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🔗 Technology 🔗 Visual arts

A camera lucida is an optical device used as a drawing aid by artists.

The camera lucida performs an optical superimposition of the subject being viewed upon the surface upon which the artist is drawing. The artist sees both scene and drawing surface simultaneously, as in a photographic double exposure. This allows the artist to duplicate key points of the scene on the drawing surface, thus aiding in the accurate rendering of perspective.

🔗 United States 🔗 Aviation 🔗 Spaceflight 🔗 Rocketry

The Space Transportation System (STS), also known internally to NASA as the Integrated Program Plan (IPP), was a proposed system of reusable manned space vehicles envisioned in 1969 to support extended operations beyond the Apollo program. (NASA appropriated the name for its Space Shuttle Program, the only component of the proposal to survive Congressional funding approval). The purpose of the system was twofold: to reduce the cost of spaceflight by replacing the current method of launching capsules on expendable rockets with reusable spacecraft; and to support ambitious follow-on programs including permanent orbiting space stations around the Earth and Moon, and a human landing mission to Mars.

In February 1969, President Richard Nixon appointed a Space Task Group headed by Vice President Spiro Agnew to recommend human space projects beyond Apollo. The group responded in September with the outline of the STS, and three different program levels of effort culminating with a human Mars landing by 1983 at the earliest, and by the end of the twentieth century at the latest. The system's major components consisted of:

• A permanent space station module designed for 6 to 12 occupants, in a 270-nautical-mile (500 km) low Earth orbit, and as a permanent lunar orbit station. Modules could be combined in Earth orbit to create a 50 to 100 person permanent station.
• A chemically fueled Earth-to-station shuttle.
• A chemically fueled space tug to move crew and equipment between Earth orbits as high as geosynchronous orbit, which could be adapted as a lunar orbit-to-surface shuttle.
• A nuclear-powered ferry using the NERVA engine, to move crew, spacecraft and supplies between low Earth orbit and lunar orbit, geosynchronous orbit, or to other planets in the solar system.

The tug and ferry vehicles would be of a modular design, allowing them to be clustered and/or staged for large payloads or interplanetary missions. The system would be supported by permanent Earth and lunar orbital propellant depots. The Saturn V might still have been used as a heavy lift launch vehicle for the nuclear ferry and space station modules. A special "Mars Excursion Module" would be the only remaining vehicle necessary for a human Mars landing.

As Apollo accomplished its objective of landing the first men on the Moon, political support for further manned space activities began to wane, which was reflected in unwillingness of the Congress to provide funding for most of these extended activities. Based on this, Nixon rejected all parts of the program except the Space Shuttle, which inherited the STS name. As funded, the Shuttle was greatly scaled back from its planned degree of reusability, and deferred in time. The Shuttle first flew in 1981, and was retired in 2011.

A second part of the system, Space Station Freedom, was approved in the early 1980s and announced in 1984 by president Ronald Reagan. However, this also became politically unviable by 1993, and was replaced with the International Space Station (ISS), with substantial contribution by Russia. The ISS was completed in 2010.

🔗 Architecture 🔗 Firearms 🔗 Metalworking

A shot tower is a tower designed for the production of small diameter shot balls by freefall of molten lead, which is then caught in a water basin. The shot is primarily used for projectiles in shotguns, and also for ballast, radiation shielding and other applications where small lead balls are useful.

🔗 Religion 🔗 Iran 🔗 Central Asia 🔗 Syria 🔗 Iraq 🔗 Turkey 🔗 Ukraine 🔗 Holidays 🔗 Pakistan 🔗 Afghanistan 🔗 Caucasia 🔗 Kurdistan 🔗 Tajikistan 🔗 Georgia (country) 🔗 Azerbaijan 🔗 North Macedonia 🔗 Bahá'í Faith 🔗 Albania

Nowruz (Persian: نوروز‎, pronounced [nowˈɾuːz]; lit.  "new day") is the Iranian New Year, also known as the Persian New Year, which is celebrated worldwide by various ethno-linguistic groups.

Nowruz has Iranian and Zoroastrian origins, however, it has been celebrated by diverse communities for over 7,000 years in Western Asia, Central Asia, the Caucasus, the Black Sea Basin, the Balkans, and South Asia. It is a secular holiday for most celebrants that is enjoyed by people of several different faiths, but remains a holy day for Zoroastrians, Bahais, and some Muslim communities.

Nowruz is the day of the vernal equinox, and marks the beginning of spring in the Northern Hemisphere. It marks the first day of the first month (Farvardin) of the Iranian calendars. It usually occurs on March 21 or the previous or following day, depending on where it is observed. The moment the Sun crosses the celestial equator and equalizes night and day is calculated exactly every year, and families gather together to observe the rituals.

While Nowruz has been celebrated since the reform of the Iranian Calendar in the 11th century CE to mark the new year, the United Nations officially recognized the "International Day of Nowruz" with the adoption of UN resolution 64/253 in 2010.

🔗 Video games

The Compact Disc-Interactive (CD-I, later CD-i) is a digital optical disc data storage format that was mostly developed and marketed by Dutch company Philips. It was created as an extension of CDDA and CD-ROM and specified in the Green Book, co-developed by Philips and Sony, to combine audio, text and graphics. The two companies initially expected to impact the education/training, point of sale, and home entertainment industries, but CD-i eventually became best known for its video games.

CD-i media physically have the same dimensions as CD, but with up to 744 MiB of digital data storage, including up to 72 minutes of full motion video. CD-i players were usually standalone boxes that connect to a standard television; some less common setups included integrated CD-i television sets and expansion modules for personal computers. Most players were created by Philips; the format was licensed by Philips and Microware for use by other manufacturers, notably Sony who released professional CD-i players under the "Intelligent Discman" brand. Unlike CD-ROM drives, CD-i players are complete computer systems centered around dedicated Motorola 68000-based microprocessors and its own operating system called CD-RTOS, which is an acronym for "Compact Disc – Real Time Operating System".

Media released on the format included video games and "edutainment" and multimedia reference titles, such as interactive encyclopedias and museum tours – which were popular before public Internet access was widespread – as well as business software. Philips's CD-i system also implemented Internet features, including subscriptions, web browsing, downloading, e-mail, and online play. Philips's aim with its players was to introduce interactive multimedia content for the general public by combining features of a CD player and game console, but at a lower price than a personal computer with a CD-ROM drive.

Authoring kits for the format were released first in 1988, and the first player aimed for home consumers, Philips's CDI 910/205, at the end of 1991, initially priced around US$1,000 (equivalent to $1,877 in 2019), and capable of playing interactive CD-i discs, Audio CDs, CD+G (CD+Graphics), Photo CDs and Video CDs (VCDs), though the latter required an optional "Digital Video Card" to provide MPEG-1 decoding. Initially marketed to consumers as "home entertainment systems", and in later years as a "gaming platform", CD-i did not manage to find enough success in the market, and was mostly abandoned by Philips in 1996. The format continued to be supported for licensees for a few more years after.

🔗 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.

🔗 Psychology 🔗 Neuroscience

The Weber–Fechner law refers to two related hypotheses in the field of psychophysics, known as Weber's law and Fechner's law. Both laws relate to human perception, more specifically the relation between the actual change in a physical stimulus and the perceived change. This includes stimuli to all senses: vision, hearing, taste, touch, and smell.

🔗 Computing 🔗 Computing/Software 🔗 Computing/Early computers 🔗 Project-independent assessment

MUMPS ("Massachusetts General Hospital Utility Multi-Programming System"), or M, is an imperative, high-level programming language with an integrated transaction processing key–value database. It was originally developed at Massachusetts General Hospital for managing patient medical records and hospital laboratory information systems.

MUMPS technology has since expanded as the predominant database for health information systems and electronic health records in the United States. MUMPS-based information systems, such as Epic Systems', provide health information services for over 78% of patients across the U.S.

A unique feature of the MUMPS technology is its integrated database language, allowing direct, high-speed read-write access to permanent disk storage.

🔗 Food and drink 🔗 Glass

A teasmade is a machine for making tea automatically, which was once common in the United Kingdom and some British Commonwealth countries. Teasmades generally include an analogue alarm clock and are designed to be used at the bedside, to ensure tea is ready first thing in the morning. Although crude versions existed in Victorian times, they only became practical with the availability of electric versions in the 1930s. They reached their peak in popularity in the 1960s and 1970s, since when their use has declined, but they are now enjoying a revival, partly as a retro novelty item.

The name teasmade is an example of a genericised trademark, now commonly used to refer to any automatic tea-making appliance.

WikimediaUI Dark mode is a gadget for enabling dark mode in modern browsers, based on experimental work of Wikimedia Design team members Volker E. and Alex Hollender in support by volunteer MusikAnimal and others.

Preview dark mode on the Main Page.

To enable, go to your gadget preferences, and enable the gadget "Dark mode toggle: Enable a toggle for using a light text on dark background color scheme".

You should now see a "Dark mode" switch at the top of pages. If you wish to enable/disable dark mode automatically based on your system colour scheme, add the following to your common.js page:

Any modern browser works with the only exception being Opera Mini, which lacks filter support.

The CSS was written with Wikipedia sites in mind (see phab:T221425) so experience on other wikis may not be optimal.

To set up the gadget on your wiki, ask an interface-admin to do the following:

• Create the pages MediaWiki:Gadget-dark-mode.css, MediaWiki:Gadget-dark-mode-toggle-pagestyles.css and MediaWiki:Gadget-dark-mode-toggle.js by copying the English Wikipedia versions. Adjust the localisation strings as appropriate.
  • While the CSS pages need to be copied to avoid FOUCs arising from slow load, for the JS page you may instead dynamically load the enwiki version:
  • Replace "Dark mode" and "Light mode" after content: in the CSS files with the localised labels.
• Add to MediaWiki:Gadgets-definition:
• Add the following to the bottom of MediaWiki:Gadgets-definition. This is an internal gadget which can't be marked as hidden, for technical reasons.
• Create the gadget description pages MediaWiki:Gadget-dark-mode-toggle (the main "dark mode" gadget) and MediaWiki:Gadget-dark-mode (this is the internal gadget – make sure the description is such that users don't enable this one).

The gadget has several limitations due to the way it achieves the dark mode. Known issues are:

• It can be slow, especially on larger pages.
• Images are colorshifted
• Native Emojis are inverted
• Text only SVGs with transparent backgrounds can be unreadable (as they are treated as images, and thus do not get dark mode)
• The color legends in captions, might not match the colors of images for maps and/or graphs.

Most problems are due to how the gadget was implemented. It first inverts and colorshifts the entire page, and then tries to 'undo' the areas you do not want inverted, such as images. The benefit to this approach is that it takes care of dark mode everywhere, without having hundreds and hundreds of lines of codes for all the nooks and crannies of Wikipedia/MediaWiki that have their own styling. The downside are the problems listed.

For an example of what to expect on invert "dark mode" and double-invert "undo", see the question pictures in this StackOverflow question. The question uses the same invert and hue-rotate filter used by this extension.