Portal:Physics
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Physics is the natural science of matter, involving the study of matter, its fundamental constituents, its motion and behavior through space and time, and the related entities of energy and force. Physics is one of the most fundamental scientific disciplines, with its main goal being to understand how the universe behaves. A scientist who specializes in the field of physics is called a physicist.
Physics is one of the oldest academic disciplines and, through its inclusion of astronomy, perhaps the oldest. Over much of the past two millennia, physics, chemistry, biology, and certain branches of mathematics were a part of natural philosophy, but during the Scientific Revolution in the 17th century these natural sciences emerged as unique research endeavors in their own right. Physics intersects with many interdisciplinary areas of research, such as biophysics and quantum chemistry, and the boundaries of physics are not rigidly defined. New ideas in physics often explain the fundamental mechanisms studied by other sciences and suggest new avenues of research in these and other academic disciplines such as mathematics and philosophy.
Advances in physics often enable new technologies. For example, advances in the understanding of electromagnetism, solid-state physics, and nuclear physics led directly to the development of new products that have dramatically transformed modern-day society, such as television, computers, domestic appliances, and nuclear weapons; advances in thermodynamics led to the development of industrialization; and advances in mechanics inspired the development of calculus. (Full article...)
A white dwarf is a stellar core remnant composed mostly of electron-degenerate matter. A white dwarf is very dense: its mass is comparable to the Sun's, while its volume is comparable to Earth's. A white dwarf's low luminosity comes from the emission of residual thermal energy; no fusion takes place in a white dwarf. The nearest known white dwarf is Sirius B, at 8.6 light years, the smaller component of the Sirius binary star. There are currently thought to be eight white dwarfs among the hundred star systems nearest the Sun. The unusual faintness of white dwarfs was first recognized in 1910. The name white dwarf was coined by Willem Jacob Luyten in 1922.
White dwarfs are thought to be the final evolutionary state of stars whose mass is not high enough to become a neutron star or black hole. This includes over 97% of the stars in the Milky Way. After the hydrogen-fusing period of a main-sequence star of low or medium mass ends, such a star will expand to a red giant during which it fuses helium to carbon and oxygen in its core by the triple-alpha process. If a red giant has insufficient mass to generate the core temperatures required to fuse carbon (around 1 billion K), an inert mass of carbon and oxygen will build up at its center. After such a star sheds its outer layers and forms a planetary nebula, it will leave behind a core, which is the remnant white dwarf. Usually, white dwarfs are composed of carbon and oxygen (CO white dwarf). If the mass of the progenitor is between 7 and 9 solar masses (M☉), the core temperature will be sufficient to fuse carbon but not neon, in which case an oxygen–neon–magnesium (ONeMg or ONe) white dwarf may form. Stars of very low mass will be unable to fuse helium; hence, a helium white dwarf may form by mass loss in binary systems. (Full article...)Did you know -
- ... that Aristotle's ideas of physics held that because an object could not move without an immediate source of energy, arrows created a vacuum behind them that pushed them through the air.
- ... that there are up to 6 candidates for the Theory of everything, minus String theory and Loop quantum gravity?
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June anniversaries
- 1 June 1831 – James Clark Ross discovers the North Magnetic Pole.
- 1 June 1869 – Thomas Edison receives a patent for his electric voting machine.
- 1 June 1910 – Robert Falcon Scott expedition leaves England for South Pole.
- 1 June 1978 – First Patent Cooperation Treaty international filings.
- 1 June 1980 – Cable News Network (CNN) begins broadcasting.
- 1 June 1990 – Bush and Gorbachev sign chemical weapons ban.
- 1 June 2000 – Patent Law Treaty is signed.
- 2 June 1966 – Surveyor 1 lands on the Moon.
- 2 June 2003 - ESA launches Mars Express probe to Mars.
- 3 June 1965 - First American spacewalk, mission Gemini IV
- 3 June 1973 – A Soviet supersonic Tupolev Tu-144 crashes.
- 4 June 781 BC – First historic solar eclipse is recorded in China.
- 4 June 1973 – A patent for the ATM is granted.
- 4 June 1996 - First flight. Ariane 5 rocket explodes after roughly 20 seconds.
- 5 June 1977 – Apple II, personal computer goes on sale.
Birthdays
- 1 June 1633 – Geminiano Montanari, Italian astronomer (d. 1687)
- 1 June 1796 – Nicolas Léonard Sadi Carnot, French physicist (d. 1832)
- 1 June 1899 – Edward Charles Titchmarsh, English mathematician (d. 1963)
- 1 June 1907 – Frank Whittle, invented jet engine. (d. 1996)
- 1 June 1917 – William S. Knowles Nobel Prize laureate
- 1 June 1940 – Kip Thorne, American physicist
- 2 June 1930 – Pete Conrad, American astronaut (d. 1999)
- 2 June 1949 – Heather Couper, British astronomer
- 3 June 1659 – David Gregory, Scottish astronomer (d. 1708)
- 3 June 1923 – Igor Shafarevich, Russian mathematician
- 4 June 1704 – Benjamin Huntsman, English inventor and manufacturer (d. 1776)
- 4 June 1877 – Heinrich Wieland, German biochemist & Nobel laureate (d. 1957)
- 4 June 1916 – Robert F. Furchgott, American chemist & Nobel laureate (d. 2009)
- 4 June 1967 – Robert Shane Kimbrough, American astronaut
- 5 June 1760 – Johan Gadolin, Finnish scientist (d. 1852)
- 5 June 1819 – John Couch Adams, English astronomer (d. 1892)
- 5 June 1862 – Allvar Gullstrand, Swedish ophthalmologist Nobel laureate (d. 1930)
- 5 June 1900 – Dennis Gabor, Hungarian physicist, Nobel laureate (d. 1979)
- 5 June 1965 – Michael E. Brown, American astronomer
- 13 June 1831 - James Clerk Maxwell, Scottish physicist (d. 1879)
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Fundamentals: Concepts in physics | Constants | Physical quantities | Units of measure | Mass | Length | Time | Space | Energy | Matter | Force | Gravity | Electricity | Magnetism | Waves
Basic physics: Mechanics | Electromagnetism | Statistical mechanics | Thermodynamics | Quantum mechanics | Theory of relativity | Optics | Acoustics
Specific fields: Acoustics | Astrophysics | Atomic physics | Molecular physics | Optical physics | Computational physics | Condensed matter physics | Nuclear physics | Particle physics | Plasma physics
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Other: Physics in fiction | Physics lists | Physics software | Physics stubs
Physics topics
Classical physics traditionally includes the fields of mechanics, optics, electricity, magnetism, acoustics and thermodynamics. The term Modern physics is normally used for fields which rely heavily on quantum theory, including quantum mechanics, atomic physics, nuclear physics, particle physics and condensed matter physics. General and special relativity are usually considered to be part of modern physics as well.
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