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🔗 Mathematics

Hilbert's paradox of the Grand Hotel (colloquial: Infinite Hotel Paradox or Hilbert's Hotel) is a thought experiment which illustrates a counterintuitive property of infinite sets. It is demonstrated that a fully occupied hotel with infinitely many rooms may still accommodate additional guests, even infinitely many of them, and this process may be repeated infinitely often. The idea was introduced by David Hilbert in a 1924 lecture "Über das Unendliche", reprinted in (Hilbert 2013, p.730), and was popularized through George Gamow's 1947 book One Two Three... Infinity.

🔗 Apple Inc. 🔗 Video games 🔗 Computing

The Apple Pippin is a defunct open multimedia technology platform, designed by Apple Computer, and marketed as PiPP!N. According to Apple, Pippin was directed at the home market as "an integral part of the consumer audiovisual, stereo, and television environment."

Pippin is based on the Apple Macintosh platform, including the classic Mac OS architecture. Apple built a demonstration device based on Pippin called "Pippin Power Player," and used it to demonstrate the platform at trade shows and to the media, in order to attract potential software developers and hardware manufacturers. Apple licensed the Pippin technology to third-party companies. Bandai Company Ltd. developed the ATMARK and @WORLD models, and focused them on the gaming and entertainment business in Japan and the United States. Katz Media developed the KMP 2000, and focused it on vertical markets throughout Europe and Canada.

🔗 Novels 🔗 Novels/Science fiction 🔗 Science Fiction

A Canticle for Leibowitz is a post-apocalyptic science fiction novel by American writer Walter M. Miller Jr., first published in 1959. Set in a Catholic monastery in the desert of the southwestern United States after a devastating nuclear war, the book spans thousands of years as civilization rebuilds itself. The monks of the Albertian Order of Leibowitz preserve the surviving remnants of man's scientific knowledge until the world is again ready for it.

The novel is a fixup of three short stories Miller published in The Magazine of Fantasy & Science Fiction that were inspired by the author's participation in the bombing of the monastery at the Battle of Monte Cassino during World War II. The book is considered one of the classics of science fiction and has never been out of print. Appealing to mainstream and genre critics and readers alike, it won the 1961 Hugo Award for best science fiction novel, and its themes of religion, recurrence, and church versus state have generated a significant body of scholarly research. A sequel, Saint Leibowitz and the Wild Horse Woman, was published posthumously in 1997.

🔗 Music theory

The Parsons code, formally named the Parsons code for melodic contours, is a simple notation used to identify a piece of music through melodic motion — movements of the pitch up and down. Denys Parsons developed this system for his 1975 book The Directory of Tunes and Musical Themes. Representing a melody in this manner makes it easier to index or search for pieces, particularly when the notes values are unknown.

The book was also published in Germany in 2002 and reprinted by Piatkus as The Directory of Classical Themes in 2008.

🔗 Marine life 🔗 Animals

The Venus' flower basket (Euplectella aspergillum) is a glass sponge in the phylum Porifera. It is a marine sponge found in the deep waters of the Pacific ocean. As other glass sponges, they build their skeletons out of silica, which is of great interest in materials science as they do not require heat to form their glass latices, which in some ways makes their properties superior to manufactured fiber optics. As other sponges, they feed by filtering sea water to capture plankton.

The sponges are often found to house glass sponge shrimp, usually a breeding pair, whom are typically unable to exit the sponge's lattice due to their size. Consequently, they live in and around these sponges, where the shrimp perform a mutuallistic relationship with the sponge until they die. This may have influenced the adoption of the sponge as a symbol of undying love in Japan, where the skeletons of these sponges are presented as nuptial gifts.

🔗 Novels 🔗 Philosophy 🔗 Philosophy/Philosophical literature 🔗 Novels/Science fiction 🔗 Anthropology 🔗 Anti-war

Cat's Cradle is a satirical postmodern novel, with science fiction elements, by American writer Kurt Vonnegut. Vonnegut's fourth novel, it was first published in 1963, exploring and satirizing issues of science, technology, the purpose of religion, and the arms race, often through the use of black humor. After turning down his original thesis in 1947, the University of Chicago awarded Vonnegut his master's degree in anthropology in 1971 for Cat's Cradle.

🔗 Databases

Third normal form (3NF) is a database schema design approach for relational databases which uses normalizing principles to reduce the duplication of data, avoid data anomalies, ensure referential integrity, and simplify data management. It was defined in 1971 by Edgar F. Codd, an English computer scientist who invented the relational model for database management.

A database relation (e.g. a database table) is said to meet third normal form standards if all the attributes (e.g. database columns) are functionally dependent on solely the primary key. Codd defined this as a relation in second normal form where all non-prime attributes depend only on the candidate keys and do not have a transitive dependency on another key.

A hypothetical example of a failure to meet third normal form would be a hospital database having a table of patients which included a column for the telephone number of their doctor. The phone number is dependent on the doctor, rather than the patient, thus would be better stored in a table of doctors. The negative outcome of such a design is that a doctor's number will be duplicated in the database if they have multiple patients, thus increasing both the chance of input error and the cost and risk of updating that number should it change (compared to a third normal form-compliant data model that only stores a doctor's number once on a doctor table).

Codd later realized that 3NF did not eliminate all undesirable data anomalies and developed a stronger version to address this in 1974, known as Boyce–Codd normal form.

🔗 United States/U.S. Government 🔗 United States 🔗 Biography 🔗 Computing 🔗 Military history 🔗 Military history/North American military history 🔗 United States/Military history - U.S. military history 🔗 Military history/Military science, technology, and theory 🔗 New York City 🔗 Women scientists 🔗 Biography/science and academia 🔗 Women's History 🔗 Military history/Military biography 🔗 Biography/military biography 🔗 Software 🔗 Software/Computing 🔗 Military history/Maritime warfare 🔗 Pritzker Military Library

Grace Brewster Murray Hopper (née Murray December 9, 1906 – January 1, 1992) was an American computer scientist and United States Navy rear admiral. One of the first programmers of the Harvard Mark I computer, she was a pioneer of computer programming who invented one of the first linkers. She popularized the idea of machine-independent programming languages, which led to the development of COBOL, an early high-level programming language still in use today.

Prior to joining the Navy, Hopper earned a Ph.D. in mathematics from Yale University and was a professor of mathematics at Vassar College. Hopper attempted to enlist in the Navy during World War II but was rejected because she was 34 years old. She instead joined the Navy Reserves. Hopper began her computing career in 1944 when she worked on the Harvard Mark I team led by Howard H. Aiken. In 1949, she joined the Eckert–Mauchly Computer Corporation and was part of the team that developed the UNIVAC I computer. At Eckert–Mauchly she began developing the compiler. She believed that a programming language based on English was possible. Her compiler converted English terms into machine code understood by computers. By 1952, Hopper had finished her program linker (originally called a compiler), which was written for the A-0 System. During her wartime service, she co-authored three papers based on her work on the Harvard Mark 1.

In 1954, Eckert–Mauchly chose Hopper to lead their department for automatic programming, and she led the release of some of the first compiled languages like FLOW-MATIC. In 1959, she participated in the CODASYL consortium, which consulted Hopper to guide them in creating a machine-independent programming language. This led to the COBOL language, which was inspired by her idea of a language being based on English words. In 1966, she retired from the Naval Reserve, but in 1967 the Navy recalled her to active duty. She retired from the Navy in 1986 and found work as a consultant for the Digital Equipment Corporation, sharing her computing experiences.

The U.S. Navy Arleigh Burke-class guided-missile destroyer USS Hopper was named for her, as was the Cray XE6 "Hopper" supercomputer at NERSC. During her lifetime, Hopper was awarded 40 honorary degrees from universities across the world. A college at Yale University was renamed in her honor. In 1991, she received the National Medal of Technology. On November 22, 2016, she was posthumously awarded the Presidential Medal of Freedom by President Barack Obama.

🔗 History of Science 🔗 Robotics

Leachim was an early example of Diphone synthetic speech and demonstrated how voice branching could be done quickly via computer discs to create understandable speech (i.e. verbal output). This method combined phonemes, words, and sentences to form verbal responsive messages when prompted by the computer. The device received attention on a world-wide basis because hundreds of articles were written about it.

🔗 Time

The Pax calendar was invented by James A. Colligan, SJ in 1930 as a perennializing reform of the annualized Gregorian calendar.