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๐ Granfalloon technique
A granfalloon, in the fictional religion of Bokononism (created by Kurt Vonnegut in his 1963 novel Cat's Cradle), is defined as a "false karass". That is, it is a group of people who affect a shared identity or purpose, but whose mutual association is meaningless.
As quoted in And So It Goes: Kurt Vonnegut: A Life (2011) by Charles J. Shields, Vonnegut writes in his introduction to Wampeters, Foma and Granfalloons (1974) that a "granfalloon is a proud and meaningless collection of human beings"; Shields also comments that in the same book, Vonnegut later cites the demonym of 'Hoosiers' as "one of [Vonnegut's] favorite examples" of what the term embodies.
Discussed on
- "Granfalloon technique" | 2020-04-15 | 54 Upvotes 47 Comments
๐ Mobile phones on aircraft
In the U.S., Federal Communications Commission (FCC) regulations prohibit the use of mobile phones aboard aircraft in flight. Contrary to popular misconception, the Federal Aviation Administration (FAA) does not actually prohibit the use of personal electronic devices (including cell phones) on aircraft. Paragraph (b)(5) of 14 CFR 91.21 leaves it up to the airlines to determine if devices can be used in flight, allowing use of "Any other portable electronic device that the operator of the aircraft has determined will not cause interference with the navigation or communication system of the aircraft on which it is to be used."
In Europe, regulations and technology have allowed the limited introduction of the use of passenger mobile phones on some commercial flights, and elsewhere in the world many airlines are moving towards allowing mobile phone use in flight. Many airlines still do not allow the use of mobile phones on aircraft. Those that do often ban the use of mobile phones during take-off and landing.
Many passengers are pressing airlines and their governments to allow and deregulate mobile phone use, while some airlines, under the pressure of competition, are also pushing for deregulation or seeking new technology which could solve the present problems. On the other hand, official aviation agencies and safety boards are resisting any relaxation of the present safety rules unless and until it can be conclusively shown that it would be safe to do so. There are both technical and social factors which make the issues more complex than a simple discussion of safety versus hazard.
Discussed on
- "Mobile phones on aircraft" | 2021-08-04 | 48 Upvotes 50 Comments
๐ Gรถdel, Escher, Bach
Gรถdel, Escher, Bach: An Eternal Golden Braid, also known as GEB, is a 1979 book by Douglas Hofstadter. By exploring common themes in the lives and works of logician Kurt Gรถdel, artist M. C. Escher, and composer Johann Sebastian Bach, the book expounds concepts fundamental to mathematics, symmetry, and intelligence. Through illustration and analysis, the book discusses how, through self-reference and formal rules, systems can acquire meaning despite being made of "meaningless" elements. It also discusses what it means to communicate, how knowledge can be represented and stored, the methods and limitations of symbolic representation, and even the fundamental notion of "meaning" itself.
In response to confusion over the book's theme, Hofstadter emphasized that Gรถdel, Escher, Bach is not about the relationships of mathematics, art, and musicโbut rather about how cognition emerges from hidden neurological mechanisms. One point in the book presents an analogy about how individual neurons in the brain coordinate to create a unified sense of a coherent mind by comparing it to the social organization displayed in a colony of ants.
The tagline "a metaphorical fugue on minds and machines in the spirit of Lewis Carroll" was used by the publisher to describe the book.
Discussed on
- "Gรถdel, Escher, Bach" | 2019-11-17 | 56 Upvotes 37 Comments
- "Gรถdel, Escher, Bach: An Eternal Golden Braid" | 2014-05-16 | 65 Upvotes 72 Comments
๐ List of countries by home ownership rate
This is a list of countries and territories by home ownership rate, which is the ratio of owner-occupied units to total residential units in a specified area.
๐ Balloonomania
Balloonomania was a strong public interest or fad in balloons that originated in France in the late 18th century and continued into the 19th century, during the advent of balloon flights. The interest began with the first flights of the Montgolfier brothers in 1783 (in a balloon inflated with hot air). Soon afterwards Jacques Alexandre Cรฉsar Charles flew another type of balloon (inflated with hydrogen) and both types of balloon were in use from then on. The fad quickly spread in France and across the channel in England.
Discussed on
- "Balloonomania" | 2021-02-26 | 42 Upvotes 21 Comments
๐ MU puzzle
The MU puzzle is a puzzle stated by Douglas Hofstadter and found in Gรถdel, Escher, Bach involving a simple formal system called "MIU". Hofstadter's motivation is to contrast reasoning within a formal system (ie., deriving theorems) against reasoning about the formal system itself. MIU is an example of a Post canonical system and can be reformulated as a string rewriting system.
Discussed on
- "MU puzzle" | 2018-12-15 | 83 Upvotes 45 Comments
๐ Potoooooooo
Potoooooooo or variations of Pot-8-Os (1773 โ November 1800) was an 18th-century thoroughbred racehorse who won over 30 races and defeated some of the greatest racehorses of the time. He went on to be a sire. He is now best known for the unusual spelling of his name, pronounced 'Potatoes'.
Discussed on
- "Potoooooooo" | 2025-01-16 | 104 Upvotes 42 Comments
- "Potoooooooo" | 2021-07-28 | 128 Upvotes 32 Comments
๐ Charlieplexing
Charlieplexing (also known as tristate multiplexing, reduced pin-count LED multiplexing, complementary LED drive and crossplexing) is a technique for accessing a large number of LEDs, switches, micro-capacitors or other I/O entities, using very few tri-state logic wires from a microcontroller, these entities being wired as discrete components, x/y arrays, or woven in a diagonally intersecting pattern to form diagonal arrays.
The method uses the tri-state logic capabilities of microcontrollers in order to gain efficiency over traditional multiplexing, each I/O pin being capable, when required, of rapidly changing between the three states, logical 1, logical 0, and high impedance.
This enables these I/O entities (LEDs, switches etc.) to be connected between any two microcontroller I/Os - e.g. with 4 I/Os, each I/O can pair with 3 other I/Os, resulting in 6 unique pairings (1/2, 1/3, 1/4, 2/3, 2/4, 3/4). Only 4 pairings are possible with standard x/y multiplexing (1/3, 1/4, 2/3, 2/4). Also, due to the microcontroller's ability to reverse the polarity of the 6 I/O pairs, the number of LEDS (or diodes) that are uniquely addressable, can be doubled to 12 - adding LEDS 2/1, 3/1, 4/1, 3/2, 4/2 and 4/3.
Although it is more efficient in its use of I/O, a small amount of address manipulation is required when trying to fit Charlieplexing into a standard x/y array.
Other issues that affect standard multiplexing but are exacerbated by Charlieplexing are:
- consideration of current requirements and the forward voltages of the LEDs.
- a requirement to cycle through the in-use LEDs rapidly so that the persistence of the human eye perceives the display to be lit as a whole. Multiplexing can generally be seen by a strobing effect and skewing if the eye's focal point is moved past the display rapidly.
Discussed on
- "Charlieplexing" | 2024-05-12 | 69 Upvotes 12 Comments
๐ Hofstadter's Law
Hofstadter's law is a self-referential adage, coined by Douglas Hofstadter in his book Gรถdel, Escher, Bach: An Eternal Golden Braid (1979) to describe the widely experienced difficulty of accurately estimating the time it will take to complete tasks of substantial complexity:
Hofstadter's Law: It always takes longer than you expect, even when you take into account Hofstadter's Law.
The law is often cited by programmers in discussions of techniques to improve productivity, such as The Mythical Man-Month or extreme programming.
Discussed on
- "Hofstadter's Law" | 2016-03-21 | 10 Upvotes 1 Comments
- "Hofstadter's law" | 2011-02-25 | 94 Upvotes 18 Comments
๐ New England's Dark Day
New England's Dark Day occurred on May 19, 1780, when an unusual darkening of the day sky was observed over the New England states and parts of Canada. The primary cause of the event is believed to have been a combination of smoke from forest fires, a thick fog, and cloud cover. The darkness was so complete that candles were required from noon on. It did not disperse until the middle of the next night.
Discussed on
- "New England's Dark Day" | 2020-09-16 | 107 Upvotes 44 Comments