James Clerk Maxwell, 1831-1879, 19th-century Scottish physicist, further developed the field.concept.in his electromagnetic theory. Maxwell developed a mathematical theory relating the properties of electric and magnetic fields. Maxwell's work led him to predict the existence of electromagnetic waves, energy carriers that travel at the speed of light. His ideas also helped lead to some of the major innovations made in physics in the 20th century, including Einstein's special theory of relativity and quantum theory. 

Maxwell's equations describe the electric and magnetic fields set up by an arbitrary collection of charges. Physicist Albert Einstein developed an analogous set of equations for the gravitational fields that result from an arbitrary distribution of masses. Both sets of equations have wavelike solutions, with waves that travel at the speed of light. Electromagnetic waves, such as visible light and radio waves are the solutions to Maxwell's equations.(see Electromagnetic Radiation). Comprehension of the nature and behavior of these waves is one of the most important consequences of using the concept of fields.

Although there is no direct evidence for gravitational waves, their existence is indirectly confirmed by astronomical phenomena associated with binary.pulsars.

Another significant consequence of electromagnetic and gravitational fields arises in quantum theory involving quantum electrodynamics.....(back to field equation)

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