Random Articles (Page 3)
Have a deep view into what people are curious about.
π Nagle's Algorithm
Nagle's algorithm is a means of improving the efficiency of TCP/IP networks by reducing the number of packets that need to be sent over the network. It was defined by John Nagle while working for Ford Aerospace. It was published in 1984 as a Request for Comments (RFC) with title Congestion Control in IP/TCP Internetworks in RFCΒ 896.
The RFC describes what he called the "small-packet problem", where an application repeatedly emits data in small chunks, frequently only 1 byte in size. Since TCP packets have a 40-byte header (20 bytes for TCP, 20 bytes for IPv4), this results in a 41-byte packet for 1 byte of useful information, a huge overhead. This situation often occurs in Telnet sessions, where most keypresses generate a single byte of data that is transmitted immediately. Worse, over slow links, many such packets can be in transit at the same time, potentially leading to congestion collapse.
Nagle's algorithm works by combining a number of small outgoing messages and sending them all at once. Specifically, as long as there is a sent packet for which the sender has received no acknowledgment, the sender should keep buffering its output until it has a full packet's worth of output, thus allowing output to be sent all at once.
Discussed on
- "Nagle's Algorithm" | 2022-12-30 | 25 Upvotes 2 Comments
π W54
The W54 (also known as the Mark 54 or B54) was a tactical nuclear warhead developed by the United States in the late 1950s. The weapon is notable for being the smallest nuclear weapon in both weight and yield to have entered US service. It was a compact implosion device containing plutonium-239 as its fissile material, and in its various versions and mods it had a yield of 10 to 1,000 tons of TNT (42 to 4,184 gigajoules).
The weapon had two distinct versions: a warhead used in the AIM-26 Falcon air-to-air missile and in the Davy Crockett recoilless gun, and another used in the Special Atomic Demolition Munition (SADM) system, along with several mods for each version. The two types are distinct in that much of the design between them was different, to the point that during the development of the SADM it was proposed that it be given its own unique mark designation.
A later development was the W72, which was a rebuilt W54 used with the AGM-62 Walleye guided bomb. The W72 was in service until 1979.
Discussed on
- "W54" | 2024-12-18 | 46 Upvotes 33 Comments
π Gold (1934 Film)
Gold is a 1934 German science fiction film directed by Karl Hartl. The film involves a British scientist who is attempting to create a device that turns base materials into gold. He later forces the German scientist's assistant Werner Holk (Hans Albers), who was working on a similar experiment, to come to his underwater nuclear reactor to help him. Gold was made in both German-language and French-language versions with Brigitte Helm reprising her role in both.
Discussed on
- "Gold (1934 Film)" | 2022-11-23 | 41 Upvotes 20 Comments
π Cyberpunk Derivatives
Since the advent of the cyberpunk genre, a number of derivatives of cyberpunk have become recognized in their own right as distinct subgenres in speculative fiction, especially in science fiction.
Rather than necessarily sharing the digitally- and mechanically-focused setting of cyberpunk, these derivatives can display other futuristic, or even retrofuturistic, qualities that are drawn from or analogous to cyberpunk: a world built on one particular technology that is extrapolated to a highly sophisticated level (this may even be a fantastical or anachronistic technology, akin to retrofuturism), a gritty transreal urban style, or a particular approach to social themes.
Steampunk, one of the most well-known of these subgenres, has been defined as a "kind of technological fantasy;" others in this category sometimes also incorporate aspects of science fantasy and historical fantasy. Scholars have written of the stylistic place of these subgenres in postmodern literature, as well as their ambiguous interaction with the historical perspective of postcolonialism.
Discussed on
- "Cyberpunk Derivatives" | 2021-07-11 | 76 Upvotes 36 Comments
π Wake Therapy
Wake therapy is a form of sleep deprivation used as a treatment for depression. The subject stays awake all night, or is woken at 1AM and stays awake all morning, and the next full day. While sleepy, patients find that their depression vanishes, until they sleep again. Combining this with bright light therapy make the beneficial effects last longer than one day. Partial sleep deprivation in the second half of the night may be as effective as an all-night sleep deprivation session.
Wake therapy is a therapy that falls under chronotherapeutics. Chronotherapy (treatment scheduling) is a process to manipulate biological rhythms and sleep that can help to improve affective disorders quickly.
Wake therapy is beneficial for those experiencing major depression along with unipolar, bipolar, and melancholic types of depression. Wake therapy is best used to jump start the effects of the use of an antidepressant. Wake therapy is the use of prolonged times of wakefulness, along with periods of recovering sleep. It is a fast way to improve symptoms of depression. This therapy is best used with other chronotherapeutic techniques. Months of use of this therapy and other therapies can be quite effective to help prevent relapse of depression.
Discussed on
- "Wake Therapy" | 2019-04-19 | 16 Upvotes 3 Comments
π Order of the Occult Hand
The Order of the Occult Hand is a secret society of American journalists who slip the meaningless and telltale phrase "It was as if an occult hand hadβ¦" in print as an inside joke.
Discussed on
- "Order of the Occult Hand" | 2023-09-09 | 38 Upvotes 7 Comments
π Wetware computer
A wetware computer is an organic computer (which can also be known as an artificial organic brain or a neurocomputer) composed of organic material such as living neurons. Wetware computers composed of neurons are different than conventional computers because they are thought to be capable in a way of "thinking for themselves", because of the dynamic nature of neurons. While wetware is still largely conceptual, there has been limited success with construction and prototyping, which has acted as a proof of the concept's realistic application to computing in the future. The most notable prototypes have stemmed from the research completed by biological engineer William Ditto during his time at the Georgia Institute of Technology. His work constructing a simple neurocomputer capable of basic addition from leech neurons in 1999 was a significant discovery for the concept. This research acted as a primary example driving interest in the creation of these artificially constructed, but still organic brains.
Discussed on
- "Wetware computer" | 2017-08-26 | 40 Upvotes 6 Comments
π Svalbard Global Seed Vault
The Svalbard Global Seed Vault (Norwegian: Svalbard globale frΓΈhvelv) is a secure seed bank on the Norwegian island of Spitsbergen in the remote Arctic Svalbard archipelago. Conservationist Cary Fowler, in association with the Consultative Group on International Agricultural Research (CGIAR), started the vault to preserve a wide variety of plant seeds that are duplicate samples, or "spare" copies, of seeds held in gene banks worldwide. The seed vault is an attempt to ensure against the loss of seeds in other genebanks during large-scale regional or global crises. The seed vault is managed under terms spelled out in a tripartite agreement among the Norwegian government, the Crop Trust, and the Nordic Genetic Resource Center (NordGen).
The Norwegian government entirely funded the vault's approximately 45 million kr (US$8.8 million in 2008) construction. Storing seeds in the vault is free to end users; Norway and the Crop Trust pay for operational costs. Primary funding for the Trust comes from organisations such as the Bill & Melinda Gates Foundation and from various governments worldwide.
Discussed on
- "Svalbard Global Seed Vault" | 2019-06-13 | 108 Upvotes 13 Comments
- "Svalbard Global Seed Vault" | 2016-05-15 | 63 Upvotes 11 Comments
π Yo-yo problem
In software development, the yo-yo problem is an anti-pattern that occurs when a programmer has to read and understand a program whose inheritance graph is so long and complicated that the programmer has to keep flipping between many different class definitions in order to follow the control flow of the program. It often happens in object-oriented programming. The term comes from comparing the bouncing attention of the programmer to the up-down movement of a toy yo-yo. Taenzer, Ganti, and Podar described the problem by name, explaining: "Often we get the feeling of riding a yoyo when we try to understand one of these message trees."
Most practices of object-oriented programming recommend keeping the inheritance graph as shallow as possible, in part to avoid this problem. The use of composition instead of inheritance is also strongly preferred, although this still requires that a programmer keep multiple class definitions in mind at once.
More generally, the yo-yo problem can also refer to any situation where a person must keep flipping between different sources of information in order to understand a concept.
Object-oriented design techniques such as documenting layers of the inheritance hierarchy can reduce the effect of this problem, as they collect in one place the information that the programmer is required to understand.
Discussed on
- "Yo-yo problem" | 2014-06-26 | 10 Upvotes 2 Comments
π Solar eclipse of August 12, 2026
A total solar eclipse will occur at the Moon's descending node of the orbit on Wednesday, August 12, 2026, 2 days past perigee (Perigee on Monday, August 10, 2026), in North America and Europe. The total eclipse will pass over the Arctic, Greenland, Iceland, Atlantic Ocean and northern Spain. The points of greatest duration and greatest eclipse will be just 45Β km off the western coast of Iceland by 65Β°10.3' N and 25Β°12.3' W, where the totality will last 2m 18.21s. It will be the first total eclipse visible in Iceland since June 30, 1954, also Solar Saros series 126 (descending node), and the only one to occur in the 21st century as the next one will be in 2196.
Occurring only 2.3 days after perigee (Perigee on August 10, 2026), the Moon's apparent diameter will be larger. Lunar Perigee will occur on Monday, August 10, 2026, two days before the total solar eclipse.
The total eclipse will pass over northern Spain from the Atlantic coast to the Mediterranean coast as well as the Balearic Islands. The total eclipse will be visible from the cities of Valencia, Zaragoza, Palma and Bilbao but both Madrid and Barcelona will be just outside the path of totality.
The last total eclipse in continental Europe occurred on March 29, 2006 and in continental part of European Union it occurred on August 11, 1999. The last total solar eclipse happened in Spain on August 30, 1905 and followed a similar path across the country. The next total eclipse visible in Spain will happen less than a year later on 2 August 2027. A partial eclipse will cover more than 90% of the area of the sun in Ireland, Great Britain, Portugal, France, Italy, the Balkans and North Africa and to a lesser extent in most of Europe, North Africa and North America.
Discussed on
- "Solar eclipse of August 12, 2026" | 2023-10-14 | 21 Upvotes 6 Comments