Hertz experimentally confirmed the
existence of electromagnetic waves, the measured propagation velocity
of electromagnetic waves with the speed of light is indeed the same,
while electromagnetic waves can also produce reflection, refraction,
interference, diffraction, polarization and other phenomena, from the
experiment proved that light is a kind of electromagnetic waves.
Just as a mode of transmission of energy. So, given light source,
because light of atomic movement. There are three ways: hot sports,
transition radiation, stimulated emission. The former is the most
common in life, such as lights and flame; the latter more used in laser.
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