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Physics (Greek: physis – φύσις meaning "nature") is a natural science that involves the study of matter, its motion through spacetime, and all allied components, such as energy and force. This has led to the discovery and understanding of the laws and principles which govern the physical universe. More broadly, Physics is the general analysis of nature, conducted in order to understand how the world and universe behave. One tool which helps with this general analysis is the study of the elementary constituents of the universe and their interactions.

Physics is one of the oldest academic disciplines, perhaps the oldest through its inclusion of astronomy. Evidence exists that the earliest civilizations dating back to beyond 3000 BCE, such as the Sumerians, Ancient Egyptians, and the Indus Valley Civilization, all had a predictive knowledge and a very basic understanding of the motions of the Sun, Moon, and stars. Although originally part of other physical sciences and mathematics, Physics emerged to become a unique modern science during the Scientific Revolution of the 16th century.

Physics is both significant and influential, in part because advances in its understanding have often translated into new technologies, but also because new ideas in physics often resonate with other sciences, mathematics, and philosophy. For example, advances in the understanding of electromagnetism or nuclear physics led directly to the development of new products which have dramatically transformed modern-day society (e.g., television, computers, domestic appliances, and nuclear weapons); advances in thermodynamics led to the development of motorized transport; and advances in mechanics inspired the development of calculus.

Physics also has philosophical implications. It can be historically traced back to ancient Greek philosophy. From Thales' first attempt to characterize matter, to Democritus' deduction that matter ought to reduce to an invariant state, the Ptolemaic astronomy of a crystalline firmament, and Aristotle's book Physics, different Greek philosophers advanced their own theories of nature. Well into the 18th century, physics was known as "Natural philosophy". By the 19th century physics was realized as a positive science and a distinct discipline separate from philosophy and the other sciences. Physics, as with the rest of science, relies on philosophy of science to give an adequate description of the scientific method.

More about physics edit Selected article Portrait of Galileo Galilei by Giusto Sustermans

Galileo Galilei was an Italian physicist, mathematician, astronomer, and philosopher who played a major role in the Scientific Revolution. His achievements include improvements to the telescope and consequent astronomical observations and support for Copernicanism. Galileo has been called the "father of modern observational astronomy", the "father of modern physics", the "father of science", and "the Father of Modern Science".

His contributions to observational astronomy include the telescopic confirmation of the phases of Venus, the discovery of the four largest satellites of Jupiter (named the Galilean moons in his honour), and the observation and analysis of sunspots. Galileo also worked in applied science and technology, inventing an improved military compass and other instruments.

Galileo's championing of heliocentrism was controversial within his lifetime, when most subscribed to either geocentrism or the Tychonic system.[9] He met with opposition from astronomers, who doubted heliocentrism due to the absence of an observed stellar parallax. The matter was investigated by the Roman Inquisition in 1615, and they concluded that it could only be supported as a possibility, not as an established fact. Galileo later defended his views in Dialogue Concerning the Two Chief World Systems, which appeared to attack Pope Urban VIII and thus alienated him and the Jesuits, who had both supported Galileo up until this point. He was tried by the Inquisition, found "vehemently suspect of heresy", forced to recant, and spent the rest of his life under house arrest. It was while Galileo was under house arrest that he wrote one of his finest works, Two New Sciences. Here he summarized the work he had done some forty years earlier, on the two sciences now called kinematics and strength of materials.

Classical mechanics describes the motion of macroscopic objects, from projectiles to parts of machinery, as well as astronomical objects, such as spacecraft, planets, stars, and galaxies. Within these domains, it produces very accurate results. And thus, is one of the oldest and largest subjects in science, engineering and technology. Besides this, many related specialties deal with gases, liquids, and solids, and so on. In addition, classical mechanics is enhanced by special relativity for high velocity objects that are approaching the speed of light. General relativity is employed to handle gravitation at a deeper level, and finally, quantum mechanics handles the wave-particle duality of atoms and molecules.

More selected articles edit Selected picture

The Hubble Deep Field (HDF) is an image of a small region in the constellation Ursa Major, constructed from a series of observations by the Hubble Space Telescope. It covers an area 2.5 arcminutes across, two parts in a million of the whole sky The Hubble Deep Field

Details from the Hubble Deep Field illustrate the wide variety of galaxy shapes, sizes and colours found in the distant universe. More selected pictures edit Did you know... Mock mirage of the setting sun

...the mirage of astronomical objects is an optical phenomenon, which produces distorted or multiple images of astronomical objects such as the Sun, the Moon, the planets, bright stars and very bright comets

...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 nuclear fusion reactions are probably occurring at or above the sun's photosphere; it is a process called solar surface fusion.

...that, in the Large Hadron Collider, protons move at 99.9999991% of the speed of light when accelerated to the energy of 7 TeV?

...that, at a speed of 299,792,458 m/s, light can travel from the Earth to the Moon in 1.2 seconds?

...that the submarine telescope ANTARES, intended to detect neutrinos, may also be used to observe bioluminescent plankton and fish?

Artist's depiction of the WMAP satellite measuring the Cosmic Microwave Background Radiation to help scientists understand the Big Bang

...that lasers can be used to separate two isotopes very efficiently?

...that neutron stars are so dense that a teaspoonful (5 mL) would have ten times the mass of all human world population?

...that every year, the Moon moves 3.82 cm away from Earth?

...that gold leaf is about 500 atoms thick?

...that the Big Bang was secured as the best theory of origin of the universe by the discovery of the cosmic microwave background radiation in 1964?

...that if we travel at the speed of light it would take us no time at all to cross the universe according to our watches?

...that Neptune was discovered by its gravitational pull on Uranus?

More interesting facts

Suggest a fact edit Physics news

January 11. 2012. The Worldwide LHC Computing Grid processes ATLAS data by sending chunks of data to universities and labs all around the world. ATLAS experiment blog.

January 10, 2012. Photons from a distant gamma ray burst provide insights into the possible existence of a grainy (or quantized) space-time. Nature News

January 04, 2012. The Baryon Oscillation Spectroscopic Survey presents its initial findings after completeing half its survey pertaining to the influence of dark energy. Nature News.

January 04, 2012. U.S. federal support for science favors prestigous basic research over science applied to the public's well being. Nature News.

November 30, 2011. €80-billion European Commission plan for research raises the level of funding in some areas. Nature News.

November 29, 2011. Funding problems for fusion-energy test reactor and the Global Monitoring for Environment and Security (GMES) programme. Nature News.

Older news edit March anniversaries

1 March 1966 – first spacecraft crash-lands on Venus 14 March 1879 – Albert Einstein's birthday 20 March 1942 - Gabriele Veneziano's Birthday 24 March 1993 – Comet Shoemaker-Levy 9 discovered

More anniversaries edit Things you can do Summary

Edit a physics article

Whether you are an expert or a novice, be bold, improve an article by editing it. Practice in the sandbox if you must. But hurry back to fix that glaring error that has been bothering you.

Join WikiProject Physics. Watch the WikiProject Physics talk page for physics-related issues on Wikipedia. Improve Physics Portal Add to Did you know, and Upcoming anniversaries. Add new Selected articles and Selected pictures to the queues. Add to Physics news. Review articles Assign importance and quality to unassessed articles (See Physics quality control) Review an article for techno babble and report confusing sections in articles talk page. (Give enough detail to help the editors.) Advanced Editing Expand a physics stub. Fix a page needing attention: Modern physics, Classical physics, Other physics topics. Create a requested article. Add a requested image. Check out other physics-related WikiProjects: WikiProject Science, WikiProject Fluid dynamics, WikiProject Elements.

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Edit a physics article

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Register with wikipedia for a user name. (See the username policy) Visit the help page Add articles to your watch list. Check your watchlist on regular basis Revert an obvious vandalism edit Remove unnecessary jargon. Edit your user page to tell wikipedia enough about you to help other editors get to know you Review an article and make a useful comment on the talk page Add your name to the WikiProject Physics members list

Activities for physics novices and experts familiar with wikipedia

Edit a physics article Add your name to the WikiProject Physics members list Revert Vandalism Add or improve diagrams and figures Assign importance and quality to unassessed articles (See Physics quality control) Review article for techno babble and suggest areas that need improving on talk page (or add clean up tag.) Fix a page needing attention: Modern physics, Classical physics, Other physics topics.

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