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
Rice physicists find reappearing quantum trios
Dec 11, 2009 |
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Using atoms at temperatures colder than deep space, Rice University physicists have delivered overwhelming proof for a once-scoffed-at theory that's become a hotbed for research some 40 years after it first ...
Elusive 'hot' electrons captured in ultra-thin solar cells
Dec 11, 2009 |
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Boston College researchers have observed the "hot electron" effect in a solar cell for the first time and successfully harvested the elusive charges using ultra-thin solar cells, opening a potential avenue to improved solar ...
Researchers engineer bacteria to turn carbon dioxide into liquid fuel
Dec 10, 2009 |
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(PhysOrg.com) -- The genetically modified cyanobacterium consumes carbon dioxide and produces the liquid fuel isobutanol by using energy from sunlight.
Solar power coming to a store near you
Dec 10, 2009 |
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(AP) -- Solar technology is going where it has never gone before: onto the shelves at retail stores where do-it-yourselfers can now plunk a panel into a shopping cart and bring it home to install.
New techniques make carbon-based integrated circuits more practical
Dec 09, 2009 |
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(PhysOrg.com) -- Stanford engineers have built what they believe is a chip with the most advanced computing and storage elements made of carbon nanotubes to date by devising a way to root out the stubborn ...
Scientists discover mechanism behind superinsulation
16 hours ago |
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(PhysOrg.com) -- Scientists at the U.S. Department of Energy's Argonne National Laboratory have discovered the microscopic mechanism behind the phenomenon of superinsulation, the ability of certain materials ...
New structure could produce efficient semiconductor laser sources
17 hours ago |
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(PhysOrg.com) -- University of Wisconsin-Madison researchers have achieved a nanoscale laser structure they anticipate will produce semiconductor lasers in the next two years that are more than twice as efficient ...
3-D microchips for more powerful and environmentally friendly computers
Dec 11, 2009 |
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Not so long ago our computers had a single core which had to be boosted for performance - making each machine into a great central heating system. Beyond 85° C, however, electronic components become unstable. ...
Staying Power: Senate Hearing Focuses On Energy Storage
Dec 10, 2009 |
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Thursday's Senate Energy and Natural Resources Committee hearing featured testimony from experts about the power industry's need to develop systems capable of storing large amounts of electricity if the nation's ...
Taiwan chip giant TSMC to enter solar energy
Dec 10, 2009 |
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Chip giant Taiwan Semiconductor Manufacturing Co. is planning its first foray into solar energy with an investment in the island's largest producer of solar cells, a spokesman said Thursday.
Fermi sees brightest-ever blazar flare
Dec 09, 2009 |
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(PhysOrg.com) -- A galaxy located billions of light-years away is commanding the attention of NASA's Fermi Gamma-ray Space Telescope and astronomers around the globe. Thanks to a series of flares that began ...
Aussie galaxy survey to lead to 'new physics'
Dec 08, 2009 |
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(PhysOrg.com) -- Australian astronomers have released the first set of data from the first project to look at the effects of "dark energy" halfway back in the Universe's lifetime.
Weir in space and dimmed sun creates 200-million-mile-long lab bench for turbulence research
Dec 11, 2009 |
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Physicists working in space plasmas have made clever use of the Ulysses spacecraft and the solar minimum to create a massive virtual lab bench to provide a unique test for the science underlying turbulent ...
Clean energy to grow into 1.6 trillion euros industry: WWF
Dec 10, 2009 |
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The clean energy technology sector will grow into a 1.6 trillion-euro (2.4 trillion-dollar) industry by 2020, becoming the third largest industrial sector after automobiles and electronics, WWF said Friday.
World Bank musters $5.5 billion for solar projects
Dec 09, 2009 |
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The World Bank announced Wednesday 5.5 billion dollars would be invested in solar energy projects in five countries of the Middle East and North Africa in a bid to combat climate change.
