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
UN climate official warns of Indian energy 'crisis'
11 hours ago |
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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.
Taiwan unveils Asia's biggest solar plant: govt
16 hours ago |
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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.
Digital Quantum Battery Could Boost Energy Density Tenfold
Dec 22, 2009 |
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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 ...
Tiny nano-electromagnets turn a cloak of invisibility into a possibility
Dec 22, 2009 |
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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.
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 ...
