theoretical frequency
51Mihai Gavrilă — Born October 10, 1929 Cluj, Romania Citizenship France Nationality …
52Antenna (radio) — Whip antenna on car …
53radar — /ray dahr/, n. 1. Electronics. a device for determining the presence and location of an object by measuring the time for the echo of a radio wave to return from it and the direction from which it returns. 2. a means or sense of awareness or… …
54Precision tests of QED — Quantum electrodynamics (QED), a relativistic quantum field theory of electrodynamics, is among the most stringently tested theories in physics.Precision tests of QED consist of measurements of the electromagnetic fine structure constant, α, in… …
55earthquake — /errth kwayk /, n. 1. a series of vibrations induced in the earth s crust by the abrupt rupture and rebound of rocks in which elastic strain has been slowly accumulating. 2. something that is severely disruptive; upheaval. [1300 50; ME erthequake …
56Earth Sciences — ▪ 2009 Introduction Geology and Geochemistry The theme of the 33rd International Geological Congress, which was held in Norway in August 2008, was “Earth System Science: Foundation for Sustainable Development.” It was attended by nearly… …
57Photon — This article is about the elementary particle of light. For other uses, see Photon (disambiguation). Photon Photons emitted in a coherent beam from a laser Composition Elementary particle …
58river — river1 riverless, adj. riverlike, adj. /riv euhr/, n. 1. a natural stream of water of fairly large size flowing in a definite course or channel or series of diverging and converging channels. 2. a similar stream of something other than water: a… …
59Analog sound vs. digital sound — Analog sound versus digital sound compares the two ways in which sound is recorded and stored. Actual sound waves consist of continuous variations in air pressure. Representations of these signals can be recorded in either digital or analog… …
60Sound from ultrasound — Contents 1 Parametric array 2 Applications 2.1 Commercial advertising …
