Search results
Results from the WOW.Com Content Network
Light exerts physical pressure on objects in its path, a phenomenon which can be deduced by Maxwell's equations, but can be more easily explained by the particle nature of light: photons strike and transfer their momentum. Light pressure is equal to the power of the light beam divided by c, the speed of light.
James Clerk Maxwell's 1865 prediction [46] that light was an electromagnetic wave – which was confirmed experimentally in 1888 by Heinrich Hertz's detection of radio waves [47] – seemed to be the final blow to particle models of light. In 1900, Maxwell's theoretical model of light as oscillating electric and magnetic fields seemed complete.
In the late 17th century, Sir Isaac Newton had advocated that light was corpuscular (particulate), but Christiaan Huygens took an opposing wave description. While Newton had favored a particle approach, he was the first to attempt to reconcile both wave and particle theories of light, and the only one in his time to consider both, thereby anticipating modern wave-particle duality.
The fact that light could be polarized was for the first time qualitatively explained by Newton using the particle theory. Étienne-Louis Malus in 1810 created a mathematical particle theory of polarization. Jean-Baptiste Biot in 1812 showed that this theory explained all known phenomena of light polarization. At that time polarization was ...
The difference in phase between the two waves is determined by the difference in the distance travelled by the two waves. If the viewing distance is large compared with the separation of the slits (the far field ), the phase difference can be found using the geometry shown in the figure below right.
The light source can be a laser, a discharge tube, or a synchrotron radiation source. [56] The concentric hemispherical analyzer is a typical electron energy analyzer. It uses an electric field between two hemispheres to change (disperse) the trajectories of incident electrons depending on their kinetic energies.
Some phenomena depend on light having both wave-like and particle-like properties. Explanation of these effects requires quantum mechanics. When considering light's particle-like properties, the light is modelled as a collection of particles called "photons". Quantum optics deals with the application of quantum mechanics to optical systems.
In the physical sciences, a particle (or corpuscule in older texts) is a small localized object which can be described by several physical or chemical properties, such as volume, density, or mass. [ 1 ] [ 2 ] They vary greatly in size or quantity, from subatomic particles like the electron , to microscopic particles like atoms and molecules ...