Related topics: renewable energy , energy consumption , climate change , solar cells , electricity
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.
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News tagged with energy
Digital Quantum Battery Could Boost Energy Density Tenfold
Dec 22, 2009 |
4.9 / 5 (39) |
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(PhysOrg.com) -- Physicists theorize that quantum phenomena could provide a major boost to batteries, with the potential to increase energy density up to 10 times that of lithium ion batteries. According to ...
Researcher Uses Graphene Quilts to Keep Things Cool
Nanotechnology / Nanomaterials
Dec 21, 2009 |
4.8 / 5 (17) |
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(PhysOrg.com) -- University of California, Riverside Professor of Electrical Engineering and Chair of Materials Science and Engineering Alexander Balandin is leading several projects to explore ways to use ...
Tiny nano-electromagnets turn a cloak of invisibility into a possibility
Dec 22, 2009 |
4.6 / 5 (15) |
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A team of researchers at the FOM institute AMOLF (The Netherlands) has succeeded for the first time in powering an energy transfer between nano-electromagnets with the magnetic field of light.
Chicken waste turned to watts
Dec 26, 2009 |
3.7 / 5 (16) |
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A Nevada energy developer says it has developed an environmentally clean way of using animal waste from chicken farms across the state to light up homes and offices. Green Energy Solutions wants to convert ...
Switchable Nanostructures Made with DNA
Nanotechnology / Bio & Medicine
Dec 21, 2009 |
4.6 / 5 (9) |
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(PhysOrg.com) -- Scientists at the U.S. Department of Energy’s Brookhaven National Laboratory have found a new way to use a synthetic form of DNA to control the assembly of nanoparticles — this time resulting ...
China adopts law to boost renewable energy industry
Dec 27, 2009 |
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China's national assembly Saturday signalled the country's commitment to reducing greenhouse gas emissions by adopting a law supporting its renewable energy industry.
Taiwan unveils Asia's biggest solar plant: govt
Dec 23, 2009 |
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Taiwan has unveiled what it calls Asia's biggest solar power plant as the island, which imports almost all its energy, seeks to tap into clean renewable resources, the government said Wednesday.
UN climate official warns of Indian energy 'crisis'
Dec 23, 2009 |
3.4 / 5 (8) |
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India's reliance on coal means the country is heading for an energy crisis unless it diversifies its sources of power, the chairman of the UN's top climate change panel predicted on Wednesday.
Method makes refineries more efficient
Dec 22, 2009 |
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(PhysOrg.com) -- Refineries could trim millions of dollars in energy costs annually by using a new method developed at Purdue University to rearrange the distillation sequence needed to separate crude petroleum into products.
NREL Evaluates UPS Hybrid-Electric Van Performance
Dec 22, 2009 |
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(PhysOrg.com) -- The U.S. Department of Energy's National Renewable Energy Laboratory (NREL) has collected and analyzed fuel economy, maintenance and other vehicle performance data from UPS’s first generation hybrid diesel ...
Many take dim view of new-fangled Christmas lights
Dec 21, 2009 |
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(AP) -- To Steven Walls, it's beginning to look nothing like Christmas, anywhere he goes.
Making New Enzymes to Engineer Plants for Biofuel Production
Dec 21, 2009 |
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(PhysOrg.com) -- Brookhaven scientists have created a new enzyme with the potential to interfere with a key cell-wall component in plants, possibly leading to plants that are easier to "digest" and convert ...
