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The V-2 No. 13 was a modified V-2 rocket that became the first object to take a photograph of the Earth from outer space. Launched on 24 October 1946, at the White Sands Missile Range in White Sands, New Mexico, the rocket reached a maximum altitude of 65 mi (105 km).

The Corpus Clock, also known as the Grasshopper clock, is a large sculptural clock at street level on the outside of the Taylor Library at Corpus Christi College, Cambridge University, in the United Kingdom, at the junction of Bene't Street and Trumpington Street, looking out over King's Parade. It was conceived and funded by John C. Taylor, an old member of the college.

It was officially unveiled to the public on 19 September 2008 by Cambridge physicist Stephen Hawking. The clock was named one of Time's Best Inventions of 2008.

The AARD code was a segment of code in a beta release of Microsoft Windows 3.1 that would determine whether Windows was running on MS-DOS or PC DOS, rather than a competing workalike such as DR-DOS, and would result in a cryptic error message in the latter case. This XOR-encrypted, self-modifying, and deliberately obfuscated machine code used a variety of undocumented DOS structures and functions to perform its work, and appeared in the installer, WIN.COM, and several other executables in the OS.

The AARD code was originally discovered by Geoff Chappell on 17 April 1992 and then further analyzed and documented in a joint effort with Andrew Schulman. The name was derived from Microsoft programmer Aaron R. Reynolds (1955–2008), who used "AARD" to sign his work; "AARD" was found in the machine code of the installer. Microsoft disabled the AARD code for the final release of Windows 3.1, but did not remove it, so that it could have become reactivated later by the change of a single byte in an installed system, thereby constituting a "smoking gun".

DR-DOS publisher Digital Research released a patch named "business update" in 1992 to enable the AARD tests to pass on its operating system.

The rationale for the AARD code came to light when internal memos were released during the United States v. Microsoft Corp. antitrust case in 1999. Internal memos released by Microsoft revealed that the specific focus of these tests was DR-DOS. At one point, Microsoft CEO Bill Gates sent a memo to a number of employees, reading "You never sent me a response on the question of what things an app would do that would make it run with MS-DOS and not run with DR-DOS. Is there [sic] feature they have that might get in our way?" Microsoft Senior Vice President Brad Silverberg later sent another memo, stating: "What the [user] is supposed to do is feel uncomfortable, and when he has bugs, suspect that the problem is DR-DOS and then go out to buy MS-DOS."

Following the purchase of DR-DOS by Novell and its renaming to "Novell DOS", Microsoft Co-President Jim Allchin stated in a memo, "If you're going to kill someone there isn't much reason to get all worked up about it and angry. Any discussions beforehand are a waste of time. We need to smile at Novell while we pull the trigger."

What had been DR-DOS changed hands again. The new owner, Caldera, Inc., began a lawsuit against Microsoft over the AARD code, Caldera v. Microsoft, which was later settled. It was believed that the settlement ran in the order of $150 million, but was revealed in November 2009 with the release of the Settlement Agreement to be $280 million.

In computer science, a skip list is a data structure that allows ${\displaystyle {\mathcal {O}}(\log n)}$ search complexity as well as ${\displaystyle {\mathcal {O}}(\log n)}$ insertion complexity within an ordered sequence of ${\displaystyle n}$ elements. Thus it can get the best features of an array (for searching) while maintaining a linked list-like structure that allows insertion, which is not possible in an array. Fast search is made possible by maintaining a linked hierarchy of subsequences, with each successive subsequence skipping over fewer elements than the previous one (see the picture below on the right). Searching starts in the sparsest subsequence until two consecutive elements have been found, one smaller and one larger than or equal to the element searched for. Via the linked hierarchy, these two elements link to elements of the next sparsest subsequence, where searching is continued until finally we are searching in the full sequence. The elements that are skipped over may be chosen probabilistically or deterministically, with the former being more common.

A Swedish torch (also Swedish candle, Finn candle, Swedish fire, Siberian tree torch or Russian tree torch; German: Schwedenfeuer) is a source of heat and light from a vertically set tree trunk, incised and burning in the middle. It became known in Europe during the 1600s and is now used by forest workers, and for leisure activities (especially in southern Germany). Due to its flat surface and good embers, it can also be used for cooking. Compared to a campfire, it is more compact, and therefore several small heat sources can be distributed over an area.

Oral tradition attributes the development of the torch to the Swedish military during the Thirty Years' War; using a saw or hacksaw or an axe, the Swedes are said to have made burning and glowing logs to warm their soldiers. This method of providing heat meant that their troops did not have to carry their own firewood with them but were able to get supplies on site, as the freshly cut, green wood can burn due to the chimney effect.

The Peter principle is a concept in management developed by Laurence J. Peter, which observes that people in a hierarchy tend to rise to their "level of incompetence": employees are promoted based on their success in previous jobs until they reach a level at which they are no longer competent, as skills in one job do not necessarily translate to another. The concept was elucidated in the book The Peter Principle (William Morrow and Company, 1969) by Dr Peter and Raymond Hull.

Peter and Hull intended the book to be satire, but it became popular as it was seen to make a serious point about the shortcomings of how people are promoted within hierarchical organizations. Hull wrote the text, based on Peter's research. The Peter principle has been the subject of much subsequent commentary and research.

Säkkijärven polkka ("the Säkkijärvi polka"), also called the "Karelian-Finnish Polka," is a well-known folk tune from Finland, very popular with Finnish accordionists. It was especially popularized by Viljo "Vili" Vesterinen (1907–1961). The tune was first recorded in Säkkijärvi (now Kondratyevo in the Leningrad Oblast, Russia), and the lyrics sometimes sung with the tune state that while Säkkijärvi itself might have been lost (ceded to the Soviet Union in 1940), the Finns at least still had the polka.

xv6 is a modern reimplementation of Sixth Edition Unix in ANSI C for multiprocessor x86 and RISC-V systems. It is used for pedagogical purposes in MIT's Operating Systems Engineering (6.828) course as well as Georgia Tech's (CS 3210) Design of Operating Systems Course, IIIT Hyderabad, IIIT Delhi and as well as many other institutions.

Nsibidi (also known as nsibiri, nchibiddi or nchibiddy) is a system of symbols indigenous to what is now southeastern Nigeria that are apparently pictograms, though there have been suggestions that some are logograms or syllabograms. The symbols are at least over 4,000 years old. Early forms appeared on excavated pottery as well as what are most likely ceramic stools and headrests from the Calabar region with a range of dates from at least 400 AD (and possibly earlier), to 1400 AD. Nsibidi was used to decorate the skin, calabashes, sculptures, and clothing items, as well as to communicate messages on houses.“ There are thousands of nsibidi symbols, of which over 500 have been recorded. They were once taught in a school to children. Many of the signs deal with love affairs; those that deal with warfare and the sacred are kept secret. Nsibidi is used on wall designs, calabashes, metals (such as bronze), leaves, swords, and tattoos. It is primarily used by the Ekpe leopard society (also known as Ngbe or Egbo), a secret society that is found across Cross River State among the Ekoi, Efik, Igbo people, and other nearby peoples.

Outside knowledge of nsibidi came in 1904 when T. D. Maxwell noticed the symbols. Before the British colonisation of the area, nsibidi was divided into a sacred version and a public, more decorative version which could be used by women. Aspects of colonisation such as Western education and Christian doctrine drastically reduced the number of nsibidi-literate people, leaving the secret society members as some of the last literate in the symbols. Nsibidi was and is still a means of transmitting Ekpe symbolism. Nsibidi was transported to Cuba and Haiti via the Atlantic slave trade, where it developed into the anaforuana and veve symbols.

Balloonomania was a strong public interest or fad in balloons that originated in France in the late 18th century and continued into the 19th century, during the advent of balloon flights. The interest began with the first flights of the Montgolfier brothers in 1783 (in a balloon inflated with hot air). Soon afterwards Jacques Alexandre César Charles flew another type of balloon (inflated with hydrogen) and both types of balloon were in use from then on. The fad quickly spread in France and across the channel in England.