Have a deep view into what people are curious about.

🔗 Biography 🔗 China/Chinese history 🔗 Italy 🔗 China

Katarina Vilioni (died 1342) was one of the first Europeans known to have resided in China. She was apparently a member of a Genoese trading family that lived in Yangzhou during the mid-14th century.

Vilioni is known through her tombstone, which was rediscovered at Yangzhou in 1951. It suggests that Vilioni died in 1342 and was the daughter of a man named Domenico Vilioni.

"Fart Proudly" (also called "A Letter to a Royal Academy about farting", and "To the Royal Academy of Farting") is the popular name of an essay about flatulence written by Benjamin Franklin c. 1781 while he was living abroad as United States Ambassador to France. It is an example of flatulence humor.

🔗 California 🔗 Companies 🔗 California/San Francisco Bay Area 🔗 Computing 🔗 Open 🔗 Mozilla

The Mozilla Corporation (stylized as moz://a) is a wholly owned subsidiary of the Mozilla Foundation that coordinates and integrates the development of Internet-related applications such as the Firefox web browser, by a global community of open-source developers, some of whom are employed by the corporation itself. The corporation also distributes and promotes these products. Unlike the non-profit Mozilla Foundation, and the Mozilla open source project, founded by the now defunct Netscape Communications Corporation, the Mozilla Corporation is a taxable entity. The Mozilla Corporation reinvests all of its profits back into the Mozilla projects. The Mozilla Corporation's stated aim is to work towards the Mozilla Foundation's public benefit to "promote choice and innovation on the Internet."

A MozillaZine article explained:

The Mozilla Foundation will ultimately control the activities of the Mozilla Corporation and will retain its 100 percent ownership of the new subsidiary. Any profits made by the Mozilla Corporation will be invested back into the Mozilla project. There will be no shareholders, no stock options will be issued and no dividends will be paid. The Mozilla Corporation will not be floating on the stock market and it will be impossible for any company to take over or buy a stake in the subsidiary. The Mozilla Foundation will continue to own the Mozilla trademarks and other intellectual property and will license them to the Mozilla Corporation. The Foundation will also continue to govern the source code repository and control who is allowed to check in.

🔗 Lists 🔗 Brands

The following three lists of generic and genericized trademarks are:

• marks which were originally legally protected trademarks, but have been genericized and have lost their legal status due to becoming generic terms,
• marks which have been abandoned and are now generic terms
• marks which are still legally protected as trademarks, at least in some jurisdictions

🔗 Military history 🔗 Military history/Military science, technology, and theory 🔗 Equine 🔗 Military history/Medieval warfare

The Great Stirrup Controversy is the academic debate about the Stirrup Thesis, the theory that feudalism in Europe developed largely as a result of the introduction of the stirrup to cavalry in the 8th century CE. It relates to the hypothesis suggested by Lynn Townsend White Jr. in his 1962 book, Medieval Technology and Social Change. White believed that the stirrup enabled heavy cavalry and shock combat, which in turn prompted the Carolingian dynasty of the 8th and 9th centuries to organize its territory into a vassalage system, rewarding mounted warriors with land grants for their service. White's book has proved very influential, but others have accused him of speculation, oversimplification, and ignoring contradictory evidence on the subject. Scholars have debated whether the stirrup actually provided the impetus for this social change, or whether the rise of heavy cavalry resulted from political changes in Medieval Europe.

🔗 China

Counting rods (traditional Chinese: 籌; simplified Chinese: 筹; pinyin: chóu; Japanese: 算木; rōmaji: sangi; Korean: sangaji) are small bars, typically 3–14 cm long, that were used by mathematicians for calculation in ancient East Asia. They are placed either horizontally or vertically to represent any integer or rational number.

The written forms based on them are called rod numerals. They are a true positional numeral system with digits for 1–9 and a blank for 0, from the Warring states period (circa 475 BCE) to the 16th century.

🔗 Mathematics

Legendre's constant is a mathematical constant occurring in a formula conjectured by Adrien-Marie Legendre to capture the asymptotic behavior of the prime-counting function ${\displaystyle \pi (x)}$. Its value is now known to be exactly 1.

Examination of available numerical evidence for known primes led Legendre to suspect that ${\displaystyle \pi (x)}$ satisfies an approximate formula.

Legendre conjectured in 1808 that

${\displaystyle \pi (x)={\frac {x}{\ln(x)-B(x)}}}$

where ${\displaystyle \lim _{x\to \infty }B(x)=1.08366}$....OEIS: A228211

Or similarly,

${\displaystyle \lim _{n\to \infty }\left(\ln(n)-{n \over \pi (n)}\right)=B}$

where B is Legendre's constant. He guessed B to be about 1.08366, but regardless of its exact value, the existence of B implies the prime number theorem.

Pafnuty Chebyshev proved in 1849 that if the limit B exists, it must be equal to 1. An easier proof was given by Pintz in 1980.

It is an immediate consequence of the prime number theorem, under the precise form with an explicit estimate of the error term

${\displaystyle \pi (x)={\rm {Li}}(x)+O\left(xe^{-a{\sqrt {\ln x}}}\right)\quad {\text{as }}x\to \infty }$

(for some positive constant a, where O(…) is the big O notation), as proved in 1899 by Charles de La Vallée Poussin, that B indeed is equal to 1. (The prime number theorem had been proved in 1896, independently by Jacques Hadamard and La Vallée Poussin, but without any estimate of the involved error term).

Being evaluated to such a simple number has made the term Legendre's constant mostly only of historical value, with it often (technically incorrectly) being used to refer to Legendre's first guess 1.08366... instead.

Pierre Dusart proved in 2010

${\displaystyle {\frac {x}{\ln x-1}}<\pi (x)}$ for ${\displaystyle x\geq 5393}$, and

${\displaystyle \pi (x)<{\frac {x}{\ln x-1.1}}}$ for ${\displaystyle x\geq 60184}$. This is of the same form as

${\displaystyle \pi (x)={\frac {x}{\ln(x)-B(x)}}}$ with ${\displaystyle 1<B(x)<1.1}$.

🔗 International relations 🔗 Ancient Egypt 🔗 Politics 🔗 Sociology 🔗 Asia

A hydraulic empire, also known as a hydraulic despotism, hydraulic society, hydraulic civilization, or water monopoly empire, is a social or government structure which maintains power and control through exclusive control over access to water. It arises through the need for flood control and irrigation, which requires central coordination and a specialized bureaucracy.

Often associated with these terms and concepts is the notion of a water dynasty. This body is a political structure which is commonly characterized by a system of hierarchy and control often based on class or caste. Power, both over resources (food, water, energy) and a means of enforcement such as the military, is vital for the maintenance of control.

🔗 Biography 🔗 Biography/arts and entertainment 🔗 Japan 🔗 Photography 🔗 Japan/History 🔗 Japan/Science and technology 🔗 Photography/History of photography 🔗 Japan/Biography

Ichiki Shirō (市来 四郎, January 29, 1828 – February 12, 1903) was a pioneering Japanese photographer.

Ichiki was born in Satsuma Province (now Kagoshima Prefecture) in Kyūshū on 24 December 1828. He excelled in the study of topics related to gunpowder production in the Takashima-ryū school of gunnery. This talent was recognized by Shimazu Nariakira, the daimyō of Satsuma, who selected Ichiki to be one of his personal retainers. In 1848, Shimazu obtained the first daguerreotype camera ever imported into Japan. Ever fascinated by Western technology, he ordered his retainers (including Ichiki) to study it and produce working photographs. Due to the limitations of the lens used and the lack of formal training, it took many years for a quality photograph to be created, but on 17 September 1857, Ichiki created a portrait of Shimazu in formal attire. All this was recorded in detail in Ichiki's memoirs, which were compiled in 1884.

This photograph became an object of worship in Terukuni jinja after Shimazu's death, but it later went missing. Lost for a century, the daguerreotype was discovered in a warehouse in 1975 and was later determined to be the oldest daguerreotype in existence that was created by a Japanese photographer. For this reason, it was designated an Important Cultural Property by the government of Japan in 1999, the first photograph so designated.

🔗 Computing

Secure Scuttlebutt (SSB) is a peer-to peer communication protocol, mesh network, and self-hosted social media ecosystem. Each user hosts their own content and the content of the peers they follow, which provides fault tolerance and eventual consistency. Messages are digitally signed and added to an append-only list of messages published by an author. SSB is primarily used for implementing distributed social networks, and utilizes cryptography to assure that content remains unforged as it is propagated through the network.