity and magnetism . ..
But even when Faraday had discovered electromagnetic
induction, he was not satisfied. He wanted to
know why it had occurred. Unable to approach the
subject mathematically, he resorted to a physical model: the
familiar phenomenon of the way that iron filings
on a sheet of paper arrange themselves in lines about
a magnet. Why in lines?
Faraday put forward the idea that the space surrounding
the magnet was filled with lines of force.
Nor did he stop there. He filled
all space with lines of
force. In other words, he suggested that all space was
pervaded by various kinds of
force: magnetic, radiant,
electric, thermal, and gravitational. In other words,
these forces fill all of space.
This was the beginning of