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
Chicago Pile-1 (CP-1) was the world's first artificial nuclear reactor. On 2 December 1942, the first human-made self-sustaining nuclear chain reaction was initiated in CP-1 during an experiment led by Enrico Fermi. The secret development of the reactor was the first major technical achievement for the Manhattan Project, the Allied effort to create nuclear weapons during World War II. Developed by the Metallurgical Laboratory at the University of Chicago, CP-1 was built under the west viewing stands of the original Stagg Field. Although the project's civilian and military leaders had misgivings about the possibility of a disastrous runaway reaction, they trusted Fermi's safety calculations and decided they could carry out the experiment in a densely populated area. Fermi described the reactor as "a crude pile of black bricks and wooden timbers".
After a series of attempts, the successful reactor was assembled in November 1942 by a team of about 30 that, in addition to Fermi, included scientists Leo Szilard (who had previously formulated an idea for non-fission chain reaction), Leona Woods, Herbert L. Anderson, Walter Zinn, Martin D. Whitaker, and George Weil. The reactor used natural uranium. This required a very large amount of material in order to reach criticality, along with graphite used as a neutron moderator. The reactor contained 45,000 ultra-pure graphite blocks weighing 360 short tons (330 tonnes) and was fueled by 5.4 short tons (4.9 tonnes) of uranium metal and 45 short tons (41 tonnes) of uranium oxide. Unlike most subsequent nuclear reactors, it had no radiation shielding or cooling system as it operated at very low power – about one-half watt. (Full article...)
Selected image
Photo credit: Björn Appel
A solar furnace can be used to generate electricity, melt steel or make hydrogen fuel.
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
Edison invented the first commercially practical electric light bulb which, by 1879 would burn for hundreds of hours. He was able to sell the concept to homes and businesses by mass-producing them and creating a complete system for the generation and distribution of electricity.
Edison patented an electric distribution system in 1880, and in January 1882 he switched on the first steam generating power station at Holborn Viaduct in London, UK. The direct current (DC) supply system provided electricity supplies to street lamps and a number of private dwellings within a short distance of the station. The first investor-owned electric utility, Pearl Street Station, New York City, started generating on September 4, 1882, providing 110 volts direct current to 59 customers in lower Manhattan.
Life magazine (USA), in a special double issue, placed Edison first in the list of the "100 Most Important People in the Last 1000 Years," noting that the light bulb he promoted "lit up the world." He was ranked thirty-fifth on Michael H. Hart's list of the most influential figures in history.
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 must not waste time and energy disputing the IPCC's report or debating the right machinery for making progress. The International Panel's work should be taken as our sign post: and the United Nations Environment Programme and the World Meteorological Organisation as the principal vehicles for reaching our destination." – Margaret Thatcher, 1990
- "The Kyoto treaty would have wrecked our economy, if I can be blunt." – George W. Bush, 2005
- "We strongly believe that the efforts needed to combat climate change do not have to be regarded as constraints on the economy. Instead, they can be used as a lever for new, green technology." – Maud Olofsson, 2007
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