Brief History of electromagnetism

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Brief History of electromagnetism
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Contents

• History
• 1. Ancient times.
• 2. Mid-times
• 3. Early modern times.
• 2. Unification.

3
Ancient times

• Amber rubbed with fur attracts bits of dust and
  hairs.
• Static electricity - spikes on cold, dry days,
  lightening.
• Lode stone compass

4
Mid-times

• 1600. English scientist, William Giber, publishes
  De Magnete.
• 1700. Lectures and demonstrations given by
  various scientists using electricity and
  entertain audiences

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Mid-times

• 1700.Ben Franklin(1706-1790)
• Two kinds of charges positive and
  negative
• Like charges repel, unlike charges attract
• Conservation of Charges an isolated system
  has constant total charge

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Mid-times

• 1785. Charles Austin de Coulomb
• The force between two charges Q1 and Q2 is
  proportional to their product divided by the
  separation distance r squared inverse square law.
• 1790. Alessandro Volta finds chemistry acting on
  two dissimilar metals generates electricity. He
  later invents the voltaic pile-the battery.

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Early Modern times

• 1820. Hans Christian Oersted.
• electric current affects compass needle
• 1820. Adre Marie Ampere in Pairs finds that wires
  carrying current produce forces on each other.
• 1820. Michael Faraday at royal Society develops
  the idea of electric field and studies the effect
  of currents on magnets and magnets inducing
  electric currents.

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Early Modern times

• 1860. James Clerk Maxwell, a Scottish physicist
  and mathematician, puts the theory of
  electromagnetism on mathematical basis.
• 1873.Maxwell publishes "Treatise on Electricity
  and Magnetism" in which he summarizes and
  synthesizes the discoveries of Coloumb, Oersted,
  Ampere, Faraday, et. al. in four mathematical
  equations. Maxwell's Equations are used today as
  the basis of electromagnetic theory. Maxwell
  makes a prediction about the connections of
  magnetism and electricity leading directly to the
  prediction of electromagnetic waves.
• 1885. Hertz shows Maxwell was correct and
  generates and detects electromagnetic waves.
• 1895.Guglielmo Marconi puts the discovery to
  practical use by sending messages over long
  distances by means of radio signals.

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Maxwells Equations
                              

• Gauss' law for electricity
• Gauss' law for magnetism
• Faraday's law of induction
• Ampere's law

                
                     
                                      
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Chaos
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Order
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Einsteins Dream

• Is there an underlying simplicity behind vast
  phenomena in Nature?
• Einstein dreamed to come up with a unified
  description
• But he failed to unify electromagnetism and
  gravity (GR)

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History of Unification
electric
magnetic
planets
atoms
apple
electromagnetiesm
Quantum mechanics
gravity
mechanics
g-decay
b-decay
a-decay
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The End

• Thank you!