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πŸ”— AlphaSmart

πŸ”— Brands

The AlphaSmart was a brand of portable, battery powered, word-processing keyboards manufactured by NEO Direct, Inc. (formerly Renaissance Learning, Inc, formerly AlphaSmart, Inc., formerly Intelligent Peripheral Devices, Inc.). Originally released in 1993, the first AlphaSmart models were intended for writing on-the-go and could be plugged into a computer to transfer saved written text. The units' portability and long battery life made them valuable to journalists, writers, and students. Later models expanded functionality by spell-checking, running applications, and accessing wireless printers.

The last model, Neo 2, was released in 2007, and production was discontinued by the company in late September 2013, although the company still offers support and software to existing users.

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πŸ”— Cox-Zucker_machine

πŸ”— Mathematics

The Cox–Zucker machine is an algorithm created by David A. Cox and Steven Zucker. This algorithm determines if a given set of sections provides a basis (up to torsion) for the Mordell–Weil group of an elliptic surface E β†’ S where S is isomorphic to the projective line.

The algorithm was first published in the 1979 paper "Intersection numbers of sections of elliptic surfaces" by Cox and Zucker, and it was later named the "Cox–Zucker machine" by Charles Schwartz in 1984. The name is a homophone for an obscenity, and this was a deliberate move by Cox and Zucker, who conceived of the idea of coauthoring a paper as graduate students at Princeton for the express purpose of enabling this joke, a joke they followed through on while professors at Rutgers five years later. As Cox explained in a memorial tribute to Zucker in Notices of the American Mathematical Society in 2021: "A few weeks after we met, we realized that we had to write a joint paper because the combination of our last names, in the usual alphabetical order, is remarkably obscene."

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πŸ”— Andreas Raab passed away

πŸ”— Computer science

The Squeak programming language is a dialect of Smalltalk. It is object-oriented, class-based, and reflective.

It was derived directly from Smalltalk-80 by a group at Apple Computer that included some of the original Smalltalk-80 developers. Its development was continued by the same group at Walt Disney Imagineering, where it was intended for use in internal Disney projects. Later on the group moved on to be supported by HP labs, SAP Labs and most recently Y Combinator.

Squeak is cross-platform. Programs produced on one platform run bit-identical on all other platforms, and versions are available for many platforms including the obvious Windows/macOS/linux versions. The Squeak system includes code for generating a new version of the virtual machine (VM) on which it runs. It also includes a VM simulator written in Squeak. For these reasons, it is easily ported.

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πŸ”— Optical Tweezers

πŸ”— Physics πŸ”— Biophysics

Optical tweezers (originally called single-beam gradient force trap) are scientific instruments that use a highly focused laser beam to provide an attractive or repulsive force (typically on the order of piconewtons), depending on the relative refractive index between particle and surrounding medium; these forces can be used to physically hold and move microscopic objects, in a manner similar to tweezers. They are able to trap and manipulate small particles, whose size is typically in microns, including dielectric and absorbing particles. Optical tweezers have been particularly successful in studying a variety of biological systems in recent years.

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πŸ”— Jazz Kissa

πŸ”— Japan πŸ”— Jazz

Jazz kissa (Japanese: γ‚Έγƒ£γ‚Ίε–«θŒΆ), sometimes transliterated as jazu kissa, are cafΓ©s that specialise in the playing and appreciation of recorded jazz music. Unique to Japan, jazz kissa are spaces where jazz music is played for dedicated listening rather than as background music. A typical jazz kissa features a high-quality stereo system, a large music collection and dim lighting, and serves coffee and alcoholic drinks.

The first cafΓ©s focussed on playing recorded jazz opened in Japan in the late 1920s as part of a wider enthusiasm for Western culture and music. Before World War II there were about 80 jazz kissa, but during the war many of them closed. The post-war period saw jazz kissa return in even greater numbers. Jazz kissa served as places to hear imported jazz records that were too expensive for individuals to buy. They were an important musical resource for musicians, journalists and jazz enthusiasts, and, at their peak, there were around 600 jazz kissa operating across Japan.

Starting in the 1970s, easier and cheaper access to personal stereo equipment and jazz music challenged the role of the jazz kissa. Jazz kissa numbers greatly reduced and the remaining kissa were mainly visited for nostalgic reasons. However, jazz kissa continue to operate in Japan and new kissa are still being opened. Jazz kissa played a role in the reception of jazz music and modern Western culture in Japan. Their influence extends beyond Japan with listening bars inspired by jazz kissa opening in many other countries in the 21st century.

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πŸ”— Ousterhout's Dichotomy

πŸ”— Computing πŸ”— Computer science

Ousterhout's dichotomy is computer scientist John Ousterhout's categorization that high-level programming languages tend to fall into two groups, each with distinct properties and uses: system programming languages and scripting languages – compare programming in the large and programming in the small. This distinction underlies the design of his language Tcl.

System programming languages (or applications languages) usually have the following properties:

  • They are typed statically
  • They support creating complex data structures
  • Programs in them are compiled into machine code
  • Programs in them are meant to operate largely independently of other programs

System programming languages tend to be used for components and applications with large amounts of internal functionality such as operating systems, database servers, and Web browsers. These applications typically employ complex algorithms and data structures and require high performance. Prototypical examples of system programming languages include C and Modula-2.

By contrast, scripting languages (or glue languages) tend to have the following properties:

  • They are typed dynamically
  • They have little or no provision for complex data structures
  • Programs in them (scripts) are interpreted

Scripting languages tend to be used for applications where most of the functionality comes from other programs (often implemented in system programming languages); the scripts are used to glue together other programs or add additional layers of functionality on top of existing programs. Ousterhout claims that scripts tend to be short and are often written by less sophisticated programmers, so execution efficiency is less important than simplicity and ease of interaction with other programs. Common applications for scripting include Web page generation, report generation, graphical user interfaces, and system administration. Prototypical examples of scripting languages include AppleScript, C shell, DOS batch files, and Tcl.

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πŸ”— IBM 5100

πŸ”— Computing

The IBM 5100 Portable Computer is a portable computer (one of the first) introduced in September 1975, six years before the IBM Personal Computer. It was the evolution of a prototype called the SCAMP (Special Computer APL Machine Portable) that was developed at the IBM Palo Alto Scientific Center in 1973. In January 1978, IBM announced the IBM 5110, its larger cousin, and in February 1980 IBM announced the IBM 5120. The 5100 was withdrawn in March 1982.

When the IBM PC was introduced in 1981, it was originally designated as the IBM 5150, putting it in the "5100" series, though its architecture was unrelated to the IBM 5100's.

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πŸ”— Gravitation water vortex power plant

πŸ”— Energy

The gravitation water vortex power plant is a type of micro hydro vortex turbine system which is capable of converting energy in a moving fluid to rotational energy using a low hydraulic head of 0.7–3 metres (2Β ft 4Β in–9Β ft 10Β in). The technology is based on a round basin with a central drain. Above the drain the water forms a stable line vortex which drives a water turbine.

It was first patented by Greek-Australian Lawyer & Inventor Paul Kouris in 1996, who was searching for a way to harness the power inherent in a vortex.

Later, Austrian Inventor Franz ZotlΓΆterer created a similar turbine while attempting to find a way to aerate water without an external power source.

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πŸ”— Montessori Education

πŸ”— Psychology πŸ”— Education πŸ”— Homeschooling πŸ”— Alternative education

The Montessori method of education is a type of educational method that involves children's natural interests and activities rather than formal teaching methods. A Montessori classroom places an emphasis on hands-on learning and developing real-world skills. It emphasizes independence and it views children as naturally eager for knowledge and capable of initiating learning in a sufficiently supportive and well-prepared learning environment. It discourages some conventional measures of achievement, such as grades and tests.

The method was started in the early 20th century by Italian physician Maria Montessori, who developed her theories through scientific experimentation with her students; the method has since been used in many parts of the world, in public and private schools alike.

A range of practices exist under the name "Montessori", which is not trademarked. Popular elements include mixed-age classrooms, student freedom (including their choices of activity), long blocks of uninterrupted work time, specially trained teachers and prepared environment. Scientific studies regarding the Montessori method are mostly positive, with a 2017 review stating that "broad evidence" exists for its efficacy.

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πŸ”— Computus – The calculation to determine the day of Easter

πŸ”— Time πŸ”— Christianity

The computus (Latin for 'computation') is a calculation that determines the calendar date of Easter. Easter is traditionally celebrated on the first Sunday after the Paschal full moon, which is the first full moon on or after 21 March (an approximation of the March equinox). Determining this date in advance requires a correlation between the lunar months and the solar year, while also accounting for the month, date, and weekday of the calendar. The calculations produce different results depending on whether the Julian calendar or the Gregorian calendar is used.

In late antiquity, it was feasible for the entire Christian church to receive the date of Easter each year through an annual announcement from the Pope. By the early third century, however, communications had deteriorated to the point that the church put great value in a system that would allow the clergy to independently and consistently determine the date for themselves. Additionally, the church wished to eliminate dependencies on the Hebrew calendar, by deriving Easter directly from the vernal equinox.

In The Reckoning of Time (725), Bede uses computus as a general term for any sort of calculation, although he refers to the Easter cycles of Theophilus as a "Paschal computus." By the end of the 8th century, computus came to refer specifically to the calculation of time.

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