Have a deep view into what people are curious about.

🔗 United States 🔗 Biography 🔗 United States/Ohio 🔗 Backpacking

Emma Rowena (Caldwell) Gatewood, known as Grandma Gatewood, (October 25, 1887 – June 4, 1973), was an American ultra-light hiking pioneer. After a difficult life as a farm wife, mother of eleven children, and survivor of domestic violence, she became famous as the first solo female thru-hiker of the 2,168-mile (3,489 km) Appalachian Trail (A.T.) in 1955 at the age of 67. She subsequently became the first person (male or female) to hike the A.T. three times, after completing a second thru-hike two years later, followed by a section-hike in 1964. In the meantime, she hiked 2,000 miles (3,200 km) of the Oregon Trail in 1959. In her later years, she continued to travel and hike, and worked on a section of what would become the Buckeye Trail. The media coverage surrounding her feats was credited for generating interest in maintaining the A.T. and in hiking generally. Among many other honors, she was posthumously inducted into the Appalachian Trail Hall of Fame in 2012.

🔗 Technology 🔗 Aviation 🔗 Computing 🔗 Military history 🔗 Military history/Military aviation 🔗 Military history/North American military history 🔗 Military history/United States military history 🔗 Military history/Military science, technology, and theory 🔗 Aviation/aircraft 🔗 Military history/World War II

The Norden Mk. XV, known as the Norden M series in U.S. Army service, is a bombsight that was used by the United States Army Air Forces (USAAF) and the United States Navy during World War II, and the United States Air Force in the Korean and the Vietnam Wars. It was an early tachometric design that directly measured the aircraft's ground speed and direction, which older bombsights could only estimate with lengthy manual procedures. The Norden improved on older designs by using an analog computer that continuously recalculated the bomb's impact point based on changing flight conditions, and an autopilot that reacted quickly and accurately to changes in the wind or other effects.

Together, these features promised unprecedented accuracy for daytime bombing from high altitudes. During prewar testing the Norden demonstrated a circular error probable (CEP) of 75 feet (23 m), an astonishing performance for that period. This accuracy would enable direct attacks on ships, factories, and other point targets. Both the Navy and the USAAF saw it as a means to conduct successful high-altitude bombing. For example, an invasion fleet could be destroyed long before it could reach U.S. shores. To protect these advantages, the Norden was granted the utmost secrecy well into the war, and was part of a production effort on a similar scale as the Manhattan Project. Carl L. Norden, Inc. ranked 46th among United States corporations in the value of World War II military production contracts.

Under combat conditions the Norden did not achieve its expected accuracy, yielding an average CEP in 1943 of 1,200 feet (370 m), similar to other Allied and German results. Both the Navy and Air Forces had to give up using pinpoint attacks. The Navy turned to dive bombing and skip bombing to attack ships, while the Air Forces developed the lead bomber procedure to improve accuracy, and adopted area bombing techniques for ever larger groups of aircraft. Nevertheless, the Norden's reputation as a pin-point device endured, due in no small part to Norden's own advertising of the device after secrecy was reduced late in the war.

The Norden's secrecy had already been compromised by espionage before the United States entered the war. As early as January 1941, the Germans introduced a lightened derivative of the Norden called the Carl Zeiss Lotfernrohr 7 as the primary bombsight for most Luftwaffe level bombers and the first of its bombsights to have gyroscopic stabilization.

The Norden saw reduced use in the post-World War II period after radar-based targeting was introduced, but the need for accurate daytime attacks kept it in service, especially during the Korean War. The last combat use of the Norden was in the U.S. Navy's VO-67 squadron, which used them to drop sensors onto the Ho Chi Minh Trail as late as 1967. The Norden remains one of the best-known bombsights ever invented.

🔗 Websites 🔗 Websites/Computing

Hacker News is a social news website focusing on computer science and entrepreneurship. It is run by Paul Graham's investment fund and startup incubator, Y Combinator. In general, content that can be submitted is defined as "anything that gratifies one's intellectual curiosity".

🔗 Food and drink 🔗 Fisheries and Fishing 🔗 Food and drink/Desserts

Pumpable ice (PI) technology is a technology to produce and use fluids or secondary refrigerants, also called coolants, with the viscosity of water or jelly and the cooling capacity of ice. Pumpable ice is typically a slurry of ice crystals or particles ranging from 5 micrometers to 1 cm in diameter and transported in brine, seawater, food liquid, or gas bubbles of air, ozone, or carbon dioxide.

🔗 Writing systems

A lipogram (from Ancient Greek: λειπογράμματος, leipográmmatos, "leaving out a letter") is a kind of constrained writing or word game consisting of writing paragraphs or longer works in which a particular letter or group of letters is avoided. Extended Ancient Greek texts avoiding the letter sigma are the earliest examples of lipograms.

Writing a lipogram may be a trivial task when avoiding uncommon letters like Z, J, Q, or X, but it is much more challenging to avoid common letters like E, T, or A in the English language, as the author must omit many ordinary words. Grammatically meaningful and smooth-flowing lipograms can be difficult to compose. Identifying lipograms can also be problematic, as there is always the possibility that a given piece of writing in any language may be unintentionally lipogrammatic. For example, Poe's poem The Raven contains no Z, but there is no evidence that this was intentional.

A pangrammatic lipogram is a text that uses every letter of the alphabet except one. For example, "The quick brown fox jumped over the lazy dog" omits the letter S, which the usual pangram includes by using the word jumps.

🔗 Biography 🔗 New York City 🔗 Law Enforcement

Adrian Schoolcraft (born 1976) is a former New York City Police Department (NYPD) officer who secretly recorded police conversations from 2008 to 2009. He brought these tapes to NYPD investigators in October 2009 as evidence of corruption and wrongdoing within the department. The tapes were used as evidence of arrest quotas leading to police abuses such as wrongful arrests, and that emphasis on fighting crime sometimes resulted in under-reporting of crimes to artificially deflate CompStat numbers.

After voicing his concerns, Schoolcraft was repeatedly harassed by members of the NYPD and reassigned to a desk job. After he left work early one day, an ESU unit illegally entered his apartment, physically abducted him and forcibly admitted him to a psychiatric facility, where he was held against his will for six days. In 2010, he released the audio recordings to The Village Voice, leading to the reporting of a multi-part series titled The NYPD Tapes. The same year, Schoolcraft filed a lawsuit against Jamaica Hospital and the NYPD. In 2012 The Village Voice reported that a 2010 unpublished report of an internal NYPD investigation found the 81st precinct had evidence of quotas and underreporting. Both of Schoolcraft's claims were settled in 2015, with him receiving $600,000 for the NYPD portion of the lawsuit.

🔗 Computing

PL/0 is a programming language, intended as an educational programming language, that is similar to but much simpler than Pascal, a general-purpose programming language. It serves as an example of how to construct a compiler. It was originally introduced in the book, Algorithms + Data Structures = Programs, by Niklaus Wirth in 1976. It features quite limited language constructs: there are no real numbers, very few basic arithmetic operations and no control-flow constructs other than "if" and "while" blocks. While these limitations make writing real applications in this language impractical, it helps the compiler remain compact and simple.

🔗 Apple Inc. 🔗 Computing

The term bozo bit has been used in two contexts. Initially a weak copy protection system in the 1980s Apple classic Mac OS, the term "flipping the bozo bit" was later reused to describe a decision to ignore a person's input. It is a whimsical term, possibly derived from the classic children's comedy character, Bozo the Clown.

🔗 Philosophy 🔗 Philosophy/Logic 🔗 Philosophy/Philosophy of mind

The knowledge argument (also known as Mary's room or Mary the super-scientist) is a philosophical thought experiment proposed by Frank Jackson in his article "Epiphenomenal Qualia" (1982) and extended in "What Mary Didn't Know" (1986). The experiment is intended to argue against physicalism—the view that the universe, including all that is mental, is entirely physical. The debate that emerged following its publication became the subject of an edited volume—There's Something About Mary (2004)—which includes replies from such philosophers as Daniel Dennett, David Lewis, and Paul Churchland.

🔗 Soviet Union 🔗 Military history 🔗 Military history/Cold War 🔗 Cold War 🔗 Military history/Russian, Soviet and CIS military history

On 26 September 1983, the nuclear early-warning radar of the Soviet Union reported the launch of one intercontinental ballistic missile with four more missiles behind it, from bases in the United States. These missile attack warnings were suspected to be false alarms by Stanislav Petrov, an officer of the Soviet Air Defence Forces on duty at the command center of the early-warning system. He decided to wait for corroborating evidence—of which none arrived—rather than immediately relaying the warning up the chain-of-command. This decision is seen as having prevented a retaliatory nuclear attack against the United States and its NATO allies, which would likely have resulted in an escalation to a full-scale nuclear war. Investigation of the satellite warning system later determined that the system had indeed malfunctioned.