Electricity - SWF U3A Home Page

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The most important advance in our
modern world
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No telephone, telegraph, radio, television or
computers
No lighting other than that produced by burn
something
No cars busses or trains
No central heating
No music in our homes
Almost no industrial output
No advanced medical monitoring and diagnostics
Distribution of food and goods at a near standstill
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Heating
Magnetic
Chemical
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Newton took control of The Royal Society. Head of
demonstrations Frances Hauksbee demonstrates a
blue glow by placing his hand close to an revolving
evacuated glass sphere.
Elizabeth 1 the first marvelled at static electricity's
power to lift feather.
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Stephen Grey at Charterhouse charged up a
boy and his hand picked up gold leaf and
feather. This led to him realising that electricity
could travel through some things and not
other. He called them conductors and
insulators.
Grey could not store electricity
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Professor Pieter van Musschenbroek in
Leiden Holland, discover the Leyden jar for
storing electricity. The equivalent of the
capacitors we use today.
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Benjamin Franklin set out to
explain lightning and
designed experiments to
prove his theories.
Later invented the lightning
conductor
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Georges-Louis Leclerc and Thomas-François
Dalibard conducted Franklins experiment and
stored a charge in a wine bottle acting as a
Leyden jar.
Benjamin Franklin solve the problem of the
Leyden jar
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Henry Cavendish made an artificial Torpedo
fish using Leyden jars but the real fish did not
produce a spark. Leyden jar high voltage low
charge fish high charge low voltage. Fish
produces about 240 volts. Ten times less than
the Leyden jar.
He published very little but some years after
his death Maxwell read his papers and realised
he had actually discovered much that others
had been given credit for
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Luigi Galvani said that the body worked through
body electricity which flowed from the brain to the
muscles.
Alessandro Volta rejected Galvani and built the
Voltaic pile (first battery) to backup his belief.
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Alessandro Volta studied the structure of the
torpedo fish and replicated it in metal to
produce the pile. This was the first battery and
it was now possible to produce constant
electricity.
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Humphrey Davy built the worlds largest
battery in the Royal Institution. It filled a room
with over 800 voltaic piles. He connected it to
two carbon electrodes and when they touched
they produce a blindingly bright light The arc
lamp.
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Michael Faraday a 20 year old book binder
enters the Royal Institution.
Faraday got a ticket to see one of Sir
Humphrey Davys last lectures and that
changed his life.
Faraday became assistant to Royal Institution
Oersted discovered that if you pass an electric
current through a wire it will deflect a compass
needle
Faraday demonstrated circular motion
Faraday designed the first dynamo
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William Sturgeon (Britain) and Joseph Henry
(America) invented the electro magnet
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Ohms law published
by Geog Simon Ohm
R =V/I
V=IR
I=V/I
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First Transatlantic telegraph cable
The first message of 98 words took 16 hours to
send
Cable soon failed when a British engineer
thought it would work better at a higher signal
voltage
A new successful cable was laid in 1866
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1n 1864 published his theory
that light was an
electromagnetic wave after
he measured the speed
electricity travels is the same
as the speed of light
Developed the Maxwell
equations which explained
many of Faradays theories'
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Edison and Swan formed the Swan Edison
Company
Edison lit the financial district of New York
with his DC system and underground cables
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The young German physicist Heinrich Hertz is
remembered as the first person to detect radio
waves, and in doing so he also proved that
Maxwell's calculations and theories were all
correct.
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Tesla invented AC motors
and designed AC
transmission systems
Westinghouse were nearly
crippled by high royalties on
Tesla’s patents so Tesla came
to a settlement with them
The battle of the currents also
almost ruined Edison and the
AC system finally won the
day over his DC system
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Did Marconi invent the radio?
What he did was to turn the
research work of Maxwell, Hertz,
Righi, Lodge and others into a
practical and commercial
communications system
In 1909 he shared the Nobel Prize
for Physics, with Professor Karl
Braun
John Bardeen
William Shockley
Walter Brattain
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23 December 1947 demonstration at Bell Labs of the
first point contact transistor
Augusts 1948 Herbert F. Mataré and Heinrich Welker
announced the transistron
July 4, 1951 Shockley announced the junction transistor
January 1954 first silicon transistor
In 1956 John Bardeen, Walter Houser Brattain, and
William Bradford Shockley were honoured with the
Nobel Prize in Physics
Robert Noyce and Jack Kilby independently invent the
integrated circuit
Ted Hoff's invention of the microprocessor
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At a critically low temperature certain
materials become superconductive and
have no electrical resistance.
The phenomenon was discovered by
Heike Kamerlingh Onnes in 1911
Bardeen, Cooper and Schrieffer proposed
the complete microscopic theory of super
conductors in 1957 and were later
awarded the Nobel Prize. Bardeen is the
only physicist to have been awarded two
Nobel Prizes as he shared the award for
the invention of the transistor in 1956
In 1986, a new compound was discovered
that broke the theoretical temperature
limit that the theory (known as BCS
theory) predicted for superconductivity. It
had to be working in a different way.
We are still waiting for a brilliant mind to
come along and explain
John Bardeen
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Sustainability
Alternative power sources
The nuclear debate
Thinking the unthinkable

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