Hint: You are looking at the most popular articles. If you are interested in popular topics instead, click here.

🔗 Automobiles 🔗 Japan 🔗 Japan/Car

Kei car (or keijidōsha, kanji: 軽自動車, "light automobile", pronounced [keːdʑidoːɕa]), known variously outside Japan as Japanese city car, ultramini, or Japanese microcar, is the Japanese vehicle category for the smallest highway-legal passenger cars. Similar Japanese categories exist for microvans, and kei trucks. These vehicles are most often the Japanese equivalent of the EU A-segment (city cars).

The kei-car category was created by the Japanese government in 1949, and the regulations have been revised several times since. These regulations specify a maximum vehicle size, engine capacity, and power output, so that owners may enjoy both tax and insurance benefits. In most rural areas they are also exempted from the requirement to certify that adequate parking is available for the vehicle.

Kei cars have become very successful in Japan, consisting of over one-third of domestic new-car sales in fiscal 2016, despite dropping from a record 40% market share in 2013, after the government increased the kei-car tax by 50% in 2014. In 2018, seven of the 10 top-selling models were kei cars, including the top four, all boxy passenger vans: Honda N-Box, Suzuki Spacia, Nissan Dayz, and Daihatsu Tanto. Isuzu is the only manufacturer that has never offered a kei-sized vehicle for either private ownership or commercial trucks and microvans.

In export markets, though, the genre is generally too specialized and too small for most models to be profitable. Notable exceptions exist, though, for instance the Suzuki Alto and Jimny models, which were exported consistently from around 1980. Kei cars are not only popular with the elderly, but they are also popular with youths because of their affordability.

Nearly all kei cars have been designed and manufactured in Japan, but a version of the French-made Smart was briefly imported and officially classified as a kei car, and since then, the British Caterham 7 160 has also received such classification.

🔗 Computing

Better Portable Graphics (BPG) is a file format for coding digital images, which was created by programmer Fabrice Bellard in 2014. He has proposed it as a replacement for the JPEG image format as the more compression-efficient alternative in terms of image quality or file size.

It is based on the intra-frame encoding of the High Efficiency Video Coding (HEVC) video compression standard. Tests on photographic images in July 2014 found that BPG produced smaller files for a given quality than JPEG, JPEG XR and WebP.

The format has been designed to be portable and work in low memory environments, and used in portable handheld and IoT devices, where those properties are particularly important. Current research works on designing and developing more energy-efficient BPG hardware which can then be integrated in portable devices such as digital cameras.

While there is no built-in native support for BPG in any mainstream browsers, websites can still deliver BPG images to all browsers by including a JavaScript library written by Bellard.

🔗 Energy

The gravitation water vortex power plant is a type of micro hydro vortex turbine system which is capable of converting energy in a moving fluid to rotational energy using a low hydraulic head of 0.7–3 metres (2 ft 4 in–9 ft 10 in). The technology is based on a round basin with a central drain. Above the drain the water forms a stable line vortex which drives a water turbine.

It was first patented by Greek-Australian Lawyer & Inventor Paul Kouris in 1996, who was searching for a way to harness the power inherent in a vortex.

Later, Austrian Inventor Franz Zotlöterer created a similar turbine while attempting to find a way to aerate water without an external power source.

🔗 Human rights 🔗 Computing 🔗 Finance & Investment 🔗 Law 🔗 Computing/Software 🔗 Software 🔗 Software/Computing 🔗 United Kingdom

The British Post Office scandal is a widespread and long-lasting series of individual miscarriages of justice which, between 1999 and 2015, involved over 700 subpostmasters being wrongly convicted of theft, false accounting and fraud when shortfalls at their branches were in fact due to errors of the Post Office's Horizon accounting software. In 2019, the High Court ruled that the Horizon system was faulty and in 2020 the government established a public inquiry. Courts began to quash convictions from 2010. As of January 2024, some victims are still fighting to have their convictions overturned and receive compensation, the public inquiry is ongoing, and the Metropolitan Police is investigating the Post Office for potential fraud offences.

The Horizon accounting system was developed by ICL Pathway, owned by the Japanese company Fujitsu. In 1999, the Post Office started to roll out the new software to its branch and sub-offices, the latter managed by subpostmasters on a self-employed basis under contracts with the Post Office. Almost immediately, some subpostmasters noticed the new system reporting false shortfalls, sometimes for thousands of pounds. The Post Office insisted that the system was robust and, when shortfalls occurred, prosecuted the subpostmasters or forced them to make up the amount. The impact of court cases, criminal convictions, imprisonment, loss of livelihood and homes, debt and bankruptcy took a heavy toll on victims and their families, leading to stress, illness, divorce and, in at least four cases, suicide. In May 2009, Computer Weekly broke the story about problems with Horizon software and in September 2009 subpostmaster Alan Bates set up the Justice for Subpostmasters Alliance (JFSA). In 2012, as a result of pressure from campaigners and Members of Parliament, the Post Office appointed forensic accountants Second Sight to conduct an investigation into Horizon. The investigators concluded that Horizon contained faults that could result in accounting discrepancies, but the Post Office insisted that there were no system-wide problems with the software.

In 2019 a group of 555 subpostmasters led by Bates won a group action brought in court against the Post Office, with the judge ruling that Horizon contained bugs, errors and defects. The Post Office agreed to settle out of court for £58 million. The subpostmasters' legal costs amounted to £47 million of, leaving them with only about £20,000 each. The government later agreed to supplement the settlement, as they were excluded from the compensation scheme set up by the Post Office for other victims of the scandal. The first convictions to be quashed were those of six subpostmasters who had been convicted in magistrates' courts and whose appeals were heard at Southwark Crown Court in December 2020. In allowing the appeal by 39 subpostmasters in April 2021, the Court of Appeal judges ruled that in cases that relied on Horizon data a fair trial was not possible. Further appeal cases followed.

In September 2020, the government established the Post Office Horizon IT Inquiry, chaired by retired judge Sir Wyn Williams, to look into the implementation and failings of the Horizon system that led to the prosecution of subpostmasters and termination of their contracts. Evidence was due to be heard from subpostmasters, the Post Office, UK Government Investment, the Department for Business and Trade, and others.

A four-part television drama, Mr Bates vs the Post Office, was broadcast on ITV in January 2024, after which the scandal became a major news story and political issue.

🔗 Physics 🔗 Astronomy

Entropic gravity, also known as emergent gravity, is a theory in modern physics that describes gravity as an entropic force—a force with macro-scale homogeneity but which is subject to quantum-level disorder—and not a fundamental interaction. The theory, based on string theory, black hole physics, and quantum information theory, describes gravity as an emergent phenomenon that springs from the quantum entanglement of small bits of spacetime information. As such, entropic gravity is said to abide by the second law of thermodynamics under which the entropy of a physical system tends to increase over time.

At its simplest, the theory holds that when gravity becomes vanishingly weak—levels seen only at interstellar distances—it diverges from its classically understood nature and its strength begins to decay linearly with distance from a mass.

Entropic gravity provides the underlying framework to explain Modified Newtonian Dynamics, or MOND, which holds that at a gravitational acceleration threshold of approximately 1.2×10⁻¹⁰ m/s², gravitational strength begins to vary inversely (linearly) with distance from a mass rather than the normal inverse-square law of the distance. This is an exceedingly low threshold, measuring only 12 trillionths gravity's strength at earth's surface; an object dropped from a height of one meter would fall for 36 hours were earth's gravity this weak. It is also 3,000 times less than exists at the point where Voyager 1 crossed our solar system's heliopause and entered interstellar space.

The theory claims to be consistent with both the macro-level observations of Newtonian gravity as well as Einstein's theory of general relativity and its gravitational distortion of spacetime. Importantly, the theory also explains (without invoking the existence of dark matter and its accompanying math featuring new free parameters that are tweaked to obtain the desired outcome) why galactic rotation curves differ from the profile expected with visible matter.

The theory of entropic gravity posits that what has been interpreted as unobserved dark matter is the product of quantum effects that can be regarded as a form of positive dark energy that lifts the vacuum energy of space from its ground state value. A central tenet of the theory is that the positive dark energy leads to a thermal-volume law contribution to entropy that overtakes the area law of anti-de Sitter space precisely at the cosmological horizon.

The theory has been controversial within the physics community but has sparked research and experiments to test its validity.

🔗 Systems 🔗 Systems/Chaos theory

The Burning Ship fractal, first described and created by Michael Michelitsch and Otto E. Rössler in 1992, is generated by iterating the function:

${\displaystyle z_{n+1}=(|\operatorname {Re} \left(z_{n}\right)|+i|\operatorname {Im} \left(z_{n}\right)|)^{2}+c,\quad z_{0}=0}$

in the complex plane ${\displaystyle \mathbb {C} }$ which will either escape or remain bounded. The difference between this calculation and that for the Mandelbrot set is that the real and imaginary components are set to their respective absolute values before squaring at each iteration. The mapping is non-analytic because its real and imaginary parts do not obey the Cauchy–Riemann equations.

🔗 Time 🔗 Writing

Kairos (Ancient Greek: καιρός) is an Ancient Greek word meaning the right, critical, or opportune moment. The ancient Greeks had two words for time: chronos (χρόνος) and kairos. The former refers to chronological or sequential time, while the latter signifies a proper or opportune time for action. While chronos is quantitative, kairos has a qualitative, permanent nature. Kairos also means weather in Modern Greek. The plural, καιροί (kairoi (Ancient and Modern Greek)) means the times. Kairos is a term, idea, and practice that has been applied in several fields including classical rhetoric, modern rhetoric, digital media, Christian theology, and science.

🔗 United States 🔗 Numismatics 🔗 Numismatics/American currency 🔗 United States/Massachusetts

BerkShares is a local currency that circulates in The Berkshires region of Massachusetts. It was launched on September 29, 2006 by BerkShares Inc., with research and development assistance from the Schumacher Center for a New Economics. The BerkShares website lists around 400 businesses in Berkshire County that accept the currency. Since launch, over 10 million BerkShares have been issued from participating branch offices of local banks (as of February 2020, 9 branches of 3 different banks). The bills were designed by John Isaacs and were printed by Excelsior Printing on special paper with incorporated security features from Crane & Co.. BerkShares are pegged with an exchange rate to the US dollar, but the Schumacher Center has discussed the possibility of pegging its value to a basket of local goods in order to insulate the local economy against volatility in the US economy.

Wikipedia offers free copies of all available content to interested users. These databases can be used for mirroring, personal use, informal backups, offline use or database queries (such as for Wikipedia:Maintenance). All text content is licensed under the Creative Commons Attribution-ShareAlike 4.0 License (CC-BY-SA), and most is additionally licensed under the GNU Free Documentation License (GFDL). Images and other files are available under different terms, as detailed on their description pages. For our advice about complying with these licenses, see Wikipedia:Copyrights.

Some of the many ways to read Wikipedia while offline:

• Kiwix: (§ Kiwix) – index of images (2024)
• XOWA: (§ XOWA) – index of images (2015)
• WikiTaxi: § WikiTaxi (for Windows)
• aarddict: § Aard Dictionary / Aard 2
• BzReader: § BzReader and MzReader (for Windows)
• WikiFilter: § WikiFilter
• Wikipedia on rockbox: § Wikiviewer for Rockbox
• Selected Wikipedia articles as a printed document: Help:Printing

Some of them are mobile applications – see "List of Wikipedia mobile applications".

🔗 Mathematics

The Trachtenberg system is a system of rapid mental calculation. The system consists of a number of readily memorized operations that allow one to perform arithmetic computations very quickly. It was developed by the Russian Jewish engineer Jakow Trachtenberg in order to keep his mind occupied while being in a Nazi concentration camp.

The rest of this article presents some methods devised by Trachtenberg. Some of the algorithms Trachtenberg developed are ones for general multiplication, division and addition. Also, the Trachtenberg system includes some specialised methods for multiplying small numbers between 5 and 13.

The section on addition demonstrates an effective method of checking calculations that can also be applied to multiplication.