Portal:Physics
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Physics
Physics (from Ancient Greek: φυσική (ἐπιστήμη), romanized: physikḗ (epistḗmē), lit. 'knowledge of nature', from φύσις phýsis "nature") is the natural science that studies matter, its motion and behavior through space and time, and that studies the related entities of energy and force. Physics is one of the most fundamental scientific disciplines, and its main goal is to understand how the universe behaves.
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 academic disciplines such as mathematics and philosophy.
Advances in physics often enable advances in 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.
Selected article
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.
Selected image
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 It was widely used starting in the 1870s for street and large building lighting until it was superseded by the incandescent light in the early 20th century.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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Did you know...
- ... that it is estimated that The Sun burns around 620 million metric tons of Hydrogen per second into 616 million metric tons of Helium?
- ... that Femto satellites are the smallest types of satellites, and the Kalam SAT is one of the smallest Femto satellite ever made?
- ... that if the Andromeda galaxy 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 feet are slightly younger than your head, because time runs slow at a lower Gravitational Potential. This is a consequence of Gravitational Time Dilation
- ... 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% the speed of light when accelerated with 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 (10¹⁷ kg/m³) that a teaspoonful (5 mL) would have ten times the mass of the total human population?
- ... that the Big Bang was secured as the best theory for the origin of the universe by the discovery of the cosmic microwave background radiation in 1964?
- ... that Neptune was discovered by its gravitational pull on Uranus?
- ... that a touch flash releases about a billion photons a second far less produced in a particle accelerator?
- ... that homing pigeons wouldn't be able to navigate on Mercury because the planet has no magnetic field or atmosphere?
- ... that there are up to 6 candidates for the Theory of everything, minus String theory and Loop quantum gravity?
July anniversaries
- July 1654 – Blaise Pascal's letters to Pierre de Fermat on the "Problem of Points"
- July 1820 – Hans Christian Oersted published pamphlet about the relation between electricity and magnetism
- July 1849 – Fizeau publishes results of speed of light experiment.
- July 1914 – AT&T tested the first working transcontinental telephone line when the president of the company spoke from one coast to the other. Months later Alexander Graham Bell repeated his famous statement over the phone in New York City which was heard by Dr. Watson in San Francisco.
- July 1957 – John Bardeen, Leon Cooper and Robert Schrieffer submit detailed research report, "Theory of Superconductivity" to the Physical Review (it was published in December).
- July 1994 – Comet Shoemaker–Levy 9 collides with Jupiter.
- 16 July 1945 – Trinity test, named by J. Robert Oppenheimer.
- 16 July 1969 – Apollo 11 launched.
- 20 July 1969 – Apollo 11 landed on the Moon.
- 23 July 1995 – Comet Hale-Bopp discovered.
Physics in the news
No recent news
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 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
