24.1 Maxwell's Equations: Electromagnetic Waves Predicted and Observed

24.1 Maxwell's Equations: Electromagnetic Waves Predicted and Observed

• The 50-foot radar dish antenna at Kennedy Space Center in Florida helps track expendable launch vehicles with high-definition imagery.
• The first use of this C-band radar dish was for the launch of the Atlas V rocket.
• The greatest theoretical physicist of the 19th century was from Scotland.

• A 19th-century physicist named James Clerk Maxwell developed a theory that explained the relationship between electricity and magnetism and predicted the cause of visible light.

• The work of brilliant physicists such as Oersted, Coulomb, Gauss, and Faraday were brought together by Maxwell and he added his own insights to develop the overarching theory of electromagnetism.
• The mathematical statement of the equations is beyond the level of the text.
• The equations show how simple mathematical statements can unite and express a lot of concepts.

• The electric field is defined as the force per unit charge on a test charge, and the strength of the force is related to the electric constant, also known as the permittivity of free space.
• Gauss's law for electricity is a special form of Coulomb's law that was obtained from the first equation.

• There are no magnetic monopoles.
• The permeability of free space is related to the strength of the magnetic force.

• Gauss's law for magnetism is the second part of the equations.

• An electric field is created by a changing magnetic field.
• The emf is against the change.
• The third of Maxwell's equations is the law of induction.

• Magnetic fields can be generated by moving charges or electric fields.
• Ampere's law is encompassed by this fourth of the equations.

• The major laws of electricity and magnetism are encompassed in the equations.
• The symmetry that was introduced in his framework is not apparent.
• The hypothesis that changing electric fields create magnetic fields is important.
• This is similar to the law of induction and fits nicely into the equations.

• Symmetry can be seen in a wide range of situations.
• Symmetry plays a major part in the search for sub-atomic particles using large multinational particle accelerators.

• The electric and magnetic forces are both manifestations of the same thing.
• Current attempts to unify the four basic forces in nature are motivated by the classical unification of forces.

• The weak magnetic fields could not be easily detected at the time of the hypothesis.
• AC circuits produce changing electric fields.
• He predicted that the waves generated by the jumping fish would travel from the source to the lake.

• The waves predicted by Maxwell would consist of magnetic and electric fields.
• It is possible that the waves are capable of exert force on charges far from their source.

• According to Maxwell, light can be detected by the eye because it has such wavelength.

• It remained to be seen if other wavelengths existed.
• The greatest triumph of physics sinceNewton would be verified if that was the case.
• It took a few years for experimental verification to come about.

• The German physicist was the first to generate and detect certain types of waves.
• He did a series of experiments in the 19th century that proved that the waves travel at the speed of light.

• There were sparks that were visible evidence of the current in the circuit that was generated by high voltages across the gap in the loop.