transverse gradient
71Optics — For the book by Sir Isaac Newton, see Opticks. Optical redirects here. For the musical artist, see Optical (artist). Optics includes study of dispersion of light. Optics is the branch of …
72Neural tube — Transverse section of half of a chick embryo of forty five hours incubation. The dorsal (back) surface of the embryo is towards the top of this page, while the ventral (front) surface is towards the bottom. (Neural tube is in green.) …
73Nordström's theory of gravitation — In theoretical physics, Nordström s theory of gravitation was a predecessor of general relativity. Strictly speaking, there were actually two distinct theories proposed by the Finnish theoretical physicist Gunnar Nordström, in 1912 and 1913… …
74Pakistan — /pak euh stan , pah keuh stahn /, n. 1. Islamic Republic of, a republic in S Asia, between India and Afghanistan: formerly part of British India; known as West Pakistan from 1947 71 to distinguish it from East Pakistan (now Bangladesh).… …
75Glass transition — The liquid glass transition (or glass transition for short) is the reversible transition in amorphous materials (or in amorphous regions within semicrystalline materials) from a hard and relatively brittle state into a molten or rubber like state …
76Space tether — Artist s conception of satellite with a tether Space tethers are cables, usually long and very strong, which can be used for propulsion, stabilization, or maintaining the formation of space systems by determining the trajectory of spacecraft and… …
77Laser — For other uses, see Laser (disambiguation). United States Air Force laser experiment …
78Refractive index — Refraction of light at the interface between two media. In optics the refractive index or index of refraction of a substance or medium is a measure of the speed of light in that medium. It is expressed as a ratio of the speed of light in vacuum… …
79Road — This article is about a route, thoroughfare or way that supports travel by a means of conveyance. For a place outside a harbor where a ship can lie at anchor, see Roadstead. For public roads, see Highway. For other routes, see thoroughfare. For… …
80Surface wave — Diving grebe creates surface waves In physics, a surface wave is a mechanical wave that propagates along the interface between differing media, usually two fluids with different densities. A surface wave can also be an electromagnetic wave guided …
