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🔗 Computing 🔗 Computing/Software 🔗 Computer graphics

Xsnow is a software application that was originally created as a virtual greeting card for Macintosh systems in 1984. In 1993, the concept was ported to the X Window System as Xsnow, and was included on a number of Linux distributions in the late 1990s.

🔗 Mathematics

In mathematics, Young's lattice is a partially ordered set and a lattice that is formed by all integer partitions. It is named after Alfred Young, who, in a series of papers On quantitative substitutional analysis, developed representation theory of the symmetric group. In Young's theory, the objects now called Young diagrams and the partial order on them played a key, even decisive, role. Young's lattice prominently figures in algebraic combinatorics, forming the simplest example of a differential poset in the sense of Stanley (1988). It is also closely connected with the crystal bases for affine Lie algebras.

🔗 Video games 🔗 Computing 🔗 Computing/Computer hardware 🔗 Japan 🔗 Japan/Business and economy 🔗 Video games/Sega

SuperH (or SH) is a 32-bit reduced instruction set computing (RISC) instruction set architecture (ISA) developed by Hitachi and currently produced by Renesas. It is implemented by microcontrollers and microprocessors for embedded systems.

At the time of introduction, SuperH was notable for having fixed-length 16-bit instructions in spite of its 32-bit architecture. This was a novel approach; at the time, RISC processors always used an instruction size that was the same as the internal data width, typically 32-bits. Using smaller instructions had consequences, the register file was smaller and instructions were generally two-operand format. But for the market the SuperH was aimed at, this was a small price to pay for the improved memory and processor cache efficiency.

Later versions of the design, starting with SH-5, included both 16- and 32-bit instructions, with the 16-bit versions mapping onto the 32-bit version inside the CPU. This allowed the machine code to continue using the shorter instructions to save memory, while not demanding the amount of instruction decoding logic needed if they were completely separate instructions. This concept is now known as a compressed instruction set and is also used by other companies, the most notable example being ARM for its Thumb instruction set.

As of 2015, many of the original patents for the SuperH architecture are expiring and the SH-2 CPU has been reimplemented as open source hardware under the name J2.

🔗 Spaceflight 🔗 Physics

Electrodynamic tethers (EDTs) are long conducting wires, such as one deployed from a tether satellite, which can operate on electromagnetic principles as generators, by converting their kinetic energy to electrical energy, or as motors, converting electrical energy to kinetic energy. Electric potential is generated across a conductive tether by its motion through a planet's magnetic field.

A number of missions have demonstrated electrodynamic tethers in space, most notably the TSS-1, TSS-1R, and Plasma Motor Generator (PMG) experiments.

🔗 Plants 🔗 Psychoactive and Recreational Drugs 🔗 Altered States of Consciousness 🔗 South America

Ayahuasca is a South American (pan-Amazonian) psychoactive brew used both socially and as ceremonial spiritual medicine among the indigenous peoples of the Amazon basin. It is a psychedelic and entheogenic brew commonly made out of the Banisteriopsis caapi vine, the Psychotria viridis shrub or a substitute, and possibly other ingredients. A chemically similar preparation, sometimes called "pharmahuasca", can be prepared using N,N-Dimethyltryptamine (DMT) and a pharmaceutical monoamine oxidase inhibitor (MAOI), such as isocarboxazid. B. caapi contains several alkaloids that act as MAOIs, which are required for DMT to be orally active. Ayahuasca is prepared in a tea that, when consumed, causes an altered state of consciousness or "high", including visual hallucinations and altered perceptions of reality.

The other required ingredient is a plant that contains the primary psychoactive, DMT. This is usually the shrub P. viridis, but Diplopterys cabrerana may be used as a substitute. Other plant ingredients often or occasionally used in the production of ayahuasca include Justicia pectoralis, one of the Brugmansia (especially Brugmansia insignis and Brugmansia versicolor, or a hybrid breed) or Datura species, and mapacho (Nicotiana rustica).

🔗 Judaism

Yiddish words used in the English language include both words that have been assimilated into English - used by both Yiddish and English speakers - and many that have not. An English sentence that uses either may be described by some as Yinglish (or Hebronics), though a secondary sense of the term Yinglish describes the distinctive way certain Jews in English-speaking countries add many Yiddish words into their conversation, beyond general Yiddish words and phrases used by English speakers.

In this meaning, Yinglish is not the same as Yeshivish, which is spoken by many Orthodox Jews, though the two share many parallels.

🔗 Biography 🔗 Anthropology 🔗 Brazil 🔗 Indigenous peoples of the Americas

The Man of the Hole (also known as "Indian of the Hole", Portuguese: índio do buraco) is a man indigenous to Brazil who lives alone in the Amazon rainforest. He is believed to be the last surviving member of his tribe. It is unknown what language he speaks or what his tribe was called. The term "Man of the Hole" is a nickname used by officials and the media; his real name is unknown.

🔗 Medicine 🔗 Ancient Egypt

The Ebers Papyrus, also known as Papyrus Ebers, is an Egyptian medical papyrus of herbal knowledge dating to circa 1550 BC. Among the oldest and most important medical papyri of ancient Egypt, it was purchased at Luxor in the winter of 1873–74 by Georg Ebers. It is currently kept at the library of the University of Leipzig, in Germany.

🔗 Poetry

"Fragments of Olympian Gossip" is a poem that Nikola Tesla composed in the late 1920s for his friend the German poet and mystic George Sylvester Viereck. It made fun of the scientific establishment of the day.

While listening on my cosmic phone
I caught words from the Olympus blown.
A newcomer was shown around;
That much I could guess, aided by sound.

"There's Archimedes with his lever
Still busy on problems as ever.
Says: matter and force are transmutable
And wrong the laws you thought immutable."

"Below, on Earth, they work at full blast
And news are coming in thick and fast.
The latest tells of a cosmic gun.
To be pelted is very poor fun.
We are wary with so much at stake,
Those beggars are a pest—no mistake."

"Too bad, Sir Isaac, they dimmed your renown
And turned your great science upside down.
Now a long haired crank, Einstein by name,
Puts on your high teaching all the blame.
Says: matter and force are transmutable
And wrong the laws you thought immutable."

"I am much too ignorant, my son,
For grasping schemes so finely spun.
My followers are of stronger mind
And I am content to stay behind,
Perhaps I failed, but I did my best,
These masters of mine may do the rest.
Come, Kelvin, I have finished my cup.
When is your friend Tesla coming up."

"Oh, quoth Kelvin, he is always late,
It would be useless to remonstrate."

Then silence—shuffle of soft slippered feet—
I knock and—the bedlam of the street.

Nikola Tesla, Novice

🔗 Radio

A crystal detector is an obsolete electronic component used in some early 20th century radio receivers that consists of a piece of crystalline mineral which rectifies the alternating current radio signal. It was employed as a detector (demodulator) to extract the audio modulation signal from the modulated carrier, to produce the sound in the earphones. It was the first type of semiconductor diode, and one of the first semiconductor electronic devices. The most common type was the so-called cat whisker detector, which consisted of a piece of crystalline mineral, usually galena (lead sulfide), with a fine wire touching its surface.

The "asymmetric conduction" of electric current across electrical contacts between a crystal and a metal was discovered in 1874 by Karl Ferdinand Braun. Crystals were first used as radio wave detectors in 1894 by Jagadish Chandra Bose in his microwave experiments. Bose first patented a crystal detector in 1901. The crystal detector was developed into a practical radio component mainly by G. W. Pickard, who began research on detector materials in 1902 and found hundreds of substances that could be used in forming rectifying junctions. The physical principles by which they worked were not understood at the time they were used, but subsequent research into these primitive point contact semiconductor junctions in the 1930s and 1940s led to the development of modern semiconductor electronics.

The unamplified radio receivers that used crystal detectors were called crystal radios. The crystal radio was the first type of radio receiver that was used by the general public, and became the most widely used type of radio until the 1920s. It became obsolete with the development of vacuum tube receivers around 1920, but continued to be used until World War II and remains a common educational project today thanks to its simple design.