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The Boltzmann brain argument suggests that it is more likely for a single brain to spontaneously and briefly form in a void (complete with a false memory of having existed in our universe) than it is for our universe to have come about in the way modern science thinks it actually did. It was first proposed as a reductio ad absurdum response to Ludwig Boltzmann's early explanation for the low-entropy state of our universe.

In this physics thought experiment, a Boltzmann brain is a fully formed brain, complete with memories of a full human life in our universe, that arises due to extremely rare random fluctuations out of a state of thermodynamic equilibrium. Theoretically over a period of time on the order of hundreds of billions of years, by sheer chance atoms in a void could spontaneously come together in such a way as to assemble a functioning human brain. Like any brain in such circumstances, it would almost immediately stop functioning and begin to deteriorate.

The idea is ironically named after the Austrian physicist Ludwig Boltzmann (1844–1906), who in 1896 published a theory that tried to account for the fact that we find ourselves in a universe that is not as chaotic as the budding field of thermodynamics seemed to predict. He offered several explanations, one of them being that the universe, even one that is fully random (or at thermal equilibrium), would spontaneously fluctuate to a more ordered (or low-entropy) state. One criticism of this "Boltzmann universe" hypothesis is that the most common thermal fluctuations are as close to equilibrium overall as possible; thus, by any reasonable criterion, actual humans in the actual universe would be vastly less likely than "Boltzmann brains" existing alone in an empty universe.

Boltzmann brains gained new relevance around 2002, when some cosmologists started to become concerned that, in many existing theories about the Universe, human brains in the current Universe appear to be vastly outnumbered by Boltzmann brains in the future Universe who, by chance, have exactly the same perceptions that we do; this leads to the conclusion that statistically we ourselves are likely to be Boltzmann brains. Such a reductio ad absurdum argument is sometimes used to argue against certain theories of the Universe. When applied to more recent theories about the multiverse, Boltzmann brain arguments are part of the unsolved measure problem of cosmology. Boltzmann brains remain a thought experiment; physicists do not believe that we are actually Boltzmann brains, but rather use the thought experiment as a tool for evaluating competing scientific theories.

Pi Day is an annual celebration of the mathematical constant π (pi). Pi Day is observed on March 14 (3/14 in the month/day format) since 3, 1, and 4 are the first three significant digits of π. In 2009, the United States House of Representatives supported the designation of Pi Day. UNESCO's 40th General Conference decided Pi Day as the International Day of Mathematics in November 2019.

Pi Approximation Day is observed on July 22 (22/7 in the day/month format), since the fraction ​²²⁄₇ is a common approximation of π, which is accurate to two decimal places and dates from Archimedes.

Two Pi Day, also known as Tau Day for the mathematical constant Tau, is observed on June 28 (6/28 in the month/day format).

Project Cybersyn was a Chilean project from 1971–1973 during the presidency of Salvador Allende aimed at constructing a distributed decision support system to aid in the management of the national economy. The project consisted of four modules: an economic simulator, custom software to check factory performance, an operations room, and a national network of telex machines that were linked to one mainframe computer.

Project Cybersyn was based on viable system model theory approach to organizational design, and featured innovative technology for its time: it included a network of telex machines (Cybernet) in state-run enterprises that would transmit and receive information with the government in Santiago. Information from the field would be fed into statistical modeling software (Cyberstride) that would monitor production indicators, such as raw material supplies or high rates of worker absenteeism, in "almost" real time, alerting the workers in the first case and, in abnormal situations, if those parameters fell outside acceptable ranges by a very large degree, also the central government. The information would also be input into economic simulation software (CHECO, for CHilean ECOnomic simulator) that the government could use to forecast the possible outcome of economic decisions. Finally, a sophisticated operations room (Opsroom) would provide a space where managers could see relevant economic data, formulate feasible responses to emergencies, and transmit advice and directives to enterprises and factories in alarm situations by using the telex network.

The principal architect of the system was British operations research scientist Stafford Beer, and the system embodied his notions of organisational cybernetics in industrial management. One of its main objectives was to devolve decision-making power within industrial enterprises to their workforce in order to develop self-regulation of factories.

The Sweden Solar System is the world's largest permanent scale model of the Solar System. The Sun is represented by the Ericsson Globe in Stockholm, the largest hemispherical building in the world. The inner planets can also be found in Stockholm but the outer planets are situated northward in other cities along the Baltic Sea. The system was started by Nils Brenning and Gösta Gahm and is on the scale of 1:20 million.

Emerging technologies are those technical innovations that represent progressive innovations within a field for competitive advantage.

The 52-hertz whale is an individual whale of unidentified species which calls at the very unusual frequency of 52 Hz. This pitch is a much higher frequency than that of the other whale species with migration patterns most closely resembling this whale's – the blue whale (10–39 Hz) or fin whale (20 Hz). It has been detected regularly in many locations since the late 1980s and appears to be the only individual emitting a whale call at this frequency. It has been described as the "world's loneliest whale".

Benford's law, also called the Newcomb–Benford law, the law of anomalous numbers, or the first-digit law, is an observation about the frequency distribution of leading digits in many real-life sets of numerical data. The law states that in many naturally occurring collections of numbers, the leading significant digit is likely to be small. For example, in sets that obey the law, the number 1 appears as the leading significant digit about 30% of the time, while 9 appears as the leading significant digit less than 5% of the time. If the digits were distributed uniformly, they would each occur about 11.1% of the time. Benford's law also makes predictions about the distribution of second digits, third digits, digit combinations, and so on.

The graph to the right shows Benford's law for base 10. There is a generalization of the law to numbers expressed in other bases (for example, base 16), and also a generalization from leading 1 digit to leading n digits.

It has been shown that this result applies to a wide variety of data sets, including electricity bills, street addresses, stock prices, house prices, population numbers, death rates, lengths of rivers, physical and mathematical constants. Like other general principles about natural data—for example the fact that many data sets are well approximated by a normal distribution—there are illustrative examples and explanations that cover many of the cases where Benford's law applies, though there are many other cases where Benford's law applies that resist a simple explanation. It tends to be most accurate when values are distributed across multiple orders of magnitude, especially if the process generating the numbers is described by a power law (which are common in nature).

It is named after physicist Frank Benford, who stated it in 1938 in a paper titled "The Law of Anomalous Numbers", although it had been previously stated by Simon Newcomb in 1881.

Braess' paradox is the observation that adding one or more roads to a road network can slow down overall traffic flow through it. The paradox was postulated in 1968 by German mathematician Dietrich Braess, who noticed that adding a road to a particular congested road traffic network would increase overall journey time.

The paradox may have analogies in electrical power grids and biological systems. It has been suggested that in theory, the improvement of a malfunctioning network could be accomplished by removing certain parts of it. The paradox has been used to explain instances of improved traffic flow when existing major roads are closed.

A broadcast signal hijacking of two television stations in Chicago, Illinois was carried out on November 22, 1987, in an act of video piracy. The stations' broadcasts were interrupted by a video of an unknown person wearing a Max Headroom mask and costume, accompanied by distorted audio.

The first incident took place for 25 seconds during the sports segment of WGN-TV's 9:00 p.m. news broadcast; the second occurred around two hours later, for about 90 seconds during PBS affiliate WTTW's broadcast of Doctor Who.

The hacker made references to Max Headroom's endorsement of Coca-Cola, the TV series Clutch Cargo, WGN anchor Chuck Swirsky; and "all the greatest world newspaper nerds", a reference to WGN's call letters, which stand for "World's Greatest Newspaper". A corrugated panel swiveled back and forth mimicking Max Headroom's geometric background effect. The video ended with a pair of exposed buttocks being spanked with a flyswatter before normal programming resumed. The culprits were never caught or identified.

Hy (alternately, Hylang) is a programming language, a dialect of the language Lisp designed to interact with the language Python by translating expressions into Python's abstract syntax tree (AST). Hy was introduced at Python Conference (PyCon) 2013 by Paul Tagliamonte.

Similar to Kawa's and Clojure's mapping of s-expressions onto the Java virtual machine (JVM), Hy is meant to operate as a transparent Lisp front end to Python's abstract syntax. Lisp allows operating on code as data (metaprogramming). Thus, Hy can be used to write domain-specific languages. Hy also allows Python libraries, including the standard library, to be imported and accessed alongside Hy code with a compiling step converting the data structure of both into Python's AST.