Have a deep view into what people are curious about.

🔗 Mathematics

The probabilistic method is a nonconstructive method, primarily used in combinatorics and pioneered by Paul Erdős, for proving the existence of a prescribed kind of mathematical object. It works by showing that if one randomly chooses objects from a specified class, the probability that the result is of the prescribed kind is strictly greater than zero. Although the proof uses probability, the final conclusion is determined for certain, without any possible error.

This method has now been applied to other areas of mathematics such as number theory, linear algebra, and real analysis, as well as in computer science (e.g. randomized rounding), and information theory.

🔗 Telecommunications 🔗 Software 🔗 Software/Computing 🔗 Hong Kong

KaiOS is a mobile operating system based on Linux, developed by KaiOS Technologies, a US-based company. It is forked from B2G OS (Boot to Gecko OS), an open source community-driven fork of Firefox OS, which was discontinued by Mozilla in 2016.

The primary features of KaiOS bring support for 4G LTE E, VoLTE, GPS and Wi-Fi with HTML5-based apps and longer battery life to non-touch devices with optimized user interface, less memory and energy consumption. It also features over-the-air updates. A dedicated app marketplace (KaiStore) enables users to download applications. Some services are preloaded as HTML5 applications, including Twitter, Facebook and YouTube. The operating system is comparatively lightweight on hardware resource usage, and is able to run on devices with just 256 MB of memory.

The operating system first appeared in 2017 and is developed by KaiOS Technologies Inc., a San Diego, California-based company headed by CEO Sebastien Codeville with offices in other countries. In June 2018, Google invested US$22 million in the operating system. India-based telecom operator Reliance Jio also invested $7 million in cash to pick up a 16% stake in the company.

In market share study results announced in May 2018, KaiOS beat Apple's iOS for second place in India, while Android dominates with 71%, albeit down by 9%. KaiOS growth is being largely attributed to popularity of the competitively-priced Jio Phone. In Q1 2018, 23 million KaiOS devices were shipped.

KaiOS is also the name of an unrelated Linux project, dating from 2014 and targeted at embedded systems.

🔗 United States 🔗 Military history 🔗 Military history/North American military history 🔗 Military history/United States military history 🔗 United States/Military history - U.S. military history 🔗 Military history/Military science, technology, and theory 🔗 Physics 🔗 Women's History 🔗 History of Science 🔗 Tennessee 🔗 Military history/World War II 🔗 Physics/History 🔗 Science

The Calutron Girls were a group of young women, mostly high school graduates who joined the World War II efforts in Oak Ridge, Tennessee in 1945.

Although they were not allowed to know at the time, they were monitoring dials and watching meters for a calutron, a mass spectrometer that separates uranium isotopes. The enriched uranium was used to make the first atomic bomb.

Calutron Girls were trained and employed at the Y-12 National Security Complex. Wartime labor shortages forced the Tennessee Eastman Corporation to hire women to work at the Y-12 plant.

According to Gladys Owens, one of the few Calutron Girls, a manager at the facility once told them: "We can train you how to do what is needed, but cannot tell you what you are doing. I can only tell you that if our enemies beat us to it, God have mercy on us!"

🔗 Computing 🔗 Computing/Software

dvdisaster is a computer program aimed to enhance data survivability on optical discs by creating error detection and correction data, which is used for data recovery. dvdisaster works exclusively at the image level. This program can be used either to generate Error-Correcting Code (ECC) data from an existing media or to augment an ISO image with ECC data prior to being written onto a medium. dvdisaster is free software available under the GNU General Public License.

🔗 Software 🔗 Software/Computing

Waterfox is an open-source web browser for x64, ARM64, and PPC64LE systems. It is intended to be speedy and ethical, and maintain support for legacy extensions dropped by Firefox, from which it is forked. There are official releases for Windows (including a portable version), Mac OS, Linux and Android.

Waterfox is based on Firefox and is compiled using various compilers and using Intel's Math Kernel Library, Streaming SIMD Extensions 3 and Advanced Vector Extensions. Linux builds are built with Clang on all architectures other than PPC64LE. Waterfox is continuing to support the long-standing XUL and XPCOM add-on capability that Firefox removed in version 57.

🔗 Physics 🔗 Physics/Fluid Dynamics

A jiggle syphon (or siphon) is the combination of a syphon pipe and a simple priming pump that uses mechanical shaking action to pump enough liquid up the pipe to reach the highest point, and thus start the syphoning action.

🔗 Geology 🔗 Michigan 🔗 Gemology and Jewelry/Gemstones 🔗 Gemology and Jewelry

A Petoskey stone is a rock and a fossil, often pebble-shaped, that is composed of a fossilized rugose coral, Hexagonaria percarinata. Such stones were formed as a result of glaciation, in which sheets of ice plucked stones from the bedrock, grinding off their rough edges and depositing them in the northwestern (and some in the northeastern) portion of Michigan's lower peninsula. In those same areas of Michigan, complete fossilized coral colony heads can be found in the source rocks for the Petoskey stones.

Petoskey stones are found in the Gravel Point Formation of the Traverse Group. They are fragments of a coral reef that was originally deposited during the Devonian period. When dry, the stone resembles ordinary limestone but when wet or polished using lapidary techniques, the distinctive mottled pattern of the six-sided coral fossils emerges. It is sometimes made into decorative objects. Other forms of fossilized coral are also found in the same location.

In 1965, it was named the state stone of Michigan.

🔗 Sanitation

A bidet shower—also known as a handheld bidet, commode shower, toilet shower, health faucet, bum shower, shatafa (from the Arabic: شَطَّافَة [ʃɑtˤˈtˤɑːfɑ], "rinser") or bum gun—is a hand-held triggered nozzle that is placed near the toilet and delivers a spray of water used for anal cleansing and cleaning of the genitals after using the toilet for defecation and urination, popularised by Arab nations where the bidet shower is a common bathroom accessory. The device is similar to that of a kitchen sink sprayer.

In predominantly Catholic countries, the Muslim world, in the Eastern Orthodox and Hindu cultures, and in some Protestant countries such as Finland, water is usually used for anal cleansing, using a jet (bidet shower, bidet) or vessel, and a person's hand (in some places only the left hand is used).

🔗 Death 🔗 LGBT studies 🔗 Iraq 🔗 Post-hardcore

The emo killings in Iraq were a string of homicides that were part of a campaign against Iraqi teenage boys who dressed in a Westernized emo style. Between 6 and 70 young men were kidnapped, tortured and murdered in Baghdad and Iraq during March 2012. In September 2012, BBC News reported that gay men in Baghdad said the killings had not abated.

🔗 Physics 🔗 Biophysics

Optical tweezers (originally called single-beam gradient force trap) are scientific instruments that use a highly focused laser beam to provide an attractive or repulsive force (typically on the order of piconewtons), depending on the relative refractive index between particle and surrounding medium; these forces can be used to physically hold and move microscopic objects, in a manner similar to tweezers. They are able to trap and manipulate small particles, whose size is typically in microns, including dielectric and absorbing particles. Optical tweezers have been particularly successful in studying a variety of biological systems in recent years.