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
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 ...
Doubts raised on nuclear industry viability
Nov 19, 2009 |
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(PhysOrg.com) -- The investment in nuclear power has been growing around the world over the last few years, being viewed as a means for countries to control their energy security, avoid the price fluctuations ...
On the Crest of Wave Energy
Nov 19, 2009 |
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(PhysOrg.com) -- The ocean is a potentially vast source of electric power, yet as engineers test new technologies for capturing it, the devices are plagued by battering storms, limited efficiency, and the ...
Just use less: Energy savings to be big part of nation’s energy future
Nov 19, 2009 |
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(PhysOrg.com) -- Energy adviser and former Honeywell executive Maxine Savitz says there are enormous energy savings available through increased efficiency, as much as 30 percent by 2030.
Liquid battery big enough for the electric grid?
Nov 19, 2009 |
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(PhysOrg.com) -- There's one major drawback to most proposed renewable-energy sources: their variability. The sun doesn't shine at night, the wind doesn’t always blow, and tides, waves and currents fluctuate. ...
Battery Research Aims To Store Renewable Energy
Nov 19, 2009 |
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The biggest chemical battery in the United States is located near Interstate 90 in the small town of Luverne, Minn. The 80 ton device -- the size of two tractor-trailers stacked on top of each other -- stores ...
Boosting the amount of energy obtained from water
Nov 18, 2009 |
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The energy generated in places where fresh water and salt water meet is known as blue energy. This is a relatively new but highly promising renewable energy source. Piotr Długołęcki of the University ...
NASA Develops Algae Bioreactor as a Sustainable Energy Source
Nov 18, 2009 |
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(PhysOrg.com) -- As a clean energy alternative, NASA invented an algae photo-bioreactor that grows algae in municipal wastewater to produce biofuel and a variety of other products.
Unique Uranium Source in Naturally Bioreduced Sediment
Nov 18, 2009 |
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(PhysOrg.com) -- A recently published Pacific Northwest National Laboratory study of a naturally bioreduced sediment sample from a former uranium mill tailings site reveals insights that enhance understanding ...
Calif. requires TVs to be more energy-efficient (Update)
Nov 18, 2009 |
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(AP) -- California regulators adopted the nation's first energy-efficiency standards for televisions Wednesday in hopes of reducing electricity use at a time when millions of American households are switching ...
Turning heat to electricity... efficiently
Nov 18, 2009 |
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(PhysOrg.com) -- In everything from computer processor chips to car engines to electric powerplants, the need to get rid of excess heat creates a major source of inefficiency. But new research points the way ...
