Archimedes

Acorn, Arkansas is an unincorporated community and census-designated place (CDP) in Polk County, Arkansas, United States, approximately 6 miles north of Mena. The town is located at the junction of U.

Acorn or Acorn Projects are a series of housing projects in the Acorn Redevelopment Project Area or the Acorn neighborhood of West Oakland. Acorn, also known as "The Corns" or the "Cornfields", neighbors a wide variety of public housing.

<company> A UK computer manufacturer, part of the {Acorn Computer Group} plc. Acorn was founded on 1978-12-05, on a kitchen table in a back room. Their first creation was an electronic slot machine. After the Acorn System 1, 2 and 3, Acorn launched the first commercial microcomputer - the ATOM in March 1980. In April 1981, Acorn won a contract from the BBC to provide the PROTON. In January 1982 Acorn launched the BBC Microcomputer System. At one time, 70% of microcomputers bought for UK schools were BBC Micros. The Acorn Computer Group went public on the Unlisted Securities Market in September 1983. In April 1984 Acorn won the Queen's Award for Technology for the BBC Micro and in September 1985 Olivetti took a controlling interest in Acorn. The Master 128 Series computers were launched in January 1986 and the BBC Domesday System in November 1986. In 1983 Acorn began to design the Acorn RISC Machine (ARM), the first low-cost, high volume RISC processor chip (later renamed the Advanced RISC Machine). In June 1987 they launched the Archimedes range - the first 32-bit RISC based microcomputers - which sold for under UKP 1000. In February 1989 the R140 was launched. This was the first Unix workstation under UKP 4000. In May 1989 the A3000 (the new BBC Microcomputer) was launched. In 1990 Acorn formed Advanced RISC Machines Ltd. (ARM) in partnership with Apple Computer, Inc. and VLSI to develop the ARM processor. Acorn has continued to develop RISC based products. With 1992 revenues of 48.2 million pounds, Acorn Computers was the premier supplier of Information Technology products to UK education and had been the leading provider of 32-bit RISC based personal computers since 1987. Acorn finally folded in the late 1990s. Their operating system, RISC OS was further developed by a consortium of suppliers. Usenet newsgroups: news:comp.sys.acorn, news:comp.sys.acorn.announce, news:comp.sys.acorn.tech, news:comp.binaries.acorn, news:comp.sources.acorn, news:comp.sys.acorn.advocacy, news:comp.sys.acorn.games. Acorn's FTP server (ftp://ftp.acorn.co.uk/). {HENSA software archive (http://micros.hensa.ac.uk/micros/arch.html)}. {Acorn Computers Ltd.phudv/">Richard Birkby's Acorn page (http://csv.warwick.ac.uk/Acorn Computers Ltd.phudv/)}. RiscMan's Acorn page (http://geko.com.au/riscman/). Acorn Computers Ltd.rhh01/Main.html">Acorn On The Net (http://stir.ac.uk/Acorn Computers Ltd.rhh01/Main.html). {"The Jungle" by Simon Truss (http://csc.liv.ac.uk/users/u1smt/u1smt.html)}. [Recent history?] (2000-09-26)

The Archimedes screw, also known as the Archimedean screw, hydrodynamic screw, water screw or Egyptian screw, is one of the earliest hydraulic machines. Using Archimedes screws as water pumps (Archimedes screw pump (ASP) or screw pump) dates back many centuries.

<computer> A family of microcomputers produced by {Acorn Computers}, Cambridge, UK. The Archimedes, launched in June 1987, was the first RISC based personal computer (predating Apple Computer's Power Mac by some seven years). It uses the Advanced RISC Machine (ARM) processor and includes Acorn's multitasking operating system and graphical user interface, RISC OS on ROM, along with an interpreter for Acorn's enhanced BASIC, BASIC V. The Archimedes was designed as the successor to Acorn's sucessful BBC Microcomputer series and includes some backward compatibility and a 6502 emulator. Several utilities are included free on disk (later in ROM) such as a text editor, paint and draw programs. Software emulators are also available for the IBM PC as well as add-on Intel processor cards. There have been several series of Archimedes: A300, A400, A3000, A5000, A4000 and RISC PC. {acorn/">Usenet FAQ (ftp://rtfm.mit.edu/pub/usenet/news.answers/acorn/)}. {acorn/acorn-archives.txt">Archive site list (http://cs.vu.nl/Archimedesgerben/acorn/acorn-archives.txt)}. HENSA archive (ftp://micros.hensa.ac.uk/). {acorn">Stuttgart archive (ftp://ftp.uni-stuttgart.de/pub/systems/acorn)}. See also Crisis Software, Warm Silence Software. (1998-04-03)

Archimedes of Syracuse (; Ancient Greek: Ἀρχιμήδης; Doric Greek: [ar.kʰi.mɛː.dɛ̂ːs]; c. 287 – c. 212 BC) was a Greek mathematician, physicist, engineer, astronomer, and inventor from the ancient city of Syracuse in Sicily. Although few details of his life are known, he is regarded as one of the leading scientists in classical antiquity. Considered to be the greatest mathematician of ancient history, and one of the greatest of all time, Archimedes anticipated modern calculus and analysis by applying the concept of the infinitely small and the method of exhaustion to derive and rigorously prove a range of geometrical theorems, including: the area of a circle; the surface area and volume of a sphere; area of an ellipse; the area under a parabola; the volume of a segment of a paraboloid of revolution; the volume of a segment of a hyperboloid of revolution; and the area of a spiral.

Archimedes' other mathematical achievements include deriving an approximation of pi; defining and investigating the spiral that now bears his name; and devising a system using exponentiation for expressing very large numbers. He was also one of the first to apply mathematics to physical phenomena, founding hydrostatics and statics. Archimedes' achievements in this area include a proof of the principle of the lever, the widespread use of the concept of center of gravity, and the enunciation of the law of buoyancy. He is also credited with designing innovative machines, such as his screw pump, compound pulleys, and defensive war machines to protect his native Syracuse from invasion.

Archimedes died during the siege of Syracuse, when he was killed by a Roman soldier despite orders that he should not be harmed. Cicero describes visiting Archimedes' tomb, which was surmounted by a sphere and a cylinder, which Archimedes had requested be placed on his tomb to represent his mathematical discoveries.

Unlike his inventions, Archimedes' mathematical writings were little known in antiquity. Mathematicians from Alexandria read and quoted him, but the first comprehensive compilation was not made until c. 530 AD by Isidore of Miletus in Byzantine Constantinople, while commentaries on the works of Archimedes by Eutocius in the 6th century opened them to wider readership for the first time. The relatively few copies of Archimedes' written work that survived through the Middle Ages were an influential source of ideas for scientists during the Renaissance and again in the 17th century, while the discovery in 1906 of previously lost works by Archimedes in the Archimedes Palimpsest has provided new insights into how he obtained mathematical results.

Archimedes' principle states that the upward buoyant force that is exerted on a body immersed in a fluid, whether fully or partially, is equal to the weight of the fluid that the body displaces. Archimedes' principle is a law of physics fundamental to fluid mechanics.