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Maxwell's Demon
Maxwell's demon is a thought experiment that appears to disprove the second law of thermodynamics. It was proposed by the physicist James Clerk Maxwell in 1867. In his first letter, Maxwell referred to the entity as a "finite being" or a "being who can play a game of skill with the molecules". Lord Kelvin would later call it a "''demon''". In the thought experiment, a demon controls a door between two chambers containing gas. As individual gas molecules (or atoms) approach the door, the demon quickly opens and closes the door to allow only fast-moving molecules to pass through in one direction, and only slow-moving molecules to pass through in the other. Because the kinetic temperature of a gas depends on the velocities of its constituent molecules, the demon's actions cause one chamber to warm up and the other to cool down. This would decrease the total entropy of the system, seemingly without applying any work, thereby violating the second law of thermodynamics. The concept ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Leff Rex 02
Leff may refer to: People Surname * Ari Leff, musician * Arthur Allen Leff (1935–1981), American professor of law * Barbara Leff (born 1947), American politician * Enrique Leff Enrique Leff (born 1946) is a Mexican economist, environmental sociologist and environmentalist. He has written 25 books and 180 articles on political ecology, environmental sociology, environmental economics, environmental epistemology and env ..., a Mexican economist * Harvey S. Leff (born 1937), United States physicist * Laurel Leff, author * Michael Leff (1941–2010), hi U.S. scholar of rhetoric * Nathaniel Leff, American economist * Pincus Leff, comedian * Robert Leff, American businessman * Zev Leff, Israeli Rabbi * Andre Leff,Boxer, Sportsperson and businessman * Yolande Lesley Ann Leff,married to André Leff, Writer,Fiction Novelist, Businesswoman Given name * Leff Pouishnoff (1891–1959), Ukrainian-born pianist and composer Other uses * Leff (river), in Brittany, Fr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Energy
Energy () is the physical quantity, quantitative physical property, property that is transferred to a physical body, body or to a physical system, recognizable in the performance of Work (thermodynamics), work and in the form of heat and light. Energy is a Conservation law, conserved quantity—the law of conservation of energy states that energy can be Energy transformation, converted in form, but not created or destroyed. The unit of measurement for energy in the International System of Units (SI) is the joule (J). Forms of energy include the kinetic energy of a moving object, the potential energy stored by an object (for instance due to its position in a Classical field theory, field), the elastic energy stored in a solid object, chemical energy associated with chemical reactions, the radiant energy carried by electromagnetic radiation, the internal energy contained within a thermodynamic system, and rest energy associated with an object's rest mass. These are not mutual ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Work (physics)
In science, work is the energy transferred to or from an Physical object, object via the application of force along a Displacement (vector), displacement. In its simplest form, for a constant force aligned with the direction of motion, the work equals the Product (mathematics), product of the force strength and the distance traveled. A force is said to do ''positive work'' if it has a component in the direction of the displacement of the point of application. A force does ''negative work'' if it has a component opposite to the direction of the displacement at the point of application of the force. For example, when a ball is held above the ground and then dropped, the work done by the gravitational force on the ball as it falls is positive, and is equal to the weight of the ball (a force) multiplied by the distance to the ground (a displacement). If the ball is thrown upwards, the work done by the gravitational force is negative, and is equal to the weight multiplied by the dis ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Heat Engine
A heat engine is a system that transfers thermal energy to do mechanical or electrical work. While originally conceived in the context of mechanical energy, the concept of the heat engine has been applied to various other kinds of energy, particularly electrical, since at least the late 19th century. The heat engine does this by bringing a working substance from a higher state temperature to a lower state temperature. A heat source generates thermal energy that brings the working substance to the higher temperature state. The working substance generates work in the working body of the engine while transferring heat to the colder sink until it reaches a lower temperature state. During this process some of the thermal energy is converted into work by exploiting the properties of the working substance. The working substance can be any system with a non-zero heat capacity, but it usually is a gas or liquid. During this process, some heat is normally lost to the surroundings ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Speed
In kinematics, the speed (commonly referred to as ''v'') of an object is the magnitude of the change of its position over time or the magnitude of the change of its position per unit of time; it is thus a non-negative scalar quantity. Introduction of the speed/velocity terminology by Prof. Tait, in 1882. The average speed of an object in an interval of time is the distance travelled by the object divided by the duration of the interval; the instantaneous speed is the limit of the average speed as the duration of the time interval approaches zero. Speed is the magnitude of ''velocity'' (a vector), which indicates additionally the direction of motion. Speed has the dimensions of distance divided by time. The SI unit of speed is the metre per second (m/s), but the most common unit of speed in everyday usage is the kilometre per hour (km/h) or, in the US and the UK, miles per hour (mph). For air and marine travel, the knot is commonly used. The fastest possible speed at wh ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Molecule
A molecule is a group of two or more atoms that are held together by Force, attractive forces known as chemical bonds; depending on context, the term may or may not include ions that satisfy this criterion. In quantum physics, organic chemistry, and biochemistry, the distinction from ions is dropped and ''molecule'' is often used when referring to polyatomic ions. A molecule may be homonuclear, that is, it consists of atoms of one chemical element, e.g. two atoms in the oxygen molecule (O2); or it may be heteronuclear, a chemical compound composed of more than one element, e.g. water (molecule), water (two hydrogen atoms and one oxygen atom; H2O). In the kinetic theory of gases, the term ''molecule'' is often used for any gaseous particle regardless of its composition. This relaxes the requirement that a molecule contains two or more atoms, since the noble gases are individual atoms. Atoms and complexes connected by non-covalent interactions, such as hydrogen bonds or ionic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Leff Rex 90
Leff may refer to: People Surname * Ari Leff, musician * Arthur Allen Leff (1935–1981), American professor of law * Barbara Leff (born 1947), American politician * Enrique Leff Enrique Leff (born 1946) is a Mexican economist, environmental sociologist and environmentalist. He has written 25 books and 180 articles on political ecology, environmental sociology, environmental economics, environmental epistemology and env ..., a Mexican economist * Harvey S. Leff (born 1937), United States physicist * Laurel Leff, author * Michael Leff (1941–2010), hi U.S. scholar of rhetoric * Nathaniel Leff, American economist * Pincus Leff, comedian * Robert Leff, American businessman * Zev Leff, Israeli Rabbi * Andre Leff,Boxer, Sportsperson and businessman * Yolande Lesley Ann Leff,married to André Leff, Writer,Fiction Novelist, Businesswoman Given name * Leff Pouishnoff (1891–1959), Ukrainian-born pianist and composer Other uses * Leff (river), in Brittany, Fr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Isolated System
In physical science, an isolated system is either of the following: # a physical system so far removed from other systems that it does not interact with them. # a thermodynamic system enclosed by rigid immovable walls through which neither mass nor energy can pass. Though subject internally to its own gravity, an isolated system is usually taken to be outside the reach of external gravitational and other long-range forces. This can be contrasted with what (in the more common terminology used in thermodynamics) is called a closed system, being enclosed by selective walls through which energy can pass as heat or work, but not matter; and with an open system, which both matter and energy can enter or exit, though it may have variously impermeable walls in parts of its boundaries. An isolated system obeys the conservation law that its total energy–mass stays constant. Most often, in thermodynamics, mass and energy are treated as separately conserved. Because of the requir ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Temperature
Temperature is a physical quantity that quantitatively expresses the attribute of hotness or coldness. Temperature is measurement, measured with a thermometer. It reflects the average kinetic energy of the vibrating and colliding atoms making up a substance. Thermometers are calibrated in various temperature scales that historically have relied on various reference points and thermometric substances for definition. The most common scales are the Celsius scale with the unit symbol °C (formerly called ''centigrade''), the Fahrenheit scale (°F), and the Kelvin scale (K), with the third being used predominantly for scientific purposes. The kelvin is one of the seven base units in the International System of Units (SI). Absolute zero, i.e., zero kelvin or −273.15 °C, is the lowest point in the thermodynamic temperature scale. Experimentally, it can be approached very closely but not actually reached, as recognized in the third law of thermodynamics. It would be impossible ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Broadview Press
Broadview Press is an independent academic publisher that focuses on the humanities. Founded in 1985 by Don LePan, the company now employs over 30 people, has over 800 titles in print, and publishes approximately 35 titles each year. Broadview's offices are located across Canada in Calgary, Peterborough, Nanaimo, Guelph and Wolfville. History In its early years, Broadview operated out of LePan's home in Peterborough, Ontario, publishing a small number of titles for both Trade and academic markets. With the publication of books such as ''The Broadview Anthology of Poetry'', ''The Broadview Reader'', and the first few titles in the Broadview Editions series in the early 1990s, Broadview began to focus exclusively on the academic market. In May 2008, Broadview's social science and history lists were sold to the University of Toronto Press. Michael Harrison (Broadview Vice-President 1992-2004, and President 2005-2008) and several staff members went on to form the Higher Education d ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Daimon
The daimon (), also spelled daemon (meaning "god", "godlike", "power", "fate"), denotes an "unknown superfactor", which can be either good or hostile. In ancient Greek religion and Greek mythology, mythology a daimon was imagined to be a lesser deity or guiding spirit. The word is derived from Proto-Indo-European ''daimon'' "provider, divider (of fortunes or destinies)," from the root ''*da-'' "to divide". Daimons were possibly seen as the Ensoulment#Ancient Greeks, souls of men of the golden age, Tutelary deity, tutelary deities, or the forces of fate. Description Daimons are lesser divinity, divinities or spirits, often personifications of abstraction, abstract concepts, beings of the same nature as both mortals and deities, similar to ghosts, chthonic heroes, spirit guides, forces of nature, or the deities themselves (see Plato's ''Symposium (Plato), Symposium''). According to Hesiod's myth, "great and powerful figures were to be honoured after death as a daimon…" A daimon ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
