Have a deep view into what people are curious about.

🔗 Astronomy 🔗 Astronomy/Astronomical objects

Hoag's Object is a non-typical galaxy of the type known as a ring galaxy. The galaxy is named after Arthur Hoag who discovered it in 1950 and identified it as either a planetary nebula or a peculiar galaxy with eight billion stars, spanning roughly 100,000 light years.

🔗 Military history 🔗 Religion 🔗 Anthropology 🔗 Sociology 🔗 Archaeology 🔗 Mythology 🔗 Military history/Military culture, traditions, and heraldry

The kóryos (Proto-Indo-European: "army, people under arms" or "detachment, war party") refers to the hypothetical Proto-Indo-European brotherhood of warriors in which unmarried young males served for a number of years before their full integration to the host society, in the context of a rite of passage into manhood.

Subsequent Indo-European traditions and myths feature parallel linkages between property-less adolescent males, perceived as an age-class not yet fully integrated into the community of the married men; their service in a "police-army" sent away for a part of the year in the wild (where they hunted animals and raided foreign communities) and defending the host society during the remaining part of the year; their mystical self-identification with wolves and dogs as symbols of death, promiscuity, lawlessness, and warrior fury; and the idea of a liminality between invulnerability and death on one side, and youth and adulthood on the other side.

🔗 Lists 🔗 Countries

The following nations prohibit civilians wearing or possessing camouflage print clothing:

• Azerbaijan
• Antigua and Barbuda
• Bahamas
• Barbados
• Dominica
• Ghana
• Grenada
• Jamaica
• Nigeria
• Oman
• Philippines (uniforms only)
• Saint Lucia
• Saint Vincent and the Grenadines
• Saudi Arabia
• Trinidad and Tobago
• Uganda
• Zambia
• Zimbabwe

🔗 Computing 🔗 Computing/Early computers

The IBM 7950, also known as Harvest, was a one-of-a-kind adjunct to the Stretch computer which was installed at the United States National Security Agency (NSA). Built by IBM, it was delivered in 1962 and operated until 1976, when it was decommissioned. Harvest was designed to be used for cryptanalysis.

🔗 Color 🔗 Amusement Parks 🔗 Disney

Go Away Green refers to a range of paint colors used in Disney Parks to divert attention away from infrastructure. It has been compared to military camouflage like Olive Drab.

Imagineer John Hench wrote about developing such colors, "We chose a neutral gray-brown for the railing, a 'go away' color that did not call attention to itself, even though it was entirely unrelated to the Colonial color scheme."

Large attraction buildings visible either inside or outside a park such as Soarin’ at California Adventure or Indiana Jones Adventure at Disneyland are often painted a muted green. Necessary in-park infrastructure like speakers, lamp posts, fences, trash cans, and the former entrance to Club 33 are also painted various shades of green.

This concept also extends to grays, browns, and blues for spaces with less greenery or buildings that extend above the tree line, such as Guardians of the Galaxy: Cosmic Rewind.

🔗 Palaeontology 🔗 Amphibians and Reptiles 🔗 Mammals

Dimetrodon ( (listen) or , meaning "two measures of teeth") is an extinct genus of non-mammalian synapsids that lived during the Cisuralian (Early Permian), around 295–272 million years ago (Ma). It is a member of the family Sphenacodontidae. The most prominent feature of Dimetrodon is the large neural spine sail on its back formed by elongated spines extending from the vertebrae. It walked on four legs and had a tall, curved skull with large teeth of different sizes set along the jaws. Most fossils have been found in the southwestern United States, the majority coming from a geological deposit called the Red Beds of Texas and Oklahoma. More recently, fossils have been found in Germany. Over a dozen species have been named since the genus was first described in 1878.

Dimetrodon is often mistaken for a dinosaur or as a contemporary of dinosaurs in popular culture, but it became extinct some 40 million years before the first appearance of dinosaurs. Reptile-like in appearance and physiology, Dimetrodon is nevertheless more closely related to mammals than to modern reptiles, though it is not a direct ancestor of mammals. Dimetrodon is assigned to the "non-mammalian synapsids", a group traditionally called "mammal-like reptiles". This groups Dimetrodon together with mammals in a clade (evolutionary group) called Synapsida, while placing dinosaurs, reptiles and birds in a separate clade, Sauropsida. Single openings in the skull behind each eye, known as temporal fenestrae, and other skull features distinguish Dimetrodon and mammals from most of the earliest sauropsids.

Dimetrodon was probably one of the apex predators of the Cisuralian ecosystems, feeding on fish and tetrapods, including reptiles and amphibians. Smaller Dimetrodon species may have had different ecological roles. The sail of Dimetrodon may have been used to stabilize its spine or to heat and cool its body as a form of thermoregulation. Some recent studies argue that the sail would have been ineffective at removing heat from the body due to large species being discovered with small sails and small species being discovered with large sails, essentially ruling out heat regulation as its main purpose. The sail was most likely used in courtship display with methods such as threatening rivals or showing off to potential mates.

🔗 Geography 🔗 Romania 🔗 Ecology 🔗 Caves

Movile Cave (Romanian: Peștera Movile) is a cave near Mangalia, Constanța County, Romania discovered in 1986 by Cristian Lascu a few kilometers from the Black Sea coast. It is notable for its unique groundwater ecosystem abundant in hydrogen sulfide and carbon dioxide, but low in oxygen. Life in the cave has been separated from the outside for the past 5.5 million years and it is based completely on chemosynthesis rather than photosynthesis.

🔗 Computer science

In computer science, a succinct data structure is a data structure which uses an amount of space that is "close" to the information-theoretic lower bound, but (unlike other compressed representations) still allows for efficient query operations. The concept was originally introduced by Jacobson to encode bit vectors, (unlabeled) trees, and planar graphs. Unlike general lossless data compression algorithms, succinct data structures retain the ability to use them in-place, without decompressing them first. A related notion is that of a compressed data structure, in which the size of the data structure depends upon the particular data being represented.

Suppose that ${\displaystyle Z}$ is the information-theoretical optimal number of bits needed to store some data. A representation of this data is called:

• implicit if it takes ${\displaystyle Z+O(1)}$ bits of space,
• succinct if it takes ${\displaystyle Z+o(Z)}$ bits of space, and
• compact if it takes ${\displaystyle O(Z)}$ bits of space.

For example, a data structure that uses ${\displaystyle 2Z}$ bits of storage is compact, ${\displaystyle Z+{\sqrt {Z}}}$ bits is succinct, ${\displaystyle Z+\lg Z}$ bits is also succinct, and ${\displaystyle Z+3}$ bits is implicit.

Implicit structures are thus usually reduced to storing information using some permutation of the input data; the most well-known example of this is the heap.

🔗 Toys

A pop-pop boat is a toy with a very simple steam engine without moving parts, typically powered by a candle or vegetable oil burner. The name comes from the noise made by some versions of the boats. Other names are putt-putt boat, crazy boat, flash-steamer, hot-air-boat, pulsating water engine boat. Around the world they may be called Can-Can-boot, Knatterboot, toc-toc, Puf-Puf boat, Poof Poof craft, Phut-Phut, or Pouet-Pouet.

🔗 Typography

In typography, an asterism, ⁂, is a typographic symbol consisting of three asterisks placed in a triangle, which is used for a variety of purposes. The name originates from the astronomical term for a group of stars.

The asterism was originally used as a type of dinkus in typography, though increasingly rarely. It can also be used to mean "untitled" or author or title withheld – as seen, for example, in some editions of Album for the Young by composer Robert Schumann (№ 21, 26, and 30). In meteorology, an asterism in a station model indicates moderate snowfall.