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
Petrodollar recycling is the international spending or investment of a country's revenues from petroleum exports ("petrodollars"). It generally refers to the phenomenon of major petroleum-exporting states, mainly the OPEC members plus Russia and Norway, earning more money from the export of crude oil than they could efficiently invest in their own economies. The resulting global interdependencies and financial flows, from oil producers back to oil consumers, can reach a scale of hundreds of billions of US dollars per year – including a wide range of transactions in a variety of currencies, some pegged to the US dollar and some not. These flows are heavily influenced by government-level decisions regarding international investment and aid, with important consequences for both global finance and petroleum politics. The phenomenon is most pronounced during periods when the price of oil is historically high.
The term petrodollar was coined in the early 1970s during the oil crisis, and the first major petrodollar surge (1974–1981) resulted in more financial complications than the second (2005–2014). (Full article...)
Selected image
Photo credit: NASA/TRACE
Plasma being channeled by the magnetic field loops of a sunspot.
Did you know?
- According to research by the IPCC, government funding for most energy research programmes has been flat or declining for nearly 20 years, and is now about half the 1980 level?
- Renewable energy in Iceland provides over 70% of the country's primary energy needs, and 99.9% of Iceland's electricity?
- The Rance tidal power plant in France was the world's 1st electrical generating station powered by tidal energy?
- A tropical cyclone (example pictured) can release heat energy at the rate of 50 to 200 trillion joules per day, roughly 200 times the world-wide electrical generating capacity?
- Ordinary fossil fuel power plants convert between 36% and 48% of the fuel's energy into electricity, with the remainder being lost as waste heat, about half of which is unavoidable due to the second law of thermodynamics?
- Burning biomass indoors leads to between 1.5 and 2 million deaths each year from indoor air pollution in developing nations?
- Over 50% of world small hydroelectricity generating capacity is in China?
- Charles Fritts developed the first solar cell in 1884, although its efficiency was less than 1%?
Selected biography
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
- 1 June 2024 – Russian invasion of Ukraine
- Russia launches missile and drone strikes across Ukraine, injuring at least four people and damaging critical infrastructure, including energy facilities. Ukraine says that it shot down 35 of 53 missiles and 46 of 47 drones. (Reuters)
General images
Quotations
- "Our children will enjoy in their homes electrical energy too cheap to meter." – Lewis Lichtenstein Strauss, 1954
- "There is every possibility that you will soon be able to tax it." – Michael Faraday, talking to William Gladstone on the future purpose of electricity.
- "Higher energy prices act like a tax. They reduce the disposable income people have available for other things after they've paid their energy bills." – John W. Snow, 2005
- "Our dependence on foreign energy is like a foreign tax on the American people." – George W. Bush, 2005
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