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
Scientist explore future of high-energy physics
23 hours ago |
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In a 1954 speech to the American Physical Society, the University of Chicago's Enrico Fermi fancifully envisioned a particle accelerator that encircled the globe. Such would be the ultimate theoretical outcome, ...
In Utah, company aims to store energy in air
Feb 09, 2010 |
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A Utah company plans to dig a series of underground caverns that it hopes to one day fill with compressed air, releasing it to generate electricity by turning a turbine and solving one of the most vexing problems facing the ...
Composite nanomaterials show promise for solar hydrogen generation
Nanotechnology / Nanomaterials
Feb 08, 2010 |
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(PhysOrg.com) -- A novel strategy for engineering semiconductor materials can boost the performance of water-splitting solar cells for hydrogen production, according to a new study by researchers at the University ...
Texas entrepreneur hopes to turn mesquite into power
Feb 05, 2010 |
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Randy Hill lives amid the fossil fuels of America, a place where natural gas and crude oil made millionaires and the landscape is dotted with pump jacks. But Hill, who lives outside Abilene in West Texas, is spending much ...
Wind power capacity grows at record pace, but industry jobs actually fall
Feb 05, 2010 |
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America's wind energy industry enjoyed a banner year in 2009, thanks largely to tax credits and other incentives packed into the $787 billion economic stimulus bill.
X-Ray Emission from Young Stars
Feb 05, 2010 |
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(PhysOrg.com) -- The star TW Hydrae is located about 150 light-years from earth in the direction of the constellation of Hydrae, the Water Snake. This star is relatively young -- at about 10 million years ...
Renewable oil companies
Feb 05, 2010 |
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The entry of oil companies into the realm of renewable energy could present major obstacles for the development of a sustainable economy that is not based on carbon resources, according to a report in the International Jo ...
Physicist proposes method to teleport energy
Feb 05, 2010 |
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(PhysOrg.com) -- Using the same quantum principles that enable the teleportation of information, a new proposal shows how it may be possible to teleport energy. By exploiting the quantum energy fluctuations ...
Conductive eTextiles: Researchers move from making batteries from paper to making batteries from cloth
Nanotechnology / Nanomaterials
Feb 05, 2010 |
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(PhysOrg.com) -- Stanford researchers have moved from making batteries from paper to making batteries from cloth. Your-T-shirt could become a lighted, moving display.
Cars of the future could be powered by their bodywork thanks to new battery technology
Feb 05, 2010 |
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Parts of a car's bodywork could one day double up as its battery, according to the scientists behind a new €3.4 million project announced today.
Google awards $1 million for research effort to slash energy consumption in Internet data centers
Feb 04, 2010 |
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Google Inc. has awarded a two-year, $1 million research grant aimed at slashing energy usage in large Internet data centers to a team of computer scientists at the University of California at Santa Barbara (UCSB), Rutgers ...
5 Sources of Alternative Energy You May Not Have Heard Of
Feb 04, 2010 |
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(PhysOrg.com) -- As fossil fuels increasingly fall out of favor, many are looking into alternative energy sources to help us power our lives with a smaller impact on the environment. You already know about ...
According to new survey, Americans support strong climate, energy policies
Feb 04, 2010 |
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Despite a sharp drop in public concern over global warming, Americans—regardless of political affiliation—support the passage of federal climate and energy policies, according to the results of a national survey released ...
Habit-Learning Device will Lower Energy Bills Under New Clean Energy Cashback Scheme
Feb 04, 2010 |
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(PhysOrg.com) -- Smart control units that learn householders' energy habits and provide immediate feedback on consumption could give home energy savings of up to 20% without compromising comfort.
Organic Layers Pave Way for Next Generation of Biosensors and Solar Cells
Feb 03, 2010 |
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(PhysOrg.com) -- UT Dallas researchers have laid the groundwork for attaching virtually any organic molecule to silicon, a technological feat that promises to greatly improve semiconductor devices’ performance ...
