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Peryton (astronomy)
In radio astronomy, perytons are short man-made radio signals of a few milliseconds resembling fast radio bursts. First detected at the Parkes Observatory in 1998, they were found to be caused by premature opening of a microwave oven door nearby. The radio signals are named after the peryton, a pseudo-mythical winged stag that casts the shadow of a man. This name was chosen for these signals because they are man-made but have characteristics that mimick the natural phenomenon of fast radio bursts. Detection Perytons were observed at the Parkes Observatory and Bleien Radio Observatory. Between 1998 and 2015, 46 perytons were identified at the Parkes Observatory. On June 23, 1998, 16 perytons were detected at that same location within 7 minutes. In 2011, a group of researchers from Australia identified 16 signals resembling man-made fast radio bursts and gave them the name peryton. A peryton is a fictional animal from the Book of Imaginary Beings, by Jorge Luis Borges. In ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Popular Science
''Popular Science'' (also known as ''PopSci'') is an American digital magazine carrying popular science content, which refers to articles for the general reader on science and technology subjects. ''Popular Science'' has won over 58 awards, including the American Society of Magazine Editors awards for its journalistic excellence in 2003 (for General Excellence), 2004 (for Best Magazine Section), and 2019 (for Single-Topic Issue). With roots beginning in 1872, ''Popular Science'' has been translated into over 30 languages and is distributed to at least 45 countries. Early history ''The Popular Science Monthly'', as the publication was originally called, was founded in May 1872 by Edward L. Youmans to disseminate scientific knowledge to the educated layman. Youmans had previously worked as an editor for the weekly ''Appleton's Journal'' and persuaded them to publish his new journal. Early issues were mostly reprints of English periodicals. The journal became an outlet for writings ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Astrophysics
Astrophysics is a science that employs the methods and principles of physics and chemistry in the study of astronomical objects and phenomena. As one of the founders of the discipline said, Astrophysics "seeks to ascertain the nature of the heavenly bodies, rather than their positions or motions in space–''what'' they are, rather than ''where'' they are." Among the subjects studied are the Sun, other stars, galaxies, extrasolar planets, the interstellar medium and the cosmic microwave background. Emissions from these objects are examined across all parts of the electromagnetic spectrum, and the properties examined include luminosity, density, temperature, and chemical composition. Because astrophysics is a very broad subject, ''astrophysicists'' apply concepts and methods from many disciplines of physics, including classical mechanics, electromagnetism, statistical mechanics, thermodynamics, quantum mechanics, relativity, nuclear and particle physics, and atomic and m ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Wow! Signal
The Wow! signal was a strong narrowband radio signal detected on August 15, 1977, by Ohio State University's Big Ear radio telescope in the United States, then used to support the search for extraterrestrial intelligence. The signal appeared to come from the direction of the constellation Sagittarius and bore the expected hallmarks of extraterrestrial origin. Astronomer Jerry R. Ehman discovered the anomaly a few days later while reviewing the recorded data. He was so impressed by the result that he circled on the computer printout the reading of the signal's intensity, "6EQUJ5", and wrote the comment "Wow!" beside it, leading to the event's widely used name. The entire signal sequence lasted for the full 72-second window during which Big Ear was able to observe it, but has not been detected since, despite several subsequent attempts by Ehman and others. Many hypotheses have been advanced on the origin of the emission, including natural and human-made sources, but none of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fast Radio Burst
In radio astronomy, a fast radio burst (FRB) is a transient radio pulse of length ranging from a fraction of a millisecond to 3 seconds, caused by some high-energy astrophysical process not yet understood. Astronomers estimate the average FRB releases as much energy in a millisecond as the Sun puts out in three days. While extremely energetic at their source, the strength of the signal reaching Earth has been described as 1,000 times less than from a mobile phone on the Moon. The first FRB was discovered by Duncan Lorimer and his student David Narkevic in 2007 when they were looking through archival pulsar survey data, and it is therefore commonly referred to as the Lorimer Burst. Many FRBs have since been recorded, including several that have been detected to repeat in seemingly irregular ways. Only one FRB has been detected to repeat in a regular way: FRB 180916 seems to pulse every 16.35 days. Most FRBs are extragalactic, but the first Milky Way FRB was detected by the CHIME ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stack Exchange
Stack Exchange is a network of question-and-answer (Q&A) websites on topics in diverse fields, each site covering a specific topic, where questions, answers, and users are subject to a reputation award process. The reputation system allows the sites to be self-moderating. As of August 2019, the three most actively-viewed sites in the network are Stack Overflow, Super User, and Ask Ubuntu. All sites in the network are modeled after the initial site Stack Overflow, a Q&A site for computer programming questions created by Jeff Atwood and Joel Spolsky. Further Q&A sites in the network are established, defined and eventually if found relevant brought to creation by registered users through a special site named Area 51. User contributions since May 2, 2018 are licensed under Creative Commons Attribution-ShareAlike 4.0 International. Older content, contributed while the site used the Creative Commons Attribution-ShareAlike 3.0 Unported license or the earlier Creative Commons ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Matsushita Corporation
formerly between 1935 and 2008 and the first incarnation of between 2008 and 2022, is a major Japanese multinational conglomerate corporation, headquartered in Kadoma, Osaka. It was founded by Kōnosuke Matsushita in 1918 as a lightbulb socket manufacturer. In addition to consumer electronics, of which it was the world's largest maker in the late 20th century, Panasonic offers a wide range of products and services, including rechargeable batteries, automotive and avionic systems, industrial systems, as well as home renovation and construction. Panasonic has a primary listing on the Tokyo Stock Exchange and is a constituent of the Nikkei 225 and TOPIX 100 indices. It has a secondary listing on the Nagoya Stock Exchange. Corporate name From 1935 to October 1, 2008, the company's corporate name was "Matsushita Electric Industrial Co." (MEI). On January 10, 2008, the company announced that it would change its name to "Panasonic Corporation", in effect on October 1, 2008, to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cavity Magnetron
The cavity magnetron is a high-power vacuum tube used in early radar systems and subsequently in microwave ovens and in linear particle accelerators. A cavity magnetron generates microwaves using the interaction of a stream of electrons with a magnetic field, while moving past a series of cavity resonators, which are small, open cavities in a metal block. Electrons pass by the cavities and cause microwaves to oscillate within, similar to the functioning of a whistle producing a tone when excited by an air stream blown past its opening. The resonant frequency of the arrangement is determined by the cavities' physical dimensions. Unlike other vacuum tubes, such as a klystron or a traveling-wave tube (TWT), the magnetron cannot function as an amplifier for increasing the intensity of an applied microwave signal; the magnetron serves solely as an electronic oscillator generating a microwave signal from direct current electricity supplied to the vacuum tube. The use of magnetic fie ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Watt
The watt (symbol: W) is the unit of power or radiant flux in the International System of Units (SI), equal to 1 joule per second or 1 kg⋅m2⋅s−3. It is used to quantify the rate of energy transfer. The watt is named after James Watt (1736–1819), an 18th-century Scottish inventor, mechanical engineer, and chemist who improved the Newcomen engine with his own steam engine in 1776. Watt's invention was fundamental for the Industrial Revolution. Overview When an object's velocity is held constant at one metre per second against a constant opposing force of one newton, the rate at which work is done is one watt. : \mathrm In terms of electromagnetism, one watt is the rate at which electrical work is performed when a current of one ampere (A) flows across an electrical potential difference of one volt (V), meaning the watt is equivalent to the volt-ampere (the latter unit, however, is used for a different quantity from the real power of an electrical circuit). : ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Narrow Bipolar Pulse
Narrow bipolar pulses are high-energy, high-altitude, intra-cloud electrical discharges associated with thunderstorms. NBP are similar to other forms of lightning Lightning is a naturally occurring electrostatic discharge during which two electric charge, electrically charged regions, both in the atmosphere or with one on the land, ground, temporarily neutralize themselves, causing the instantaneous ... events such as return strokes and dart leaders, but produce an optical emission of at least an order of magnitude smaller. They typically occur in the 10–20 km altitude range and can emit a power on the order of a few hundred gigawatts. They produce far-field asymmetric bipolar electric field change signatures (called narrow bipolar events). References * M.A. Uman et al., The Electromagnetic Radiation from a Finite Antenna, AJP Vol. 43, 1975. * A.V. Gurevich, K.P. Zybin, Runaway Breakdown and the Mysteries of Lightning, Physics Today 37-43, 2005. * K. B. Eack ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Solar Flare
A solar flare is an intense localized eruption of electromagnetic radiation in the Sun's atmosphere. Flares occur in active regions and are often, but not always, accompanied by coronal mass ejections, solar particle events, and other solar phenomena. The occurrence of solar flares varies with the 11-year solar cycle. Solar flares are thought to occur when stored magnetic energy in the Sun's atmosphere accelerates charged particles in the surrounding plasma. This results in the emission of electromagnetic radiation across the electromagnetic spectrum. High-energy electromagnetic radiation from solar flares is absorbed by the daylight side of Earth's upper atmosphere, in particular the ionosphere, and does not reach the surface. This absorption can temporarily increase the ionization of the ionosphere which may interfere with short-wave radio communication. The prediction of solar flares is an active area of research. Flares also occur on other stars, where the term ''stellar ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ionosphere
The ionosphere () is the ionized part of the upper atmosphere of Earth, from about to above sea level, a region that includes the thermosphere and parts of the mesosphere and exosphere. The ionosphere is ionized by solar radiation. It plays an important role in atmospheric electricity and forms the inner edge of the magnetosphere. It has practical importance because, among other functions, it influences radio propagation to distant places on Earth. History of discovery As early as 1839, the German mathematician and physicist Carl Friedrich Gauss postulated that an electrically conducting region of the atmosphere could account for observed variations of Earth's magnetic field. Sixty years later, Guglielmo Marconi received the first trans-Atlantic radio signal on December 12, 1901, in St. John's, Newfoundland (now in Canada) using a kite-supported antenna for reception. The transmitting station in Poldhu, Cornwall, used a spark-gap transmitter to produce a signal with a freq ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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