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The IBM 7030, also known as Stretch, was IBM's first transistorized supercomputer. It was the fastest computer in the world from 1961 until the first CDC 6600 became operational in 1964.

Originally designed to meet a requirement formulated by Edward Teller at Lawrence Livermore National Laboratory, the first example was delivered to Los Alamos National Laboratory in 1961, and a second customized version, the IBM 7950 Harvest, to the National Security Agency in 1962. The Stretch at the Atomic Weapons Research Establishment at Aldermaston, England was heavily used by researchers there and at AERE Harwell, but only after the development of the S2 Fortran Compiler which was the first to add dynamic arrays, and which was later ported to the Ferranti Atlas of Atlas Computer Laboratory at Chilton.

Since the 7030 was much slower than expected and failed to meet its aggressive performance estimates, IBM was forced to drop its price from $13.5 million to only $7.78 million and withdrew the 7030 from sales to customers beyond those having already negotiated contracts. PC World magazine named Stretch one of the biggest project management failures in IT history.

Within IBM, being eclipsed by the smaller Control Data Corporation seemed hard to accept. The project lead, Stephen W. Dunwell, was initially blackballed for his role in the "failure", but as the success of the IBM System/360 became obvious, he was given an official apology and, in 1966 was made an IBM Fellow.

In spite of Stretch's failure to meet its own performance goals, it served as the basis for many of the design features of the successful IBM System/360, which shipped in 1964.

Rekursiv was a computer processor designed by David M. Harland in the mid-1980s for Linn Smart Computing in Glasgow, Scotland. It was one of the few computer architectures intended to implement object-oriented concepts directly in hardware, a form of high-level language computer architecture. The Rekursiv operated directly on objects rather than bits, nibbles, bytes and words. Virtual memory was used as a persistent object store and unusually, the processor instruction set supported recursion (hence the name).

The project originated in an initiative within the hi-fi manufacturer Linn Products to improve its manufacturing automation systems, which at the time ran on a DEC VAX minicomputer. This resulted in the design of Lingo, an object-oriented programming language derived from Smalltalk and ALGOL. Due to the poor performance of Lingo on the VAX, a subsidiary company, Linn Smart Computing Ltd., was formed to develop a new processor to efficiently run Lingo.

The Rekursiv processor consisted of four gate-array chips named Numerik (32-bit ALU), Logik (instruction sequencer), Objekt (object-oriented memory management unit) and Klock (processor clock and support logic). A small number of prototype VMEbus boards, called Hades, comprising these four chips plus 80 MB of RAM were produced. These were intended for installation in a host system such as a Sun-3 workstation.

Although the Rekursiv was never fully developed and was not a commercial success, several Hades boards were used in academic research projects in the UK. The last known copy of a Rekursiv computer ended up at the bottom of the Forth and Clyde canal in Glasgow.

Pourquoi Pas? IV (English: Why Not? IV) was the fourth ship built for Jean-Baptiste Charcot, which completed the second Charcot expedition of the Antarctic regions from 1908 to 1910. Charcot died aboard when the ship was wrecked on 16 September 1936, off the coast of Iceland. Of the forty men on board, only one survived.

Evolution of metal ions in biological systems refers to the incorporation of metallic ions into living organisms and how it has changed over time. Metal ions have been associated with biological systems for billions of years, but only in the last century have scientists began to truly appreciate the scale of their influence. Major (iron, manganese, magnesium and zinc) and minor (copper, cobalt, nickel, molybdenum, tungsten) metal ions have become aligned with living organisms through the interplay of biogeochemical weathering and metabolic pathways involving the products of that weathering. The associated complexes have evolved over time.

Natural development of chemicals and elements challenged organisms to adapt or die. Current organisms require redox reactions to induce metabolism and other life processes. Metals have a tendency to lose electrons and are important for redox reactions.

Metals have become so central to cellular function that the collection of metal-binding proteins (referred to as the metallomes) accounts for over 30% of all proteins in the cell. Metals are known to be involved in over 40% of enzymatic reactions, and metal-binding proteins carry out at least one step in almost all biological pathways.

Metals are also toxic so a balance must be acquired to regulate where the metals are in an organism as well as in what quantities. Many organisms have flexible systems in which they can exchange one metal for another if one is scarce. Metals in this discussion are naturally occurring elements that have a tendency to undergo oxidation. Vanadium, molybdenum, cobalt, copper, chromium, iron, manganese, nickel, and zinc are deemed essential because without them biological function is impaired.

The TP-82 (Russian: ТП-82) was a triple-barrelled Soviet pistol that was carried by cosmonauts on space missions.

It was intended as a survival aid to be used after landings and before recovery in the Siberian wilderness. The TP-82 was the result of cosmonaut Alexei Leonov's concerns after being stranded in the Siberian wilderness when his Voskhod capsule malfunctioned. He feared that the 9mm pistol that was provided in the survival kit would be ineffective against the Siberian wildlife, namely bears and wolves.

The upper two shotgun barrels used 12.5×70 mm ammunition (40 gauge), and the lower rifled barrel used 5.45×39mm ammunition developed for the AK-74 assault rifle. The TP-82 has a large lever on the left side of the receiver that opens the action and a small grip-safety under the trigger-guard that resembles a secondary trigger.

The pistol could be used for hunting, to defend against predators and for visible and audible distress signals. The detachable buttstock was also a machete that came with a canvas sheath. TP-82s were carried regularly on Soviet and Russian space missions from 1986 to 2007. They were part of the Soyuz Portable Emergency-Survival Kit (Носимый аварийный запас, Nosimyi Avariynyi Zapas, NAZ). In 2007, the media reported that the remaining ammunition for the TP-82 had become unusable and that a regular semi-automatic pistol would be used on future missions.

This list ranks the countries of the world by the number of mobile phone numbers in use. Note that it is not the number of phone devices that are being given here, but the number of phone numbers in a country. In some countries, one person might have two mobile phones. Also, some mobile phone numbers may be used by machines as a modem (examples: intrusion detection systems, home automation, leak detection).

Mach () is a kernel developed at Carnegie Mellon University to support operating system research, primarily distributed and parallel computing. Mach is often mentioned as one of the earliest examples of a microkernel. However, not all versions of Mach are microkernels. Mach's derivatives are the basis of the operating system kernel in GNU Hurd and of Apple's XNU kernel used in macOS, iOS, iPadOS, tvOS, and watchOS.

The project at Carnegie Mellon ran from 1985 to 1994, ending with Mach 3.0, which is a true microkernel. Mach was developed as a replacement for the kernel in the BSD version of Unix, so no new operating system would have to be designed around it. Mach and its derivatives exist within a number of commercial operating systems. These include all using the XNU operating system kernel which incorporates an earlier non-microkernel Mach as a major component. The Mach virtual memory management system was also adopted in 4.4BSD by the BSD developers at CSRG, and appears in modern BSD-derived Unix systems, such as FreeBSD.

Mach is the logical successor to Carnegie Mellon's Accent kernel. The lead developer on the Mach project, Richard Rashid, has been working at Microsoft since 1991 in various top-level positions revolving around the Microsoft Research division. Another of the original Mach developers, Avie Tevanian, was formerly head of software at NeXT, then Chief Software Technology Officer at Apple Inc. until March 2006.

A sun dog (or sundog) or mock sun, formally called a parhelion (plural parhelia) in meteorology, is an atmospheric optical phenomenon that consists of a bright spot to one or both sides of the Sun. Two sun dogs often flank the Sun within a 22° halo.

The sun dog is a member of the family of halos, caused by the refraction of sunlight by ice crystals in the atmosphere. Sun dogs typically appear as a pair of subtly colored patches of light, around 22° to the left and right of the Sun, and at the same altitude above the horizon as the Sun. They can be seen anywhere in the world during any season, but are not always obvious or bright. Sun dogs are best seen and most conspicuous when the Sun is near the horizon.

A kleroterion (Ancient Greek: κληρωτήριον) was a randomization device used by the Athenian polis during the period of democracy to select citizens to the boule, to most state offices, to the nomothetai, and to court juries.

The kleroterion was a slab of stone incised with rows of slots and with an attached tube. Citizens' tokens—pinakia—were placed randomly in the slots so that every member of each of the tribes of Athens had their tokens placed in the same column. There was a pipe attached to the stone which could then be fed dice that were coloured differently (assumed to be black and white) and could be released individually by a mechanism that has not survived to posterity (but is speculated to be by two nails; one used to block the open end and another to separate the next die to fall from the rest of the dice above it). When a die was released, a complete row of tokens (so, one citizen from each of the tribes of Athens) was either selected if the die was coloured one colour, or discarded if it was the alternate colour. This process continued until the requisite number of citizens was selected.

Gödel's completeness theorem is a fundamental theorem in mathematical logic that establishes a correspondence between semantic truth and syntactic provability in first-order logic. It makes a close link between model theory that deals with what is true in different models, and proof theory that studies what can be formally proven in particular formal systems.

It was first proved by Kurt Gödel in 1929. It was then simplified in 1947, when Leon Henkin observed in his Ph.D. thesis that the hard part of the proof can be presented as the Model Existence Theorem (published in 1949). Henkin's proof was simplified by Gisbert Hasenjaeger in 1953.