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🔗 Internet 🔗 Computing 🔗 Law 🔗 Computing/Software 🔗 Computing/Websites 🔗 Computing/Networking

In computer networking, HTTP 451 Unavailable For Legal Reasons is an error status code of the HTTP protocol to be displayed when the user requests a resource which cannot be served for legal reasons, such as a web page censored by a government. The number 451 is a reference to Ray Bradbury's 1953 dystopian novel Fahrenheit 451, in which books are outlawed. 451 intends to provide more information than 403 Forbidden, which is often used for the same purpose. This status code is standardized in RFC 7725.

Examples of situations where an HTTP 451 error code could be displayed include web pages deemed a danger to national security, or web pages deemed to violate copyright, privacy, blasphemy laws, or any other law or court order.

The RFC is specific that a 451 response does not indicate whether the resource exists but requests for it have been blocked, if the resource has been removed for legal reasons and no longer exists, or even if the resource has never existed, but any discussion of its topic has been legally forbidden (see superinjunction). Some sites have previously returned HTTP 404 (Not Found) or similar if they are not legally permitted to disclose that the resource has been removed. Such a tactic is used in the United Kingdom by some internet service providers utilising the Internet Watch Foundation blacklist, returning a 404 message or another error message instead of showing a message indicating the site is blocked.

The status code was formally proposed in 2013 by Tim Bray, following earlier informal proposals by Chris Applegate in 2008 and Terence Eden in 2012. It was approved by the IESG on December 18, 2015. It was published as RFC 7725 in February 2016.

HTTP 451 was mentioned by the BBC's From Our Own Correspondent program, as an indication of the effects of sanctions on Sudan and the inability to access Airbnb, iOS's App Store, or other Western web services.

After introduction of the GDPR in European Economic Area (EEA) many websites located outside EEA started to serve HTTP 451 instead of trying to comply with this new privacy law.

🔗 Physics 🔗 Education 🔗 Toys

The Gilbert U-238 Atomic Energy Lab was a toy lab set designed to allow children to create and watch nuclear and chemical reactions using radioactive material. The Atomic Energy Lab was released by the A. C. Gilbert Company in 1950.

🔗 Biography 🔗 Australia 🔗 Crime 🔗 Australia/Australian crime 🔗 South Africa 🔗 Zimbabwe

Paul Calder Le Roux (born 24 December 1972) is a former programmer, former criminal cartel boss and informant to the US Drug Enforcement Administration (DEA).

In 1999, he created E4M, a free and open-source disk encryption software program for Microsoft Windows, and is sometimes credited for open-source TrueCrypt, which is based on E4M's code, though he denies involvement with TrueCrypt.

He was arrested on 26 September 2012 for conspiracy to import narcotics into the United States, and agreed to cooperate with authorities in exchange for a lesser sentence and immunity to any crimes he might admit to afterwards. He subsequently admitted to arranging or participating in seven murders, carried out as part of an extensive illegal business empire.

Le Roux was sentenced to 25 years in prison in June 2020.

🔗 Japan 🔗 Japan/Culture

Chindōgu (珍道具) is the practice of inventing ingenious everyday gadgets that seem to be ideal solutions to particular problems, but which may cause more problems than they solve. The term is of Japanese origin.

🔗 Computing 🔗 Computing/Software 🔗 Computing/Free and open-source software

xv6 is a modern reimplementation of Sixth Edition Unix in ANSI C for multiprocessor x86 and RISC-V systems. It is used for pedagogical purposes in MIT's Operating Systems Engineering (6.828) course as well as Georgia Tech's (CS 3210) Design of Operating Systems Course, IIIT Hyderabad, IIIT Delhi and as well as many other institutions.

🔗 Novels 🔗 Transhumanism

The Metamorphosis of Prime Intellect is a 1994 novel by Roger Williams, a programmer living in New Orleans. It deals with the ramifications of a powerful, superintelligent supercomputer that discovers god-like powers to alter reality while studying a quirk of quantum physics discovered during the prototyping of its own specialised processors, ultimately heralding a technological singularity. After remaining unpublished for years, the novel was published online in 2002, hosted by Kuro5hin; Williams later published a print edition via print-on-demand publisher Lulu. One reviewer called the novel "a well-written and very creative, if flawed, piece of work" and ranked it as one of the more important works of fiction to deal with the idea of a technological singularity.

🔗 Pharmacology

The oligodynamic effect (from Greek oligos "few", and dynamis "force") is a biocidal effect of metals, especially heavy metals, that occurs even in low concentrations.

In modern times, the effect was observed by Karl Wilhelm von Nägeli, although he did not identify the cause. Scholarly texts from ancient India promoted the use of brass and silver in ritual cleansing practice as well as in consumption of food and drink. The ancient Indian medical text Sushruta Samhita promoted the use of specific metals in surgical procedures as a measure to prevent infection. Brass doorknobs and silverware both exhibit this effect to an extent.

🔗 Linguistics 🔗 Linguistics/Applied Linguistics

The word dord is a dictionary error in lexicography. It was accidentally created, as a ghost word, by the staff of G. and C. Merriam Company (now part of Merriam-Webster) in the New International Dictionary, second edition (1934). That dictionary defined the term a synonym for density used in physics and chemistry in the following way: "dord (dôrd), n. Physics & Chem. Density."

Philip Babcock Gove, an editor at Merriam-Webster who became editor-in-chief of Webster's Third New International Dictionary, wrote a letter to the journal American Speech, fifteen years after the error was caught, in which he explained how the "dord" error was introduced and corrected.

On 31 July 1931, Austin M. Patterson, the dictionary's chemistry editor, sent in a slip reading "D or d, cont./density." This was intended to add "density" to the existing list of words that the letter "D" can abbreviate. The phrase "D or d" was misinterpreted as a single, run-together word: Dord. This was a plausible mistake, because headwords on slips were typed with spaces between the letters, so "D or d" looked very much like "D o r d". The original slip went missing, so a new slip was prepared for the printer, which assigned a part of speech (noun) and a pronunciation. The would-be word was not questioned or corrected by proofreaders. The entry appeared on page 771 of the dictionary around 1934, between the entries for Dorcopsis (a type of small kangaroo) and doré (golden in color).

On 28 February 1939, an editor noticed "dord" lacked an etymology and investigated, discovering the error. An order was sent to the printer marked "plate change/imperative/urgent". The non-word "dord" was excised; "density" was added as an additional meaning for the abbreviation "D or d" as originally intended, and the definition of the adjacent entry "Doré furnace" was expanded from "A furnace for refining dore bullion" to "a furnace in which dore bullion is refined" to close up the space. Gove wrote that this was "probably too bad, for why shouldn't dord mean 'density'?" In 1940, bound books began appearing without the ghost word, although inspection of printed copies well into the 1940s show "dord" still present. The entry "dord" was not completely removed until 1947.

🔗 Mathematics

A tautochrone or isochrone curve (from Greek prefixes tauto- meaning same or iso- equal, and chrono time) is the curve for which the time taken by an object sliding without friction in uniform gravity to its lowest point is independent of its starting point on the curve. The curve is a cycloid, and the time is equal to π times the square root of the radius (of the circle which generates the cycloid) over the acceleration of gravity. The tautochrone curve is related to the brachistochrone curve, which is also a cycloid.

🔗 Arab world

The elephant clock was a medieval invention by Al-Jazari (1136–1206), an Arab engineer and inventor of various clocks. The device consisted of a weight powered water clock in the form of an Asian elephant. This horological technology was derived from earlier Indian clocks and Chinese clocks.

In China clock escapement mechanism was invented by the polymath and Buddhist monk Yi Xing as well as the hydraulic powered waterwheel and water clock in the mechanically-driven and rotated equatorial armillary sphere of the polymaths Zhang Heng and Ma Jun. The Elephant clock had some design differences compared to earlier Indian and Chinese clocks and the various elements of the clock are in the housing (howdah) on top of the elephant.

Al-Jazari upon finishing the development and construction of his Elephant clock wrote: "The elephant represents the Indian and African cultures, the two dragons represents Chinese culture, the phoenix represents Persian culture, the water work represents Greek culture, and the turban represents Islamic culture" signifying the multicultural mentality of the intellectual Al-Jazari.

In addition to its mechanical innovations, the clock itself is seen as an early example of multiculturalism represented in technology.