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is the electric breakdown of air by strong electric fields. Heat and light from a lightning produces a plasma motion of air molecules.]] [Site] Energy Information Administration In physics and other sciences, energy (from the Greek - energeia, "activity, operation", from - energos, "active, working") is a scalar physical quantity that is a property of objects and systems which is conserved by nature. Energy is often defined as the ability to do work. [News] Arrow Energy Says Currency Rates Boost Returns From Shell Deal Several different forms of energy, including kinetic, potential, thermal, gravitational, sound energy, light energy, elastic, electromagnetic, chemical, nuclear, and mass have been defined to explain all known natural phenomena. [Image] Energy is converted from one form to another. This principle, the conservation of energy, was first postulated in the early 19th century, and applies to any isolated system. According to Noether's theorem, the conservation of energy is a consequence of the fact that the laws of physics do not change over time. [Video] Mega Man 9 (Follow-Up) - Plug Man Although the total energy of a system does not change with time, its value may depend on the frame of reference. For example, a seated passenger in a moving airplane has zero kinetic energy relative to the airplane, but non-zero kinetic energy relative to the earth. [Auction] STIMEREX ES 90 TABLETS DIET ENERGY WEIGHT LOSS PILLS
HistoryThe concept of energy emerged out of the idea of vis viva, which Leibniz defined as the product of the mass of an object and its velocity squared; he believed that total vis viva was conserved. To account for slowing due to friction, Leibniz claimed that heat consisted of the random motion of the constituent parts of matter — a view shared by Isaac Newton, although it would be more than a century until this was generally accepted. In 1807, Thomas Young was the first to use the term "energy", instead of vis viva, in its modern sense. Gustave-Gaspard Coriolis described "kinetic energy" in 1829 in its modern sense, and in 1853, William Rankine coined the term "potential energy."It was argued for some years whether energy was a substance (the caloric) or merely a physical quantity, such as momentum.[Post] Home energy monitors get wise to solar Energy has many different forms. Kinetic, Sound, Nuclear and Electrical are the main forms. He amalgamated all of these laws into the laws of thermodynamics, which aided in the rapid development of explanations of chemical processes using the concept of energy by Rudolf Clausius, Josiah Willard Gibbs and Walther Nernst. It also led to a mathematical formulation of the concept of entropy by Clausius, and to the introduction of laws of radiant energy by Jožef Stefan. [Site] U.S. Department of Energy During a 1961 lecture for undergraduate students at the California Institute of Technology, Richard Feynman, a celebrated physics teacher and Nobel Laureate, said this about the concept of energy: [News] Clean Energy Says Plan to Buy Honda's FuelMaker Ended (Update3) Since 1918 it has been known that the law of conservation of energy is the direct mathematical consequence of the translational symmetry of the quantity conjugate to energy, namely time. That is, energy is conserved because the laws of physics do not distinguish between different moments of time (see Noether's theorem). [Image]
Energy in various contexts since the beginning of the universeThe concept of energy and its transformations is useful in explaining and predicting most natural phenomena. The direction of transformations in energy (what kind of energy is transformed to what other kind) is often described by entropy (equal energy spread among all available degrees of freedom) considerations, since in practice all energy transformations are permitted on a small scale, but certain larger transformations are not permitted because it is statistically unlikely that energy or matter will randomly move into more concentrated forms or smaller spaces.[Video] Energy- Kerri Hilson The concept of energy is used often in all fields of science. [Auction] Oil Refinery & Energy Economics Trade History DVD
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[News] New Energy Star 5.0 Update Targets Game Consoles Energy transformations in the universe over time are characterized by various kinds of potential energy which has been available since the Big Bang, later being "released" (transformed to more active types of energy such as kinetic or radiant energy), when a triggering mechanism is available. [Image] Familiar examples of such processes include nuclear decay, in which energy is released which was originally "stored" in heavy isotopes (such as uranium and thorium), by nucleosynthesis, a process which ultimately uses the gravitational potential energy released from the gravitational collapse of supernovae, to store energy in the creation of these heavy elements before they were incorporated into the solar system and the Earth. This energy is triggered and released in nuclear fission bombs. In a slower process, heat from nuclear decay of these atoms in the core of the Earth releases heat, which in turn may lift mountains, via orogenesis. This slow lifting represents a kind of gravitational potential energy storage of the heat energy, which may be released to active kinetic energy in landslides, after a triggering event. Earthquakes also release stored elastic potential energy in rocks, a store which has been produced ultimately from the same radioactive heat sources. Thus, according to present understanding, familiar events such as landslides and earthquakes release energy which has been stored as potential energy in the Earth's gravitational field or elastic strain (mechanical potential energy) in rocks; but prior to this, represents energy that has been stored in heavy atoms since the collapse of long-destroyed stars created these atoms. [Video] Water Car Run on WATER Fuel Hydrogen Save Gas FREE ENERGY ea In another similar chain of transformations beginning at the dawn of the universe, nuclear fusion of hydrogen in the Sun releases another store of potential energy which was created at the time of the Big Bang. At that time, according to theory, space expanded and the universe cooled too rapidly for hydrogen to completely fuse into heavier elements. This meant that hydrogen represents a store of potential energy which can be released by fusion. Such a fusion process is triggered by heat and pressure generated from gravitational collapse of hydrogen clouds when they produce stars, and some of the fusion energy is then transformed into sunlight. Such sunlight from our Sun may again be stored as gravitational potential energy after it strikes the Earth, as (for example) water evaporates from oceans and is deposited upon mountains (where, after being released at a hydroelectric dam, it can be used to drive turbine/generators to produce electricity). Sunlight also drives all weather phenomenon, including such events as those triggered in a hurricane, when large unstable areas of warm ocean, heated over months, give up some of their thermal energy suddenly to power a few days of violent air movement. Sunlight is also is captured by plants as chemical potential energy, when carbon dioxide and water are converted into a combustible combination of carbohydrates, lipids, and oxygen. Release of this energy as heat and light may be triggered suddenly by a spark, in a forest fire; or it may be available more slowly for animal or human metabolism, when these molecules are ingested, and catabolism is triggered by enzyme action. Through all of these transformation chains, potential energy stored at the time of the Big Bang is later released by intermediate events, sometimes being stored in a number of ways over time between releases, as more active energy. In all these events, one kind of energy is converted to other types of energy, including heat. [Auction] 100% Legal Brazilian Extreme Diet Energy Pills 18+ ONLY
Regarding applications of the concept of energyEnergy is subject to a strict global conservation law; that is, whenever one measures (or calculates) the total energy of a system of particles whose interactions do not depend explicitly on time, it is found that the total energy of the system always remains constant. Berkeley Physics Course Volume 1. Charles Kittel, Walter D Knight and Malvin A Ruderman
[Post] Marketing Energy. In classical physics energy is considered a scalar quantity, the canonical conjugate to time. In special relativity energy is also a scalar (although not a Lorentz scalar but a time component of the energy-momentum 4-vector). In other words, energy is invariant with respect to rotations of space, but not invariant with respect to rotations of space-time (= boosts).
Energy transferBecause energy is strictly conserved and is also locally conserved (wherever it can be defined), it is important to remember that by definition of energy the transfer of energy between the "system" and adjacent regions is work. A familiar example is mechanical work. In simple cases this is written as:[Site] Audio Products International
[News] OPEC is latest energy group to predict weaker oil demand growth if there are no other energy-transfer processes involved. Here is the amount of energy transferred, and represents the work done on the system. [Image] More generally, the energy transfer can be split into two categories: [Video] Power Save Systems LLC
[Auction] DARK ENERGY NUTRIENT! where represents the heat flow into the system. [Post] With Energy, It’s Time to Hop on the Fast Track There are other ways in which an open system can gain or lose energy. If mass is counted as energy (as in many relativistic problems) then must contain a term for mass lost or gained. In chemical systems, energy can be added to a system by means of adding substances with different chemical potentials, which potentials are then extracted (both of these process are illustrated by fueling an auto, a system which gains in energy thereby, without addition of either work or heat). Winding a clock would be adding energy to a mechanical system. These terms may be added to the above equation, or they can generally be subsumed into a quantity called "energy addition term " which refers to any type of energy carried over the surface of a control volume or system volume. Examples may be seen above, and many others can be imagined (for example, the kinetic energy of a stream of particles entering a system, or energy from a laser beam adds to system energy, without either being either work-done or heat-added, in the classic senses).
[Site] Energy Efficiency and Renewable Energy Where E in this general equation represents other additional advected energy terms not covered by work done on a system, or heat added to it. [News] Kinder Morgan Energy Lifts Profit, Dividend Energy is also transferred from potential energy () to kinetic energy () and then back to potential energy constantly. This is referred to as conservation of energy. In this closed system, energy can not be created or destroyed, so the initial energy and the final energy will be equal to each other. This can be demonstrated by the following: [Image] [Video] Water Car Run on WATER Fuel Hydrogen Save Gas FREE ENERGY ea The equation can then be simplified further since (mass times acceleration due to gravity times the height) and (half times mass times velocity squared). Then the total amount of energy can be found by adding . [Auction] Blue Motion Solar Energy Windmill Toy for Home, Office
Energy and the laws of motionIn classical mechanics, energy is a conceptually and mathematically useful property since it is a conserved quantity.[Post] Energy Seed Lamp Powered by Recycled Batteries
The HamiltonianThe total energy of a system is sometimes called the Hamiltonian, after William Rowan Hamilton. The classical equations of motion can be written in terms of the Hamiltonian, even for highly complex or abstract systems. These classical equations have remarkably direct analogs innonrelativistic quantum mechanics. The Hamiltonian MIT OpenCourseWare website 18.013A Chapter 16.3 Accessed February 2007[Book] The Energy Medicine Kit Sounds True
The LagrangianAnother energy-related concept is called the Lagrangian, after Joseph Louis Lagrange. This is even more fundamental than the Hamiltonian, and can be used to derive the equations of motion. In non-relativistic physics, the Lagrangian is the kinetic energy minus potential energy.[Site] Energy Star Program Usually, the Lagrange formalism is mathematically more convenient than the Hamiltonian for non-conservative systems (like systems with friction). [News] Energy, Metals Lead Commodity Slump as Economic Outlook Dims
Energy and thermodynamicsInternal energyInternal energy – the sum of all microscopic forms of energy of a system. It is related to the molecular structure and the degree of molecular activity and may be viewed as the sum of kinetic and potential energies of the molecules; it comprises the following types of energy:[Image] [Video] Judas Priest - Reckless
The laws of thermodynamicsAccording to the second law of thermodynamics, work can be totally converted into heat, but not vice versa.This is a mathematical consequence of statistical mechanics. The first law of thermodynamics simply asserts that energy is conserved, and that heat is included as a form of energy transfer. A commonly-used corollary of the first law is that for a "system" subject only to pressure forces and heat transfer (e.g. a cylinder-full of gas), the differential change in energy of the system (with a gain in energy signified by a positive quantity) is given by:[Auction] (15)$2.00/2 BOOST ENERGY DRINK MULTIPACK CPNS exp 10/31
[Post] Energy Debate Fact Check #2 - Is Energy Independence Good For the ... where the first term on the right is the heat transfer into the system, defined in terms of temperature T and entropy S (in which entropy increases and the change dS is positive when the system is heated); and the last term on the right hand side is identified as "work" done on the system, where pressure is P and volume V (the negative sign results since compression of the system requires work to be done on it and so the volume change, dV, is negative when work is done on the system). Although this equation is the standard text-book example of energy conservation in classical thermodynamics, it is highly specific, ignoring all chemical, electric, nuclear, and gravitational forces, effects such as advection of any form of energy other than heat, and because it contains a term that depends on temperature. The most general statement of the first law (i.e., conservation of energy) is valid even in situations in which temperature is undefinable. [Book] Energy Medicine Tarcher Energy is sometimes expressed as: [Site] Energy for America's Future
[News] Caucasus key to European energy diversity which is unsatisfactory because there cannot exist any thermodynamic state functions W or Q that are meaningful on the right hand side of this equation, except perhaps in trivial cases. [Image]
Equipartition of energyThe energy of a mechanical harmonic oscillator (a mass on a spring) is alternatively kinetic and potential. At two points in the oscillation cycle it is entirely kinetic, and alternatively at two other points it is entirely potential. Over the whole cycle, or over many cycles net energy is thus equally split between kinetic and potential. This is called equipartition principle - total energy of a system with many degrees of freedom is equally split among all available degrees of freedom.[Video] Michele Paiva, www.myspace.com/michelepaiva This principle is vitally important to understanding the behavior of a quantity closely related to energy, called entropy. Entropy is a measure of evenness of a distribution of energy between parts of a system. When an isolated system is given more degrees of freedom (= is given new available energy states which are the same as existing states), then total energy spreads over all available degrees equally without distinction between "new" and "old" degrees. This mathematical result is called the second law of thermodynamics. [Auction] ELEGANT 4.45 CTS ENERGY WHITE QUARTZ GEM (27A/77) 85 NR
Oscillators, phonons, and photonsIn an ensemble (connected collection) of unsynchronized oscillators, the average energy is spread equally between kinetic and potential types.[Post] Famous Arctic Explorer talks about energy crossroads In a solid, thermal energy (often referred to loosely as heat content) can be accurately described by an ensemble of thermal phonons that act as mechanical oscillators. In this model, thermal energy is equally kinetic and potential. In an ideal gas, the interaction potential between particles is essentially the delta function which stores no energy: thus, all of the thermal energy is kinetic. [Site] Energy Center - MoDNR Because an electric oscillator (LC circuit) is analogous to a mechanical oscillator, its energy must be, on average, equally kinetic and potential. It is entirely arbitrary whether the magnetic energy is considered kinetic and the electric energy considered potential, or vice versa. That is, either the inductor is analogous to the mass while the capacitor is analogous to the spring, or vice versa. [News] EDF Says It Won't Make New Bid for Constellation Energy
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[Video] Energy Independence The two analyses are entirely consistent. The electric and magnetic degrees of freedom in item 1 are transverse to the direction of motion, while the speed in item 2 is along the direction of motion. For non-relativistic particles these two notions of potential versus kinetic energy are numerically equal, so the ambiguity is harmless, but not so for relativistic particles. [Auction] 18KW Saver Power Save Electricity Energy Reduce Cost
Work and virtual workWork is roughly force times distance. But more precisely, it is[Post] Palin unaware of Russian energy meeting in Alaska This says that the work () is equal to the integral (along a certain path) of the force; for details see the mechanical work article. [Site] What is Energy? - Forms of Energy, Renewable and Non-renewable ... Work and thus energy is frame dependent. For example, consider a ball being hit by a bat. In the center-of-mass reference frame, the bat does no work on the ball. But, in the reference frame of the person swinging the bat, considerable work is done on the ball. [News] Hess puts energy into eco-friendly program
Quantum mechanicsIn quantum mechanics energy is defined in terms of the energy operatoras a time derivative of the wave function. The Schrödinger equation equates the energy operator to the full energy of a particle or a system. It thus can be considered as a definition of measurement of energy in quantum mechanics. The Schrödinger equation describes the space- and time-dependence of slow changing (non-relativistic) wave function of quantum systems. The solution of this equation for bound system is discrete (a set of permitted states, each characterized by an energy level) which results in the concept of quanta. In the solution of the Schrödinger equation for any oscillator (vibrator) and for electromagnetic wave in vacuum, the resulting energy states are related to the frequency by the Planck equation (where is the Planck's constant and the frequency). In the case of electromagnetic wave these energy states are called quanta of light or photons.[Image]
RelativityWhen calculating kinetic energy (= work to accelerate a mass from zero speed to some finite speed) relativistically - using Lorentz transformations instead of Newtonian mechanics, Einstein discovered unexpected by-product of these calculations to be an energy term which does not vanish at zero speed. He called it rest mass energy - energy which every mass must possess even when being at rest. The amount of energy is directly proportional to the mass of body:[Video] Global Resorts Network Summit in Denver, August 2008
[Auction] Oil Industry Energy Crisis DVD Saudi Arabia Middle East For example, consider electron-positron annihilation, in which the rest mass of individual particles is destroyed, but the inertia equivalent of the system of the two particles (its invariant mass) remains (since all energy is associated with mass), and this inertia and invariant mass is carried off by photons which individually are massless, but as a system retain their mass. This is a reversible process - the inverse process is called pair creation - in which the rest mass of particles is created from energy of two (or more) annihilating photons. [Post] Paul Loeb: Volunteer Energy and Political Tipping Points--What We ... In general relativity, the stress-energy tensor serves as the source term for the gravitational field, in rough analogy to the way mass serves as the source term in the non-relativistic Newtonian approximation. [Book] The Energy of Money: A Spiritual Guide to Financial and Personal Fulfillment Wellspring/Ballantine It is not uncommon to hear that energy is "equivalent" to mass. It would be more accurate to state that every energy has inertia and gravity equivalent, and because mass is a form of energy, then mass too has inertia and gravity associated with it.
MeasurementThere is no absolute measure of energy, because energy is defined as the work that one system does (or can do) on another. Thus, only of the transition of a system from one state into another can be defined and thus measured.[News] Energy, Metals Lead Commodity Slump as Economic Outlook Dims
MethodsThe methods for the measurement of energy often deploy methods for the measurement of still more fundamental concepts of science, namely mass, distance, radiation, temperature, time, electric charge and electric current. - An instrument used by physicists to measure energy]] Conventionally the technique most often employed is calorimetry, a thermodynamic technique that relies on the measurement of temperature using a thermometer or of intensity of radiation using a bolometer.[Image]
UnitsThroughout the history of science, energy has been expressed in several different units such as ergs and calories. At present, the accepted unit of measurement for energy is the SI unit of energy, the joule.[Video] Solar Panel Energy
Forms of energy, a form of energy, is partly potential energy and partly kinetic energy.]][Auction] 3 LOT BCAA AMINO ACIDS RETAIN MUSCLE PROTEIN ENERGY Classical mechanics distinguishes between potential energy, which is a function of the position of an object, and kinetic energy, which is a function of its movement. Both position and movement are relative to a frame of reference, which must be specified: this is often (and originally) an arbitrary fixed point on the surface of the Earth, the terrestrial frame of reference. Some introductory authors attempt to separate all forms of energy in either kinetic or potential: this is not incorrect, but neither is it clear that it is a real simplification, as Feynman points out: [Post] Candidates & Energy: Obama Revisited {| class="wikitable" align=right width=150px|-|+ Examples of the interconversion of energy|-! colspan=2 | Mechanical energy is converted|-! into! by|-| Mechanical energy| Lever|-| Thermal energy| Brakes|-| Electric energy| Dynamo|-| Electromagnetic radiation| Synchrotron|-| Chemical energy| Matches|-| Nuclear energy| Particle accelerator|-|} | |
