Changes
Jump to navigation
Jump to search
Line 1:
Line 1: − + − The experiment is easy to do, but difficult to understand. It consists of setting up a light source on one side, facing a barrier (such as a piece of cardboard) that has two slits in it to permit some light to pass through to a distant wall on the other side. If both slits are open, a distinct pattern of bright and dark bands is observed on the distant wall. If one slit is covered, a different pattern is seen on the distant wall.+ − This simple experiment demonstrates the wave-particle duality of light. Light behaves as a wave when both slits are open, such that the wave simultaneously passes through both slits and creates an interference pattern on the distant wall.+ − + + + + + + + + + + + + + + + +
Double-slit experiment (view source)
Revision as of 14:25, September 26, 2016
, 14:25, September 26, 2016Tidy up and added some more description
The '''double-slit experiment''' is a [[physics]] [[experiment]] which demonstrates [[wave-particle duality]].
The '''double-slit experiment''' is a [[physics]] [[experiment]] which demonstrates both wave-like nature of [[light]]. It can also show [[wave-particle duality]].
==Light==
For a long time there was some debate as to whether [[light]] was a [[wave]] or a [[particle]]. For example, the [[reflection]] of light can be explained just as easily using particles as waves. However [[diffraction]] is a phenomenon that only waves exhibit and forms the basis of the experiment.
The experiment can also be done with particles, e.g. electrons, such that a series of particles are directed at a grid, or other similar device, while observing the pattern on the other side.
The experiment is easy to do, but difficult to understand. It consists of setting up a light source on one side, facing a barrier (such as a piece of cardboard) that has two slits in it to permit some light to pass through to a distant wall on the other side. If both slits are open, a distinct pattern of bright and dark bands is observed on the distant wall. This is known as an "interference pattern". If one slit is covered, a different pattern is seen on the distant wall. The fact [[light]] undergoes [[diffraction]] means that it has wave-like behaviour.
==Wave-Particle Duality==
Other experiments, such as the [[photoelectric effect]] can only be explained assuming light consists of particles. So along with the [[photoelectric effect]], this experiment demonstrates the [[wave-particle duality]] of light.
The experiment can also be done with particles such as [[electron]]s. When many (perhaps 1000) they are accelerated at two slits, an interference pattern emerges. This shows the wave-like nature of [[matter]]. [[Wave-particle duality]] was proposed in 1924 by Louis De Broglie, as he considered if light can behave as particles, should the reverse be true<ref>http://www.nobelprize.org/nobel_prizes/physics/laureates/1929/broglie-bio.html</ref>. The [[wavelength]] of a particle can be found as:
<math>\lambda = \frac{h}{p} </math>
where
:<math>\lambda</math> is the [[wavelength]] of the particle
:<math>p</math> is its [[momentum]]
:<math>h</math> is [[Planck's constant]]
==Reference==
[[Category:Physics]]
[[Category:Physics]]
[[Category:Quantum Mechanics]]
[[Category:Quantum Mechanics]]
[[Category:Physics experiments]]
[[Category:Physics experiments]]
(username removed)