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🔗 Military history 🔗 Military history/Intelligence

The analysis of competing hypotheses (ACH) is a methodology for evaluating multiple competing hypotheses for observed data. It was developed by Richards (Dick) J. Heuer, Jr., a 45-year veteran of the Central Intelligence Agency, in the 1970s for use by the Agency. ACH is used by analysts in various fields who make judgments that entail a high risk of error in reasoning. ACH aims to help an analyst overcome, or at least minimize, some of the cognitive limitations that make prescient intelligence analysis so difficult to achieve.

ACH was a step forward in intelligence analysis methodology, but it was first described in relatively informal terms. Producing the best available information from uncertain data remains the goal of researchers, tool-builders, and analysts in industry, academia and government. Their domains include data mining, cognitive psychology and visualization, probability and statistics, etc. Abductive reasoning is an earlier concept with similarities to ACH.

🔗 Climate change 🔗 Environment 🔗 Books 🔗 Systems 🔗 Futures studies 🔗 Energy

The Limits to Growth (often abbreviated LTG) is a 1972 report that discussed the possibility of exponential economic and population growth with finite supply of resources, studied by computer simulation. The study used the World3 computer model to simulate the consequence of interactions between the Earth and human systems. The model was based on the work of Jay Forrester of MIT,^: 21 as described in his book World Dynamics.

Commissioned by the Club of Rome, the study saw its findings first presented at international gatherings in Moscow and Rio de Janeiro in the summer of 1971.^: 186 The report's authors are Donella H. Meadows, Dennis L. Meadows, Jørgen Randers, and William W. Behrens III, representing a team of 17 researchers.^: 8

The report's findings suggest that, in the absence of significant alterations in resource utilization, it is highly likely that there will be an abrupt and unmanageable decrease in both population and industrial capacity. Despite the report's facing severe criticism and scrutiny upon its release, subsequent research consistently finds that the global use of natural resources has been inadequately reformed since to alter its basic predictions.

Since its publication, some 30 million copies of the book in 30 languages have been purchased. It continues to generate debate and has been the subject of several subsequent publications.

Beyond the Limits and The Limits to Growth: The 30-Year Update were published in 1992 and 2004 respectively; in 2012, a 40-year forecast from Jørgen Randers, one of the book's original authors, was published as 2052: A Global Forecast for the Next Forty Years; and in 2022 two of the original Limits to Growth authors, Dennis Meadows and Jørgen Randers, joined 19 other contributors to produce Limits and Beyond.

🔗 Software 🔗 Software/Computing

This is a list of notable software packages which were published as free and open-source software, or into the public domain, but were made proprietary software, or otherwise switched to a license (including source-available licenses) that is not considered to be free and open source.

🔗 Technology 🔗 Physics 🔗 Energy

The Crookes radiometer (also known as a light mill) consists of an airtight glass bulb containing a partial vacuum, with a set of vanes which are mounted on a spindle inside. The vanes rotate when exposed to light, with faster rotation for more intense light, providing a quantitative measurement of electromagnetic radiation intensity.

The reason for the rotation was a cause of much scientific debate in the ten years following the invention of the device, but in 1879 the currently accepted explanation for the rotation was published. Today the device is mainly used in physics education as a demonstration of a heat engine run by light energy.

It was invented in 1873 by the chemist Sir William Crookes as the by-product of some chemical research. In the course of very accurate quantitative chemical work, he was weighing samples in a partially evacuated chamber to reduce the effect of air currents, and noticed the weighings were disturbed when sunlight shone on the balance. Investigating this effect, he created the device named after him.

It is still manufactured and sold as an educational aid or for curiosity.

🔗 Physics 🔗 Geology 🔗 Physics/Acoustics

Singing sand, also called whistling sand, barking sand or singing dune, is sand that produces sound. The sound emission may be caused by wind passing over dunes or by walking on the sand.

Certain conditions have to come together to create singing sand:

1. The sand grains have to be round and between 0.1 and 0.5 mm in diameter.
2. The sand has to contain silica.
3. The sand needs to be at a certain humidity.

The most common frequency emitted seems to be close to 450 Hz.

There are various theories about the singing sand mechanism. It has been proposed that the sound frequency is controlled by the shear rate. Others have suggested that the frequency of vibration is related to the thickness of the dry surface layer of sand. The sound waves bounce back and forth between the surface of the dune and the surface of the moist layer, creating a resonance that increases the sound's volume. The noise may be generated by friction between the grains or by the compression of air between them.

Other sounds that can be emitted by sand have been described as "roaring" or "booming".

🔗 Germany 🔗 Jewish history 🔗 Adoption, fostering, orphan care and displacement

The Kindertransport (German for "children's transport") was an organised rescue effort of children from Nazi-controlled territory that took place in 1938–1939 during the nine months prior to the outbreak of the Second World War. The United Kingdom took in nearly 10,000 children, most of them Jewish, from Germany, Austria, Czechoslovakia, Poland, and the Free City of Danzig. The children were placed in British foster homes, hostels, schools, and farms. Often they were the only members of their families who survived the Holocaust that was to come. The programme was supported, publicised, and encouraged by the British government, which waived the visa immigration requirements that were not within the ability of the British Jewish community to fulfil. The British government placed no numerical limit on the programme; it was the start of the Second World War that brought it to an end, by which time about 10,000 kindertransport children had been brought to the country.

Smaller numbers of children were taken in via the programme by the Netherlands, Belgium, France, Sweden, and Switzerland. The term "kindertransport" may also be applied to the rescue of mainly Jewish children from Nazi German territory to the Netherlands, Belgium, and France. An example is the 1,000 Chateau de La Hille children who went to Belgium. However, most often the term is restricted to the organised programme of the United Kingdom.

The Central British Fund for German Jewry (now World Jewish Relief) was established in 1933 to support in whatever way possible the needs of Jews in Germany and Austria.

In the United States, the Wagner–Rogers Bill was introduced in Congress, which would have increased the quota of immigrants by bringing to the U.S. a total of 20,000 refugee children, but it did not pass.

🔗 Computer science 🔗 Systems 🔗 Human–Computer Interaction

In artificial intelligence, an expert system is a computer system emulating the decision-making ability of a human expert. Expert systems are designed to solve complex problems by reasoning through bodies of knowledge, represented mainly as if–then rules rather than through conventional procedural code. The first expert systems were created in the 1970s and then proliferated in the 1980s. Expert systems were among the first truly successful forms of artificial intelligence (AI) software. An expert system is divided into two subsystems: the inference engine and the knowledge base. The knowledge base represents facts and rules. The inference engine applies the rules to the known facts to deduce new facts. Inference engines can also include explanation and debugging abilities.

🔗 Television 🔗 Star Trek

Star Trek: Phase II was the initial working title for what officially became titled Star Trek II, an unproduced American science fiction television series created by Gene Roddenberry as a sequel to (and continuation of) the original Star Trek, which had run from 1966 to 1969. The plans for the series were first developed after several failed attempts to create a feature film based on the property, coupled with plans for a Paramount Television Service (PTS) as a fourth broadcast television network in the United States.

Both PTS and the Star Trek revival were announced in early June 1977, with PTS to debut as one evening of programming each Saturday night and to gradually expand to other nights; a strategy successfully employed by the Fox Broadcasting Company a decade later. Star Trek: Phase II was to be the flagship show, and be broadcast at 8pm EST, followed by a movie of the week starting at 9pm. The initial order was for a two-hour pilot, followed by 13 hour-long episodes.

With the exception of Leonard Nimoy as Mr. Spock, who had ongoing disputes with Roddenberry and Paramount, the entire regular and recurring cast of The Original Series were contracted to return, notably William Shatner as Captain Kirk. Three new and younger regular characters were created, science officer Lt. Xon, navigator Lt. Ilia, and ship's executive officer Willard Decker. Xon, Decker and Ilia were later influential in the development of characters on Star Trek: The Next Generation, and two of the scripts written for Phase II would be re-developed for use in that series.

Behind the cameras, Roddenberry recruited Trek-novices Harold Livingston and Robert Goodwin as producers. Veterans of The Original Series were few, and included costume designer William Ware Theiss and illustrator Mike Minor. Art director Matt Jefferies was otherwise employed and brought in as a "technical advisor" and to update the design of the starship USS Enterprise. Special effects (on set) were to be by Jim Rugg. Science fiction novelist Alan Dean Foster received the assignment to write the story outline for the two-hour pilot, but, with a looming production deadline and unable to find a suitable writer to develop this story into a teleplay, Harold Livingston took on the writing job himself. Of the remaining 12 script assignments handed out, about half were to veterans of The Original Series.

Pre-production began in earnest, with the emphasis on what would be the standing sets of the Enterprise, which differed radically in layout, design and detailing from those for The Original Series. Many costumes and props, too, were designed. Ultimately, Paramount's plans for its network and Star Trek's TV return faltered, as the low anticipated advertising revenues for the Paramount Television Service indicated that it was not viable, and the Paramount Pictures parent company Gulf and Western's chairman, Charles Bluhdorn, refused to back the plan, resulting in the eventual exit of Paramount chief executive officer Barry Diller. In August 1977 Paramount president Michael Eisner announced—internally—that the two-hour pilot script was to be the long sought-after feature film story. However, In order to prevent negative publicity, the "cancellation" of the series and network was not immediately disclosed and development of the series and its scripts continued for a further five months, during which time tests were filmed on the incomplete Enterprise sets in widescreen format - a clear indication that whatever Star Trek would be, it would not be a TV movie.

On March 28, 1978, any illusions that Star Trek would be returning to television were ended when Paramount announced that instead of a series it would be producing what became the big budget film titled Star Trek: The Motion Picture (1979), which was itself a massive reworking of the "In Thy Image" two-hour pilot script.

Preproduction work on the series did not entirely go to waste. The standing Enterprise sets would be extensively reworked for the film (and its eventual sequels), and an unfinished admiral's office set's walls became part of the Enterprise cargo deck. However, the visual effects people hired for the feature film decided that the miniatures under construction were not up to the standards of a post-Star Wars feature, and all were scrapped. Director Robert Collins, who had been hired to direct the pilot, and promised he was to direct the feature, was replaced by Robert Wise.

The concept of a "Paramount Network" led by a flagship Star Trek series finally came to fruition in January 1995 when Paramount launched the United Paramount Network (UPN) and the Star Trek: Voyager series.

🔗 Computing 🔗 Books

Hacker's Delight is a software algorithm book by Henry S. Warren, Jr. first published in 2002. It presents fast bit-level and low-level arithmetic algorithms for common tasks such as counting bits or improving speed of division by using multiplication.

🔗 Computing 🔗 Biology 🔗 Computing/Software 🔗 Stanford University 🔗 Pharmacology 🔗 Molecular Biology 🔗 Molecular Biology/Molecular and Cell Biology 🔗 Molecular Biology/Computational Biology

Folding@home (FAH or F@h) is a distributed computing project aimed to help scientists develop new therapeutics for a variety of diseases by the means of simulating protein dynamics. This includes the process of protein folding and the movements of proteins, and is reliant on simulations run on volunteers' personal computers. Folding@home is currently based at the University of Pennsylvania and led by Greg Bowman, a former student of Vijay Pande.

The project utilizes graphics processing units (GPUs), central processing units (CPUs), and ARM processors like those on the Raspberry Pi for distributed computing and scientific research. The project uses statistical simulation methodology that is a paradigm shift from traditional computing methods. As part of the client–server model network architecture, the volunteered machines each receive pieces of a simulation (work units), complete them, and return them to the project's database servers, where the units are compiled into an overall simulation. Volunteers can track their contributions on the Folding@home website, which makes volunteers' participation competitive and encourages long-term involvement.

Folding@home is one of the world's fastest computing systems. With heightened interest in the project as a result of the COVID-19 pandemic, the system achieved a speed of approximately 1.22 exaflops by late March 2020 and reached 2.43 exaflops by April 12, 2020, making it the world's first exaflop computing system. This level of performance from its large-scale computing network has allowed researchers to run computationally costly atomic-level simulations of protein folding thousands of times longer than formerly achieved. Since its launch on October 1, 2000, Folding@home was involved in the production of 226 scientific research papers. Results from the project's simulations agree well with experiments.