Portal:Physics
Physics (from Greek φυσική (ἐπιστήμη), i.e. "knowledge of nature", from φύσις, physis "nature"), is the natural science that involves the study of matter (anything that has mass and occupies space) and its motion (movement from place to another) through space and time, along with related concepts such as energy and force. More broadly, it is the general analysis of nature, conducted in order to understand how the universe behaves.
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, atomic power, and nuclear weapons); advances in thermodynamics led to the development of motorized transport and advances in aviation engineering; 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. Template:/box-footer
Template:/box-header Below are links to pages that are rated "Good Article" within WikiProject Physics from letters "A" through "L". The small good article icon (
), which can be found on the top right corner of a rated Wikipedia page, symbolizes content held to a high standard on Wikipedia, although these have not reached Featured Article status.
The Arc lamp
An arc lamp or arc light is a lamp that produces light by an electric arc (also called a voltaic arc). The carbon arc light, which consists of an arc between carbon electrodes in air, invented by Humphry Davy in the early 1800s, was the first practical electric light. It was widely used starting in the 1870s for street and large building lighting until it was superseded by the incandescent light in the early 20th century. It continued in use in more specialized applications where a high intensity point light source was needed, such as searchlights and movie projectors until after World War II.
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A krypton long arc lamp (top) is shown above a xenon flashtube. The two lamps, used for laser pumping, are very different in the shape of the electrodes, in particular, the cathode, (on the left).
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Template:/box-header europa is a moon of jupiter.europa is smooth and icy and may contain water.
- ...that if the galaxy Andromeda were bright enough to be fully visible to the naked eye it would appear six times as wide as our moon?
- ...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 your watch would run slower when orbiting a black hole than it would on Earth?
- ...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?
- ...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 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?
- ...light takes 8.3 minutes to reach the earth's surface from the sun?
- ... the temperature of the infant universe was 2 billion billion°C but only for 1 millionth of a trillionth of a trillionth (1×10^30) of a second?
- ...that Neptune was discovered by its gravitational pull on Uranus?
- ...that gravitational force is one of the weakest forces?
- ...that the sun revolves the centre of Milky Way in 250 million years?
- 1 April 1997 – Comet Hale-Bopp at perihelion
- 12 April 1633 – Galileo Galilei's trial starts
- 15 April 1707 – Leonhard Euler's birthday
- 18 April 1955 – Albert Einstein's death
- 22 April 1904 – J. Robert Oppenheimer's birthday
- 23 April 1858 – Max Planck's birthday
- 24 April 1990 – Hubble Space Telescope launched
- 25 April 1990 – Hubble Space Telescope deployed from the shuttle Discovery
- 30 April 1777 – Carl Friedrich Gauss's birthday
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 and other physics topics.
- Create a requested article.
- Add a requested image.
- Check out other physics-related WikiProjects: WikiProject Science, WikiProject Fluid dynamics, WikiProject Elements.
Check list for physics novices and experts new to wikipedia
- 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.
- 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.)
- Review, nominate, or submit a physics education article in Wikiversity:Second Journal of Science
- Fix a page needing attention: Modern physics, Classical physics, Other physics topics.
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