History of Magnetism and Electricity History of Magnetism and Electricity ● As the result of successfully completing this unit, the students will – Discuss the historical background of electricity, electromagnetism, and circuits – Compare and Contrast the time frame needed to discover the basic laws of electromagnetism and the time frame this course is taking to introduce those same concepts to the students Static Electricity – Thales from Milet ● Ca 600 BC ● Amber rubbed will attract light objects sources: http://en.wikipedia.org/wiki/File:Thales.jpg Static Electricity Static Electricity Static Electricity Static Electricity Static Electricity Static Electricity Static Electricity Static Electricity – Thales from Milet ● Ca 600 BC ● Amber rubbed will attract light objects sources: http://en.wikipedia.org/wiki/File:Thales.jpg Static Electricity – Thales from Milet ● Ca 600 BC ● Amber rubbed will attract light objects ● ηλεκτρον (greek for amber) sources: http://en.wikipedia.org/wiki/File:Thales.jpg Static Electricity η λ ε κ τ ρ ο ν η = Eta λ = Lambda ε = Epsilon κ = Kappa τ = Tau ρ = Rho ο = Omega ν = Nu Static Electricity η λ ε κ τ ρ ο ν η = E E L E K T R O N λ = L ε = E κ = K τ = T ρ = R ο = O ν = N Static Electricity – Thales from Milet ● Ca 600 BC ● Amber rubbed will attract light objects ● ηλεκτρον (greek for amber) → electron sources: http://en.wikipedia.org/wiki/File:Thales.jpg William Gilbert - Magnetism ● 1600 sources: http://en.wikipedia.org/wiki/File:William_Gilbert.jpg http://www.solarnavigator.net/compass.htm http://www.physics.ubc.ca/~outreach/phys420/p420_01/shaun/shaun/why_it_works.htm James Watt – Unit of Power ● 1769 ● steam engines ● unit of power → connects mechanical and electrical power sources: http://en.wikipedia.org/wiki/James_Watt Charles-Augustin de Coulomb – Quantitative Electrostatics ● ca 1790 ● Unit of Charge sources: http://en.wikipedia.org/wiki/Charles-Augustin_de_Coulomb http://en.wikipedia.org/wiki/Coulomb%27s_law author of coulomb's Law Picture: Dennis Nilsson Alessandro Volta – Voltaic Pile ● 1800 ● Essentially first battery ● Unit of voltage sources: http://en.wikipedia.org/wiki/Alessandro_Volta Hans Christian Ørsted – Electric Current & Magnetic Field Connected ● 1820 ● Interactive Tutorial on Ørsteds experiment: http://www.magnet.fsu.edu/education/tutorials/java/oersted/index.html (National High Magnetic Field Laboratory) sources: http://en.wikipedia.org/wiki/Hans_Christian_Oersted http://www.phy6.org/earthmag/oersted.htm André-Marie Ampère – Mathematical Follow-Up ● 1820 ● Mathematical Description of Ørsted's experiment ● Unit of Current ● Ampère's Law sources: http://en.wikipedia.org/wiki/Ampere_Law Georg Simon Ohm – Resistance ● 1827 ● Ohm's Law V =IR ● Unit of Resistance sources: http://en.wikipedia.org/wiki/Georg_Ohm http://en.wikipedia.org/wiki/File:Ohms_law_voltage_source.svg Michael Faraday – Electromagnetic Induction ● 1831 ● Farad: unit of Capacitance ● http://new.wvic.com/index.php?option=com_content&task=view&id=9&Itemid=46 sources: http://en.wikipedia.org/wiki/Michael_Faraday Joseph Henry – Self-Inductance ● 1831 ● Unit of Inductance sources: http://en.wikipedia.org/wiki/Joseph_Henry http://www.ndt-ed.org/EducationResources/CommunityCollege/EddyCurrents/Physics/selfinductance.htm James Clerk Maxwell – Maxwell's Equations ● 1865 ● Unifies mathematical Formulation of electromagnetics ● Adds Displacement Current to Ampère's Law sources: http://en.wikipedia.org/wiki/James_Clerk_Maxwell Heinrich Hertz – Electromagnetic Waves ● 1888 ● Experimentally confirmed EM Waves ● Unit of frequency sources: http://en.wikipedia.org/wiki/Heinrich_Hertz Heinrich Hertz – Electromagnetic Waves sources: http://www.sparkmuseum.com/BOOK_HERTZ.HTM Nikola Tesla – AC ● 1888 ● Unit of Magnetic Flux Density sources: http://en.wikipedia.org/wiki/Nikola_Tesla Further Reading ● Emilio Segré: – From Falling Bodies to Radio Waves – From X-Rays to Quarks.