Have a deep view into what people are curious about.

🔗 Mathematics 🔗 Statistics

The Gompertz curve or Gompertz function is a type of mathematical model for a time series, named after Benjamin Gompertz (1779–1865). It is a sigmoid function which describes growth as being slowest at the start and end of a given time period. The right-side or future value asymptote of the function is approached much more gradually by the curve than the left-side or lower valued asymptote. This is in contrast to the simple logistic function in which both asymptotes are approached by the curve symmetrically. It is a special case of the generalised logistic function. The function was originally designed to describe human mortality, but since has been modified to be applied in biology, with regard to detailing populations.

🔗 Volcanoes 🔗 Islands 🔗 British Overseas Territories 🔗 Argentina 🔗 South America/South Georgia and the South Sandwich Islands 🔗 South America

South Georgia and the South Sandwich Islands (SGSSI) is a British Overseas Territory in the southern Atlantic Ocean. It is a remote and inhospitable collection of islands, consisting of South Georgia Island and a chain of smaller islands known as the South Sandwich Islands. South Georgia is 165 kilometres (103 mi) long and 35 kilometres (22 mi) wide and is by far the largest island in the territory. The South Sandwich Islands lie about 700 kilometres (430 mi) southeast of South Georgia. The territory's total land area is 3,903 km² (1,507 sq mi). The Falkland Islands are about 1,300 kilometres (810 mi) west from its nearest point.

No permanent native population lives in the South Sandwich Islands, and a very small non-permanent population resides on South Georgia. There are no scheduled passenger flights or ferries to or from the territory, although visits by cruise liners to South Georgia are increasingly popular, with several thousand visitors each summer.

The United Kingdom claimed sovereignty over South Georgia in 1775 and the South Sandwich Islands in 1908. The territory of "South Georgia and the South Sandwich Islands" was formed in 1985; previously, it had been governed as part of the Falkland Islands Dependencies. Argentina claimed South Georgia in 1927 and claimed the South Sandwich Islands in 1938.

Argentina maintained a naval station, Corbeta Uruguay, on Thule Island in the South Sandwich Islands from 1976 until 1982 when it was closed by the Royal Navy. The Argentine claim over South Georgia contributed to the 1982 Falklands War, during which Argentine forces briefly occupied the island. Argentina continues to claim sovereignty over South Georgia and the South Sandwich Islands.

Toothfish are vital to the islands' economy; as a result, Toothfish Day is celebrated on 4 September as a bank holiday in the territory.

🔗 Evolutionary biology 🔗 Ecology 🔗 Project-independent assessment

Motion camouflage is camouflage which provides a degree of concealment for a moving object, given that motion makes objects easy to detect however well their coloration matches their background or breaks up their outlines.

The principal form of motion camouflage, and the type generally meant by the term, involves an attacker's mimicking the optic flow of the background as seen by its target. This enables the attacker to approach the target while appearing to remain stationary from the target's perspective, unlike in classical pursuit (where the attacker moves straight towards the target at all times, and often appears to the target to move sideways). The attacker chooses its flight path so as to remain on the line between the target and some landmark point. The target therefore does not see the attacker move from the landmark point. The only visible evidence that the attacker is moving is its looming, the change in size as the attacker approaches.

Camouflage is sometimes facilitated by motion, as in the leafy sea dragon and some stick insects. These animals complement their passive camouflage by swaying like plants in the wind or ocean currents, delaying their recognition by predators.

First discovered in hoverflies in 1995, motion camouflage by minimizing optic flow has been demonstrated in another insect order, dragonflies, as well as in two groups of vertebrates, falcons and echolocating bats. Since bats hunt at night, they cannot use camouflage. Instead they use an efficient homing strategy called constant absolute target direction. It has been suggested that anti-aircraft missiles could benefit from similar techniques.

🔗 Technology 🔗 Physics 🔗 Ancient Near East 🔗 Ancient Egypt 🔗 Archaeology 🔗 Spectroscopy 🔗 Blades

Tutankhamun's meteoric iron dagger, also known as Tutankhamun's iron dagger and King Tut's dagger, is an iron-bladed dagger from the tomb of the ancient Egyptian Pharaoh Tutankhamun (reigned c. 1334–1325 BC). As the blade composition and homogeneity closely correlate with meteorite composition and homogeneity, the material for the blade is determined to have originated by way of a meteoritic landing. The dagger is currently displayed at the Egyptian Museum in Cairo.

🔗 Technology 🔗 Physics 🔗 Neuroscience 🔗 Molecular Biology 🔗 Molecular Biology/Molecular and Cell Biology

Confocal microscopy, most frequently confocal laser scanning microscopy (CLSM) or laser scanning confocal microscopy (LSCM), is an optical imaging technique for increasing optical resolution and contrast of a micrograph by means of using a spatial pinhole to block out-of-focus light in image formation. Capturing multiple two-dimensional images at different depths in a sample enables the reconstruction of three-dimensional structures (a process known as optical sectioning) within an object. This technique is used extensively in the scientific and industrial communities and typical applications are in life sciences, semiconductor inspection and materials science.

Light travels through the sample under a conventional microscope as far into the specimen as it can penetrate, while a confocal microscope only focuses a smaller beam of light at one narrow depth level at a time. The CLSM achieves a controlled and highly limited depth of field.

🔗 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".

🔗 Mathematics

A mathematical coincidence is said to occur when two expressions with no direct relationship show a near-equality which has no apparent theoretical explanation.

For example, there is a near-equality close to the round number 1000 between powers of 2 and powers of 10:

${\displaystyle 2^{10}=1024\approx 1000=10^{3}.}$

Some mathematical coincidences are used in engineering when one expression is taken as an approximation of another.

🔗 Computing 🔗 Computing/Software 🔗 Computing/Computer science 🔗 Linux

The Unix philosophy, originated by Ken Thompson, is a set of cultural norms and philosophical approaches to minimalist, modular software development. It is based on the experience of leading developers of the Unix operating system. Early Unix developers were important in bringing the concepts of modularity and reusability into software engineering practice, spawning a "software tools" movement. Over time, the leading developers of Unix (and programs that ran on it) established a set of cultural norms for developing software; these norms became as important and influential as the technology of Unix itself; this has been termed the "Unix philosophy."

The Unix philosophy emphasizes building simple, short, clear, modular, and extensible code that can be easily maintained and repurposed by developers other than its creators. The Unix philosophy favors composability as opposed to monolithic design.

🔗 Computing 🔗 Statistics 🔗 Computational Biology

The following is a list of algorithms along with one-line descriptions for each.

🔗 Internet culture 🔗 Death 🔗 Lists 🔗 Photography 🔗 Photography/History of photography

This is a list of serious injuries and deaths in which one or more subjects of a selfie were killed or injured, either before, during or after having taken a photo of themselves, with the accident at least in part attributed to the taking of the photo.

The United States Department of Transportation estimated that during 2014, the so-called "year of the selfie", 33,000 people were injured while driving and using a cell-phone in some fashion, which can include talking, listening, and "manual button/control actuation" including taking, uploading, downloading, editing, or opening of selfies. A 2015 survey by Erie Insurance Group found that 4% of all drivers admitted to taking selfies while driving.

The Washington Post reported in January 2016 that "about half" of at least 27 "selfie related" deaths in 2015 had occurred in India. No official datasets on the number of people who died taking selfies in India exists, but reports show from 2014 up to August 2016, there have been at least 54 deaths in India while taking selfies. The Indian Ministry of Tourism asked states to identify and barricade 'selfie danger' areas, its first national attempt to deal with the selfie deaths. Mumbai Police identified at least 16 danger zones after a man drowned attempting to save a selfie-taker. No-selfie zones were also established in certain areas of the Kumbh Mela because organizers feared bottlenecks caused by selfie-takers could spark stampedes.

A 2018 study of news reports showed that between October 2011 and November 2017, there were 259 selfie deaths in 137 incidents reported globally, with the highest occurrences in India, followed by Russia, United States, and Pakistan. The mean age was 23 years old, with male deaths outnumbering female about three to one.