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Billiard Ball Computer
A billiard-ball computer, a type of conservative logic circuit, is an idealized model of a reversible mechanical computer based on Newtonian dynamics, proposed in 1982 by Edward Fredkin and Tommaso Toffoli. Instead of using electronic signals like a conventional computer, it relies on the motion of spherical billiard balls in a friction-free environment made of buffers against which the balls bounce perfectly. It was devised to investigate the relation between computation and reversible processes in physics. Simulating circuits with billiard balls This model can be used to simulate Boolean circuits in which the wires of the circuit correspond to paths on which one of the balls may travel, the signal on a wire is encoded by the presence or absence of a ball on that path, and the gates of the circuit are simulated by collisions of balls at points where their paths cross. In particular, it is possible to set up the paths of the balls and the buffers around them to form a revers ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Toffoli BilliardBall-en
Toffoli is an Italian surname. Notable people with the surname include: * Dario De Toffoli, Italian board game designer *Dias Toffoli (born 1967), President of the Supreme Federal Court of Brazil *Elisa (Italian singer) (born 1977), full name Elisa Toffoli, Italian singer-songwriter * Gaúcho (footballer) (1964–2016), full name Luís Carlos Toffoli, Brazilian footballer * Patricia Tóffoli (born 1960), Venezuelan beauty pageant titleholder *Tommaso Toffoli (born 1943), Italian-American professor of engineering at Boston University **Toffoli gate In logic circuits, the Toffoli gate, also known as the CCNOT gate (“controlled-controlled-not”), invented by Tommaso Toffoli in 1980 is a CNOT gate with two control bits and one target bit. That is, the target bit (third bit) will be inver ..., a reversible logic gate invented by Tommaso Toffoli * Tyler Toffoli (born 1992), Canadian ice hockey player {{surname Italian-language surnames ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Block Cellular Automaton
A block cellular automaton or partitioning cellular automaton is a special kind of cellular automaton in which the lattice of cells is divided into non-overlapping blocks (with different partitions at different time steps) and the transition rule is applied to a whole block at a time rather than a single cell. Block cellular automata are useful for simulations of physical quantities, because it is straightforward to choose transition rules that obey physical constraints such as reversibility and conservation laws. Definition A block cellular automaton consists of the following components: *A regular lattice of cells *A finite set of the states that each cell may be in *A partition of the cells into a uniform tessellation in which each tile of the partition has the same size and shape *A rule for shifting the partition after each time step *A transition rule, a function that takes as input an assignment of states for the cells in a single tile and produces as output another assign ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Models Of Computation
In computer science, and more specifically in computability theory and computational complexity theory, a model of computation is a model which describes how an output of a mathematical function is computed given an input. A model describes how units of computations, memories, and communications are organized. The computational complexity of an algorithm can be measured given a model of computation. Using a model allows studying the performance of algorithms independently of the variations that are specific to particular implementations and specific technology. Categories Models of computation can be classified into three categories: sequential models, functional models, and concurrent models. Sequential models Sequential models include: * Finite-state machines * Post machines ( Post–Turing machines and tag machines). * Pushdown automata * Register machines ** Random-access machines * Turing machines * Decision tree model * External memory model Functional models Functio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fluidics
Fluidics, or fluidic logic, is the use of a fluid to perform analog signal, analog or Digital data, digital operations similar to those performed with electronics. The physical basis of fluidics is pneumatics and hydraulics, based on the theoretical foundation of fluid dynamics. The term ''fluidics'' is normally used when devices have no moving parts, so ordinary hydraulic components such as hydraulic cylinders and spool valves are not considered or referred to as fluidic devices. A jet of fluid can be deflected by a weaker jet striking it at the side. This provides nonlinearity, nonlinear amplifier, amplification, similar to the transistor used in electronic digital logic. It is used mostly in environments where electronic digital logic would be unreliable, as in systems exposed to high levels of electromagnetic interference or ionizing radiation. Nanotechnology considers fluidics as one of its instruments. In this domain, effects such as fluid–solid and fluid–fluid interf ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Unconventional Computing
Unconventional computing (also known as alternative computing or nonstandard computation) is computing by any of a wide range of new or unusual methods. The term ''unconventional computation'' was coined by Cristian S. Calude and John Casti and used at the First International Conference on Unconventional Models of Computation in 1998. Background The general theory of computation allows for a variety of methods of computation. Computing technology was first developed using mechanical systems and then evolved into the use of electronic devices. Other fields of modern physics provide additional avenues for development. Models of Computation A model of computation describes how the output of a mathematical function is computed given its input. The model describes how units of computations, memories, and communications are organized. The computational complexity of an algorithm can be measured given a model of computation. Using a model allows studying the performance of algorit ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
New Scientist
''New Scientist'' is a popular science magazine covering all aspects of science and technology. Based in London, it publishes weekly English-language editions in the United Kingdom, the United States and Australia. An editorially separate organisation publishes a monthly Dutch-language edition. First published on 22 November 1956, ''New Scientist'' has been available in online form since 1996. Sold in retail outlets (paper edition) and on subscription (paper and/or online), the magazine covers news, features, reviews and commentary on science, technology and their implications. ''New Scientist'' also publishes speculative articles, ranging from the technical to the philosophical. ''New Scientist'' was acquired by Daily Mail and General Trust (DMGT) in March 2021. History Ownership The magazine was founded in 1956 by Tom Margerison, Max Raison and Nicholas Harrison as ''The New Scientist'', with Issue 1 on 22 November 1956, priced at one shilling (). An article in the magazi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Wired (magazine)
''Wired'' is a bi-monthly American magazine that focuses on how emerging technologies affect culture, the economy, and politics. It is published in both print and Online magazine, online editions by Condé Nast. The magazine has been in publication since its launch in January 1993. Its editorial office is based in San Francisco, California, with its business headquarters located in New York City. ''Wired'' quickly became recognized as the voice of the emerging digital economy and culture and a pace setter in print design and web design. From 1998 until 2006, the magazine and its website, ''Wired.com'', experienced separate ownership before being fully consolidated under Condé Nast in 2006. It has won multiple National Magazine Awards and has been credited with shaping discourse around the digital revolution. The magazine also coined the term Crowdsourcing, ''crowdsourcing'', as well as its annual tradition of handing out Vaporware Awards. ''Wired'' has launched several in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Complex Systems (journal)
''Complex Systems'' is a quarterly peer-reviewed open access scientific journal covering subjects ranging across a number of scientific and engineering fields, including computational biology, computer science, mathematics, and physics. It was established in 1987 with Stephen Wolfram as founding editor-in-chief. The journal is published by Complex Systems Publications. Abstracting and indexing The journal is abstracted and indexed in: See also *List of journals in systems science References External links * Academic journals established in 1987 Systems journals Computer science journals Quarterly journals English-language journals Open access journals {{compu-journal-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mictyris Guinotae
''Mictyris guinotae'' is a species of soldier crab of genus '' Mictyris'', endemic to the Ryukyu Islands of Japan. They were named after Danièle Guinot, a professor at the Muséum national d'histoire naturelle in France, and were first treated as a separate species in a tribute volume to Guinot. Description ''Mictyris guinotae'' has a well-defined subglobular body, slightly less wide than long, a relatively smooth carapace, and long thin legs. They range in color from pale to dark blue, with occasional pale pink variants; they tend to be darker when they are younger and lighter when they are older. The adult male specimens observed had carapaces between 8 and 16 mm long; adult female carapace lengths ranged from 6 to 14 mm. Behavior These crabs live in colonies of hundreds to hundreds of thousands of individuals, in flat lagoon areas of the islands they inhabit. In times of low tide, they form large swarms or "armies" that cross the lagoons ''en masse'', while at high ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mictyris
''Mictyris'' is a genus of brightly coloured crabs, placed in its own taxonomical family, the Mictyridae. It inhabits the central Indo-West Pacific region. These crabs congregate on mud flats or beaches in groups of a few thousand, and filter sand or mud for microscopic organisms. They congregate during low tide, and bury themselves in the sand during high tide or whenever they are threatened. This is done in wet sand, and they dig in a corkscrew pattern, leaving many small round pellets of sand behind them. Species The genus contains eight species: The predictable behaviour of these crabs has led them to be used in experiments in a form of billiard ball computer A billiard-ball computer, a type of conservative logic circuit, is an idealized model of a reversible mechanical computer based on Newtonian dynamics, proposed in 1982 by Edward Fredkin and Tommaso Toffoli. Instead of using electronic signals .... References Ocypodoidea Decapod genera {{Ocypodoidea- ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nonlinear Phenomena
In mathematics and science, a nonlinear system (or a non-linear system) is a system in which the change of the output is not proportional to the change of the input. Nonlinear problems are of interest to engineers, biologists, physicists, mathematicians, and many other scientists since most systems are inherently nonlinear in nature. Nonlinear dynamical systems, describing changes in variables over time, may appear chaotic, unpredictable, or counterintuitive, contrasting with much simpler linear systems. Typically, the behavior of a nonlinear system is described in mathematics by a nonlinear system of equations, which is a set of simultaneous equations in which the unknowns (or the unknown functions in the case of differential equations) appear as variables of a polynomial of degree higher than one or in the argument of a function which is not a polynomial of degree one. In other words, in a nonlinear system of equations, the equation(s) to be solved cannot be written as a linea ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Second-order Cellular Automaton
A second-order cellular automaton is a type of reversible cellular automaton (CA) invented by Edward Fredkin. Reprinted in . where the state of a cell at time depends not only on its neighborhood at time , but also on its state at time .. General technique In general, the evolution rule for a second-order automaton may be described as a function that maps the neighborhood of a cell to a permutation on the states of the automaton. In each time step , for each cell of the automaton, this function is applied to the neighborhood of to give a permutation . Then, this permutation is applied to the state of cell at time , and the result is the state of the cell at time . In this way, the configuration of the automaton at each time step is computed from two previous time steps: the immediately previous step determines the permutations that are applied to the cells, and the time step before that one gives the states on which these permutations operate. The reversed time dynamics o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
