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...)

Selected article

Climate Change 2007, the fourth report of the United Nations Intergovernmental Panel on Climate Change (IPCC) to evaluate the risks of global warming since 1990, is being published in sections throughout 2007. Prior to publishing, the report - which is the combined work of hundreds of experts - is reviewed by representatives from many of the world's governments.

Due to the accumulation of evidence, the report goes further than previous reports by stating that 'warming of the climate system is unequivocal'. It goes on to say that 'most of the observed increase in globally averaged temperatures since the mid-20th century is 'very likely' due to the observed increase in anthropogenic greenhouse gas concentrations'. Fossil fuel use is given as the primary source of the increase in atmospheric carbon dioxide, with the increase in methane being very likely caused by a combination of agricultural practices and fossil fuel use.

Based on an analysis of computer climate models, the report states that average surface temperatures will rise during this century, most likely between 1.1 to 4.3°C (5.2 to 11.5 °F), depending on the mitigation actions taken. Excluding the effects of ice sheet flow, they also predict a sea level rise of 18 to 26 cm (7 to 23 inches), more heat waves and more heavy rain. An increase in areas affected by droughts, in the intensity of tropical cyclones and in extreme high tides is also likely. The IPCC believe that stabilization of greenhouse gas concentrations is possible at a reasonable cost, with stabilization between 445 and 535 ppm costing less than 3% of global GDP. They do warn, however, that a 'large shift in the pattern of investment' is required.

Selected image

Photo credit: United States Department of Energy
The fireball created as energy is released in a nuclear explosion.

Did you know?

SEGS solar power plant
SEGS solar power plant
  • The concentration of the greenhouse gas carbon dioxide has increased from about 280 parts per million to about 380 ppm since the start of the Industrial Revolution. That's an increase of 35.71%. The estimated population of the world in 1750 was 791 Million people. The estimated population of the world on June 30th, 2007 was 6.6 Billion people. That's an increase of 734.39%.?
  • In the 1990s Bougainville conflict, islanders cut off from oil supplies due to a blockade used coconut oil to fuel their vehicles?

Selected biography

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James Clerk Maxwell (13 June 1831 – 5 November 1879) was a Scottish mathematician and theoretical physicist. His most significant achievement was formulating a set of equations – eponymously named Maxwell's equations – that for the first time expressed the basic laws of electricity and magnetism in a unified fashion. Maxwell's contributions to physics are considered by many to be of the same magnitude as those of Isaac Newton and Albert Einstein.

Maxwell studied natural philosophy, moral philosophy, and mental philosophy at the University of Edinburgh, before graduating in mathematics at the University of Cambridge, where he would conduct much of his career. He built on Michael Faraday's work on magnetic induction, using elements of geometry and algebra to demonstrate that electric and magnetic fields travel through space, in the form of waves, and at the constant speed of light. Finally, in 1861, Maxwell proposed that light consisted of undulations in the same medium that is the cause of electric and magnetic phenomena. In the same year he was elected to the Royal Society.

In 1864, Maxwell presented what are now known as Maxwell's equations to the Royal Society. These collectively describe the behaviour of both the electric and magnetic fields, as well as their interactions with matter.

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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