wave-particle duality

wave-particle duality

Principle that subatomic particles possess some wavelike characteristics, and that electromagnetic waves, such as light, possess some particlelike characteristics. In 1905, by demonstrating the photoelectric effect, Albert Einstein showed that light, which until then had been thought of as a form of electromagnetic wave (see electromagnetic radiation), must also be thought of as localized in packets of discrete energy (see photon). In 1924 Louis-Victor Broglie proposed that electrons have wave properties such as wavelength and frequency; their wavelike nature was experimentally established in 1927 by the demonstration of their diffraction. The theory of quantum electrodynamics combines the wave theory and the particle theory of electromagnetic radiation.

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The inherent contradiction in the way energy behaves. At the turn of the 20th century, it was believed that light was electromagnetic waves and electrons were particles. By the 1930s, it was determined that light behaves as if it were made up of particles (photons) as well as waves, and electrons also behave like waves. This has driven scientists to drink and is one of the most puzzling phenomena in the universe. See quantum mechanics.