group velocity of light
51Negative refraction — is the name for an electromagnetic phenomenon where light rays are refracted at an interface in the reverse sense to that normally expected. Such an effect can be obtained using a metamaterial which has been designed to achieve a negative value… …
52Lorentz ether theory — What is now called Lorentz Ether theory ( LET ) has its roots in Hendrik Lorentz s Theory of electrons , which was the final point in the development of the classical aether theories at the end of the 19th and at the beginning of the 20th century …
53Soliton (optics) — In optics, the term soliton is used to refer to any optical field that does not change during propagation because of a delicate balance between nonlinear and linear effects in the medium. There are two main kinds of solitons: spatial solitons:… …
54physical science, principles of — Introduction the procedures and concepts employed by those who study the inorganic world. physical science, like all the natural sciences, is concerned with describing and relating to one another those experiences of the surrounding… …
55Čerenkov radiation — (also spelled Cerenkov or Cherenkov) is electromagnetic radiation emitted when a charged particle (such as an electron) passes through an insulator at a speed greater than the speed of light in that medium. The characteristic blue glow of nuclear …
56Vector soliton — Among all the soliton considered, the optical soliton draws the most attention as it is possible to generate ultrafast pulses and has wider application. optical soliton can be classified as two groups:temporal soliton and spatial soliton.however …
57History of Lorentz transformations — The Lorentz transformations relate the space time coordinates, (which specify the position x , y , z and time t of an event) relative to a particular inertial frame of reference (the rest system ), and the coordinates of the same event relative… …
58Wave — A wave is a disturbance that propagates through space and time, usually with transference of energy. While a mechanical wave exists in a medium (which on deformation is capable of producing elastic restoring forces), waves of electromagnetic… …
59radiation measurement — ▪ technology Introduction technique for detecting the intensity and characteristics of ionizing radiation, such as alpha, beta, and gamma rays or neutrons, for the purpose of measurement. The term ionizing radiation refers to those… …
60particle accelerator — accelerator (def. 7). [1945 50] * * * Device that accelerates a beam of fast moving, electrically charged atoms (ions) or subatomic particles. Accelerators are used to study the structure of atomic nuclei (see atom) and the nature of subatomic… …
