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🔗 Technology

KarTrak, sometimes KarTrak ACI (for Automatic Car Identification) is a colored bar code system designed to automatically identify rail cars and other rolling stock. KarTrak was made a requirement in North America, but technical problems led to abandonment of the system in the late 1970s.

🔗 United Kingdom 🔗 Classical music 🔗 Classical music/Compositions

Edward Elgar composed his Variations on an Original Theme, Op. 36, popularly known as the Enigma Variations, between October 1898 and February 1899. It is an orchestral work comprising fourteen variations on an original theme.

Elgar dedicated the work "to my friends pictured within", each variation being a musical sketch of one of his circle of close acquaintances (see musical cryptogram). Those portrayed include Elgar's wife Alice, his friend and publisher Augustus J. Jaeger and Elgar himself. In a programme note for a performance in 1911 Elgar wrote:

This work, commenced in a spirit of humour & continued in deep seriousness, contains sketches of the composer's friends. It may be understood that these personages comment or reflect on the original theme & each one attempts a solution of the Enigma, for so the theme is called. The sketches are not 'portraits' but each variation contains a distinct idea founded on some particular personality or perhaps on some incident known only to two people. This is the basis of the composition, but the work may be listened to as a 'piece of music' apart from any extraneous consideration.

In naming his theme "Enigma", Elgar posed a challenge which has generated much speculation but has never been conclusively answered. The Enigma is widely believed to involve a hidden melody.

After its 1899 London premiere the Variations achieved immediate popularity and established Elgar's international reputation.

🔗 Television 🔗 Science Fiction

Ark II is an American live-action science fiction television series, aimed at children, that aired on CBS from September 11 to December 18, 1976 (with reruns continuing through November 13, 1977) as part of its weekend line-up. It returned again in rerun from September 16, 1978 through August 25, 1979. Only 15 half-hour episodes were ever produced. The program's central characters were created by Martin Roth; Ted Post helped Roth develop its core format.

🔗 New York City 🔗 Engineering

The Citicorp Center engineering crisis was the discovery, in 1978, of a significant structural flaw in Citicorp Center, then a recently completed skyscraper in New York City, and the subsequent effort to quietly make repairs over the next few months. The building, now known as Citigroup Center, occupied an entire block and was to be the headquarters of Citibank. Its structure, designed by William LeMessurier, had several unusual design features, including a raised base supported by four offset stilts, and diagonal bracing which absorbed wind loads from upper stories.

In the original design, potential wind loads for the building were calculated incorrectly. The flaw was discovered by Diane Hartley, an undergraduate student at Princeton University who was writing a thesis on the building, and was communicated to the firm responsible for the structural design. LeMessurier was subsequently lauded for acknowledging his error and orchestrating a successful repair effort. Estimates at the time suggested that the building could be toppled by a 70-mile-per-hour (110 km/h) wind, with possibly many people killed as a result. The crisis was kept secret until 1995 and Hartley had no knowledge of the significance of her work until after that time.

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🔗 Finance & Investment 🔗 Economics 🔗 Books 🔗 Skepticism

Extraordinary Popular Delusions and the Madness of Crowds is an early study of crowd psychology by Scottish journalist Charles Mackay, first published in 1841 under the title Memoirs of Extraordinary Popular Delusions. The book was published in three volumes: "National Delusions", "Peculiar Follies", and "Philosophical Delusions". A second edition appeared in 1852, reorganizing the three volumes into two and adding numerous engravings. Mackay was an accomplished teller of stories, though he wrote in a journalistic and somewhat sensational style.

The subjects of Mackay's debunking include alchemy, crusades, duels, economic bubbles, fortune-telling, haunted houses, the Drummer of Tedworth, the influence of politics and religion on the shapes of beards and hair, magnetisers (influence of imagination in curing disease), murder through poisoning, prophecies, popular admiration of great thieves, popular follies of great cities, and relics. Present-day writers on economics, such as Michael Lewis and Andrew Tobias, laud the three chapters on economic bubbles.

In later editions, Mackay added a footnote referencing the Railway Mania of the 1840s as another "popular delusion" which was at least as important as the South Sea Bubble. In the 21st century, the mathematician Andrew Odlyzko pointed out, in a published lecture, that Mackay himself played a role in this economic bubble; as a leader writer in The Glasgow Argus, Mackay wrote on 2 October 1845: "There is no reason whatever to fear a crash".

🔗 Plants 🔗 Forestry 🔗 Ecology

Pioneer species are resilient species that are the first to colonize barren environments, or to repopulate disrupted biodiverse steady-state ecosystems as part of ecological succession. A number of kinds of events can create good conditions for pioneers, including disruption by natural disasters, such as wildfire, flood, mudslide, lava flow or a climate-related extinction event or by anthropogenic habitat destruction, such as through land clearance for agriculture or construction or industrial damage. Pioneer species play an important role in creating soil in primary succession, and stabilizing soil and nutrients in secondary succession.

For humans, because pioneer species quickly occupy disrupted spaces they are sometimes treated as weeds or nuisance wildlife, such as the common dandelion or stinging nettle. Even though humans have mixed relationships with these plants, these species tend to help improve the ecosystem because they can break up compacted soils and accumulate nutrients that help with a transition back to a more mature ecosystem. In human managed ecological restoration or agroforestry, trees and herbaceous pioneers can be used to restore soil qualities and provide shelter for slower growing or more demanding plants. Some systems use introduced species to restore the ecosystem, or for environmental remediation. The durability of pioneer species can also make them potential invasive species.

🔗 Computing 🔗 Military history 🔗 Military history/North American military history 🔗 Military history/United States military history 🔗 Military history/Military science, technology, and theory 🔗 Military history/Cold War 🔗 Computing/Early computers

Whirlwind I was a Cold War-era vacuum tube computer developed by the MIT Servomechanisms Laboratory for the U.S. Navy. Operational in 1951, it was among the first digital electronic computers that operated in real-time for output, and the first that was not simply an electronic replacement of older mechanical systems.

It was one of the first computers to calculate in bit-parallel (rather than bit-serial), and was the first to use magnetic-core memory.

Its development led directly to the Whirlwind II design used as the basis for the United States Air Force SAGE air defense system, and indirectly to almost all business computers and minicomputers in the 1960s, particularly because of the mantra "short word length, speed, people."

🔗 Italy 🔗 Rivers 🔗 Rivers/Waterfalls

The Cascata delle Marmore (Italian: [kaˈskaːta delle ˈmarmore]) or Marmore Falls is a tiered, man-made waterfall in Italy, created by the Romans in 271 BC. At 165m (541 feet) tall, it is the largest man-made waterfall in the world. It is located 7.7 km from Terni, in the region of Umbria.