Biological interactionIn ecology, a biological interaction is the effect that a pair of organisms living together in a community have on each other. They can be either of the same species (intraspecific interactions), or of different species (interspecific interactions). These effects may be short-term, or long-term, both often strongly influence the adaptation and evolution of the species involved. Biological interactions range from mutualism, beneficial to both partners, to competition, harmful to both partners.
Earth orientation parametersIn geodesy and astrometry, earth orientation parameters (EOP) describe irregularities in the rotation of planet Earth. EOP provide the rotational transform from the International Terrestrial Reference System (ITRS) to the International Celestial Reference System (ICRS), or vice versa, as a function of time. Earth's rotational velocity is not constant over time. Any motion of mass in or on Earth causes a slowdown or speedup of the rotation speed, or a change of rotation axis.
Syzygy (astronomy)_Syzygy In astronomy, a syzygy (ˈsɪzədʒi ; ) is a roughly straight-line configuration of three or more celestial bodies in a gravitational system. When Earth is one of the bodies involved, the other objects appear to be close together (or overlapping) in the sky. The word is often used in reference to the Sun, Earth, and either the Moon or a planet, where the latter is in conjunction or opposition. Solar and lunar eclipses occur at times of syzygy, as do transits and occultations.
Vertical and horizontalIn astronomy, geography, and related sciences and contexts, a direction or plane passing by a given point is said to be vertical if it contains the local gravity direction at that point. Conversely, a direction or plane is said to be horizontal (or leveled) if it is perpendicular to the vertical direction. In general, something that is vertical can be drawn from up to down (or down to up), such as the y-axis in the Cartesian coordinate system.
SeicheA seiche (seɪʃ ) is a standing wave in an enclosed or partially enclosed body of water. Seiches and seiche-related phenomena have been observed on lakes, reservoirs, swimming pools, bays, harbors, caves and seas. The key requirement for formation of a seiche is that the body of water be at least partially bounded, allowing the formation of the standing wave. The term was promoted by the Swiss hydrologist François-Alphonse Forel in 1890, who was the first to make scientific observations of the effect in Lake Geneva.
George DarwinSir George Howard Darwin, (9 July 1845 – 7 December 1912) was an English barrister and astronomer, the second son and fifth child of Charles Darwin and Emma Darwin. George H. Darwin was born at Down House, Kent, the fifth child of biologist Charles Darwin and Emma Darwin. From the age of 11 he studied under Charles Pritchard at Clapham Grammar School, and entered St John's College, Cambridge, in 1863, though he soon moved to Trinity College, where his tutor was Edward John Routh.
PytheasPytheas of Massalia (ˈpɪθiəs; Ancient Greek: Πυθέας ὁ Μασσαλιώτης Pythéas ho Massaliōtēs; Latin: Pytheas Massiliensis; born 350 BC, 320–306 BC) was a Greek geographer, explorer and astronomer from the Greek colony of Massalia (modern-day Marseille, France). He made a voyage of exploration to northwestern Europe in about 325 BC, but his account of it, known widely in antiquity, has not survived and is now known only through the writings of others. On this voyage, he circumnavigated and visited a considerable part of modern-day Great Britain and Ireland.
NadirThe nadir (ˈneɪdɪər,_-dər, alsoUKˈnædɪər; naðʕīr) is the direction pointing directly below a particular location; that is, it is one of two vertical directions at a specified location, orthogonal to a horizontal flat surface. The direction opposite of the nadir is the zenith. Since the concept of being below is itself somewhat vague, scientists define the nadir in more rigorous terms. Specifically, in astronomy, geophysics and related sciences (e.g.
SupermoonA supermoon is a full moon or a new moon that nearly coincides with perigee—the closest that the Moon comes to the Earth in its elliptic orbit—resulting in a slightly larger-than-usual apparent size of the Moon as viewed from Earth. The technical name is a perigee syzygy (of the Earth–Moon–Sun system) or a full (or new) Moon around perigee. Because the term supermoon is astrological in origin, it has no precise astronomical definition.
Thames BarrierThe Thames Barrier is a retractable barrier system built to protect the floodplain of most of Greater London from exceptionally high tides and storm surges moving up from the North Sea. It has been operational since 1982. When needed, it is closed (raised) during high tide; at low tide, it can be opened to restore the river's flow towards the sea. Built about east of the Isle of Dogs, its northern bank is in Silvertown in the London Borough of Newham and its southern bank is in the New Charlton area of the Royal Borough of Greenwich.
