SkywaveIn radio communication, skywave or skip refers to the propagation of radio waves reflected or refracted back toward Earth from the ionosphere, an electrically charged layer of the upper atmosphere. Since it is not limited by the curvature of the Earth, skywave propagation can be used to communicate beyond the horizon, at intercontinental distances. It is mostly used in the shortwave frequency bands.
Fixed wirelessFixed wireless is the operation of wireless communication devices or systems used to connect two fixed locations (e.g., building to building or tower to building) with a radio or other wireless link, such as laser bridge. Usually, fixed wireless is part of a wireless LAN infrastructure. The purpose of a fixed wireless link is to enable data communications between the two sites or buildings. Fixed wireless data (FWD) links are often a cost-effective alternative to leasing fiber or installing cables between the buildings.
RelexificationIn linguistics, relexification is a mechanism of language change by which one language changes much or all of its lexicon, including basic vocabulary, with the lexicon of another language, without drastically changing the relexified language's grammar. The term is principally used to describe pidgins, creoles, and mixed languages. Relexification is not synonymous with lexical borrowing, by which a language merely supplements its basic vocabulary with loanwords from another language.
Dispersive prismIn optics, a dispersive prism is an optical prism that is used to disperse light, that is, to separate light into its spectral components (the colors of the rainbow). Different wavelengths (colors) of light will be deflected by the prism at different angles. This is a result of the prism material's index of refraction varying with wavelength (dispersion). Generally, longer wavelengths (red) undergo a smaller deviation than shorter wavelengths (blue).
PidginA pidgin ˈpɪdʒᵻn, or pidgin language, is a grammatically simplified means of communication that develops between two or more groups of people that do not have a language in common: typically, its vocabulary and grammar are limited and often drawn from several languages. It is most commonly employed in situations such as trade, or where both groups speak languages different from the language of the country in which they reside (but where there is no common language between the groups).
Impedance of free spaceIn electromagnetism, the impedance of free space, Z0, is a physical constant relating the magnitudes of the electric and magnetic fields of electromagnetic radiation travelling through free space. That is, where is the electric field strength and is the magnetic field strength. Its presently accepted value is Where Ω is the ohm, the SI unit of electrical resistance. The impedance of free space (that is the wave impedance of a plane wave in free space) is equal to the product of the vacuum permeability μ0 and the speed of light in vacuum c0.
Future tenseIn grammar, a future tense (abbreviated ) is a verb form that generally marks the event described by the verb as not having happened yet, but expected to happen in the future. An example of a future tense form is the French aimera, meaning "will love", derived from the verb aimer ("love"). The "future" expressed by the future tense usually means the future relative to the moment of speaking, although in contexts where relative tense is used it may mean the future relative to some other point in time under consideration.
Electric boatAn electric boat is a powered watercraft driven by electric motors, which are powered by either on-board battery packs, solar panels or generators. While a significant majority of water vessels are powered by diesel engines, with sail power and gasoline engines also popular, boats powered by electricity have been used for over 120 years. Electric boats were very popular from the 1880s until the 1920s, when the internal combustion engine became dominant.
