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

A plasma globe, using electrical energy to create plasma, light, heat, movement and a faint sound

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...)

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Coal is a readily combustible black or brownish-black rock composed primarily of carbon and formed from plant remains. It is the world's largest single source of fuel for electricity generation, and its fastest growing energy source. It is also the world's largest source of carbon dioxide emissions, one of the key greenhouse gases that are believed to be the primary cause of global warming.

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.

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Photo credit: Andreas Tille
Geysers erupt periodically due to surface water being heated by geothermal heat.

Did you know?

An incandescent light bulb
An incandescent light bulb
  • Saudi Aramco is the largest oil corporation in the world and the world's largest in terms of proven crude oil reserves and production?

Selected biography

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William Thomson, 1st Baron Kelvin, OM, GCVO, PC, PRS, FRSE, (26 June 1824 – 17 December 1907), widely known for developing the Kelvin scale of absolute temperature measurement, was a mathematical physicist, engineer, and outstanding leader in the physical sciences of the 19th century. He did important work in the mathematical analysis of electricity and thermodynamics, and did much to unify the emerging discipline of physics in its modern form.

Born in Ireland, Thomson studied at the University of Glasgow, Scotland. On graduating, he became a mathematics teacher at the Royal Belfast Academical Institution. During his life Thomson published more than 600 scientific papers and filed over 70 patents.

As early as 1845 Thomson pointed out that the experimental results of William Snow Harris were in accordance with the laws of Coulomb. Over the period 1855 to 1867, Thomson collaborated with Peter Guthrie Tait the Treatise on Natural Philosophy that unified the various branches of physical science under the common principle of energy. His inventions included the current balance for the precise specification of the ampere, the standard unit of electric current.

In 1893, Thomson headed an international commission to decide on the design of the Niagara Falls power station. Despite his previous belief in the superiority of direct current electric power transmission, he agreed to use alternating current after seeing a Westinghouse demonstration at the Chicago World's Fair.

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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