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🔗 Biography 🔗 London 🔗 Trains 🔗 Civil engineering 🔗 Ships 🔗 River Thames 🔗 Wiltshire 🔗 Hampshire 🔗 Bristol 🔗 Trains/UK Railways

Isambard Kingdom Brunel (; 9 April 1806 – 15 September 1859) was a British civil engineer who is considered "one of the most ingenious and prolific figures in engineering history", "one of the 19th-century engineering giants", and "one of the greatest figures of the Industrial Revolution, [who] changed the face of the English landscape with his groundbreaking designs and ingenious constructions". Brunel built dockyards, the Great Western Railway (GWR), a series of steamships including the first propeller-driven transatlantic steamship, and numerous important bridges and tunnels. His designs revolutionised public transport and modern engineering.

Though Brunel's projects were not always successful, they often contained innovative solutions to long-standing engineering problems. During his career, Brunel achieved many engineering firsts, including assisting in the building of the first tunnel under a navigable river and the development of SS Great Britain, the first propeller-driven, ocean-going, iron ship, which, when launched in 1843, was the largest ship ever built.

On the GWR, Brunel set standards for a well-built railway, using careful surveys to minimise gradients and curves. This necessitated expensive construction techniques, new bridges, new viaducts, and the two-mile (3.2 km) long Box Tunnel. One controversial feature was the wide gauge, a "broad gauge" of 7 ft ¹⁄₄ in (2,140 mm), instead of what was later to be known as "standard gauge" of 4 ft 8 ¹⁄₂ in (1,435 mm). He astonished Britain by proposing to extend the GWR westward to North America by building steam-powered, iron-hulled ships. He designed and built three ships that revolutionised naval engineering: the SS Great Western (1838), the SS Great Britain (1843), and the SS Great Eastern (1859).

In 2002, Brunel was placed second in a BBC public poll to determine the "100 Greatest Britons". In 2006, the bicentenary of his birth, a major programme of events celebrated his life and work under the name Brunel 200.

🔗 Technology

A blast valve is used to protect a shelter, such as a fallout shelter or bunker, from the effects of sudden outside air pressure changes. A nuclear weapon creates a shock wave, which may produce sudden pressure changes of more than an atmosphere (about 1 bar) even several kilometres from the detonation point. After the shock wave passes, a sudden negative pressure follows.

If such pressure waves enter a shelter, they will likely do substantial harm to occupants and equipment. A blast valve is placed in air intake/exhaust pipes, that remains open normally, but automatically closes when strong pressure is applied in either direction. Blast dampers operate in the same fashion and are related or identical to blast valves, the former name however is generally used to describe blast mitigation devices, for more conventional explosive events.

A typical blast valve has entries of 15–30 cm diameter, and a larger centre section. Within the centre section is a disk mounted on an axle, with weak springs that keep it centred, away from both entries. Pressure displaces the disk along the axle, until it plugs one entry or the other. After the blast, the springs return the disk to the centre, re-opening the valve.

Another type of blast valve employs rounded metal tubes held in place by springs. As pressure rises it pushes the tubes against the frame of the valve closing the opening. These valves are typically unidirectional in airflow and are employed in large wall structures where large amounts of airflow is required.

One form of blast valve, popularized by the book Nuclear War Survival Skills and tested by ORNL is worn flat rubber tire treads nailed or bolted to frames strong enough to resist the maximum overpressure, with tested closing times cited as being identical to commercial grade blast valves, however the use of this form of blast valve design must also take the risk of the flammable rubber catching fire into consideration.

🔗 Software 🔗 Software/Computing

Word2vec is a technique for natural language processing (NLP) published in 2013. The word2vec algorithm uses a neural network model to learn word associations from a large corpus of text. Once trained, such a model can detect synonymous words or suggest additional words for a partial sentence. As the name implies, word2vec represents each distinct word with a particular list of numbers called a vector. The vectors are chosen carefully such that they capture the semantic and syntactic qualities of words; as such, a simple mathematical function (cosine similarity) can indicate the level of semantic similarity between the words represented by those vectors.

🔗 Internet

Web Environment Integrity (WEI) is a controversial API proposal currently being developed for Google Chrome. As of August 2023, a Web Environment Integrity prototype exists in Chromium, but has not shipped in any browser.

🔗 Typography

A fleuron (;), also known as printers' flower, is a typographic element, or glyph, used either as a punctuation mark or as an ornament for typographic compositions. Fleurons are stylized forms of flowers or leaves; the term derives from the Old French: floron ("flower"). Robert Bringhurst in The Elements of Typographic Style calls the forms "horticultural dingbats". A commonly-encountered fleuron is the ❦, the floral heart or hedera (ivy leaf). It is also known as an aldus leaf (after Italian Renaissance printer Aldus Manutius).

🔗 Linguistics 🔗 Linguistics/Phonetics 🔗 Opera

The vocal fry register (also known as pulse register, laryngealization, pulse phonation, creaky voice, creak, croak, popcorning, glottal fry, glottal rattle, glottal scrape) is the lowest vocal register and is produced through a loose glottal closure that permits air to bubble through slowly with a popping or rattling sound of a very low frequency. During this phonation, the arytenoid cartilages in the larynx are drawn together, which causes the vocal folds to compress rather tightly and become relatively slack and compact. This process forms a large and irregularly vibrating mass within the vocal folds that produces the characteristic low popping or rattling sound when air passes through the glottal closure. The register (if well controlled) can extend far below the modal voice register, in some cases up to 8 octaves lower, such as in the case of Tim Storms who holds the world record for lowest frequency note ever produced by a human, a G₋₇, which is only 0.189 Hz, inaudible to the human ear.

Vocal fry is thought to have become more common among young female speakers of American English in the early 21st century, with the style of speaking being considered informal, nonaggressive and urban-oriented.

🔗 Video games 🔗 Computing 🔗 BBC

The British Broadcasting Corporation Microcomputer System, or BBC Micro, is a series of microcomputers and associated peripherals designed and built by Acorn Computers in the 1980s for the BBC Computer Literacy Project. Designed with an emphasis on education, it was notable for its ruggedness, expandability, and the quality of its operating system. An accompanying 1982 television series, The Computer Programme, featuring Chris Serle learning to use the machine, was broadcast on BBC2.

After the Literacy Project's call for bids for a computer to accompany the TV programmes and literature, Acorn won the contract with the Proton, a successor of its Atom computer prototyped at short notice. Renamed the BBC Micro, the system was adopted by most schools in the United Kingdom, changing Acorn's fortunes. It was also successful as a home computer in the UK, despite its high cost. Acorn later employed the machine to simulate and develop the ARM architecture.

While nine models were eventually produced with the BBC brand, the phrase "BBC Micro" is usually used colloquially to refer to the first six (Model A, B, B+64, B+128, Master 128, and Master Compact); subsequent BBC models are considered part of Acorn's Archimedes series.

🔗 Trains 🔗 Trains/UK Railways 🔗 Trains/Rail transport in Germany

Railway time was the standardised time arrangement first applied by the Great Western Railway in England in November 1840, the first recorded occasion when different local mean times were synchronised and a single standard time applied. The key goals behind introducing railway time were to overcome the confusion caused by having non-uniform local times in each town and station stop along the expanding railway network and to reduce the incidence of accidents and near misses, which were becoming more frequent as the number of train journeys increased.

Railway time was progressively taken up by all railway companies in Great Britain over the following seven years. The schedules by which trains were organised and the time station clocks displayed were brought in line with the local mean time for London or "London Time", the time set at Greenwich by the Royal Observatory, which was already widely known as Greenwich Mean Time (GMT).

The development of railway networks in North America in the 1850s, India in around 1860, and in Europe, prompted the introduction of standard time influenced by geography, industrial development, and political governance.

The railway companies sometimes faced concerted resistance from local people who refused to adjust their public clocks to bring them into line with London Time. As a consequence, two different times would be displayed in the town and in use, with the station clocks and the times published in train timetables differing by several minutes from that on other clocks. Despite this early reluctance, railway time rapidly became adopted as the default time across the whole of Great Britain, although it took until 1880 for the government to legislate on the establishment of a single standard time and a single time zone for the country.

Some contemporary commentators referred to the influence of railway time on encouraging greater precision in daily tasks and the demand for punctuality.

🔗 Physics 🔗 Astronomy

The Oh-My-God particle was the highest-energy cosmic ray detected at the time (15 October 1991) by the Fly's Eye detector in Dugway Proving Ground, Utah, US. Its energy was estimated as (3.2±0.9)×10²⁰ eV, or 51 J. This is 20 million times more energetic than the highest energy measured in electromagnetic radiation emitted by an extragalactic object and 10²⁰ (100 quintillion) times the photon energy of visible light, equivalent to a 142-gram (5 oz) baseball travelling at about 26 m/s (94 km/h; 58 mph). Although higher energy cosmic rays have been detected since then, this particle's energy was unexpected, and called into question theories of that era about the origin and propagation of cosmic rays.

Assuming it was a proton, this particle traveled at 99.99999999999999999999951% of the speed of light, its Lorentz factor was 3.2×10¹¹ and its rapidity was 27.1. At this speed, if a photon were travelling with the particle, it would take over 215,000 years for the photon to gain a 1 cm lead as seen in Earth's reference frame.

The energy of this particle is some 40 million times that of the highest energy protons that have been produced in any terrestrial particle accelerator. However, only a small fraction of this energy would be available for an interaction with a proton or neutron on Earth, with most of the energy remaining in the form of kinetic energy of the products of the interaction. The effective energy available for such a collision is √2Emc², where E is the particle's energy and mc² is the mass energy of the proton. For the Oh-My-God particle, this gives 7.5×10¹⁴ eV, roughly 60 times the collision energy of the Large Hadron Collider.

While the particle's energy was higher than anything achieved in terrestrial accelerators, it was still about 40 million times lower than the Planck energy. Particles of such energy would be required in order to explore the Planck scale. A proton with that much energy would travel 1.665×10¹⁵ times closer to the speed of light than the Oh-My-God particle. As viewed from Earth it would take about 3.579×10²⁰ years, or 2.59×10¹⁰ times the current age of the universe, for a photon to gain a 1 cm lead over a Planck energy proton as observed in Earth's reference frame.

Since the first observation, at least 72 similar (energy > 5.7×10¹⁹ eV) events have been recorded, confirming the phenomenon. These ultra-high-energy cosmic ray particles are very rare; the energy of most cosmic ray particles is between 10 MeV and 10 GeV. More recent studies using the Telescope Array have suggested a source for the particles within a 20-degree radius "warm spot" in the direction of the constellation Ursa Major.

🔗 Physics 🔗 China 🔗 Astronomy 🔗 History of Science 🔗 Astronomy/Astronomical objects 🔗 Arab world

SN 1006 was a supernova that is likely the brightest observed stellar event in recorded history, reaching an estimated −7.5 visual magnitude, and exceeding roughly sixteen times the brightness of Venus. Appearing between April 30 and May 1, 1006 AD in the constellation of Lupus, this "guest star" was described by observers across the modern day countries of China, Japan, Iraq, Egypt, and the continent of Europe, and possibly recorded in North American petroglyphs. Some reports state it was clearly visible in the daytime. Modern astronomers now consider its distance from Earth to be about 7,200 light-years.