Have a deep view into what people are curious about.

🔗 Food and drink 🔗 Insects 🔗 Forestry

Shellac () is a resin secreted by the female lac bug on trees in the forests of India and Thailand. Chemically, it is mainly composed of aleuritic acid, jalaric acid, shellolic acid, and other natural waxes. It is processed and sold as dry flakes and dissolved in alcohol to make liquid shellac, which is used as a brush-on colorant, food glaze and wood finish. Shellac functions as a tough natural primer, sanding sealant, tannin-blocker, odour-blocker, stain, and high-gloss varnish. Shellac was once used in electrical applications as it possesses good insulation qualities and seals out moisture. Phonograph and 78 rpm gramophone records were made of shellac until they were replaced by vinyl long-playing records from 1948 onwards.

From the time shellac replaced oil and wax finishes in the 19th century, it was one of the dominant wood finishes in the western world until it was largely replaced by nitrocellulose lacquer in the 1920s and 1930s.

🔗 Religion 🔗 England 🔗 Holidays 🔗 Religion/Interfaith

Guy Fawkes Night, also known as Guy Fawkes Day, Bonfire Night (predominantly Newfoundland) and Firework Night, is an annual commemoration observed on 5 November, primarily in the United Kingdom. Its history begins with the events of 5 November 1605 O.S., when Guy Fawkes, a member of the Gunpowder Plot, was arrested while guarding explosives the plotters had placed beneath the House of Lords. Celebrating the fact that King James I had survived the attempt on his life, people lit bonfires around London; and months later, the introduction of the Observance of 5th November Act enforced an annual public day of thanksgiving for the plot's failure.

Within a few decades Gunpowder Treason Day, as it was known, became the predominant English state commemoration, but as it carried strong Protestant religious overtones it also became a focus for anti-Catholic sentiment. Puritans delivered sermons regarding the perceived dangers of popery, while during increasingly raucous celebrations common folk burnt effigies of popular hate-figures, such as the pope. Towards the end of the 18th century reports appear of children begging for money with effigies of Guy Fawkes and 5 November gradually became known as Guy Fawkes Day. Towns such as Lewes and Guildford were in the 19th century scenes of increasingly violent class-based confrontations, fostering traditions those towns celebrate still, albeit peaceably. In the 1850s changing attitudes resulted in the toning down of much of the day's anti-Catholic rhetoric, and the Observance of 5th November Act was repealed in 1859. Eventually the violence was dealt with, and by the 20th century Guy Fawkes Day had become an enjoyable social commemoration, although lacking much of its original focus. The present-day Guy Fawkes Night is usually celebrated at large organised events, centred on a bonfire and extravagant firework displays.

Settlers exported Guy Fawkes Night to overseas colonies, including some in North America, where it was known as Pope Day. Those festivities died out with the onset of the American Revolution. Claims that Guy Fawkes Night was a Protestant replacement for older customs like Samhain are disputed, although another old celebration, Halloween, has lately increased in popularity in England, and according to some writers, may threaten the continued observance of 5 November.

🔗 Occupational Safety and Health

A saddle chair uses the same principles in its design as an equestrian saddle. It is equipped with a chair base on casters and a gas cylinder for adjusting the correct sitting height. The casters enable moving around and reaching out for objects while sitting. Some saddle chairs have backrests, but most do not.

Riding-like sitting on a saddle chair differs from sitting on a conventional chair. Saddle chair users sit 20–30 cm higher, which puts the hips and the knees into a 135° angle, compared to the 90° angle typically associated with sitting on a traditional chair.

Because the saddle chair is higher than a normal office chair, the desk has to be higher as well. For this purpose there are desks that can be electronically or mechanically adjusted to fit the user. A saddle chair can also be used with a normal office desk, but then the desk has to be lifted up with height extension pieces.

The saddle chair seat is either solid or divided. A divided seat reduces pressure on the perineum and lowers the temperature in the genital area. A divided seat is thought to be healthier, especially for men, than a solid seat.

Some saddle chairs include not only height adjustments but also a tilt mechanism. There is also a divided saddle chair model on the market that has an adjustable gap between the two seat parts. Accessories, such as elbow and wrist supports, are available for saddle chairs to make different work tasks easier.

Adapting to a saddle chair takes time and requires a new kind of attitude towards sitting. The most common reason for using a saddle chair is that the users feel it is healthier for the back and legs than a standard chair. An intervention study on schoolchildren found that initially saddle chairs were liked better, but the difference leveled off over time.

🔗 Germany

F60 is the series designation of five overburden conveyor bridges used in brown coal (lignite) opencast mining in the Lusatian coalfields in Germany. They were built by the former Volkseigener Betrieb TAKRAF in Lauchhammer and are the largest movable technical industrial machines in the world. As overburden conveyor bridges, they transport the overburden which lies over the coal seam. The cutting height is 60 m (200 ft), hence the name F60. In total, the F60 is up to 80 m (260 ft) high and 240 m (790 ft) wide; with a length of 502 m (1,647 ft), it is described as the lying Eiffel tower, making these behemoths not only the longest vehicle ever made—beating Seawise Giant, the longest ship—but the largest vehicle by physical dimensions ever made by humankind. In operating condition, it weighs 13,600 metric tons making the F60 also one of the heaviest land vehicles ever made, beaten only by Bagger 293, which is a giant bucket-wheel excavator. Nevertheless, despite its immense size, it is operated by only a crew of 14.

The first conveyor bridge was built from 1969 to 1972, being equipped with a feeder bridge in 1977. The second was built from 1972 to 1974, having been equipped with a feeder bridge during construction. The third conveyor bridge was built from 1976 to 1978, being provided with a feeder bridge in 1985. The fourth and fifth conveyor bridges were built 1986–1988 and 1988–1991 respectively.

There are still four F60s in operation in the Lusatian coalfields today: in the brown coal opencast mines in Jänschwalde (Brandenburg, near Jänschwalde Power Station), Welzow-Süd (Brandenburg, near Schwarze Pumpe Power Station), Nochten and Reichwalde (Saxony, both near Boxberg Power Station). The fifth F60, the last one built, is in Lichterfeld-Schacksdorf and is accessible to visitors.

🔗 Military history 🔗 Military history/Military science, technology, and theory 🔗 Architecture 🔗 England 🔗 Military history/Fortifications 🔗 Military history/Napoleonic era 🔗 Ireland 🔗 Kent 🔗 Military history/European military history 🔗 Military history/British military history 🔗 Irish Maritime

Martello towers, sometimes known simply as Martellos, are small defensive forts that were built across the British Empire during the 19th century, from the time of the French Revolutionary Wars onwards. Most were coastal forts.

They stand up to 40 feet (12 m) high (with two floors) and typically had a garrison of one officer and 15–25 men. Their round structure and thick walls of solid masonry made them resistant to cannon fire, while their height made them an ideal platform for a single heavy artillery piece, mounted on the flat roof and able to traverse, and hence fire, over a complete 360° circle. A few towers had moats or other batteries and works attached for extra defence.

The Martello towers were used during the first half of the 19th century, but became obsolete with the introduction of powerful rifled artillery. Many have survived to the present day, often preserved as historic monuments.

🔗 Mathematics 🔗 India 🔗 India/Tamil Nadu

Ramanujan's lost notebook is the manuscript in which the Indian mathematician Srinivasa Ramanujan recorded the mathematical discoveries of the last year (1919–1920) of his life. Its whereabouts were unknown to all but a few mathematicians until it was rediscovered by George Andrews in 1976, in a box of effects of G. N. Watson stored at the Wren Library at Trinity College, Cambridge. The "notebook" is not a book, but consists of loose and unordered sheets of paper described as "more than one hundred pages written on 138 sides in Ramanujan's distinctive handwriting. The sheets contained over six hundred mathematical formulas listed consecutively without proofs."

George Andrews and Bruce C. Berndt (2005, 2009, 2012, 2013, 2018) have published several books in which they give proofs for Ramanujan's formulas included in the notebook. Berndt says of the notebook's discovery: "The discovery of this 'Lost Notebook' caused roughly as much stir in the mathematical world as the discovery of Beethoven’s tenth symphony would cause in the musical world."

🔗 Biography 🔗 Biography/science and academia

Lee Felsenstein (born April 27, 1945) is an American computer engineer who played a central role in the development of personal computers. He was one of the original members of the Homebrew Computer Club and the designer of the Osborne 1, the first mass-produced portable computer.

Before the Osborne, Felsenstein designed the Intel 8080 based Sol-20 computer from Processor Technology, the PennyWhistle modem, and other early "S-100 bus" era designs. His shared-memory alphanumeric video display design, the Processor Technology VDM-1 video display module board, was widely copied and became the basis for the standard display architecture of personal computers.

Many of his designs were leaders in reducing costs of computer technologies for the purpose of making them available to large markets. His work featured a concern for the social impact of technology and was influenced by the philosophy of Ivan Illich. Felsenstein was the engineer for the Community Memory project, one of the earliest attempts to place networked computer terminals in public places to facilitate social interactions among individuals, in the era before the commercial Internet.

🔗 Chemistry 🔗 Animals 🔗 Molecular Biology/Molecular and Cell Biology

Bioluminescence is the production and emission of light by living organisms. It is a form of chemiluminescence. Bioluminescence occurs widely in marine vertebrates and invertebrates, as well as in some fungi, microorganisms including some bioluminescent bacteria, and terrestrial arthropods such as fireflies. In some animals, the light is bacteriogenic, produced by symbiotic bacteria such as those from the genus Vibrio; in others, it is autogenic, produced by the animals themselves.

In a general sense, the principal chemical reaction in bioluminescence involves a light-emitting molecule and an enzyme, generally called luciferin and luciferase, respectively. Because these are generic names, luciferins and luciferases are often distinguished by the species or group, e.g. firefly luciferin. In all characterized cases, the enzyme catalyzes the oxidation of the luciferin.

In some species, the luciferase requires other cofactors, such as calcium or magnesium ions, and sometimes also the energy-carrying molecule adenosine triphosphate (ATP). In evolution, luciferins vary little: one in particular, coelenterazine, is found in 11 different animal phyla, though in some of these, the animals obtain it through their diet. Conversely, luciferases vary widely between different species, which is evidence that bioluminescence has arisen over 40 times in evolutionary history.

Both Aristotle and Pliny the Elder mentioned that damp wood sometimes gives off a glow. Many centuries later Robert Boyle showed that oxygen was involved in the process, in both wood and glowworms. It was not until the late nineteenth century that bioluminescence was properly investigated. The phenomenon is widely distributed among animal groups, especially in marine environments. On land it occurs in fungi, bacteria and some groups of invertebrates, including insects.

The uses of bioluminescence by animals include counterillumination camouflage, mimicry of other animals, for example to lure prey, and signaling to other individuals of the same species, such as to attract mates. In the laboratory, luciferase-based systems are used in genetic engineering and biomedical research. Researchers are also investigating the possibility of using bioluminescent systems for street and decorative lighting, and a bioluminescent plant has been created.

🔗 Biography 🔗 Biography/science and academia 🔗 Middle Ages 🔗 Islam 🔗 Middle Ages/History 🔗 Watches 🔗 Islam/Muslim scholars

Badīʿ az-Zaman Abu l-ʿIzz ibn Ismāʿīl ibn ar-Razāz al-Jazarī (1136–1206, Arabic: بديع الزمان أَبُ اَلْعِزِ إبْنُ إسْماعِيلِ إبْنُ الرِّزاز الجزري‎, IPA: [ældʒæzæriː]) was a Muslim polymath: a scholar, inventor, mechanical engineer, artisan, artist and mathematician. He is best known for writing The Book of Knowledge of Ingenious Mechanical Devices (Arabic: كتاب في معرفة الحيل الهندسية‎, romanized: Kitab fi ma'rifat al-hiyal al-handasiya, lit. 'Book in knowledge of engineering tricks') in 1206, where he described 100 mechanical devices, some 80 of which are trick vessels of various kinds, along with instructions on how to construct them.

🔗 Pharmacology

Eroom's law is the observation that drug discovery is becoming slower and more expensive over time, despite improvements in technology (such as high-throughput screening, biotechnology, combinatorial chemistry, and computational drug design), a trend first observed in the 1980s. The cost of developing a new drug roughly doubles every nine years (inflation-adjusted). In order to highlight the contrast with the exponential advancements of other forms of technology (such as transistors) over time, the law was deliberately spelled as Moore's law spelled backwards.

The article proposing and naming the law attributes it to four main causes.

• the 'better than the Beatles' problem: the sense that new drugs only have modest incremental benefit over drugs already widely considered as successful, such as Lipitor, and treatment effects on top of already effective treatments are smaller than treatment effects versus placebo. The smaller size of these treatment effects mandates an increase in clinical trial sizes to show the same level of efficacy. This problem was phrased as "better than the Beatles" to highlight the fact that it would be difficult to come up with new successful pop songs if all new songs had to be better than the Beatles.
• the 'cautious regulator' problem: the progressive lowering of risk tolerance seen by drug regulatory agencies that makes R&D both costlier and harder. After older drugs (such as Thalidomide or Vioxx) are removed from the market due to safety reasons, the bar on safety for new drugs is increased.
• the 'throw money at it' tendency: the tendency to add human resources and other resources to R&D, which may lead to project overrun.
• the 'basic research–brute force' bias: the tendency to overestimate the ability of advances in basic research and brute force screening methods to show a molecule as safe and effective in clinical trials. From the 1960s to the 1990s (and later), drug discovery has shifted from whole-animal classical pharmacology testing methods (phenotypic screening) to reverse pharmacology target-approaches that result in the discovery of drugs that may tightly bind with high-affinity to target proteins, but which still often fail in clinical trials due to an under-appreciation of the complexity of the whole organism. Furthermore, drug discovery techniques have shifted from small-molecule and iterative low-throughput search strategies to target-based high-throughput screening (HTS) of large compound libraries. But despite being faster and cheaper, HTS approaches may be less productive.

While some suspect a lack of "low-hanging fruit" as a significant contribution to Eroom's law, this may be less important than the four main causes, as there are still many decades' worth of new potential drug targets relative to the number of targets which already have been exploited, even if the industry exploits 4 to 5 new targets per year. There is also space to explore selectively non-selective drugs (or "dirty drugs") that interact with several molecular targets, and which may be particularly effective as central nervous system (CNS) therapeutics, even though few of them have been introduced in the last few decades.