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
At Stanford, nanotubes + ink + paper = equal instant battery (w/ Video)
Nanotechnology / Nanomaterials
9 hours ago |
4.9 / 5 (17) |
3
(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
11 hours ago |
4.7 / 5 (10) |
21
(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 ...
Transcription factors guide differences in human and chimp brain function
9 hours ago |
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.
Metamaterials could reduce friction in nanomachines
Nanotechnology / Nanomaterials
11 hours ago |
5 / 5 (3) |
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
12 hours ago |
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
19 hours ago |
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.
Physics Model Determines Dynamics of Friends and Enemies
Dec 02, 2009 |
4.4 / 5 (12) |
5
(PhysOrg.com) -- Sometimes friends can become enemies and enemies become friends, and it’s difficult to understand exactly how or why the changes took place. A new study shows that when the shifting of alliances ...
A light touch: Iron complexes as efficient catalysts for the light-driven extraction of hydrogen from water
Dec 02, 2009 |
5 / 5 (4) |
3
(PhysOrg.com) -- Hydrogen is a promising alternative energy carrier that can be efficiently converted into electrical energy in fuel cells. One hurdle to the introduction of sustainable hydrogen technology is the fact that ...
China solar panel makers see boost from Copenhagen
Dec 03, 2009 |
3.7 / 5 (3) |
2
In Trina Solar's brilliant white factory in eastern China, masked workers in lab coats turn silicon wafers into solar power cells capable of harnessing the sun's clean and limitless energy.
Innovation puts next-generation solar cells on the horizon
Dec 01, 2009 |
4.3 / 5 (30) |
12
In a world first, a Monash University-led international research team has developed an innovative way to boost the output of the next generation of solar cells.
Large Hadron Collider sets new power world record
Nov 30, 2009 |
4.7 / 5 (25) |
13
(PhysOrg.com) -- CERN's Large Hadron Collider has today become the world's highest energy particle accelerator, having accelerated its twin beams of protons to an energy of 1.18 TeV in the early hours of the ...
Blood Enzyme Could Help Realize Clean Coal
Dec 03, 2009 |
4 / 5 (5) |
0
(PhysOrg.com) -- An enzyme in our blood that enables our lungs to exhale carbon dioxide could be the key to isolating carbon dioxide emissions from coal plants in order to store them safely underground. A ...
Researchers Identify Key Molecules in Photosynthesis
Dec 02, 2009 |
5 / 5 (8) |
0
(PhysOrg.com) -- Chemistry professor Harry Frank led an international group of researchers that identified the molecules in algae which direct the organisms to convert sunlight into oxygen. The findings may ...
The hidden lives of proteins
Dec 02, 2009 |
5 / 5 (2) |
0
An important Brandeis study appearing in the December 3 issue of Nature raises the curtain on the hidden lives of proteins at the atomic level. The study reports that for the first time, researchers used x ...
Using superconducting probes to get a picture of what it's like inside CNTs
Nov 20, 2009 |
4.4 / 5 (9) |
0
(PhysOrg.com) -- "Carbon nanotubes are exciting for fundamental physics, and for potential technological applications," Nadya Mason tells PhysOrg.com. "However, we are generally limited in the way that we can study them. ...
