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πŸ”— Self-Replicating Machine

πŸ”— Science Fiction πŸ”— Robotics πŸ”— Transhumanism

A self-replicating machine is a type of autonomous robot that is capable of reproducing itself autonomously using raw materials found in the environment, thus exhibiting self-replication in a way analogous to that found in nature. The concept of self-replicating machines has been advanced and examined by Homer Jacobson, Edward F. Moore, Freeman Dyson, John von Neumann, Konrad Zuse and in more recent times by K. Eric Drexler in his book on nanotechnology, Engines of Creation (coining the term clanking replicator for such machines) and by Robert Freitas and Ralph Merkle in their review Kinematic Self-Replicating Machines which provided the first comprehensive analysis of the entire replicator design space. The future development of such technology is an integral part of several plans involving the mining of moons and asteroid belts for ore and other materials, the creation of lunar factories, and even the construction of solar power satellites in space. The von Neumann probe is one theoretical example of such a machine. Von Neumann also worked on what he called the universal constructor, a self-replicating machine that would be able to evolve and which he formalized in a cellular automata environment. Notably, Von Neumann's Self-Reproducing Automata scheme posited that open-ended evolution requires inherited information to be copied and passed to offspring separately from the self-replicating machine, an insight that preceded the discovery of the structure of the DNA molecule by Watson and Crick and how it is separately translated and replicated in the cell.

A self-replicating machine is an artificial self-replicating system that relies on conventional large-scale technology and automation. Although suggested earlier than in the late 1940's by Von Neumann, no self-replicating machine has been seen until today. Certain idiosyncratic terms are occasionally found in the literature. For example, the term clanking replicator was once used by Drexler to distinguish macroscale replicating systems from the microscopic nanorobots or "assemblers" that nanotechnology may make possible, but the term is informal and is rarely used by others in popular or technical discussions. Replicators have also been called "von Neumann machines" after John von Neumann, who first rigorously studied the idea. However, the term "von Neumann machine" is less specific and also refers to a completely unrelated computer architecture that von Neumann proposed and so its use is discouraged where accuracy is important. Von Neumann himself used the term universal constructor to describe such self-replicating machines.

Historians of machine tools, even before the numerical control era, sometimes figuratively said that machine tools were a unique class of machines because they have the ability to "reproduce themselves" by copying all of their parts. Implicit in these discussions is that a human would direct the cutting processes (later planning and programming the machines), and would then assemble the parts. The same is true for RepRaps, which are another class of machines sometimes mentioned in reference to such non-autonomous "self-replication". In contrast, machines that are truly autonomously self-replicating (like biological machines) are the main subject discussed here.

πŸ”— The Emu War

πŸ”— Australia πŸ”— Military history πŸ”— Australia/Western Australia πŸ”— Military history/Australia, New Zealand and South Pacific military history πŸ”— Australia/Australian history

The Emu War, also known as the Great Emu War, was a nuisance wildlife management military operation undertaken in Australia over the latter part of 1932 to address public concern over the number of emus said to be running amok in the Campion district of Western Australia. The unsuccessful attempts to curb the population of emus, a large flightless bird indigenous to Australia, employed soldiers armed with Lewis gunsβ€”leading the media to adopt the name "Emu War" when referring to the incident. While a number of the birds were killed, the emu population persisted and continued to cause crop destruction.

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πŸ”— Panopticon

πŸ”— Mass surveillance πŸ”— Architecture πŸ”— Philosophy πŸ”— Philosophy/Social and political philosophy πŸ”— Law Enforcement πŸ”— Correction and Detention Facilities

The panopticon is a type of institutional building and a system of control designed by the English philosopher and social theorist Jeremy Bentham in the 18th century. The concept of the design is to allow all prisoners of an institution to be observed by a single security guard, without the inmates being able to tell whether they are being watched.

Although it is physically impossible for the single guard to observe all the inmates' cells at once, the fact that the inmates cannot know when they are being watched means that they are motivated to act as though they are being watched at all times. Thus, the inmates are effectively compelled to regulate their own behaviour. The architecture consists of a rotunda with an inspection house at its centre. From the centre the manager or staff of the institution are able to watch the inmates. Bentham conceived the basic plan as being equally applicable to hospitals, schools, sanatoriums, and asylums, but he devoted most of his efforts to developing a design for a panopticon prison. It is his prison that is now most widely meant by the term "panopticon".

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πŸ”— Perturbation Theory

πŸ”— Physics

In mathematics and applied mathematics, perturbation theory comprises methods for finding an approximate solution to a problem, by starting from the exact solution of a related, simpler problem. A critical feature of the technique is a middle step that breaks the problem into "solvable" and "perturbative" parts. In perturbation theory, the solution is expressed as a power series in a small parameter Ξ΅ {\displaystyle \varepsilon } . The first term is the known solution to the solvable problem. Successive terms in the series at higher powers of Ξ΅ {\displaystyle \varepsilon } usually become smaller. An approximate 'perturbation solution' is obtained by truncating the series, usually by keeping only the first two terms, the solution to the known problem and the 'first order' perturbation correction.

Perturbation theory is used in a wide range of fields, and reaches its most sophisticated and advanced forms in quantum field theory. Perturbation theory (quantum mechanics) describes the use of this method in quantum mechanics. The field in general remains actively and heavily researched across multiple disciplines.

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πŸ”— Aircraft Nuclear Propulsion

πŸ”— Aviation πŸ”— Military history πŸ”— Military history/Military aviation πŸ”— Military history/North American military history πŸ”— Military history/United States military history πŸ”— Aviation/aircraft πŸ”— Aviation/aircraft engine

The Aircraft Nuclear Propulsion (ANP) program and the preceding Nuclear Energy for the Propulsion of Aircraft (NEPA) project worked to develop a nuclear propulsion system for aircraft. The United States Army Air Forces initiated Project NEPA on May 28, 1946. NEPA operated until May 1951, when the project was transferred to the joint Atomic Energy Commission (AEC)/USAF ANP. The USAF pursued two different systems for nuclear-powered jet engines, the Direct Air Cycle concept, which was developed by General Electric, and Indirect Air Cycle, which was assigned to Pratt & Whitney. The program was intended to develop and test the Convair X-6, but was cancelled in 1961 before that aircraft was built. The total cost of the program from 1946 to 1961 was about $1 billion.

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πŸ”— Band-e Kaisar – β€œCaesar's damβ€β€Žβ€Ž

πŸ”— Iran πŸ”— Classical Greece and Rome πŸ”— Dams πŸ”— Bridges and Tunnels

The Band-e Kaisar (Persian: Ψ¨Ω†Ψ― Ω‚ΫŒΨ΅Ψ±, "Caesar's dam"β€Ž), Pol-e Kaisar ("Caesar's bridge"), Bridge of Valerian or Shadirwan was an ancient arch bridge in Shushtar, Iran, and the first in the country to combine it with a dam. Built by the Sassanids, using Roman prisoners of war as workforce, in the 3rdΒ centuryΒ AD on Sassanid order, it was also the most eastern example of Roman bridge design and Roman dam, lying deep in Persian territory. Its dual-purpose design exerted a profound influence on Iranian civil engineering and was instrumental in developing Sassanid water management techniques.

The approximately 500Β m long overflow dam over the Karun, Iran's most effluent river, was the core structure of the Shushtar Historical Hydraulic System (Ψ³Ψ§Ψ²Ω‡β€ŒΩ‡Ψ§ΫŒ ؒبی شوشΨͺΨ±) from which the city derived its agricultural productivity, and which has been designated by the UNESCO as Iran's 10th World Heritage Site in 2009. The arched superstructure carried across the important road between Pasargadae and the Sassanid capital Ctesiphon. Many times repaired in the Islamic period, the dam bridge remained in use until the late 19thΒ century.

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πŸ”— Sweden Solar System

πŸ”— Astronomy πŸ”— Sweden πŸ”— Solar System πŸ”— Astronomy/Solar System

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 GΓΆsta Gahm and is on the scale of 1:20 million.

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πŸ”— Beflix (Bell Labs Flicks)

πŸ”— Computing πŸ”— Animation

BEFLIX is the name of the first embedded domain-specific language for computer animation, invented by Ken Knowlton at Bell Labs in 1963. The name derives from a combination of Bell Flicks. Ken Knowlton used BEFLIX to create animated films for educational and engineering purposes. He also collaborated with the artist Stan Vanderbeek at Bell Labs to create a series of computer-animated films called Poemfields between 1966 and 1969.

BEFLIX was developed on the IBM 7090 mainframe computer using a Stromberg-Carlson SC4020 microfilm recorder for output. The programming environment targeted by BEFLIX consisted of a FORTRAN II implementation with FORTRAN II Assembly Program (FAP) macros. The first version of BEFLIX was implemented through the FAP macro facility. A later version targeting FORTRAN IV resembled a more traditional subroutine library and lost some of the unique flavor to the language.

Pixels are produced by writing characters to the screen of the microfilm recorder with a defocused electron beam. The SC4020 used a charactron tube to expose microfilm. In BEFLIX, the electron beam is defocused to draw pixels as blurred character shapes. Characters are selected to create a range of grayscale values for pixels. The microfilm recorder is not connected directly to the 7090, but communicates through magnetic tape. BEFLIX writes the magnetic tape output on the 7090 and the film recorder reads the tape to create the film output. BEFLIX also supports a preview mode where selected frames of the output are written to the line printer.

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πŸ”— Wikiid: Can Wikipedia make a Wikipedia page notable enough to avoid deletion?

User:Diikiw/Wiikid, formerly Wikiid, is an article that was created on the web site Wikipedia in 2008. It is notable in its attempt to become the first Wikipedia page to gain notoriety solely for the fact that it was a page on Wikipedia; this was intended to spark a debate as to whether or not Wikipedia could be considered a source notable enough to allow a page’s permanent entry on the site. It can be looked at both as metahumor and as a piece of postmodern art.