Related topics: power
Energy
hideIn physics, energy (from the Greek ἐνέργεια - energeia, "activity, operation", from ἐνεργός - energos, "active, working") is a scalar physical quantity that describes the amount of work that can be performed by a force, an attribute of objects and systems that is subject to a conservation law. Different forms of energy include kinetic, potential, thermal, gravitational, sound, light, elastic, and electromagnetic energy. The forms of energy are often named after a related force.
Any form of energy can be transformed into another form, but the total energy always remains the same. 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.
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.
For more information about Energy, read the full article at
Wikipedia.
This text uses material from Wikipedia and is available under the GNU Free Documentation License.
News tagged with energy
ORNL 'deep retrofits' can cut home energy bills in half
Nov 25, 2009 |
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(PhysOrg.com) -- Oak Ridge National Laboratory has announced plans to conduct a series of deep energy retrofit research projects with the potential to improve the energy efficiency in selected homes by as ...
Sustainable Corn Production Supports Advanced Biofuel Feedstocks
Nov 25, 2009 |
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(PhysOrg.com) -- Researchers worldwide are trying to economically convert cellulosic biomass such as corn stover into "cellulosic ethanol." But Agricultural Research Service (ARS) scientists have found that ...
Seeking a Smarter Grid: Integrating Wind Energy by Linking Buildings to the Grid
Nov 24, 2009 |
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In utility parlance, wind energy is known as a “variable load.” That’s because wind is naturally unpredictable and inconstant. What’s worse, it is more likely to blow at night, when demand for electricity ...
NREL Uncovers Clean Energy Leaders State by State
Nov 24, 2009 |
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(PhysOrg.com) -- That California and Texas still lead the United States in generating renewable energy probably is no surprise. But, NREL's 2009 State of the States report shows that several smaller states ...
Invention will help speed development of drug treatments for heart failure
Nov 23, 2009 |
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Research conducted by University of Minnesota scientists, in collaboration with Celladon Corporation, has led to the invention of technology to more rapidly identify compounds for the treatment of heart failure.
Harnessing the power of salt, Norway tries osmotic power
Nov 23, 2009 |
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After wind, sun, currents and tides, a company is preparing to make clean electricity by harnessing another natural phenomenon, the energy-unleashing encounter of freshwater and seawater.
How green is your house? Recycling favorite activity among Brits says new survey
Nov 23, 2009 |
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Seventy percent of households always separate their rubbish for recycling, but only 2 percent buy their energy on a green tariff, according to the early findings of a major new annual household survey, called "Understanding ...
Is global warming unstoppable?
Nov 23, 2009 |
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In a provocative new study, a University of Utah scientist argues that rising carbon dioxide emissions - the major cause of global warming - cannot be stabilized unless the world's economy collapses or society builds the ...
Generating electricity from air flow
Nov 22, 2009 |
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A group of researchers at the City College of New York is developing a new way to generate power for planes and automobiles based on materials known as piezoelectrics, which convert the kinetic energy of motion into electricity. ...
China harnesses mountain wind power
Nov 22, 2009 |
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In the mountains above the southwestern Chinese town of Dali, dozens of new wind turbines dot the landscape -- a symbol of the country's sky-high ambitions for clean, green energy.
NJIT receives funding to improve Big Bear Telescope, study solar energy
Nov 20, 2009 |
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NJIT researchers are at work on many scientific and technological frontiers. The National Science Foundation has recently provided support that totals nearly $4.3 million for the diverse efforts of the following ...
Flax and yellow flowers can produce bioethanol
Nov 20, 2009 |
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Surplus biomass from the production of flax shives, and generated from Brassica carinata, a yellow-flowered plant related to those which engulf fields in spring, can be used to produce bioethanol. This has be ...
Using superconducting probes to get a picture of what it's like inside CNTs
Nov 20, 2009 |
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(PhysOrg.com) -- "Carbon nanotubes are exciting for fundamental physics, and for potential technological applications," Nadya Mason tells PhysOrg.com. "However, we are generally limited in the way that we can study them. ...
Hunting for Planets in the Dark
Nov 19, 2009 |
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A proposed space mission that aims to measure dark energy could also detect planets that current surveys are unable to find.
Nanotube defects equal better energy and storage systems
Nanotechnology / Nanomaterials
Nov 19, 2009 |
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(PhysOrg.com) -- Most people would like to be able to charge their cell phones and other personal electronics quickly and not too often. A recent discovery made by UC San Diego engineers could lead to carbon ...
