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π SWEET16: Interpreted byte-code instruction set invented by Steve Wozniak
SWEET16 is an interpreted byte-code instruction set invented by Steve Wozniak and implemented as part of the Integer BASIC ROM in the Apple II series of computers. It was created because Wozniak needed to manipulate 16-bit pointer data, and the Apple II was an 8-bit computer.
SWEET16 was not used by the core BASIC code, but was later used to implement several utilities. Notable among these was the line renumbering routine, which was included in the Programmer's Aid #1 ROM, added to later Apple II models and available for user installation on earlier examples.
SWEET16 code is executed as if it were running on a 16-bit processor with sixteen internal 16-bit little-endian registers, named R0 through R15. Some registers have well-defined functions:
- R0Β β accumulator
- R12Β β subroutine stack pointer
- R13Β β stores the result of all comparison operations for branch testing
- R14Β β status register
- R15Β β program counter
The 16 virtual registers, 32 bytes in total, are located in the zero page of the Apple II's real, physical memory map (at $00β$1F), with values stored as low byte followed by high byte. The SWEET16 interpreter itself is located from $F689 to $F7FC in the Integer BASIC ROM.
According to Wozniak, the SWEET16 implementation is a model of frugal coding, taking up only about 300 bytes in memory. SWEET16 runs at about one-tenth the speed of the equivalent native 6502 code.
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- "SWEET16: Interpreted byte-code instruction set invented by Steve Wozniak" | 2023-10-14 | 23 Upvotes 3 Comments
π Pugachev's Cobra
In aerobatics the Cobra maneuver, also known as just the Cobra, is a dramatic and demanding maneuver in which an airplane flying at a moderate speed suddenly raises the nose momentarily to the vertical position and slightly beyond, before dropping it back to normal, effectively making the plane a full body air brake.
The maneuver relies on the ability of the plane to be able to quickly change alpha which momentarily stalls the plane without overloading the airframe and powerful engine thrust to maintain approximately constant altitude through the entire move. It is an impressive maneuver to demonstrate an aircraft's pitch control authority, high alpha stability and engine-versus-inlet compatibility, as well as the pilot's skill.
Although the maneuver is mainly performed at air shows it has use in close range air combat as a last ditch maneuver to make a pursuing plane overshoot. There is currently no widely spread or readily available evidence of the Cobra being used in real combat, although, there are records of it being used during mockup-dogfights and during border protection.
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- "Cobra Maneuver" | 2022-10-02 | 218 Upvotes 157 Comments
- "Pugachev's Cobra" | 2015-09-21 | 36 Upvotes 15 Comments
π Rabbit-proof fence
The State Barrier Fence of Western Australia, formerly known as the Rabbit Proof Fence, the State Vermin Fence, and the Emu Fence, is a pest-exclusion fence constructed between 1901 and 1907 to keep rabbits and other agricultural pests, from the east, out of Western Australian pastoral areas.
There are three fences in Western Australia: the original No. 1 Fence crosses the state from north to south, No. 2 Fence is smaller and further west, and No. 3 Fence is smaller still and runs eastβwest. The fences took six years to build. When completed in 1907, the rabbit-proof fence (including all three fences) stretched 2,023 miles (3,256Β km). The cost to build the fences at the time was about Β£168 per mile ($250/km).
When it was completed in 1907, the 1,139-mile (1,833Β km) No. 1 Fence was the longest unbroken fence in the world.
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- "Rabbit-proof fence" | 2014-06-06 | 49 Upvotes 36 Comments
π City officials attempt to doxx Wikipedians
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- "City officials attempt to doxx Wikipedians" | 2023-08-01 | 183 Upvotes 90 Comments
π Exotic Atom
An exotic atom is an otherwise normal atom in which one or more sub-atomic particles have been replaced by other particles of the same charge. For example, electrons may be replaced by other negatively charged particles such as muons (muonic atoms) or pions (pionic atoms). Because these substitute particles are usually unstable, exotic atoms typically have very short lifetimes and all currently observed atoms cannot persist under normal conditions.
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- "Exotic Atom" | 2019-03-10 | 39 Upvotes 12 Comments
π Physics Envy
The term physics envy is used to criticize modern writing and research of academics working in areas such as "softer sciences", liberal arts, business studies, and humanities. The term argues that writing and working practices in these disciplines have overused confusing jargon and complicated mathematics to seem more 'rigorous' and like mathematics-based subjects like physics.
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- "Physics Envy" | 2023-02-20 | 32 Upvotes 23 Comments
π Jazz Kissa
Jazz kissa (Japanese: γΈγ£γΊε«θΆ), sometimes transliterated as jazu kissa, are cafΓ©s that specialise in the playing and appreciation of recorded jazz music. Unique to Japan, jazz kissa are spaces where jazz music is played for dedicated listening rather than as background music. A typical jazz kissa features a high-quality stereo system, a large music collection and dim lighting, and serves coffee and alcoholic drinks.
The first cafΓ©s focussed on playing recorded jazz opened in Japan in the late 1920s as part of a wider enthusiasm for Western culture and music. Before World War II there were about 80 jazz kissa, but during the war many of them closed. The post-war period saw jazz kissa return in even greater numbers. Jazz kissa served as places to hear imported jazz records that were too expensive for individuals to buy. They were an important musical resource for musicians, journalists and jazz enthusiasts, and, at their peak, there were around 600 jazz kissa operating across Japan.
Starting in the 1970s, easier and cheaper access to personal stereo equipment and jazz music challenged the role of the jazz kissa. Jazz kissa numbers greatly reduced and the remaining kissa were mainly visited for nostalgic reasons. However, jazz kissa continue to operate in Japan and new kissa are still being opened. Jazz kissa played a role in the reception of jazz music and modern Western culture in Japan. Their influence extends beyond Japan with listening bars inspired by jazz kissa opening in many other countries in the 21st century.
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- "Jazz Kissa" | 2024-11-28 | 68 Upvotes 36 Comments
π Cybernetic Culture Research Unit
The Cybernetic Culture Research Unit (CCRU) was an experimental cultural theorist collective formed in late 1995 at Warwick University, England and gradually separated from academia until it dissolved in 2003. It garnered reputation for its idiosyncratic and surreal "theory-fiction" which incorporated cyberpunk and Gothic horror, and its work has since had an online cult following related to the rise in popularity of accelerationism. Warwick University maintains that the CCRU was never a sanctioned academic project, with some faculty going so far as to assert that the CCRU "has never existed". The CCRU are strongly associated with their former leading members, Sadie Plant, Mark Fisher and Nick Land.
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- "Cybernetic Culture Research Unit" | 2023-05-13 | 82 Upvotes 39 Comments
π Holodomor
The Holodomor (Ukrainian: ΠΠΎΠ»ΠΎΠ΄ΠΎΠΌΠΎΜΡ; ΠΠΎΠ»ΠΎΠ΄ΠΎΠΌΠΎΜΡ Π² Π£ΠΊΡΠ°ΡΜΠ½Ρ; derived from ΠΌΠΎΡΠΈΡΠΈ Π³ΠΎΠ»ΠΎΠ΄ΠΎΠΌ, "to kill by starvation") was a man-made famine in Soviet Ukraine in 1932 and 1933 that killed millions of Ukrainians. It is also known as the Terror-Famine and Famine-Genocide in Ukraine, and sometimes referred to as the Great Famine or the Ukrainian Genocide of 1932β33. It was part of the wider Soviet famine of 1932β33, which affected the major grain-producing areas of the country. During the Holodomor, millions of inhabitants of Ukraine, the majority of whom were ethnic Ukrainians, died of starvation in a peacetime catastrophe unprecedented in the history of Ukraine. Since 2006, the Holodomor has been recognized by Ukraine and 15 other countries as a genocide of the Ukrainian people carried out by the Soviet government.
Early estimates of the death toll by scholars and government officials varied greatly. According to higher estimates, up to 12 million ethnic Ukrainians were said to have perished as a result of the famine. A U.N. joint statement signed by 25 countries in 2003 declared that 7β10 million perished. Research has since narrowed the estimates to between 3.3 and 7.5 million. According to the findings of the Court of Appeal of Kiev in 2010, the demographic losses due to the famine amounted to 10 million, with 3.9 million direct famine deaths, and a further 6.1 million birth deficits.
The term Holodomor emphasises the famine's man-made and intentional aspects, such as rejection of outside aid, confiscation of all household foodstuffs, and restriction of population movement. Whether the Holodomor was genocide is still the subject of academic debate, as are the causes of the famine and intentionality of the deaths. Some scholars believe that the famine was planned by Joseph Stalin to eliminate a Ukrainian independence movement. The loss of life has been compared to that of the Holocaust. However, some historians dispute its characterization as a genocide.
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- "Holodomor" | 2022-11-26 | 50 Upvotes 13 Comments
π Ultraviolet catastrophe
The ultraviolet catastrophe, also called the RayleighβJeans catastrophe, was the prediction of late 19th century to early 20th century classical physics that an ideal black body at thermal equilibrium would emit an unbounded quantity of energy as wavelength decreased into the ultraviolet range.:β6β7β The term "ultraviolet catastrophe" was first used in 1911 by Paul Ehrenfest, but the concept originated with the 1900 statistical derivation of the RayleighβJeans law.
The phrase refers to the fact that the empirically derived RayleighβJeans law, which accurately predicted experimental results at large wavelengths, failed to do so for short wavelengths. (See the image for further elaboration.) As the theory diverged from empirical observations when these frequencies reached the ultraviolet region of the electromagnetic spectrum, there was a problem. This problem was later found to be due to a property of quanta as proposed by Max Planck: There could be no fraction of a discrete energy package already carrying minimal energy.
Since the first use of this term, it has also been used for other predictions of a similar nature, as in quantum electrodynamics and such cases as ultraviolet divergence.
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- "Ultraviolet catastrophe" | 2024-04-03 | 12 Upvotes 2 Comments