Have a deep view into what people are curious about.

🔗 Color

Cosmic latte is the average color of the universe, found by a team of astronomers from Johns Hopkins University. In 2001, Karl Glazebrook and Ivan Baldry determined that the average color of the universe was a greenish white, but they soon corrected their analysis in a 2002 paper in which they reported that their survey of the light from over 200,000 galaxies averaged to a slightly beigeish white. The hex triplet value for cosmic latte is #FFF8E7.

🔗 Electronics

A Wallace tree is an efficient hardware implementation of a digital circuit that multiplies two integers. It was devised by the Australian computer scientist Chris Wallace in 1964.

The Wallace tree has three steps:

1. Multiply (that is – AND) each bit of one of the arguments, by each bit of the other, yielding ${\displaystyle n^{2}}$ results. Depending on position of the multiplied bits, the wires carry different weights, for example wire of bit carrying result of ${\displaystyle a_{4}b_{3}}$ is 128 (see explanation of weights below).
2. Reduce the number of partial products to two by layers of full and half adders.
3. Group the wires in two numbers, and add them with a conventional adder.

The second step works as follows. As long as there are three or more wires with the same weight add a following layer:-

• Take any three wires with the same weights and input them into a full adder. The result will be an output wire of the same weight and an output wire with a higher weight for each three input wires.
• If there are two wires of the same weight left, input them into a half adder.
• If there is just one wire left, connect it to the next layer.

The benefit of the Wallace tree is that there are only ${\displaystyle O(\log n)}$ reduction layers, and each layer has ${\displaystyle O(1)}$ propagation delay. As making the partial products is ${\displaystyle O(1)}$ and the final addition is ${\displaystyle O(\log n)}$, the multiplication is only ${\displaystyle O(\log n)}$, not much slower than addition (however, much more expensive in the gate count). Naively adding partial products with regular adders would require ${\displaystyle O(\log ^{2}n)}$ time. From a complexity theoretic perspective, the Wallace tree algorithm puts multiplication in the class NC¹.

These computations only consider gate delays and don't deal with wire delays, which can also be very substantial.

The Wallace tree can be also represented by a tree of 3/2 or 4/2 adders.

It is sometimes combined with Booth encoding.

🔗 Computing 🔗 Psychology 🔗 Usability

"The Magical Number Seven, Plus or Minus Two: Some Limits on Our Capacity for Processing Information" is one of the most highly cited papers in psychology. It was published in 1956 in Psychological Review by the cognitive psychologist George A. Miller of Harvard University's Department of Psychology. It is often interpreted to argue that the number of objects an average human can hold in short-term memory is 7 ± 2. This has occasionally been referred to as Miller's law.

🔗 Television

Mechanical television or mechanical scan television is a television system that relies on a mechanical scanning device, such as a rotating disk with holes in it or a rotating mirror, to scan the scene and generate the video signal, and a similar mechanical device at the receiver to display the picture. This contrasts with modern television technology, which uses electronic scanning methods, for example electron beams in cathode ray tube (CRT) televisions, and liquid-crystal displays (LCD), to create and display the picture.

Mechanical-scanning methods were used in the earliest experimental television systems in the 1920s and 1930s. One of the first experimental wireless television transmissions was by John Logie Baird on November 25, 1925, in London. By 1928 many radio stations were broadcasting experimental television programs using mechanical systems. However the technology never produced images of sufficient quality to become popular with the public. Mechanical-scan systems were largely superseded by electronic-scan technology in the mid-1930s, which was used in the first commercially successful television broadcasts which began in the late 1930s in Great Britain.

A mechanical television receiver is also called a televisor in some countries.

🔗 Spaceflight

Project Highwater was an experiment carried out as part of two of the test flights of NASA's Saturn I launch vehicle (using battleship upper stages), successfully launched into a sub-orbital trajectory from Cape Canaveral, Florida. The Highwater experiment sought to determine the effect of a large volume of water suddenly released into the ionosphere. The project answered questions about the effect of the diffusion of propellants in the event that a rocket was destroyed at high altitude.

The first flight, SA-2, took place on April 25, 1962. After the flight test of the rocket was complete and first stage shutdown occurred, explosive charges on the dummy upper stages destroyed the rocket and released 23,000 US gallons (87,000 L) of ballast water weighing 95 short tons (86,000 kg) into the upper atmosphere at an altitude of 65 miles (105 km), eventually reaching an apex of 90 miles (145 km).

The second flight, SA-3, launched on November 16, 1962, and involved the same payload. The ballast water was explosively released at the flight's peak altitude of 104 miles (167 km). For both of these experiments, the resulting ice clouds expanded to several miles in diameter and lightning-like radio disturbances were recorded.

🔗 Australia 🔗 United States History 🔗 Australia/Australian history 🔗 Australia/South Australia

Rain follows the plow is the conventional name for a now-discredited theory of climatology that was popular throughout the American West and Australia during the late 19th century. The phrase was employed as a summation of the theory by Charles Dana Wilber:

God speed the plow. ... By this wonderful provision, which is only man's mastery over nature, the clouds are dispensing copious rains ... [the plow] is the instrument which separates civilization from savagery; and converts a desert into a farm or garden. ... To be more concise, Rain follows the plow.

The basic premise of the theory was that human habitation and agriculture through homesteading effected a permanent change in the climate of arid and semi-arid regions, making these regions more humid. The theory was widely promoted in the 1870s as a justification for the settlement of the Great Plains, a region previously known as the "Great American Desert". It was also used to justify the expansion of wheat growing on marginal land in South Australia during the same period.

According to the theory, increased human settlement in the region and cultivation of soil would result in an increased rainfall over time, rendering the land more fertile and lush as the population increased. As later historical records of rainfall indicated, the theory was based on faulty evidence arising from brief climatological fluctuations that happened to coincide with settlement, an example of the logical fallacy that correlation means causation. The theory was later refuted by climatologists and is now definitively regarded as pure superstition.

🔗 Computing 🔗 Computing/Computer hardware

N8VEM was a homebrew computing project. It featured a variety of free and open hardware and software. N8VEM builders made their own homebrew computer systems for themselves and shared their experiences with other homebrew computer hobbyists. N8VEM homebrew computer components are made in the style of vintage computers of the mid to late 1970s and early 1980s using a mix of classic and modern technologies. They are designed with ease of amateur assembly in mind.

In November 2015 the N8VEM project was ended by its creator Andrew Lynch and the community reconvened under the new name of Retrobrew Computers.

🔗 United States 🔗 International relations 🔗 Russia 🔗 Military history 🔗 Military history/North American military history 🔗 Military history/United States military history 🔗 United States/Military history - U.S. military history 🔗 Korea 🔗 Women's History 🔗 Sexology and sexuality 🔗 Military history/Asian military history 🔗 Organized crime 🔗 Gender Studies 🔗 Feminism 🔗 Sexology and sexuality/Sex work 🔗 Tambayan Philippines 🔗 Military history/Korean military history

During and following the Korean War, the United States military used regulated prostitution services in South Korean military camptowns. Despite prostitution being illegal since 1948, women in South Korea were the fundamental source of sex services for the U.S. military as well as a component of American and Korean relations. The women in South Korea who served as prostitutes are known as kijichon (기지촌) women, also called as "Korean Military Comfort Women", and were visited by the U.S. military, Korean soldiers and Korean civilians. Kijich'on women were from Korea, Philippines, China, Vietnam, Thailand, Sri Lanka, Nepal, Indonesia and the Commonwealth of Independent States, specifically Russia and Kazakhstan.

🔗 Video games 🔗 Video games/Nintendo

Link: The Faces of Evil, Zelda: The Wand of Gamelon and Zelda's Adventure are action-adventure games produced by Philips for their CD-i format as part of Nintendo's The Legend of Zelda video game series. Not designed for Nintendo platforms, the games owe their existence to negotiations related to Nintendo's decision not to have Philips create a CD add-on to the Super NES. During these negotiations, Philips secured the rights to use Nintendo characters in CD-i third-party developer games. The Faces of Evil and The Wand of Gamelon were developed by Animation Magic and were both released in North America on October 10, 1993, and Zelda's Adventure was developed by Viridis and was released in North America on June 5, 1994. The games were given little funding or development time, and Nintendo provided only cursory input. None of the games are canonical to the Zelda franchise.

CD-i players did not sell well and the games saw relatively small sales figures. Though the games initially received largely positive reviews, they have been universally criticized since the mid-2000s. This is attributed to the reaction of many gamers to the obscure games' full motion video cutscenes when they first became widely available through video-sharing websites such as YouTube. The cutscenes are perceived to be of poor quality. Because the aging early 1990s visual effects of the titles failed to live up to the graphic effects of the 2000s, and because for many fans this was their first experience of the games, the CD-i Zelda titles have developed a critical reputation as particularly poor based largely on animation quality and to an extent awkward controls. In the eyes of "devout" hardcore gamers, according to Edge, the games are now considered "tantamount to blasphemy".

Faces of Evil and Wand of Gamelon are played using the side-scrolling view introduced in Zelda II: The Adventure of Link, while Zelda's Adventure has a top-down view reminiscent of the original The Legend of Zelda. All the CD-i Zelda games begin with animated FMVs to illustrate the capabilities of the CD-ROM format, save Zelda's Adventure, which begins with a live-action video.

🔗 Psychology 🔗 Museums

Museum fatigue is a state of physical or mental fatigue caused by the experience of exhibits in museums and similar cultural institutions. The collection of phenomena that characterize museum fatigue was first described in 1916, and has since received widespread attention in popular and scientific contexts.

The first known description of museum fatigue was made by Benjamin Ives Gilman in the January 1916 edition of The Scientific Monthly. Gilman mainly focused on the efforts of museum fatigue on how the viewing displays are placed. Gilman went on to say that the way the displays were presented caused museum fatigue. In other later studies, Edward Robinson in 1928 spoke more about museum fatigue, specifically of four museums that showed a lot of characteristics of museum fatigue because of how the displays were placed. Arthur Melton provided more proof for Robinson by observing visitors' interest in the displays decreased as the number of displays increased.

In a more recent study of the phenomenon, Falk, Koran, Direking, and Dreblow studied museum fatigue at the Florida Museum of Natural History in 1985. While observing visitors they noticed a pattern of high interest in anything in the museum for about 30 minutes and then a decrease in interest. In 1997–1998, Beverly Serrell in her research determined that in less than 20 minutes people became apathetic towards the museum. Museum fatigue has also been applied in zoos to see if they had the same effect. In one study in 1986, Bitgood, Patterson, and Benefeld observed the reptile house of the Birmingham Zoo. While observing they noticed that the pattern was different from museum fatigue.