Random Articles (Page 30)

Have a deep view into what people are curious about.

πŸ”— Vega program

πŸ”— Soviet Union πŸ”— Spaceflight πŸ”— Solar System

The Vega program (Cyrillic: Π’Π΅Π“Π°) was a series of Venus missions that also took advantage of the appearance of comet 1P/Halley in 1986. Vega 1 and Vega 2 were uncrewed spacecraft launched in a cooperative effort among the Soviet Union (who also provided the spacecraft and launch vehicle) and Austria, Bulgaria, France, Hungary, the German Democratic Republic, Poland, Czechoslovakia, and the Federal Republic of Germany in December 1984. They had a two-part mission to investigate Venus and also flyby Halley's Comet.

The flyby of Halley's Comet had been a late mission change in the Venera program following on from the cancellation of the American Halley mission in 1981. A later Venera mission was canceled and the Venus part of the Vega 1 mission was reduced. Because of this, the craft was designated VeGa, a contraction of Venera and Gallei (Π’Π΅Π½Π΅Ρ€Π° and ГаллСя respectively, the Russian words for "Venus" and "Halley"). The spacecraft design was based on the previous Venera 9 and Venera 10 missions.

The two spacecraft were launched on 15 and 21 December 1984, respectively. With their redesignated dual missions, the Vega probes became part of the Halley Armada, a group of space probes that studied Halley's Comet during its 1985/1986 perihelion.

Discussed on

πŸ”— Loudness war

πŸ”— Professional sound production

The loudness war (or loudness race) refers to the trend of increasing audio levels in recorded music, which reduces audio fidelity, and according to many critics, listener enjoyment. Increasing loudness was first reported as early as the 1940s, with respect to mastering practices for 7" singles. The maximum peak level of analog recordings such as these is limited by varying specifications of electronic equipment along the chain from source to listener, including vinyl and Compact Cassette players. The issue garnered renewed attention starting in the 1990s with the introduction of digital signal processing capable of producing further loudness increases.

With the advent of the Compact Disc (CD), music is encoded to a digital format with a clearly defined maximum peak amplitude. Once the maximum amplitude of a CD is reached, loudness can be increased still further through signal processing techniques such as dynamic range compression and equalization. Engineers can apply an increasingly high ratio of compression to a recording until it more frequently peaks at the maximum amplitude. In extreme cases, efforts to increase loudness can result in clipping and other audible distortion. Modern recordings that use extreme dynamic range compression and other measures to increase loudness therefore can sacrifice sound quality to loudness. The competitive escalation of loudness has led music fans and members of the musical press to refer to the affected albums as "victims of the loudness war."

Discussed on

πŸ”— Hinged dissection

πŸ”— Mathematics

A hinged dissection, also known as a swing-hinged dissection or Dudeney dissection, is a kind of geometric dissection in which all of the pieces are connected into a chain by "hinged" points, such that the rearrangement from one figure to another can be carried out by swinging the chain continuously, without severing any of the connections. Typically, it is assumed that the pieces are allowed to overlap in the folding and unfolding process; this is sometimes called the "wobbly-hinged" model of hinged dissection.

Discussed on

πŸ”— The man who singlehandedly carved a road through a mountain

πŸ”— Biography πŸ”— India πŸ”— India/Bihar

Dashrath Manjhi (1934 – 17 August 2007), also known as Mountain Man, was a laborer in Gehlaur village, near Gaya in Bihar, India, who carved a path 110 m long (360 ft), 9.1 m (30 ft) wide and 7.7 m (25 ft) deep through a ridge of hills using only a hammer and chisel. After 22 years of work, Dashrath shortened travel between the Atri and Wazirganj blocks of Gaya town from 55Β km to 15Β km.

Discussed on

πŸ”— Theory of Constraints

πŸ”— Technology πŸ”— Business πŸ”— Marketing & Advertising

The theory of constraints (TOC) is a management paradigm that views any manageable system as being limited in achieving more of its goals by a very small number of constraints. There is always at least one constraint, and TOC uses a focusing process to identify the constraint and restructure the rest of the organization around it. TOC adopts the common idiom "a chain is no stronger than its weakest link". That means that organizations and processes are vulnerable because the weakest person or part can always damage or break them, or at least adversely affect the outcome.

Discussed on

πŸ”— Eigen's Paradox

πŸ”— Evolutionary biology πŸ”— Molecular Biology πŸ”— Molecular Biology/Genetics

In evolutionary biology and population genetics, the error threshold (or critical mutation rate) is a limit on the number of base pairs a self-replicating molecule may have before mutation will destroy the information in subsequent generations of the molecule. The error threshold is crucial to understanding "Eigen's paradox".

The error threshold is a concept in the origins of life (abiogenesis), in particular of very early life, before the advent of DNA. It is postulated that the first self-replicating molecules might have been small ribozyme-like RNA molecules. These molecules consist of strings of base pairs or "digits", and their order is a code that directs how the molecule interacts with its environment. All replication is subject to mutation error. During the replication process, each digit has a certain probability of being replaced by some other digit, which changes the way the molecule interacts with its environment, and may increase or decrease its fitness, or ability to reproduce, in that environment.

Discussed on

πŸ”— Group f/64

πŸ”— California πŸ”— California/San Francisco Bay Area πŸ”— Photography

Group f/64 or f.64 was a group founded by seven 20th-century San Francisco Bay Area photographers who shared a common photographic style characterized by sharply focused and carefully framed images seen through a particularly Western (U.S.) viewpoint. In part, they formed in opposition to the pictorialist photographic style that had dominated much of the early 20th century, but moreover, they wanted to promote a new modernist aesthetic that was based on precisely exposed images of natural forms and found objects.

Discussed on

πŸ”— Musth

πŸ”— Mammals

Musth or must (an Urdu word, from Persian, lit. drunk) is a periodic condition in bull (male) elephants characterized by highly aggressive behavior and accompanied by a large rise in reproductive hormones.

Testosterone levels in an elephant in musth can be on average 60 times greater than in the same elephant at other times (in specific individuals these testosterone levels can even reach as much as 140 times the normal). However, whether this hormonal surge is the sole cause of musth, or merely a contributing factor, is unknown.

Scientific investigation of musth is problematic because even the most placid elephants become highly violent toward humans and other elephants during musth.

Discussed on

  • "Musth" | 2020-04-06 | 77 Upvotes 15 Comments

πŸ”— Rubber duck debugging

πŸ”— Hungary

Discussed on

πŸ”— Negative Base

πŸ”— Computer science πŸ”— Mathematics

A negative base (or negative radix) may be used to construct a non-standard positional numeral system. Like other place-value systems, each position holds multiples of the appropriate power of the system's base; but that base is negativeβ€”that is to say, the base b is equal to βˆ’r for some natural number r (r β‰₯ 2).

Negative-base systems can accommodate all the same numbers as standard place-value systems, but both positive and negative numbers are represented without the use of a minus sign (or, in computer representation, a sign bit); this advantage is countered by an increased complexity of arithmetic operations. The need to store the information normally contained by a negative sign often results in a negative-base number being one digit longer than its positive-base equivalent.

The common names for negative-base positional numeral systems are formed by prefixing nega- to the name of the corresponding positive-base system; for example, negadecimal (base βˆ’10) corresponds to decimal (base 10), negabinary (base βˆ’2) to binary (base 2), negaternary (base βˆ’3) to ternary (base 3), and negaquaternary (base βˆ’4) to quaternary (base 4).

Discussed on