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🔗 History 🔗 Ancient Near East 🔗 Business 🔗 Iraq

The complaint tablet to Ea-nasir is a clay tablet from ancient Babylon written c. 1750 BC. It is a complaint to a merchant named Ea-Nasir from a customer named Nanni. Written in cuneiform, it is considered to be the oldest known written complaint. It is currently kept in the British Museum.

Ea-Nasir travelled to the Persian Gulf to buy copper and return to sell it in Mesopotamia. On one particular occasion, he had agreed to sell copper ingots to Nanni. Nanni sent his servant with the money to complete the transaction. The copper was sub-standard and not accepted. In response, Nanni created the cuneiform letter for delivery to Ea-nasir. Inscribed on it is a complaint to Ea-nasir about a copper ore delivery of the incorrect grade, and issues with another delivery. He also complained that his servant (who handled the transaction) had been treated rudely. He stated that, at the time of writing, he had not accepted the copper but had paid the money.

The tablet is 11.6 centimetres (4.6 in) high, 5 centimetres (2.0 in) wide, 2.6 centimetres (1.0 in) thick, and slightly damaged. Translated from Akkadian, it reads:

Tell Ea-nasir: Nanni sends the following message:

When you came, you said to me as follows : "I will give Gimil-Sin (when he comes) fine quality copper ingots." You left then but you did not do what you promised me. You put ingots which were not good before my messenger (Sit-Sin) and said: "If you want to take them, take them; if you do not want to take them, go away!"

What do you take me for, that you treat somebody like me with such contempt? I have sent as messengers gentlemen like ourselves to collect the bag with my money (deposited with you) but you have treated me with contempt by sending them back to me empty-handed several times, and that through enemy territory. Is there anyone among the merchants who trade with Telmun who has treated me in this way? You alone treat my messenger with contempt! On account of that one (trifling) mina of silver which I owe(?) you, you feel free to speak in such a way, while I have given to the palace on your behalf 1,080 pounds of copper, and Šumi-abum has likewise given 1,080 pounds of copper, apart from what we both have had written on a sealed tablet to be kept in the temple of Shamash.

How have you treated me for that copper? You have withheld my money bag from me in enemy territory; it is now up to you to restore (my money) to me in full.

Take cognizance that (from now on) I will not accept here any copper from you that is not of fine quality. I shall (from now on) select and take the ingots individually in my own yard, and I shall exercise against you my right of rejection because you have treated me with contempt.

The tablet was acquired by the British Museum in 1953. It was originally found in the ruins of Ur.

🔗 Aviation 🔗 Aviation/aircraft

The Giffard dirigible or Giffard airship was an airship built in France in 1852 by Henri Giffard, the first powered and steerable (French: dirigeable – "directable") airship to fly. The craft featured an elongated hydrogen-filled envelope that tapered to a point at each end. From this was suspended a long beam with a triangular, sail-like rudder at its aft end, and beneath the beam a platform for the pilot and steam engine. Due to the highly flammable nature of the lift gas, special precautions were taken to minimise the potential for the envelope to be ignited by the engine beneath it. The engine's exhaust was diverted downwards to a long pipe projecting below the platform, and the area surrounding the boiler's stoke hole was surrounded by wire gauze. On 24 September 1852, Giffard flew the airship from the hippodrome at Place de l'Etoile to Élancourt, covering the 27 km (17 mi) in around 3 hours, demonstrating maneuvering along the way. The engine, however, was not sufficiently powerful to allow Giffard to fly against the wind to make a return journey.

🔗 Technology 🔗 Military history 🔗 Military history/Military science, technology, and theory 🔗 Military history/Maritime warfare

Communication with submarines is a field within military communications that presents technical challenges and requires specialized technology. Because radio waves do not travel well through good electrical conductors like salt water, submerged submarines are cut off from radio communication with their command authorities at ordinary radio frequencies. Submarines can surface and raise an antenna above the sea level, then use ordinary radio transmissions, however this makes them vulnerable to detection by anti-submarine warfare forces. Early submarines during World War II mostly traveled on the surface because of their limited underwater speed and endurance; they dove mainly to evade immediate threats. During the Cold War, however, nuclear-powered submarines were developed that could stay submerged for months. Transmitting messages to these submarines is an active area of research. Very low frequency (VLF) radio waves can penetrate seawater a few hundred feet, and many navies use powerful VLF transmitters for submarine communications. A few nations have built transmitters which use extremely low frequency (ELF) radio waves, which can penetrate seawater to reach submarines at operating depths, but these require huge antennas. Other techniques that have been used include sonar and blue lasers.

🔗 Africa 🔗 Philosophy 🔗 Philosophy/Anarchism 🔗 Somalia

Xeer (pronounced [ħeːr]) is the traditional legal system of Somalia, and one of the three systems from which formal Somali law draws its inspiration, the others being civil law and Islamic law. It is believed to pre-date Islam, although it was influenced by Islam and retains many of the faith's conservative elements. Under this system, elders, known as the xeer begti serve as mediator judges and help settle court cases, taking precedent and custom into account. Xeer is polycentric in that different groups within Somali society have different interpretations of xeer.

🔗 California 🔗 California/San Francisco Bay Area 🔗 Education 🔗 Museums

The Exploratorium is a museum of science, technology, and arts in San Francisco. Its mission is to create inquiry-based experiences that transform learning worldwide. It has been described by the New York Times as the most important science museum to have opened since the mid-20th century, an achievement attributed to "the nature of its exhibits, its wide-ranging influence and its sophisticated teacher training program". Characterized as "a mad scientist's penny arcade, a scientific funhouse, and an experimental laboratory all rolled into one", the participatory nature of its exhibits and its self-identification as a center for informal learning has led to it being cited as the prototype for participatory museums around the world.

The Exploratorium was founded by physicist and educator Frank Oppenheimer and opened in 1969 at the Palace of Fine Arts, its home until January 2, 2013. On April 17, 2013, the Exploratorium reopened at Piers 15 and 17 on San Francisco's Embarcadero. The historic interior and exterior of Pier 15 was renovated extensively prior to the move, and is divided into several galleries mainly separated by content, including the physics of seeing and listening (Light and Sound), Human Behavior, Living Systems, Tinkering (including electricity and magnetism), the Outdoor Gallery, and the Bay Observatory Gallery, which focuses on local environment, weather, and landscape.

Since the museum's founding, over 1,000 participatory exhibits have been created, approximately 600 of which are on the floor at any given time. The exhibit-building workshop space is contained within the museum and is open to view. In addition to the public exhibition space, the Exploratorium has been engaged in the professional development of teachers, science education reform, and the promotion of museums as informal education centers since its founding. Since Oppenheimer's death in 1985, the Exploratorium has expanded into other domains, including its 50,000-page website and two iPad apps on sound and color. It has also inspired an international network of participatory museums working to engage the public with general science education. The new Exploratorium building is also working to showcase environmental sustainability efforts as part of its goal to become the largest net-zero museum in the country.

The Exploratorium offers visitors a variety of ways—including exhibits, webcasts, websites and events—for visitors to explore and understand the world around them. In 2011, the Exploratorium received the National Science Board 2011 Public Service Science Award for its contributions to public understanding of science and engineering.

🔗 International relations 🔗 China

Wolf warrior diplomacy (Chinese: 战狼外交; pinyin: Zhànláng Wàijiāo) describes an aggressive style of coercive diplomacy adopted by Chinese diplomats in the 21st century under Chinese leader Xi Jinping's administration. The term was coined from the Chinese action film, Wolf Warrior 2. This approach is in contrast to prior Chinese diplomatic practices of Deng Xiaoping, which had emphasized the avoidance of controversy and the use of cooperative rhetoric. Wolf warrior diplomacy is confrontational and combative, with its proponents loudly denouncing any criticism of China on social media and in interviews. As an attempt to gain "discourse power" in international politics, wolf warrior diplomacy forms one part of a new foreign policy strategy called Xi Jinping's "Major Country Diplomacy" (Chinese: 大国外交; pinyin: Dàguó Wàijiāo) which has legitimized a more active role for China on the world stage, including engaging in an open ideological struggle with the West.

Although the phrase "wolf warrior diplomacy" was popularized as a description of this diplomatic approach during the COVID-19 pandemic, the appearance of wolf warrior-style diplomats had begun a few years prior. Chinese leader and General Secretary of the Chinese Communist Party Xi Jinping's foreign policy writ large, perceived anti-China hostility from the West among Chinese government officials, and shifts within the Chinese diplomatic bureaucracy have been cited as factors leading to its emergence.

🔗 Books 🔗 Computer Security 🔗 Computer Security/Computing

The Hacker Crackdown: Law and Disorder on the Electronic Frontier is a work of nonfiction by Bruce Sterling first published in 1992.

The book discusses watershed events in the hacker subculture in the early 1990s. The most notable topic covered is Operation Sundevil and the events surrounding the 1987–1990 war on the Legion of Doom network: the raid on Steve Jackson Games, the trial of "Knight Lightning" (one of the original journalists of Phrack), and the subsequent formation of the Electronic Frontier Foundation. The book also profiles the likes of "Emmanuel Goldstein" (publisher of 2600: The Hacker Quarterly), the former assistant attorney general of Arizona Gail Thackeray, FLETC instructor Carlton Fitzpatrick, Mitch Kapor, and John Perry Barlow.

In 1994, Sterling released the book for the Internet with a new afterword.

🔗 Insects 🔗 Insects/Ant 🔗 Fungi

Ant–fungus mutualism is a symbiosis seen in certain ant and fungal species, in which ants actively cultivate fungus much like humans farm crops as a food source. In some species, the ants and fungi are dependent on each other for survival. The leafcutter ant is a well-known example of this symbiosis. A mutualism with fungi is also noted in some species of termites in Africa.

🔗 Comedy

Meta-joke refers to several somewhat different, but related categories: joke templates, self-referential jokes, and jokes about jokes (also known as meta-humor).

🔗 Physics

In mathematics and applied mathematics, perturbation theory comprises methods for finding an approximate solution to a problem, by starting from the exact solution of a related, simpler problem. A critical feature of the technique is a middle step that breaks the problem into "solvable" and "perturbative" parts. In perturbation theory, the solution is expressed as a power series in a small parameter ${\displaystyle \varepsilon }$. The first term is the known solution to the solvable problem. Successive terms in the series at higher powers of ${\displaystyle \varepsilon }$ usually become smaller. An approximate 'perturbation solution' is obtained by truncating the series, usually by keeping only the first two terms, the solution to the known problem and the 'first order' perturbation correction.

Perturbation theory is used in a wide range of fields, and reaches its most sophisticated and advanced forms in quantum field theory. Perturbation theory (quantum mechanics) describes the use of this method in quantum mechanics. The field in general remains actively and heavily researched across multiple disciplines.