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.
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News tagged with energy
Transcription factors guide differences in human and chimp brain function
Dec 07, 2009 |
5 / 5 (1) |
0
Humans share at least 97 percent of their genes with chimpanzees, but, as a new study of transcription factors makes clear, what you have in your genome may be less important than how you use it.
At Stanford, nanotubes + ink + paper = equal instant battery (w/ Video)
Nanotechnology / Nanomaterials
Dec 07, 2009 |
4.9 / 5 (26) |
2
(PhysOrg.com) -- Stanford scientists are harnessing nanotechnology to quickly produce ultra-lightweight, bendable batteries and supercapacitors in the form of everyday paper.
Hunt for Higgs boson: Mass of top quark narrows search
Dec 07, 2009 |
4.8 / 5 (23) |
25
(PhysOrg.com) -- New high-energy particle research by a team working with data from Fermi National Accelerator Laboratory further heightens the uncertainty about the exact nature of a key theoretical component ...
Metamaterials could reduce friction in nanomachines
Nanotechnology / Nanomaterials
Dec 07, 2009 |
5 / 5 (4) |
2
(PhysOrg.com) -- Nanoscale machines expected to have wide application in industry, energy, medicine and other fields may someday operate far more efficiently thanks to important theoretical discoveries concerning the manipulation ...
Caffeine doesn't reverse the negative cognitive impact of alcohol, study shows
Medicine & Health / Psychology & Psychiatry
Dec 07, 2009 |
5 / 5 (1) |
2
People who drink may want to know that coffee won't sober them up, according to new laboratory research. Instead, a cup of coffee may make it harder for people to realize they're drunk.
Silicon Valley getting greener with Hara
Dec 07, 2009 |
2 / 5 (2) |
1
Fresh from signing on to help green Silicon Valley, startup Hara will be at climate talks in Copenhagen this week to urge that corporations not wait for regulations to fight global warming.
