refraction time
81telecommunications media — Introduction equipment and systems metal wire, terrestrial and satellite radio, and optical fibre employed in the transmission of electromagnetic signals. Transmission media and the problem of signal degradation Every… …
82Electromagnetic radiation — Electromagnetism Electricity · …
83Nonlinear optics — (NLO) is the branch of optics that describes the behaviour of light in nonlinear media, that is, media in which the dielectric polarization P responds nonlinearly to the electric field E of the light. This nonlinearity is typically only observed… …
84Samuel R. Delany — Born Samuel Ray Delany, Jr. April 1, 1942 (1942 04 01) (age 69) New York City, New York, United States Pen name K. Leslie Steiner, S.L. Kermit …
85Speed of sound — Sound is a vibration that travels through an elastic medium as a wave. The speed of sound describes how much distance such a wave travels in a certain amount of time. In SI Units with dry air at 20 °C (68 °F), the speed of sound is 343 m/s. This… …
86Idaho National Laboratory — Coordinates: 43°32′00″N 112°56′41″W / 43.533429°N 112.94486°W / 43.533429; 112.94486 …
87Near-surface geophysics — is the use of geophysical methods to investigate small scale features in the shallow (tens of meters) subsurface. It is closely related to applied geophysics or exploration geophysics. Methods used include seismic refraction and reflection,… …
88Al-Andalus — This article is about the historical region. For the modern day region, see Andalusia. For the district in Kuwait, see Kuwait City. For the musical group, see Andalus. History of Al Andalus 711–1492 711–732 Musl …
89Lunar standstill — At a major lunar standstill, which takes place every 18.6 years, the range of the declination of the Moon reaches a maximum. As a result, at high latitudes, the Moon appears to move in just two weeks from high in the sky to low on the horizon.… …
90Evolution de l'oeil — Histoire évolutive de l œil L œil est un système sensoriel utilisé dans l ensemble du règne animal. En effet, la lumière donnant un grand nombre d informations sur l environnement, elle est, et a été, une force sélective majeure, qui a conduit à… …
