Portal:Energy
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The Energy Portal Welcome to Wikipedia's Energy portal, your gateway to energy. This portal is aimed at giving you access to all energy related topics in all of its forms.
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Introduction
In physics, energy (from Ancient Greek ἐνέργεια (enérgeia) 'activity') is the quantitative property that is transferred to a body or to a physical system, recognizable in the performance of work and in the form of heat and light. Energy is a conserved quantity—the law of conservation of energy states that energy can be converted in form, but not created or destroyed. The unit of measurement for energy in the International System of Units (SI) is the joule (J).
Common forms of energy include the kinetic energy of a moving object, the potential energy stored by an object (for instance due to its position in a field), the elastic energy stored in a solid object, chemical energy associated with chemical reactions, the radiant energy carried by electromagnetic radiation, and the internal energy contained within a thermodynamic system. All living organisms constantly take in and release energy.
Due to mass–energy equivalence, any object that has mass when stationary (called rest mass) also has an equivalent amount of energy whose form is called rest energy, and any additional energy (of any form) acquired by the object above that rest energy will increase the object's total mass just as it increases its total energy.
Human civilization requires energy to function, which it gets from energy resources such as fossil fuels, nuclear fuel, or renewable energy. The Earth's climate and ecosystems processes are driven by the energy the planet receives from the Sun (although a small amount is also contributed by geothermal energy). (Full article...)
Selected article
The use of coal dates back to the Bronze Age, but it was the Industrial Revolution that led to its large-scale use, as the steam engine took over from the water wheel. Today world coal consumption is about 5.3 billion tonnes annually, of which about 75% is used to produce electricity. The region including the China and India uses about 1.7 billion tonnes annually, forecast to exceed 2.7 billion tonnes by 2025. The United States consumes about 1.0 billion tons annually. Almost one-third of all coal used was supplied by China in 2005.
Coal mining causes a number of harmful effects, including the pollution of water sources by sulfuric acid caused by a chemical reaction between water and iron sulfide in the coal. In common with other fossil fuels, the burning coal produces carbon dioxide and nitrogen oxides. It also produces sulfur dioxide, the cause of acid rain. Coal contains traces of uranium, thorium, and other naturally-occurring radioactive isotopes which, due to the vast quantities of coal used, cause more radioactive contamination than nuclear power plants. To eliminate CO2 emissions from coal plants, carbon capture and storage technology has been proposed but has yet to be commercially used.
Selected image
Photo credit: Johnson Space Center/NASA
Tropical cyclones feed on the heat released when moist air rises and the water vapor condenses.
Did you know?
- The Stuart Shale Oil Plant (pictured) in Australia was in operation only five years?
- Atlantic LNG Company of Trinidad and Tobago operates the world's largest LNG train?
- Despite projections of producing four times as much power as it used in heating, the Riggatron fusion reactor was never built due to a lack of funding?
- In the late 1980s, as many as 50 percent of Argentina's thermal power plants had to be shut down due to lack of maintenance, causing a supply crisis?
- Kashiwazaki-Kariwa Nuclear Power Plant in Japan, the largest nuclear power plant in the world, was shut down after being hit by the Chūetsu offshore earthquake in July 2007?
- The world's largest surface oil shale pyrolysis reactor is Petrosix, operated by the Brazilian oil company Petrobras?
- Russia plans to build several floating nuclear power stations?
- Shale gas, a form of natural gas extracted from shale, may also refer to oil shale gas?
Selected biography
In 1831, Faraday began his great series of experiments in which he discovered electromagnetic induction. He established that a changing magnetic field produces an electric field, a relation mathematically modelled by Faraday's law. Faraday later used the principle to construct the electric dynamo, the ancestor of modern power generators. He went on to investigate the fundamental nature of electricity, concluding in 1839 that, contrary to opinions at the time, only a single "electricity" exists, and the changing values of quantity and intensity (voltage and charge) would produce different groups of phenomena.
Some historians refer to Faraday as the best experimentalist in the history of science. Despite this his mathematical ability did not extend so far as trigonometry or any but the simplest algebra. He nevertheless possessed the ability to present his ideas in clear and simple language. During his lifetime, Faraday rejected a knighthood and twice refused to become President of the Royal Society.
In the news
- 7 April 2024 – Russian invasion of Ukraine
- The IAEA reports that the Zaporizhzhia Nuclear Power Plant's Unit 6 was targeted by a drone strike, although nuclear safety has not been compromised, according to the statement. (IAEA)
- 4 April 2024 –
- Researchers at the Dark Energy Spectroscopic Instrument in Arizona, United States, release the largest 3D map of the universe featuring more than six million galaxies. Using this map, researchers are able to measure the acceleration of the expansion rate of the universe with unprecedented accuracy, detecting hints that the rate of expansion has been increasing over time. (The Guardian) (Berkeley Lab)
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Quotations
- "We simply must balance our demand for energy with our rapidly shrinking resources. By acting now we can control our future instead of letting the future control us." – Jimmy Carter, 1977
- "It is sensible to improve energy efficiency and to develop alternative and sustainable sources of supply; it's sensible to replant the forests which we consume; it's sensible to re-examine industrial processes; it's sensible to tackle the problem of waste. I understand that the latest vogue is to call them 'no regrets' policies. Certainly we should have none in putting them into effect." – Margaret Thatcher, 1990
- "We have the opportunity and potential to create an oil-free future today, it is potentially right around the corner - and, more often than not, the technology is already here." – John Kerry, 2003
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