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🔗 California 🔗 California/San Francisco Bay Area 🔗 Engineering

The San Jose electric light tower, also known as Owen's Electric Tower after its creator and chief booster, was constructed in 1881 at an intersection in downtown San Jose, California, as a "high light" or moonlight tower to light the city using arc lights. A pioneer use of electricity for municipal lighting, it was later strung with incandescent bulbs and was destroyed in a storm in December 1915. A half-size replica stands at History Park at Kelley Park.

🔗 Climate change 🔗 China 🔗 Meteorology 🔗 Classical Greece and Rome 🔗 Greece 🔗 Rome 🔗 Ireland 🔗 Greece/Byzantine world 🔗 Peru

The extreme weather events of 535–536 were the most severe and protracted short-term episodes of cooling in the Northern Hemisphere in the last 2,000 years. The event is thought to have been caused by an extensive atmospheric dust veil, possibly resulting from a large volcanic eruption in the tropics or in Iceland. Its effects were widespread, causing unseasonable weather, crop failures, and famines worldwide.

🔗 Germany 🔗 Anthroponymy

Kevinism and Chantalism jokingly describe the tendency of parents in German-speaking areas to name their children with what appears to them to be unusual, exotic-sounding first names.

🔗 Ships 🔗 Egypt

The Yellow Fleet was the name given to a group of fifteen ships trapped in the Suez Canal (in the Great Bitter Lake section) from 1967 to 1975 as a result of the Israel-Egypt Six-Day War. Both ends of the canal had been blocked by the Egyptians with scuttled ships and other obstacles. The name Yellow Fleet derived from their yellow appearance as they were increasingly covered in a desert sand swept on board. After eight years, the only ships that were able to return to their home port under their own power were the West German ships Münsterland and Nordwind.

🔗 Espionage 🔗 Internet 🔗 Telecommunications 🔗 Computer Security 🔗 Computer Security/Computing

Van Eck phreaking (also known as Van Eck Radiation) is a form of eavesdropping in which special equipment is used to pick up side-band electromagnetic emissions from electronic devices that correlate to hidden signals or data for the purpose of recreating these signals or data in order to spy on the electronic device. Side-band electromagnetic radiation emissions are present in (and with the proper equipment, can be captured from) keyboards, computer displays, printers, and other electronic devices.

In 1985, Wim van Eck published the first unclassified technical analysis of the security risks of emanations from computer monitors. This paper caused some consternation in the security community, which had previously believed that such monitoring was a highly sophisticated attack available only to governments; van Eck successfully eavesdropped on a real system, at a range of hundreds of metres, using just $15 worth of equipment plus a television set.

As a consequence of this research, such emanations are sometimes called "van Eck radiation", and the eavesdropping technique van Eck phreaking. Government researchers were already aware of the danger, as Bell Labs had noted this vulnerability to secure teleprinter communications during World War II and was able to produce 75% of the plaintext being processed in a secure facility from a distance of 80 feet (24 metres). Additionally the NSA published Tempest Fundamentals, NSA-82-89, NACSIM 5000, National Security Agency (Classified) on February 1, 1982. In addition, the van Eck technique was successfully demonstrated to non-TEMPEST personnel in Korea during the Korean War in the 1950s.

While Phreaking is the process of exploiting telephone networks, it is used here because of its connection to eavesdropping. Van Eck phreaking of CRT displays is the process of eavesdropping on the contents of a CRT by detecting its electromagnetic emissions.

🔗 Public Art 🔗 Textile Arts 🔗 Graffiti

Yarn bombing (or yarnbombing) is a type of graffiti or street art that employs colourful displays of knitted or crocheted yarn or fibre rather than paint or chalk. It is also called wool bombing, yarn storming, guerrilla knitting, kniffiti, urban knitting, or graffiti knitting.

🔗 Philately

Letterlocking is the act of folding and securing a written message which could be on papyrus, parchment, or paper, so that it does not require an envelope or additional enclosure. It is a document security tradition which utilizes folding and cutting. The process dates to the 13th century in Western history, corresponding with the availability of flexible writing paper. Letterlocking uses small slits, tab, and holes placed directly into a letter, which combined with folding techniques are used to secure the letter ("letterpacket"), preventing reading the letter without breaking seals or slips, providing a means of tamper resistance. These folds and holes may be additionally secured with string and sealing wax. A Scottish diplomat in Italy, William Keith of Delny, sent letters to James VI of Scotland which would tear in two if not opened with care.

Intricate letterlocking works contain artistic elements, demonstrating more than a utilitarian purpose. While the use of sealing techniques may have been limited to ecclesiastic and the nobility, letterlocking was historically performed by all classes of writers. An individual could also be recognised by their personal technique of folding, as was the case with Jane Whorwood, of whose letter Charles I, imprisoned in Carisbrooke Castle on the Isle of Wight, wrote: "This Note [...] I know, by the fowldings [...] that it is written by [Mrs Whorwood]".

Letterlocking is also a discipline focusing on "the materially engineered security and privacy of letters, both as a technology and a historically evolving tradition."

🔗 Physics 🔗 Philosophy 🔗 Skepticism 🔗 History of Science 🔗 Science

Some of the major unsolved problems in physics are theoretical, meaning that existing theories seem incapable of explaining a certain observed phenomenon or experimental result. The others are experimental, meaning that there is a difficulty in creating an experiment to test a proposed theory or investigate a phenomenon in greater detail.

There are still some deficiencies in the Standard Model of physics, such as the origin of mass, the strong CP problem, neutrino mass, matter–antimatter asymmetry, and the nature of dark matter and dark energy. Another problem lies within the mathematical framework of the Standard Model itself—the Standard Model is inconsistent with that of general relativity, to the point that one or both theories break down under certain conditions (for example within known spacetime singularities like the Big Bang and the centers of black holes beyond the event horizon).

🔗 Mathematics

The medieval Cistercian numerals, or "ciphers" in nineteenth-century parlance, were developed by the Cistercian monastic order in the early thirteenth century at about the time that Arabic numerals were introduced to northwestern Europe. They are more compact than Arabic or Roman numerals, with a single character able to indicate any integer from 1 to 9,999.

Digits are based on a horizontal or vertical stave, with the position of the digit on the stave indicating its place value (units, tens, hundreds or thousands). These digits are compounded on a single stave to indicate more complex numbers. The Cistercians eventually abandoned the system in favor of the Arabic numerals, but marginal use outside the order continued until the early twentieth century.