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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.

🔗 Disambiguation

Doom may refer to:

🔗 Food and drink 🔗 Plants

Pepper X is a cultivar of Capsicum chili pepper bred by Ed Currie, creator of the Carolina Reaper. As of 2023, it is the world's hottest pepper.

🔗 Software 🔗 Software/Computing 🔗 Norway

Razor 1911 (RZR) is a warez and demogroup founded in Norway, 1986. It was the first ever such group to be initially founded exclusively as a demogroup, before moving into warez in 1987. According to the US Justice Department, Razor 1911 is the oldest software cracking group that is still active on the internet. Razor 1911 ran the diskmag 'Propaganda' until 1995.

🔗 Disaster management

The preparedness paradox is the proposition that if a society or individual acts effectively to mitigate a potential disaster such as a pandemic, natural disaster or other catastrophe so that it causes less harm, the avoided danger will be perceived as having been much less serious because of the limited damage actually caused. The paradox is the incorrect perception that there had been no need for careful preparation as there was little harm, although in reality the limitation of the harm was due to preparation. Several cognitive biases can consequently hamper proper preparation for future risks.

🔗 Skepticism 🔗 Paranormal 🔗 Cryptozoology

The following is a list of unidentified, or formerly unidentified, sounds. All of the sound files in this article have been sped up by at least a factor of 16 to increase intelligibility by condensing them and raising the frequency from infrasound to a more audible and reproducible range.

🔗 Mathematics 🔗 Philosophy 🔗 Philosophy/Logic 🔗 Philosophy/Epistemology

In the philosophy of mathematics, intuitionism, or neointuitionism (opposed to preintuitionism), is an approach where mathematics is considered to be purely the result of the constructive mental activity of humans rather than the discovery of fundamental principles claimed to exist in an objective reality. That is, logic and mathematics are not considered analytic activities wherein deep properties of objective reality are revealed and applied, but are instead considered the application of internally consistent methods used to realize more complex mental constructs, regardless of their possible independent existence in an objective reality.

🔗 France 🔗 Economics 🔗 Cooperatives 🔗 Basque 🔗 Spain

The Mondragon Corporation is a corporation and federation of worker cooperatives based in the Basque region of Spain. It was founded in the town of Mondragon in 1956 by graduates of a local technical college. Its first product was paraffin heaters. It is the tenth-largest Spanish company in terms of asset turnover and the leading business group in the Basque Country. At the end of 2014, it employed 74,117 people in 257 companies and organizations in four areas of activity: finance, industry, retail and knowledge. By 2015, 74,335 people were employed. Mondragon cooperatives operate in accordance with the Statement on the Co-operative Identity maintained by the International Co-operative Alliance.

🔗 Computing 🔗 Classical Greece and Rome 🔗 Greece 🔗 Astronomy 🔗 History of Science 🔗 Alternative Views 🔗 Time

The Antikythera mechanism (, ) is an ancient hand powered Greek analogue computer which has also been described as the first example of such device used to predict astronomical positions and eclipses for calendar and astrological purposes decades in advance. It could also be used to track the four-year cycle of athletic games which was similar to an Olympiad, the cycle of the ancient Olympic Games.

This artefact was retrieved from the sea in 1901, and identified on 17 May 1902 as containing a gear by archaeologist Valerios Stais, among wreckage retrieved from a shipwreck off the coast of the Greek island Antikythera. The instrument is believed to have been designed and constructed by Greek scientists and has been variously dated to about 87 BC, or between 150 and 100 BC, or to 205 BC, or to within a generation before the shipwreck, which has been dated to approximately 70–60 BC.

The device, housed in the remains of a 34 cm × 18 cm × 9 cm (13.4 in × 7.1 in × 3.5 in) wooden box, was found as one lump, later separated into three main fragments which are now divided into 82 separate fragments after conservation efforts. Four of these fragments contain gears, while inscriptions are found on many others. The largest gear is approximately 14 centimetres (5.5 in) in diameter and originally had 223 teeth.

It is a complex clockwork mechanism composed of at least 30 meshing bronze gears. A team led by Mike Edmunds and Tony Freeth at Cardiff University used modern computer x-ray tomography and high resolution surface scanning to image inside fragments of the crust-encased mechanism and read the faintest inscriptions that once covered the outer casing of the machine.

Detailed imaging of the mechanism suggests that it had 37 gear wheels enabling it to follow the movements of the Moon and the Sun through the zodiac, to predict eclipses and even to model the irregular orbit of the Moon, where the Moon's velocity is higher in its perigee than in its apogee. This motion was studied in the 2nd century BC by astronomer Hipparchus of Rhodes, and it is speculated that he may have been consulted in the machine's construction.

The knowledge of this technology was lost at some point in antiquity. Similar technological works later appeared in the medieval Byzantine and Islamic worlds, but works with similar complexity did not appear again until the development of mechanical astronomical clocks in Europe in the fourteenth century. All known fragments of the Antikythera mechanism are now kept at the National Archaeological Museum in Athens, along with a number of artistic reconstructions and replicas of the mechanism to demonstrate how it may have looked and worked.

🔗 Military history 🔗 Military history/North American military history 🔗 Military history/United States military history 🔗 Military history/Military science, technology, and theory 🔗 Military history/Weaponry

The demon core was a spherical 6.2-kilogram (14 lb) subcritical mass of plutonium 89 millimetres (3.5 in) in diameter, that was involved in two criticality accidents, on August 21, 1945 and May 21, 1946. The core was intended for use in a third nuclear weapon, but remained in use for testing after Japan's surrender. It was designed with a small safety margin to ensure a successful explosion of the bomb. The device briefly went supercritical when it was accidentally placed in supercritical configurations during two separate experiments intended to guarantee the core was indeed close to the critical point. The incidents happened at the Los Alamos Laboratory in 1945 and 1946, both resulting in the acute radiation poisoning and subsequent deaths of scientists: Harry Daghlian and Louis Slotin. After these incidents the spherical plutonium core was referred to as the "demon core".