Unformatted text preview: tal data for large wavelengths
but failed for small ones. This was
known as the “ultraviolet catastrophe.” Planck’s Constant Max Plank In 1900 Max Planck came up with a revolutionary way to
resolve the problem by assuming that energy came in
discrete amounts (quanta). This was the beginning of
quantum mechanics. Each quantum of light is called a
photon, and its energy is given by E = h f, where f is the
frequency of the radiation and h is the constant of
proportionality called Plank’s constant. The formula states
that higher frequency light has proportionally more energy
per photon. Einstein lent credence to Plank’s ideas by
explaining the photoelectric effect in a similar manner.
Robert Millikan did a series of experiments involving the
photoelectric effect and calculated the constant: h = 6.626 × 1034 J s. Before Planck light was considered to be a wave. Today we know it can be
interpreted as either a particle or a wave. As a wave, bright light can be
explained as a large am...
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 Fall '11
 Burgeson
 Photon, Light

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