Portal:Science
Science is a systematic discipline that builds and organises knowledge in the form of testable hypotheses and predictions about the universe. Modern science is typically divided into two or three major branches: the natural sciences (e.g., physics, chemistry, and biology), which study the physical world; and the behavioural sciences (e.g., economics, psychology, and sociology), which study individuals and societies. The formal sciences (e.g., logic, mathematics, and theoretical computer science), which study formal systems governed by axioms and rules, are sometimes described as being sciences as well; however, they are often regarded as a separate field because they rely on deductive reasoning instead of the scientific method or empirical evidence as their main methodology. Applied sciences are disciplines that use scientific knowledge for practical purposes, such as engineering and medicine. (Full article...)
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The pigeon guillemot (Cepphus columba) (/ˈɡɪlɪmɒt/) is a species of bird in the auk family, Alcidae. One of three species in the genus Cepphus, it is most closely related to the spectacled guillemot. There are five subspecies of the pigeon guillemot; all subspecies, when in breeding plumage, are dark brown with a black iridescent sheen and a distinctive wing patch broken by a brown-black wedge. Its non-breeding plumage has mottled grey and black upperparts and white underparts. The long bill is black, as are the claws. The legs, feet, and inside of the mouth are red. It closely resembles the black guillemot, which is slightly smaller and lacks the dark wing wedge present in the pigeon guillemot. (Full article...)
The giraffe is a large African hoofed mammal belonging to the genus Giraffa. It is the tallest living terrestrial animal and the largest ruminant on Earth. Traditionally, giraffes have been thought of as one species, Giraffa camelopardalis, with nine subspecies. Most recently, researchers proposed dividing them into four extant species due to new research into their mitochondrial and nuclear DNA, and individual species can be distinguished by their fur coat patterns. Seven other extinct species of Giraffa are known from the fossil record. (Full article...)
Ceres (minor-planet designation: 1 Ceres) is a dwarf planet in the middle main asteroid belt between the orbits of Mars and Jupiter. It was the first known asteroid, discovered on 1 January 1801 by Giuseppe Piazzi at Palermo Astronomical Observatory in Sicily, and announced as a new planet. Ceres was later classified as an asteroid and then a dwarf planet, the only one not beyond Neptune's orbit. (Full article...)
Between 1956 and 1963, the United Kingdom conducted seven nuclear tests at the Maralinga site in South Australia, part of the Woomera Prohibited Area about 800 kilometres (500 mi) north west of Adelaide. Two major test series were conducted: Operation Buffalo in 1956 and Operation Antler the following year. Approximate weapon yields ranged from 1 to 27 kilotons of TNT (4 to 100 TJ). The Maralinga site was also used for minor trials, tests of nuclear weapons components not involving nuclear explosions. The tests codenamed "Kittens" were trials of neutron initiators; "Rats" and "Tims" measured how the fissile core of a nuclear weapon was compressed by the high explosive shock wave; and "Vixens" investigated the effects of fire or non-nuclear explosions on atomic weapons. The minor trials, numbering around 550, ultimately generated far more contamination than the major tests. (Full article...)
The cattle egret (formerly genus Bubulcus) is a cosmopolitan clade of heron (family Ardeidae) in the genus Ardea found in the tropics, subtropics, and warm-temperate zones. According to the IOC bird list, it contains two species, the western cattle egret and the eastern cattle egret, although some authorities regard them as a single species. Despite the similarities in plumage to the egrets of the genus Egretta, it actually belongs to the genus Ardea. Originally native to parts of Asia, Africa, and Europe, it has undergone a rapid expansion in its distribution and successfully colonised much of the rest of the world in the last century. (Full article...)