Have a deep view into what people are curious about.

🔗 Technology 🔗 Television

A Nipkow disk (sometimes Anglicized as Nipkov disk; patented in 1884), also known as scanning disk, is a mechanical, rotating, geometrically operating image scanning device, patented in 1885 by Paul Gottlieb Nipkow. This scanning disk was a fundamental component in mechanical television through the 1920s and 1930s.

🔗 Soviet Union 🔗 Socialism 🔗 Latvia 🔗 Estonia 🔗 Soviet Union/history of Russia 🔗 Soviet Union/Russia 🔗 Lithuania

The Baltic Way or Baltic Chain (also Chain of Freedom; Estonian: Balti kett; Latvian: Baltijas ceļš; Lithuanian: Baltijos kelias; Russian: Балтийский путь Baltiysky put) was a peaceful political demonstration that occurred on 23 August 1989. Approximately two million people joined their hands to form a human chain spanning 675.5 kilometres (419.7 mi) across the three Baltic states – Estonia, Latvia, and Lithuania, which were considered at the time to be constituent republics of the Soviet Union.

The demonstration originated in "Black Ribbon Day" protests held in the western cities in the 1980s. It marked the 50th anniversary of the Molotov–Ribbentrop Pact between the Soviet Union and Nazi Germany. The pact and its secret protocols divided Eastern Europe into spheres of influence and led to the occupation of the Baltic states in 1940. The event was organised by Baltic pro-independence movements: Rahvarinne of Estonia, the Tautas fronte of Latvia, and Sąjūdis of Lithuania. The protest was designed to draw global attention by demonstrating a popular desire for independence and showcasing solidarity among the three nations. It has been described as an effective publicity campaign, and an emotionally captivating and visually stunning scene. The event presented an opportunity for the Baltic activists to publicise the Soviet rule and position the question of Baltic independence not only as a political matter, but also as a moral issue. The Soviet authorities responded to the event with intense rhetoric, but failed to take any constructive actions that could bridge the widening gap between the Baltic republics and the rest of the Soviet Union. Within seven months of the protest, Lithuania became the first of the Soviet republics to declare independence.

After the Revolutions of 1989, 23 August has become an official remembrance day both in the Baltic countries, in the European Union and in other countries, known as the Black Ribbon Day or as the European Day of Remembrance for Victims of Stalinism and Nazism.

🔗 Visual arts

Iron gall ink (also known as common ink, standard ink, oak gall ink or iron gall nut ink) is a purple-black or brown-black ink made from iron salts and tannic acids from vegetable sources. It was the standard ink formulation used in Europe for the 1400-year period between the 5th and 19th centuries, remained in widespread use well into the 20th century, and is still sold today.

🔗 Aviation 🔗 Military history 🔗 Military history/Military aviation 🔗 Engineering 🔗 Industrial design

Speed tape is an aluminium pressure-sensitive tape used to perform minor repairs on aircraft and racing cars. It is used as a temporary repair material until a more permanent repair can be carried out. It has an appearance similar to duct tape, for which it is sometimes mistaken, but its adhesive is capable of sticking on an airplane fuselage or wing at high speeds, hence the name.

🔗 Philately 🔗 Netherlands

A postzegelcode is a hand-written method of franking in the Netherlands. It consists of a code containing nine numbers and letters that customers can purchase online from PostNL and write directly on their piece of mail within five days as proof-of-payment in place of a postage stamp.

For mail within the Netherlands the nine letters and numbers are written as a grid of 3x3. For international mail there is fourth additional row that contains P, N, L.

The system was started in 2013. Initially the postzegelcode was more expensive than a stamp because additional handling systems were required. Then for a while the postzegelcode was cheaper. Eventually the tariffs were set to the same price.

In December 2020, 590,000 people sent cards with postzegelcodes.

🔗 Technology 🔗 Physics

The Geneva drive or Maltese cross is a gear mechanism that translates a continuous rotation movement into intermittent rotary motion.

The rotating drive wheel is usually equipped with a pin that reaches into a slot located in the other wheel (driven wheel) that advances it by one step at a time. The drive wheel also has an elevated circular blocking disc that "locks" the rotating driven wheel in position between steps.

🔗 Languages 🔗 Melanesia 🔗 Melanesia/Papua New Guinea

Manam is a Kairiru–Manam language spoken mainly on the volcanic Manam Island, northeast of New Guinea.

Theory of the Stationary Bandit — theory of the origin of the state, developed by American scholars Martin C. McGuire and Mansur Olson.

🔗 Biography 🔗 Soviet Union 🔗 Russia 🔗 Biography/sports and games 🔗 Russia/sports and games in Russia 🔗 Armenia 🔗 Underwater diving 🔗 Swimming

Shavarsh Vladimiri (Vladimirovich) Karapetyan (Armenian: Շավարշ Կարապետյան; born May 19, 1953) is a retired former Soviet finswimmer, best known for saving the lives of 20 people in a 1976 incident in Yerevan.

🔗 Books 🔗 Sociology

The Power Elite is a 1956 book by sociologist C. Wright Mills, in which Mills calls attention to the interwoven interests of the leaders of the military, corporate, and political elements of society and suggests that the ordinary citizen in modern times is a relatively powerless subject of manipulation by those three entities.