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π Curta: a mechanical calculator
The Curta is a small mechanical calculator developed by Curt Herzstark. The Curta's design is a descendant of Gottfried Leibniz's Stepped Reckoner and Charles Thomas's Arithmometer, accumulating values on cogs, which are added or complemented by a stepped drum mechanism. It has an extremely compact design: a small cylinder that fits in the palm of the hand.
Curtas were considered the best portable calculators available until they were displaced by electronic calculators in the 1970s.
Discussed on
- "Curta" | 2023-02-05 | 66 Upvotes 12 Comments
- "Curta: a mechanical calculator" | 2015-07-17 | 28 Upvotes 6 Comments
- "Curta mechanical calculator" | 2015-01-12 | 38 Upvotes 14 Comments
- "Curta calculator - hand-held, mechanical arithmetic" | 2011-10-02 | 42 Upvotes 16 Comments
- "Curta calculator" | 2010-01-11 | 23 Upvotes 17 Comments
π The Last Man
The Last Man is an apocalyptic, dystopian science fiction novel by Mary Shelley, first published in 1826. The narrative concerns Europe in the late 21st century, ravaged by a mysterious plague pandemic that rapidly sweeps across the entire globe, ultimately resulting in the near-extinction of humanity. It also includes discussion of the British state as a republic, for which Shelley sat in meetings of the House of Commons to gain insight to the governmental system of the Romantic era. The novel includes many fictive allusions to her husband Percy Bysshe Shelley, who drowned in a shipwreck four years before the book's publication, as well as their close friend Lord Byron, who had died two years previously.
The Last Man is one of the first pieces of dystopian fiction published. It was critically savaged and remained largely obscure at the time of its publication. It was not until the 1960s that the novel resurfaced for the public.
Discussed on
- "The Last Man" | 2023-02-04 | 64 Upvotes 22 Comments
π Sraffa asks Wittgenstein: βWhat is the logical form of that?β
Piero Sraffa (5 August 1898 β 3 September 1983) was an influential Italian economist who served as lecturer of economics at the University of Cambridge. His book Production of Commodities by Means of Commodities is taken as founding the neo-Ricardian school of economics.
Discussed on
- "Sraffa asks Wittgenstein: βWhat is the logical form of that?β" | 2023-02-03 | 13 Upvotes 1 Comments
π Bir Tawil
Bir Tawil (Egyptian Arabic: Ψ¨ΩΨ± Ψ·ΩΩΩ, romanized:Β BΔ«r αΉ¬awΔ«l, lit.β'tall water well', [biΛΙΎ tΛ€ΙΛwiΛl]) is a 2,060Β km2 (795.4Β sqΒ mi) area of land along the border between Egypt and Sudan, which is uninhabited and claimed by neither country. When spoken of in association with the neighbouring Halaib Triangle, it is sometimes referred to as the Bir Tawil Triangle, despite the area's quadrilateral shape; the two "triangles" border at a quadripoint.
Its terra nulliuscode: lat promoted to code: la status results from a discrepancy between the straight political boundary between Egypt and Sudan established in 1899, and the irregular administrative boundary established in 1902. Egypt asserts the political boundary, and Sudan asserts the administrative boundary, with the result that the Hala'ib Triangle is claimed by both and Bir Tawil by neither. In 2014, author Alastair Bonnett described Bir Tawil as the only place on Earth that was habitable but was not claimed by any recognised government.
Discussed on
- "Bir Tawil" | 2023-02-02 | 40 Upvotes 17 Comments
π Contiki β OS for networked, memory-constrained systems
Contiki is an operating system for networked, memory-constrained systems with a focus on low-power wireless Internet of Things (IoT) devices. Extant uses for Contiki include systems for street lighting, sound monitoring for smart cities, radiation monitoring, and alarms. It is open-source software released under the BSD-3-Clause license.
Contiki was created by Adam Dunkels in 2002 and has been further developed by a worldwide team of developers from Texas Instruments, Atmel, Cisco, ENEA, ETH Zurich, Redwire, RWTH Aachen University, Oxford University, SAP, Sensinode, Swedish Institute of Computer Science, ST Microelectronics, Zolertia, and many others. Contiki gained popularity because of its built in TCP/IP stack and lightweight preemptive scheduling over event-driven kernel which is a very motivating feature for IoT. The name Contiki comes from Thor Heyerdahl's famous Kon-Tiki raft.
Contiki provides multitasking and a built-in Internet Protocol Suite (TCP/IP stack), yet needs only about 10 kilobytes of random-access memory (RAM) and 30 kilobytes of read-only memory (ROM). A full system, including a graphical user interface, needs about 30 kilobytes of RAM.
A new branch has recently been created, known as Contiki-NG: The OS for Next Generation IoT Devices
Discussed on
- "Contiki β OS for networked, memory-constrained systems" | 2023-01-30 | 155 Upvotes 28 Comments
π Spaghetti-Tree Hoax
The spaghetti-tree hoax was a three-minute hoax report broadcast on April Fools' Day 1957 by the BBC current-affairs programme Panorama, purportedly showing a family in southern Switzerland harvesting spaghetti from the family "spaghetti tree". At the time spaghetti was relatively unknown in the UK, so many British people were unaware that it is made from wheat flour and water; a number of viewers afterwards contacted the BBC for advice on growing their own spaghetti trees. Decades later, CNN called this broadcast "the biggest hoax that any reputable news establishment ever pulled".
Discussed on
- "Spaghetti-Tree Hoax" | 2023-01-29 | 174 Upvotes 93 Comments
π Correction Girls
Correction girls was a term describing women who were forcibly shipped from France to its colonies in America as brides for its colonists during the early 18th century.
Discussed on
- "Correction Girls" | 2023-01-29 | 59 Upvotes 14 Comments
π Electro Gyrocator
The Electro Gyro-Cator was claimed to be the world's first automated commercially available automotive navigation system. It was co-developed by Honda, Alpine, and Stanley Electric Co..
Unlike most navigation systems of today, it did not use GPS Satellites to maintain its position and discern movement of the vehicle. Rather, it was an Inertial navigation system, because it contained a helium gas gyroscope that could detect both rotation and movement. A special servo gear was also attached to the transmission housing to feed information to the Gyro-Cator to help maintain position, map speed and distance traveled.
Transparent maps were placed inside the unit and it would scroll them past a 6 inch monochrome CRT illuminated screen as the car traveled along. The monitor would indicate by a series of circles (or cross hairs) on the screen to show the vehicle's current location or display lines for path of travel. A marking pen was also included to help make personal indicators on the map if needed. Adjustments could be made to change the display scale, position, rotation, brightness, and contrast. In its only year of production in 1981, it was announced as an option on that year's Honda Accord and Honda Vigor, but at Β₯300,000 ($2,746 USD), it was almost a quarter of the value of the car. It is not clear how many units were actually sold to customers as a "dealer option". A patent for gyroscope design was introduced to the US in design patent D274332.
Documented weight for the unit was roughly 20Β lb (9Β kg). A display unit, with a cutaway of the Gyroscope, is currently shown at the Honda Collection Hall at Twin Ring Motegi, Japan.
Discussed on
- "Electro Gyrocator" | 2023-01-28 | 101 Upvotes 57 Comments
π Silkie Chickens
The Silkie (also known as the Silky or Chinese silk chicken) is a breed of chicken named for its atypically fluffy plumage, which is said to feel like silk and satin. The breed has several other unusual qualities, such as black skin and bones, blue earlobes, and five toes on each foot, whereas most chickens only have four. They are often exhibited in poultry shows, and also appear in various colors. In addition to their distinctive physical characteristics, Silkies are well known for their calm, friendly temperament. It is among the most docile of poultry. Hens are also exceptionally broody, and care for young well. Although they are fair layers themselves, laying only about three eggs a week, they are commonly used to hatch eggs from other breeds and bird species due to their broody nature.
Discussed on
- "Silkie Chickens" | 2023-01-27 | 14 Upvotes 1 Comments
π Sonic Hedgehog Protein (encoded by the SHH gene)
Sonic hedgehog protein (SHH) is encoded for by the SHH gene. The protein is named after the character Sonic the Hedgehog.
This signaling molecule is key in regulating embryonic morphogenesis in all animals. SHH controls organogenesis and the organization of the central nervous system, limbs, digits and many other parts of the body. Sonic hedgehog is a morphogen that patterns the developing embryo using a concentration gradient characterized by the French flag model. This model has a non-uniform distribution of SHH molecules which governs different cell fates according to concentration. Mutations in this gene can cause holoprosencephaly, a failure of splitting in the cerebral hemispheres, as demonstrated in an experiment using SHH knock-out mice in which the forebrain midline failed to develop and instead only a single fused telencephalic vesicle resulted.
Sonic hedgehog still plays a role in differentiation, proliferation, and maintenance of adult tissues. Abnormal activation of SHH signaling in adult tissues has been implicated in various types of cancers including breast, skin, brain, liver, gallbladder and many more.
Discussed on
- "Sonic Hedgehog Protein (encoded by the SHH gene)" | 2023-01-26 | 58 Upvotes 43 Comments