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πŸ”— Moravec's Paradox

πŸ”— Computer science πŸ”— Philosophy πŸ”— Philosophy/Logic πŸ”— Philosophy/Philosophy of science πŸ”— Philosophy/Philosophy of mind

Moravec's paradox is the observation by artificial intelligence and robotics researchers that, contrary to traditional assumptions, reasoning (which is high-level in humans) requires very little computation, but sensorimotor skills (comparatively low-level in humans) require enormous computational resources. The principle was articulated by Hans Moravec, Rodney Brooks, Marvin Minsky and others in the 1980s. As Moravec writes, "it is comparatively easy to make computers exhibit adult level performance on intelligence tests or playing checkers, and difficult or impossible to give them the skills of a one-year-old when it comes to perception and mobility".

Similarly, Minsky emphasized that the most difficult human skills to reverse engineer are those that are unconscious. "In general, we're least aware of what our minds do best", he wrote, and added "we're more aware of simple processes that don't work well than of complex ones that work flawlessly".

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πŸ”— The Thing

πŸ”— Espionage πŸ”— Military history πŸ”— Military history/Military science, technology, and theory πŸ”— Military history/Intelligence

The Thing, also known as the Great Seal bug, was one of the first covert listening devices (or "bugs") to use passive techniques to transmit an audio signal. It was concealed inside a gift given by the Soviet Union to W. Averell Harriman, the United States Ambassador to the Soviet Union, on August 4, 1945. Because it was passive, needing electromagnetic energy from an outside source to become energized and activate, it is considered a predecessor of Radio-Frequency Identification (RFID) technology.

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πŸ”— Non-English-based programming languages

πŸ”— Computing πŸ”— Computer science

Non-English-based programming languages are programming languages that do not use keywords taken from or inspired by English vocabulary.

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πŸ”— Jevons Paradox

πŸ”— Environment πŸ”— Economics

In economics, the Jevons paradox (; sometimes Jevons effect) occurs when technological progress or government policy increases the efficiency with which a resource is used (reducing the amount necessary for any one use), but the rate of consumption of that resource rises due to increasing demand. The Jevons paradox is perhaps the most widely known paradox in environmental economics. However, governments and environmentalists generally assume that efficiency gains will lower resource consumption, ignoring the possibility of the paradox arising.

In 1865, the English economist William Stanley Jevons observed that technological improvements that increased the efficiency of coal-use led to the increased consumption of coal in a wide range of industries. He argued that, contrary to common intuition, technological progress could not be relied upon to reduce fuel consumption.

The issue has been re-examined by modern economists studying consumption rebound effects from improved energy efficiency. In addition to reducing the amount needed for a given use, improved efficiency also lowers the relative cost of using a resource, which increases the quantity demanded. This counteracts (to some extent) the reduction in use from improved efficiency. Additionally, improved efficiency increases real incomes and accelerates economic growth, further increasing the demand for resources. The Jevons paradox occurs when the effect from increased demand predominates, and improved efficiency increases the speed at which resources are used.

Considerable debate exists about the size of the rebound in energy efficiency and the relevance of the Jevons paradox to energy conservation. Some dismiss the paradox, while others worry that it may be self-defeating to pursue sustainability by increasing energy efficiency. Some environmental economists have proposed that efficiency gains be coupled with conservation policies that keep the cost of use the same (or higher) to avoid the Jevons paradox. Conservation policies that increase cost of use (such as cap and trade or green taxes) can be used to control the rebound effect.

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πŸ”— Langton's Ant

πŸ”— Mathematics

Langton's ant is a two-dimensional universal Turing machine with a very simple set of rules but complex emergent behavior. It was invented by Chris Langton in 1986 and runs on a square lattice of black and white cells. The universality of Langton's ant was proven in 2000. The idea has been generalized in several different ways, such as turmites which add more colors and more states.

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πŸ”— Potato Paradox

πŸ”— Mathematics

The potato paradox is a mathematical calculation that has a counter-intuitive result. The Universal Book of Mathematics states the problem as follows:

Fred brings home 100 kg of potatoes, which (being purely mathematical potatoes) consist of 99% water. He then leaves them outside overnight so that they consist of 98% water. What is their new weight? The surprising answer is 50 kg.

In Quine's classification of paradoxes, the potato paradox is a veridical paradox.

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πŸ”— One electron universe

πŸ”— Physics

The one-electron universe postulate, proposed by John Wheeler in a telephone call to Richard Feynman in the spring of 1940, is the hypothesis that all electrons and positrons are actually manifestations of a single entity moving backwards and forwards in time. According to Feynman:

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πŸ”— Two Envelopes Problem

πŸ”— Military history/Early Muslim military history πŸ”— Games

The two envelopes problem, also known as the exchange paradox, is a brain teaser, puzzle, or paradox in logic, probability, and recreational mathematics. It is of special interest in decision theory, and for the Bayesian interpretation of probability theory. Historically, it arose as a variant of the necktie paradox. The problem typically is introduced by formulating a hypothetical challenge of the following type:

It seems obvious that there is no point in switching envelopes as the situation is symmetric. However, because you stand to gain twice as much money if you switch while risking only a loss of half of what you currently have, it is possible to argue that it is more beneficial to switch. The problem is to show what is wrong with this argument.

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πŸ”— Gimli Glider

πŸ”— Aviation πŸ”— Disaster management πŸ”— Aviation/Aviation accident project πŸ”— Canada πŸ”— Aviation/aircraft project πŸ”— Aviation/gliding project πŸ”— Canada/History of Canada πŸ”— Canada/Manitoba

Air Canada FlightΒ 143 was a Canadian scheduled domestic passenger flight between Montreal and Edmonton that ran out of fuel on JulyΒ 23, 1983, at an altitude of 41,000 feet (12,000Β m), midway through the flight. The crew was able to glide the Boeing 767 aircraft safely to an emergency landing at a former Royal Canadian Air Force base in Gimli, Manitoba, that had been turned into a motor racing track. This unusual aviation incident earned the aircraft the nickname "Gimli Glider".

The subsequent investigation revealed that a combination of company failures, human errors and confusion over unit measures had led to the aircraft being refuelled with insufficient fuel for the planned flight.

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πŸ”— GoiΓ’nia radiation accident

πŸ”— Environment πŸ”— Occupational Safety and Health πŸ”— Brazil πŸ”— Brazil/History of Brazil πŸ”— Science Policy

The GoiÒnia accident [ɑojˈjɐniɐ] was a radioactive contamination accident that occurred on September 13, 1987, in GoiÒnia, in the Brazilian state of GoiÑs, after a forgotten radiotherapy source was taken from an abandoned hospital site in the city. It was subsequently handled by many people, resulting in four deaths. About 112,000 people were examined for radioactive contamination and 249 of them were found to have been contaminated.

In the cleanup operation, topsoil had to be removed from several sites, and several hundred houses were demolished. All the objects from within those houses, including personal possessions, were seized and incinerated. Time magazine has identified the accident as one of the world's "worst nuclear disasters" and the International Atomic Energy Agency called it "one of the world's worst radiological incidents".

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