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James Clerk Maxwell
(1831 - 1879)

Maxwell's Equations

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Heinrich Hertz
     (1857 - 1894)    


 

maxwell.jpg (2582 bytes)
James Clerk Maxwell
(1831 - 1879)
James Clerk Maxwell is generally regarded as the greatest theoretical physicist of the 19th century.  Born in Edinburgh to a well-known Scottish family, he entered the University of Edinburgh at age 15, around the time that he discovered an original method for drawing a perfect oval.  Maxwell was appointed to his first professorship in 1856 at Aberdeen.  This was the beginning of  a career during which he would develop the electromagnetic theory of light and explanations of the nature of Saturn's rings, and contribute to the kinetic theory of gases.

Maxwell's development of the electromagnetic theory of light took many years and began with the paper "On Faraday's Lines of Force," in which Maxwell expanded upon Faraday's theory that the electric and magnetic effects result from force fields surrounding conductors and magnets.  His next publication, "On Physical Lines of Force," includes a series of papers explaining the known effects and the nature of electromagnetism.

Maxwell's other important contributions to theoretical physics were made in the area of the kinetic theory of gases.  Here, he furthered the work of Rudolf Clausius, who in 1858 had shown that a gas must consist of molecules in constant motion colliding with one another and with the walls of the container.  This resulted in Maxwell's distribution of molecular speeds in addition to important applications of the theory of viscosity, conduction of heat, and diffusion of gases.

Maxwell's successful interpretation of Faraday's concept of the electromagnetic field resulted in the field equation bearing Maxwell's name.   Formidable mathematical ability combined with great insight  enabled Maxwell to lead the way in the study of the two most important areas of physics at his time.   Maxwell died of cancer before he was 50.

maxwellmontes-thumb.gif (5652 bytes)Maxwell's contributions to electromagnetic theory were honored by naming a mountain on Venus for him.

This is a simulated airplane view of Maxwell Montes (65°N, 5°E). With topography, radar imagery, and a lot of imagination, it is possible to create the view an airplane pilot might see approaching Maxwell Montes from the northwest at an altitude of 7 kilometers. The SAR imagery has been false-colored and overlaid on the topography rendered as a three-dimensional surface (no vertical exaggeration). The simulated clouds and haze add to the perception of depth and distance in the image. [From David P. Anderson (Southern Methodist University).]

Source: http://cass.jsc.nasa.gov/images/sven/sven_s15.gif

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Heinrich Hertz
(1857 - 1894)
Heinrich Rudolf Hertz was born in 1857 in Hamburg, Germany.   He studied physics under Helmholtz and Kirchoff at the University of Berlin.   In 1885, Hertz accepted the position of Professor of Physics at Karlsruhe; it was here that he demonstrated radio waves in 1887, his most important accomplishment.

In 1889 Hertz succeeded Rudolf Clausius as Professor of Physics at the University of Bonn.  Hertz's subsequent experiments involving metal penetration by cathode rays led him to the conclusion that cathode rays are waves rather than particles.   Exploring radio waves, demonstrating their generations, and determining their speed are among Hertz's many achievements.  After finding that the speed of a radio wave was the same as that of light, Hertz showed that radio waves, like light waves, could be reflected, refracted, and diffracted.

Hertz died of blood poisoning at the age of 36.  During his short life, he made many contributions to science.  The hertz, equal to one complete vibration or cycle per second, is named after him.


Previously Asked Questions

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[Top] [Previously Asked Questions] [References]


References

Maxwell's Equations

Name

Equation

Gauss' law for electricity

max1.gif (209 bytes)


Relates net electric flux to net enclosed electric charge

Gauss' law for magnetism

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Relates net magnetic flux to net magnetic charge
Faraday's law

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Relates induced magnetic field to changing magnetic flux

Ampere-Maxwell law

max4.gif (399 bytes)


Relates induced magnetic field to changing
electric flux and to current

[Top] [Previously Asked Questions] [References]


List of Topics

Measurements Electric Potential Magnetism Electrical Circuits (AC) Optical Instruments: Mirrors and Lenses
Electrostatics Capacitance Sources of Magnetic Fields Maxwell's Equations Interference
Electric Fields Current and Resistance Magnetism in Matter Electromagnetic Waves Diffraction
Electric Flux Electrical Circuits (DC) Electromagnetic Induction Interaction of Radiation with Matter: Reflection, Refraction, Polarization  

 

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