Wave-particle duality

In physics, wave-particle duality holds that light and matter can exhibit properties of both waves and of particles. This concept is a key part of quantum mechanics.

Overview

In the usual formulations of classical mechanics a given object is either a particle or a wave. For example, an electron is a particle (because they are observed to behave in particle-like

~ ~ ~ ~ ~ ~ ~ ~ ~ ~

ways), and light is a wave (because it behaves in wave-like ways, such as interference: see below). This categorisation was applied even to objects below the scale of direct

~ ~ ~ ~ ~ ~ ~ ~ ~ ~

observation, essentially by analogy with macroscopic phenomena.

~ ~ ~ ~ ~ ~ ~ ~ ~ ~

However, problems emerge with the viewpoint in that electrons too can be made to interfere and thus appear wave-like. Light (especially in the photoelectric effect, as analysed in 1905 by Albert Einstein) can possess particle-like properties. Quantum mechanics emphasises the primacy of measurement and not attributing to objects properties that cannot be measured. Hence the concept of wave-particle duality arose. It is not necessary, or useful, to say that an electron is a particle - or a wave - just that in certain circumstances it behaves like a wave, and in others like a particle.

Related Topics:
Photoelectric effect - Albert Einstein

~ ~ ~ ~ ~ ~ ~ ~ ~ ~

Related Topics:
Theories - Huygens - Newton

~ ~ ~ ~ ~ ~ ~ ~ ~ ~

~ ~ ~ ~ ~ ~ ~ ~ ~ ~