a short history of electricity
TRANSCRIPT
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A Ridiculously Trite History of
Electricity
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Any discussion of the history of electricity from antiquity
accompanying topics of light and the aether(ether).
We will make three journeys through history:One for electricity
One for light
One for the ether
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Electricit Ma netism
Static
Charges
Moving
Charges
Electromagnetism
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Newton (late 1600s)
ec r c y an agne sm g
Particles
WavesFluids
Fields
Electromagnetic PhenomenaMaxwell (late 1800s)
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The Ether
, , .
e ree s:
How can nothing be something?
.
Ether must fill the heavens
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900 BC - Magnus walks across a field of black stones
which pull the iron nails out of his sandals . This region
becomes known as Magnesia.
600 BC - Thales of Miletos rubs amber with cat fur
1600 - William Gilbert discovers that the earth is agiant magnet explaining how compasses work. He also
discusses static electricity and invents the idea of an
e ec r c u w c s era e y ru ng.
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1729 - Stephen Gray shows that electricity doesn't
have to be made in place by rubbing but can also be
transferred from place to place with conducting wires.
resides on their surfaces.
1733 - Charles Francois du Fay discovers that
electricity comes in two kinds which he calledresinous(-) and vitreous(+).
- e ean- n o ne o e nven s etwo-fluid theory electricity.
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-one-fluid electricity in which one of Nollet's fluids exists
.
the principle of conservation of charge and calls the fluidthat exists and flows ``positive''. This educated guess
ensures that undergraduates will always be confused
about the direction of current flow. He also discovers thate ec r c y can ac a a s ance n s ua ons w ere u
flow makes no sense.
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1748 - Sir William Watson uses an electrostatic
machine and a vacuum pump to make the first
glowing discharge tube. His glass vessel is three feet
and three inches in diameter; the first fluorescent light bul
1752 - Johann Sulzer puts lead and silver together in`` ''
a battery.
1759 - Francis Ulrich Theodore Aepinus shows that
electrical effects are a combination of fluid flow confined
o ma er an ac on a a s ance. e a so scoverscharging by induction.
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1775 - Henry Cavendish invents the idea of capacitance
and resistance (the latter without any way of measuring
current other than the level of personal discomfort).
But being indifferent to fame he is content to wait for his
.
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with static electricity, then also discovers that the same
twitching can be caused by contact with dissimilar metals.His followers invent another invisible fluid, that
of ``animal electricity'', to describe this effect.
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1785 - Charles Augustin Coulomb uses a torsion
balance to verify that the electric force law is
inverse square. He also proposes a combined
fluid/action-at-a-distance theory with two conducting
.
Force = 1 q1 q24o r
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1793 - Alessandro Volta makes the first batteries.
electricity flowing through the frog legs. In 1800 he
develo s the Voltaic ile dissimilar metals se arated b
wet cardboard) which greatly increases the magnitudeof the effect.
1807 - Humphrey Davy shows that the essential'
gives no effect. He argues that chemical effects are
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1812 - Michael Faraday, a bookbinders apprentice,
scientific assistant. Davy interviews Faraday and finds
that he has educated himself by reading the books he
was supposed to be binding. He gets the job.
1820 - Hans Christian Oersted, during a public lecture,
compass needle to deflect.
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1820 - Andre Marie Ampere, one week afterhearing of Oersted's discovery, shows that
opposite currents attract.
1821 - Humphrey Davy shows that direct currentis carried throughout the volume of a conductorand establishes that
=
is increased as the temperature rises.
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1834 - Faraday discovers self inductance.
1841 - James Prescott Joule shows that energy
is conserved in electrical circuits involving current flow,
thermal heating, and chemical transformations.
notably Faraday, Ampere, Biot, Savard in what has
description of electromagnetism. It is now widely
accepted that light is an electromagnetic wave.
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1881 - Helmholtz, in a lecture in London, points out that
the idea of charged particles in atoms can be consistent
with Maxwell's and Faraday's ideas, helping to pave the
way for our modern picture of particles and fields
disturbance of the aether, as was popular after Maxwell.
And now, Tesla.....................