The spread (or propagation) of a disturbance in matter or in a vacuum, in space and in time. The wave is characterized by frequency, wavelength, propagation rate and amplitude.קרא עוד >
Terms beginning with W
The distance between two successive peaks of a wave, measured in units of length, such as meter (m), centimeter (cm), millimeter (mm), micron (µm), nanometer (nm) and Ångstrom (Å).קרא עוד >
A wireless communications network (e.g. Wi-Fi) that uses radio waves to transmit information and data back and forth among different end-user devices (such as mobile phones, tablets or smart phones). קרא עוד >
A branch of the United Nations Organization dealing with health. Among its main roles: acting as leader on the subject of world health, determining priorities for health research, setting norms and standards (international), elaborating policy, providing support for countries throughout the world, supervising and assessing health trends.קרא עוד >