Random Articles (Page 5)
Have a deep view into what people are curious about.
π Optacon
The Optacon (OPtical to TActile CONverter) is an electromechanical device that enables blind people to read printed material that has not been transcribed into Braille. The device consists of two parts: a scanner which the user runs over the material to be read, and a finger pad which translates the words into vibrations felt on the finger tips. The Optacon was conceived by John Linvill, a professor of Electrical Engineering at Stanford University, and developed with researchers at Stanford Research Institute (now SRI International). Telesensory Systems manufactured the device from 1971 until it was discontinued in 1996. Although effective once mastered, it was expensive and took many hours of training to reach competency. In 2005, TSI suddenly shut down. Employees were "walked out" of the building and lost accrued vacation time, medical insurance, and all benefits. Customers could not buy new machines or get existing machines fixed. Some work was done by other companies but no device with the versatility of the Optacon had been developed as of 2007. Many blind people continue to use their Optacons to this day. The Optacon offers capabilities that no other device offers including the ability to see a printed page or computer screen as it truly appears including drawings, typefaces, and specialized text layouts.
Discussed on
- "Optacon" | 2020-01-27 | 92 Upvotes 32 Comments
π Free energy principle
The free energy principle tries to explain how (biological) systems maintain their order (non-equilibrium steady-state) by restricting themselves to a limited number of states. It says that biological systems minimise a free energy function of their internal states, which entail beliefs about hidden states in their environment. The implicit minimisation of variational free energy is formally related to variational Bayesian methods and was originally introduced by Karl Friston as an explanation for embodied perception in neuroscience, where it is also known as active inference.
The free energy principle is that systemsβthose that are defined by their enclosure in a Markov blanketβtry to minimize the difference between their model of the world and their sense and associated perception. This difference can be described as "surprise" and is minimized by continuous correction of the world model of the system. As such, the principle is based on the Bayesian idea of the brain as an βinference engineβ. Friston added a second route to minimization: action. By actively changing the world into the expected state, systems can also minimize the free energy of the system. Friston assumes this to be the principle of all biological reaction.. Friston also believes his principle applies to mental disorders as well as to artificial intelligence. AI implementations based on the active inference principle have shown advantages over other methods.
The free energy principle has been criticized for being very difficult to understand, even for experts. Discussions of the principle have also been criticized as invoking metaphysical assumptions far removed from a testable scientific prediction, making the principle unfalsifiable. In a 2018 interview, Friston acknowledged that the free energy principle is not properly falsifiable: "the free energy principle is what it is β a principle. Like Hamiltonβs Principle of Stationary Action, it cannot be falsified. It cannot be disproven. In fact, thereβs not much you can do with it, unless you ask whether measurable systems conform to the principle."
Discussed on
- "Free energy principle" | 2018-07-14 | 79 Upvotes 19 Comments
π The Dyatlov Pass Incident
The Dyatlov Pass incident (Russian: ΠΠΈΠ±Π΅Π»Ρ ΡΡΡΠ³ΡΡΠΏΠΏΡ ΠΡΡΠ»ΠΎΠ²Π°) was an event where nine Russian hikers died in the northern Ural Mountains between 1 and 2 February 1959, in uncertain circumstances. The experienced trekking group, who were all from the Ural Polytechnical Institute, had established a camp on the slopes of Kholat Syakhl, in an area now named in honor of the group's leader, Igor Dyatlov. During the night, something caused them to tear their way out of their tents and flee the campsite, all while inadequately dressed for the heavy snowfall and sub-zero temperatures.
After the group's bodies were discovered, an investigation by Soviet authorities determined that six had died from hypothermia while the other three showed signs of physical trauma. One victim had a fractured skull; two others had major chest fractures and the body of one of the group was missing both its eyes. One of the victims was missing a tongue. The investigation concluded that a "compelling natural force" had caused the deaths. Numerous theories have been put forward to account for the unexplained deaths, including animal attacks, hypothermia, avalanche, katabatic winds, infrasound-induced panic, military involvement, or some combination of these.
Discussed on
- "The Dyatlov Pass Incident" | 2019-12-25 | 52 Upvotes 16 Comments
- "Dyatlov Pass Incident" | 2016-06-03 | 259 Upvotes 137 Comments
π For Edward Snowden: How to live in an airport
Mehran Karimi Nasseri (Persian: Ω ΩΨ±Ψ§Ω Ϊ©Ψ±ΫΩ Ϋ ΩΨ§Ψ΅Ψ±Ϋβ pronounced [mehΛrΙn kΓ¦riΛmi nΙseΛri]; born 1946), also known as Sir Alfred Mehran, is an Iranian refugee who lived in the departure lounge of Terminal One in Charles de Gaulle Airport from 26 August 1988 until July 2006, when he was hospitalized. His autobiography was published as a book, The Terminal Man, in 2004. His story was the inspiration for the 2004 Steven Spielberg film The Terminal.
Discussed on
- "For Edward Snowden: How to live in an airport" | 2013-06-27 | 10 Upvotes 1 Comments
π Salmonella-in-Eggs Controversy
The salmonella-in-eggs controversy was a political controversy in the United Kingdom caused by the Parliamentary Under-Secretary of State for Health, Edwina Currie's claims that "most of the egg production in this country, sadly, is now affected with salmonella" in 1988. These claims led to a 60 percent decline in egg sales over the next few weeks, and angered both politicians and those in the egg production industry. Currie's statement also resulted in the destruction of around 400 million eggs and the slaughter of around 4 million hens. The controversy dominated Currie's tenure as Parliamentary Under-Secretary of State for Health and resulted in her resignation two weeks later.
Discussed on
- "Salmonella-in-Eggs Controversy" | 2023-02-22 | 55 Upvotes 73 Comments
π Bitching Betty
Bitching Betty is a slang term used by some pilots and aircrew (mainly North American), when referring to the voices used by some aircraft warning systems.
The enunciating voice, in at least some aircraft systems, may be either male or female and in some cases this may be selected according to pilot preference. If the voice is female, it may be referred to as Bitching Betty; if the voice is male, it may be referred to as Barking Bob. A female voice is heard on military aircraft such as the F-16 Fighting Falcon, the Eurofighter Typhoon and the Mikoyan MiG-29. A male voice is heard on Boeing commercial airliners and is also used in the BAE Hawk.
In the United Kingdom the term Nagging Nora is sometimes used, and in New Zealand the term used for Boeing aircraft is Hank the Yank. The voice warning system used on London Underground trains, which also uses a female voice, is known to some staff as Sonya, as it "gets on ya nerves".
Discussed on
- "Bitching Betty" | 2016-08-01 | 20 Upvotes 6 Comments
π Siteswap
Siteswap is a numeric juggling notation used to describe or represent juggling patterns. It is also referred to as Quantum Juggling, or The Cambridge Notation. Siteswap may also be used to describe siteswap patterns, possible patterns transcribed using siteswap. Throws are represented by positive integers that specify the number of beats in the future when the object is thrown again: "The idea behind siteswap is to keep track of the order that balls are thrown and caught, and only that." It is an invaluable tool in determining which combinations of throws yield valid juggling patterns for a given number of objects, and has led to previously unknown patterns (such as 441). However, it does not describe body movements such as behind-the-back and under-the-leg. Siteswap assumes that, "throws happen on beats that are equally spaced in time."
For example, a three-ball cascade may be notated "3 ", while a shower may be notated "5 1".
Discussed on
- "Siteswap" | 2020-12-02 | 110 Upvotes 39 Comments
π Wow signal
The Wow! signal was a strong narrowband radio signal received on August 15, 1977, by Ohio State University's Big Ear radio telescope in the United States, then used to support the search for extraterrestrial intelligence. The signal appeared to come from the direction of the constellation Sagittarius and bore the expected hallmarks of extraterrestrial origin.
Astronomer Jerry R. Ehman discovered the anomaly a few days later while reviewing the recorded data. He was so impressed by the result that he circled the reading on the computer printout, "6EQUJ5", and wrote the comment "Wow!" on its side, leading to the event's widely used name.
The entire signal sequence lasted for the full 72-second window during which Big Ear was able to observe it, but has not been detected since, despite several subsequent attempts by Ehman and others. Many hypotheses have been advanced on the origin of the emission, including natural and human-made sources, but none of them adequately explains the signal.
Although the Wow! signal had no detectable modulationβa technique used to transmit information over radio wavesβit remains the strongest candidate for an alien radio transmission ever detected.
Discussed on
- "Wow Signal" | 2024-03-12 | 40 Upvotes 4 Comments
- "Wow signal" | 2015-07-05 | 43 Upvotes 31 Comments
- "Wow signal" | 2014-03-12 | 125 Upvotes 95 Comments
- "Wow signal" | 2010-03-15 | 27 Upvotes 13 Comments
π Great Oxidation Event
The Great Oxidation Event (GOE), sometimes also called the Great Oxygenation Event, Oxygen Catastrophe, Oxygen Crisis, Oxygen Holocaust, or Oxygen Revolution, was a time period when the Earth's atmosphere and the shallow ocean experienced a rise in oxygen, approximately 2.4Β billion years ago (2.4Β Ga) to 2.1β2.0 Ga during the Paleoproterozoic era. Geological, isotopic, and chemical evidence suggests that biologically induced molecular oxygen (dioxygen, O2) started to accumulate in Earth's atmosphere and changed Earth's atmosphere from a weakly reducing atmosphere to an oxidizing atmosphere, causing almost all life on Earth to go extinct. The cyanobacteria producing the oxygen caused the event which enabled the subsequent development of multicellular forms.
Discussed on
- "Great Oxidation Event" | 2025-07-26 | 21 Upvotes 5 Comments
- "Great Oxidation Event" | 2019-07-21 | 64 Upvotes 24 Comments
π Loving v. Virginia
Loving v. Virginia, 388 U.S. 1 (1967), was a landmark civil rights decision of the U.S. Supreme Court in which the Court ruled that laws banning interracial marriage violate the Equal Protection and Due Process Clauses of the Fourteenth Amendment to the U.S. Constitution. Beginning in 2013, it was cited as precedent in U.S. federal court decisions holding restrictions on same-sex marriage in the United States unconstitutional, including in the 2015 Supreme Court decision Obergefell v. Hodges.
The case involved Mildred Loving, a woman of color, and her white husband Richard Loving, who in 1958 were sentenced to a year in prison for marrying each other. Their marriage violated Virginia's Racial Integrity Act of 1924, which criminalized marriage between people classified as "white" and people classified as "colored". The Lovings appealed their conviction to the Supreme Court of Virginia, which upheld it. They then appealed to the U.S. Supreme Court, which agreed to hear their case.
In June 1967, the Supreme Court issued a unanimous decision in the Lovings' favor and overturned their convictions. Its decision struck down Virginia's anti-miscegenation law and ended all race-based legal restrictions on marriage in the United States. Virginia had argued that its law was not a violation of the Equal Protection Clause because the punishment was the same regardless of the offender's race, and thus it "equally burdened" both whites and non-whites. The Court found that the law nonetheless violated the Equal Protection Clause because it was based solely on "distinctions drawn according to race" and outlawed conductβnamely, getting marriedβthat was otherwise generally accepted and which citizens were free to do.
Discussed on
- "Loving v. Virginia" | 2022-06-25 | 18 Upvotes 5 Comments