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🔗 Military history 🔗 Military history/Military science, technology, and theory 🔗 Military history/Weaponry

Improvised firearms (sometimes called zip guns or pipe guns) are firearms manufactured other than by a firearms manufacturer or a gunsmith, and are typically constructed by adapting existing materials to the purpose. They range in quality from crude weapons that are as much a danger to the user as the target to high-quality arms produced by cottage industries using salvaged and repurposed materials.

Improvised firearms are commonly used as tools by criminals and insurgents and are often associated with such groups; other uses include self-defense in lawless areas and hunting game in poor rural areas.

🔗 China

The Lion-Eating Poet in the Stone Den (Chinese: 施氏食獅史; pinyin: Shī-shì shí shī shǐ) is a short narrative poem written in Classical Chinese that is composed of 92 characters in which every word is pronounced shi ([ʂɻ̩]) when read in present-day Standard Mandarin, with only the tones differing.

The poem was written in the 1930s by the Chinese linguist Yuen Ren Chao as a linguistic demonstration. The poem is coherent and grammatical in Classical Chinese, but the loss of older sound combinations in Chinese over the centuries has greatly increased the number of Chinese homophones, making Classical Chinese difficult to understand in oral speech. In Mandarin, the poem is incomprehensible when read aloud, since only four syllables cover the entire 92 words of the poem. The poem is less incomprehensible—but still not very intelligible—when read in other varieties of Chinese such as Cantonese, in which it has 22 different syllables, or Hokkien Chinese, in which it has 15 different syllables.

The poem is an example of a one-syllable article, a form of constrained writing possible in tonal languages such as Mandarin Chinese, where tonal contours expand the range of meaning for a single syllable.

🔗 Computing 🔗 Computing/Networking

In computer networking, IP over Avian Carriers (IPoAC) is a proposal to carry Internet Protocol (IP) traffic by birds such as homing pigeons. IP over Avian Carriers was initially described in RFC 1149, a Request for Comments (RFC) issued by the Internet Engineering Task Force (IETF), written by D. Waitzman, and released on April 1, 1990. It is one of several April Fools' Day Request for Comments.

Waitzman described an improvement of his protocol in RFC 2549, IP over Avian Carriers with Quality of Service (1 April 1999). Later, in RFC 6214—released on 1 April 2011, and 13 years after the introduction of IPv6—Brian Carpenter and Robert Hinden published Adaptation of RFC 1149 for IPv6.

IPoAC has been successfully implemented, but for only nine packets of data, with a packet loss ratio of 55% (due to operator error), and a response time ranging from 3,000 seconds (≈54 minutes) to over 6,000 seconds (≈1.77 hours). Thus, this technology suffers from poor latency. Nevertheless, for large transfers, avian carriers are capable of high average throughput when carrying flash memory devices, effectively implementing a sneakernet. During the last 20 years, the information density of storage media and thus the bandwidth of an avian carrier has increased 3 times as fast as the bandwidth of the Internet. IPoAC may achieve bandwidth peaks of orders of magnitude more than the Internet when used with multiple avian carriers in rural areas. For example: If 16 homing pigeons are given eight 512 GB SD cards each, and take an hour to reach their destination, the throughput of the transfer would be 145.6 Gbit/s, excluding transfer to and from the SD cards.

🔗 Computing

Reservoir computing is a framework for computation that may be viewed as an extension of neural networks. Typically an input signal is fed into a fixed (random) dynamical system called a reservoir and the dynamics of the reservoir map the input to a higher dimension. Then a simple readout mechanism is trained to read the state of the reservoir and map it to the desired output. The main benefit is that training is performed only at the readout stage and the reservoir is fixed. Liquid-state machines and echo state networks are two major types of reservoir computing. One important feature of this system is that it can use the computational power of naturally available systems which is different from the neural networks and it reduces the computational cost.

🔗 London 🔗 British Museum 🔗 Classical Greece and Rome 🔗 History of Science 🔗 Archaeology 🔗 Visual arts 🔗 Glass

The Lycurgus Cup is a 4th-century Roman glass cage cup made of a dichroic glass, which shows a different colour depending on whether or not light is passing through it: red when lit from behind and green when lit from in front. It is the only complete Roman glass object made from this type of glass, and the one exhibiting the most impressive change in colour; it has been described as "the most spectacular glass of the period, fittingly decorated, which we know to have existed".

The cup is also a very rare example of a complete Roman cage-cup, or diatretum, where the glass has been painstakingly cut and ground back to leave only a decorative "cage" at the original surface-level. Many parts of the cage have been completely undercut. Most cage-cups have a cage with a geometric abstract design, but here there is a composition with figures, showing the mythical King Lycurgus, who (depending on the version) tried to kill Ambrosia, a follower of the god Dionysus (Bacchus to the Romans). She was transformed into a vine that twined around the enraged king and restrained him, eventually killing him. Dionysus and two followers are shown taunting the king. The cup is the "only well-preserved figural example" of a cage cup.

The dichroic effect is achieved by making the glass with tiny proportions of nanoparticles of gold and silver dispersed in colloidal form throughout the glass material. The process used remains unclear, and it is likely that it was not well understood or controlled by the makers, and was probably discovered by accidental "contamination" with minutely ground gold and silver dust. The glass-makers may not even have known that gold was involved, as the quantities involved are so tiny; they may have come from a small proportion of gold in any silver added (most Roman silver contains small proportions of gold), or from traces of gold or gold leaf left by accident in the workshop, as residue on tools, or from other work. The very few other surviving fragments of Roman dichroic glass vary considerably in their two colours.

🔗 Environment 🔗 Automobiles 🔗 Croatia 🔗 Environment/Green vehicle

The Rimac Concept One, sometimes stylized as Concept_One, is a two-seat high-performance electric car designed and manufactured in Croatia by Rimac Automobili. With a total output of 913 kW (1,241 PS; 1,224 hp) and an acceleration time from 0–62 mph (0–100 km/h) in 2.5 seconds.

The Rimac Concept One was claimed to be the world's fastest accelerating electric vehicle in 2013.

To advertise both Rimac Automobili and Formula E, the Concept One was used as the official zero-emission race director's car during the first season of Formula E championship in 2014.

🔗 Computing 🔗 Computing/Computer hardware 🔗 Computing/Software 🔗 Java

Jazelle DBX (direct bytecode execution) is an extension that allows some ARM processors to execute Java bytecode in hardware as a third execution state alongside the existing ARM and Thumb modes. Jazelle functionality was specified in the ARMv5TEJ architecture and the first processor with Jazelle technology was the ARM926EJ-S. Jazelle is denoted by a "J" appended to the CPU name, except for post-v5 cores where it is required (albeit only in trivial form) for architecture conformance.

Jazelle RCT (Runtime Compilation Target) is a different technology based on ThumbEE mode; it supports ahead-of-time (AOT) and just-in-time (JIT) compilation with Java and other execution environments.

The most prominent use of Jazelle DBX is by manufacturers of mobile phones to increase the execution speed of Java ME games and applications. A Jazelle-aware Java virtual machine (JVM) will attempt to run Java bytecode in hardware, while returning to the software for more complicated, or lesser-used bytecode operations. ARM claims that approximately 95% of bytecode in typical program usage ends up being directly processed in the hardware.

The published specifications are very incomplete, being only sufficient for writing operating system code that can support a JVM that uses Jazelle. The declared intent is that only the JVM software needs to (or is allowed to) depend on the hardware interface details. This tight binding facilitates the hardware and JVM evolving together without affecting other software. In effect, this gives ARM Holdings considerable control over which JVMs are able to exploit Jazelle. It also prevents open source JVMs from using Jazelle. These issues do not apply to the ARMv7 ThumbEE environment, the nominal successor to Jazelle DBX.

🔗 Astronomy

The Great Debate, also called the Shapley–Curtis Debate, was held on 26 April 1920 at the Smithsonian Museum of Natural History, between the astronomers Harlow Shapley and Heber Curtis. It concerned the nature of so-called spiral nebulae and the size of the universe; Shapley believed that distant nebulae were relatively small and lay within the outskirts of Earth's home galaxy, while Curtis held that they were in fact independent galaxies, implying that they were exceedingly large and distant.

The two scientists first presented independent technical papers about "The Scale of the Universe" during the day and then took part in a joint discussion that evening. Much of the lore of the Great Debate grew out of two papers published by Shapley and by Curtis in the May 1921 issue of the Bulletin of the National Research Council. The published papers each included counter arguments to the position advocated by the other scientist at the 1920 meeting.

In the aftermath of the public debate, scientists have been able to verify individual pieces of evidence from both astronomers, but on the main point of the existence of other galaxies, Curtis has been proven correct.

🔗 Biography 🔗 Computing

Francesco Vianello (30 August 1952 – 3 May 2009), better known by his nickname Fravia (sometimes +Fravia or Fravia+), was a software reverse engineer, and hacker, known for his web archive of reverse engineering techniques and papers. He is also known for his work on steganography. He had taught on subjects such as data mining, anonymity, stalking, klebing, advertisement reversing and ad-busting.

Fravia spoke six languages (including Latin) and had a degree in the history of the early Middle Ages. He was an expert in linguistics-related informatics. For five years he made available a large quantity of material related to reverse engineering through his website, which also hosted the advice of reverse engineering experts, known as reversers, who provided tutorials and essays on how to hack software code as well as advice related to the assembly and disassembly of applications, and software protection reversing.

Fravia was a professor at the High Cracking University (+HCU), founded by Old Red Cracker (+ORC), a legendary figure in reverse engineering, to conduct research into Reverse Code Engineering. The addition of the "+" sign in front of the nickname of a reverser signified membership in the +HCU. His website was known as "+Fravia's Pages of Reverse Engineering" and he used it to challenge programmers as well as the wider society to "reverse engineer" the "brainwashing of a corrupt and rampant materialism". In its heyday, his website was receiving millions of visitors per year and its influence was "widespread".

His web presence dates from 1995 when he first got involved in research related to reverse code engineering (RCE). In 2000 he changed his focus and concentrated on advanced internet search methods and the reverse engineering of search engine code.

His websites "www.fravia.com" and "www.searchlores.org" contained a large amount of specialised information related to data mining. His website "www.searchlores.org" has been called a "very useful instrument for searching the web", and his "www.fravia.com" site has been described as "required reading for any spy wanting to go beyond simple Google searches."

🔗 Classical Greece and Rome 🔗 Greece 🔗 Theatre

In the theatre of ancient Greece, the eirôn (Ancient Greek: εἴρων) was one of three stock characters in comedy. The eirôn usually succeeded in bringing down his braggart opponent (the alazôn) by understating his own abilities.