The didgeridoo (/ˌdɪdʒəriːˈduː/) (also known as a didjeridu) is a wind instrument developed by Indigenous Australians of northern Australia potentially within the last 1,500 years and still in widespread use today both in Australia and around the world. It is sometimes described as a natural wooden trumpet or "drone pipe". Musicologists classify it as a brass aerophone.
There are no reliable sources stating the didgeridoo's exact age. Archaeological studies of rock art in Northern Australia suggest that the people of the Kakadu region of the Northern Territory have been using the didgeridoo for less than 1,000 years, based on the dating of paintings on cave walls and shelters from this period. A clear rock painting in Ginga Wardelirrhmeng, on the northern edge of the Arnhem Land plateau, from the freshwater period (that was begun 1500 years ago) shows a didgeridoo player and two songmen participating in an Ubarr Ceremony.
A modern didgeridoo is usually cylindrical or conical, and can measure anywhere from 1 to 3 m (3 to 10 ft) long. Most are around 1.2 m (4 ft) long. Generally, the longer the instrument, the lower its pitch or key. However, flared instruments play a higher pitch than unflared instruments of the same length.
Digeridoo is an EP by the musician Richard D. James under the alias Aphex Twin. All tracks were re-released on the Classics compilation. "Isopropophlex" and "Analogue Bubblebath" are reprints of tracks from Analogue Bubblebath 1. "Digeridoo" was previously released as "Aboriginal Mix" on the Analogue Bubblebath 2 EP. "Flaphead" and "Phloam" are the only new tracks on the EP.
"Digeridoo" doesn't actually feature a didgeridoo, however, "eschewing samples, James labored for three days to concoct an electronic simulacrum of the primordial drone" (Simon Reynolds, Energy Flash). "Flaphead" on the CD version of the EP is extended by about 20 seconds compared to the vinyl version (here titled "Flap Head").
All tracks by Richard D. James.
Logic (from the Ancient Greek: λογική, logike) is the branch of philosophy concerned with the use and study of valid reasoning. The study of logic also features prominently in mathematics and computer science.
Logic was studied in several ancient civilizations, including Greece, India, and China. In the West, logic was established as a formal discipline by Aristotle, who gave it a fundamental place in philosophy. The study of logic was part of the classical trivium, which also included grammar and rhetoric. Logic was further extended by Al-Farabi who categorized it into two separate groups (idea and proof). Later, Avicenna revived the study of logic and developed relationship between temporalis and the implication. In the East, logic was developed by Hindus, Buddhists and Jains.
Logic is often divided into three parts: inductive reasoning, abductive reasoning, and deductive reasoning.
The concept of logical form is central to logic. The validity of an argument is determined by its logical form, not by its content. Traditional Aristotelian syllogistic logic and modern symbolic logic are examples of formal logic.
In set theory, Ω-logic is an infinitary logic and deductive system proposed by W. Hugh Woodin (1999) as part of an attempt to generalize the theory of determinacy of pointclasses to cover the structure . Just as the axiom of projective determinacy yields a canonical theory of
, he sought to find axioms that would give a canonical theory for the larger structure. The theory he developed involves a controversial argument that the continuum hypothesis is false.
Woodin's Ω-conjecture asserts that if there is a proper class of Woodin cardinals (for technical reasons, most results in the theory are most easily stated under this assumption), then Ω-logic satisfies an analogue of the completeness theorem. From this conjecture, it can be shown that, if there is any single axiom which is comprehensive over (in Ω-logic), it must imply that the continuum is not
. Woodin also isolated a specific axiom, a variation of Martin's maximum, which states that any Ω-consistent
(over
) sentence is true; this axiom implies that the continuum is
.
Logic may refer to:
Logic may also refer to: