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The Planck postulate (or Planck's postulate), one of the fundamental principles of quantum mechanics, is the postulate that the energy of oscillators in a black body is quantized, and is given by
where is an integer (1, 2, 3, ...), is the Planck constant, and (the Greek letter nu) is the frequency of the oscillato... | Planck postulate | Wikipedia | 284 | 2898991 | https://en.wikipedia.org/wiki/Planck%20postulate | Physical sciences | Quantum mechanics | Physics |
Plasma () is one of four fundamental states of matter (the other three being solid, liquid, and gas) characterized by the presence of a significant portion of charged particles in any combination of ions or electrons. It is the most abundant form of ordinary matter in the universe, mostly in stars (including the Sun), ... | Plasma (physics) | Wikipedia | 484 | 25916521 | https://en.wikipedia.org/wiki/Plasma%20%28physics%29 | Physical sciences | States of matter | null |
Plasma is typically an electrically quasineutral medium of unbound positive and negative particles (i.e., the overall charge of a plasma is roughly zero). Although these particles are unbound, they are not "free" in the sense of not experiencing forces. Moving charged particles generate electric currents, and any movem... | Plasma (physics) | Wikipedia | 465 | 25916521 | https://en.wikipedia.org/wiki/Plasma%20%28physics%29 | Physical sciences | States of matter | null |
A dusty plasma contains tiny charged particles of dust (typically found in space). The dust particles acquire high charges and interact with each other. A plasma that contains larger particles is called grain plasma. Under laboratory conditions, dusty plasmas are also called complex plasmas.
Properties and parameters
... | Plasma (physics) | Wikipedia | 415 | 25916521 | https://en.wikipedia.org/wiki/Plasma%20%28physics%29 | Physical sciences | States of matter | null |
Since plasmas are very good electrical conductors, electric potentials play an important role. The average potential in the space between charged particles, independent of how it can be measured, is called the "plasma potential", or the "space potential". If an electrode is inserted into a plasma, its potential will ge... | Plasma (physics) | Wikipedia | 486 | 25916521 | https://en.wikipedia.org/wiki/Plasma%20%28physics%29 | Physical sciences | States of matter | null |
To completely describe the state of a plasma, all of the particle locations and velocities that describe the electromagnetic field in the plasma region would need to be written down. However, it is generally not practical or necessary to keep track of all the particles in a plasma. Therefore, plasma physicists commonly... | Plasma (physics) | Wikipedia | 473 | 25916521 | https://en.wikipedia.org/wiki/Plasma%20%28physics%29 | Physical sciences | States of matter | null |
Above the Earth's surface, the ionosphere is a plasma, and the magnetosphere contains plasma. Within our Solar System, interplanetary space is filled with the plasma expelled via the solar wind, extending from the Sun's surface out to the heliopause. Furthermore, all the distant stars, and much of interstellar space or... | Plasma (physics) | Wikipedia | 488 | 25916521 | https://en.wikipedia.org/wiki/Plasma%20%28physics%29 | Physical sciences | States of matter | null |
The potential difference and subsequent electric field pull the bound electrons (negative) toward the anode (positive electrode) while the cathode (negative electrode) pulls the nucleus. As the voltage increases, the current stresses the material (by electric polarization) beyond its dielectric limit (termed strength) ... | Plasma (physics) | Wikipedia | 417 | 25916521 | https://en.wikipedia.org/wiki/Plasma%20%28physics%29 | Physical sciences | States of matter | null |
Low-pressure discharges
Glow discharge plasmas: non-thermal plasmas generated by the application of DC or low frequency RF (<100 kHz) electric field to the gap between two metal electrodes. Probably the most common plasma; this is the type of plasma generated within fluorescent light tubes.
Capacitively coupled plasma ... | Plasma (physics) | Wikipedia | 235 | 25916521 | https://en.wikipedia.org/wiki/Plasma%20%28physics%29 | Physical sciences | States of matter | null |
Atmospheric pressure
Arc discharge: this is a high power thermal discharge of very high temperature (≈10,000 K). It can be generated using various power supplies. It is commonly used in metallurgical processes. For example, it is used to smelt minerals containing Al2O3 to produce aluminium.
Corona discharge: this is a ... | Plasma (physics) | Wikipedia | 441 | 25916521 | https://en.wikipedia.org/wiki/Plasma%20%28physics%29 | Physical sciences | States of matter | null |
A world effort was triggered in the 1960s to study magnetohydrodynamic converters in order to bring MHD power conversion to market with commercial power plants of a new kind, converting the kinetic energy of a high velocity plasma into electricity with no moving parts at a high efficiency. Research was also conducted i... | Plasma (physics) | Wikipedia | 488 | 25916521 | https://en.wikipedia.org/wiki/Plasma%20%28physics%29 | Physical sciences | States of matter | null |
Impossible colors are colors that do not appear in ordinary visual functioning. Different color theories suggest different hypothetical colors that humans are incapable of perceiving for one reason or another, and fictional colors are routinely created in popular culture. While some such colors have no basis in reality... | Impossible color | Wikipedia | 488 | 25921922 | https://en.wikipedia.org/wiki/Impossible%20color | Physical sciences | Basics | Physics |
When defining primaries, the goal is often to leave as many real colors in gamut as possible. Since the region of real colors is not a triangle (see illustration), it is not possible to pick three real colors that span the whole region. The gamut can be increased by selecting more than three real primary colors, but si... | Impossible color | Wikipedia | 280 | 25921922 | https://en.wikipedia.org/wiki/Impossible%20color | Physical sciences | Basics | Physics |
A chimerical color is an imaginary color that can be seen temporarily by looking steadily at a strong color until some of the cone cells become fatigued, temporarily changing their color sensitivities, and then looking at a markedly different color. The direct trichromatic description of vision cannot explain these co... | Impossible color | Wikipedia | 484 | 25921922 | https://en.wikipedia.org/wiki/Impossible%20color | Physical sciences | Basics | Physics |
According to the opponent-process theory, under normal circumstances, there is no hue that could be described as a mixture of opponent hues; that is, as a hue looking "redgreen" or "yellowblue".
In 1983, Hewitt D. Crane and Thomas P. Piantanida performed tests using an eye-tracker device that had a field of a vertical... | Impossible color | Wikipedia | 398 | 25921922 | https://en.wikipedia.org/wiki/Impossible%20color | Physical sciences | Basics | Physics |
In 2001, Vincent A. Billock and Gerald A. Gleason and Brian H. Tsou set up an experiment to test a theory that the 1983 experiment did not control for variations in the perceived luminance of the colors from subject to subject: two colors are equiluminant for an observer when rapidly alternating between the colors prod... | Impossible color | Wikipedia | 364 | 25921922 | https://en.wikipedia.org/wiki/Impossible%20color | Physical sciences | Basics | Physics |
Reptiles arose about 320 million years ago during the Carboniferous period. Reptiles, in the traditional sense of the term, are defined as animals that have scales or scutes, lay land-based hard-shelled eggs, and possess ectothermic metabolisms. So defined, the group is paraphyletic, excluding endothermic animals like ... | Evolution of reptiles | Wikipedia | 490 | 30600763 | https://en.wikipedia.org/wiki/Evolution%20of%20reptiles | Biology and health sciences | Basics_4 | Biology |
It was traditionally assumed that first reptiles were anapsids, having a solid skull with holes only for the nose, eyes, spinal cord, etc.; the discoveries of synapsid-like openings in the skull roof of the skulls of several members of Parareptilia, including lanthanosuchoids, millerettids, bolosaurids, some nycterolet... | Evolution of reptiles | Wikipedia | 500 | 30600763 | https://en.wikipedia.org/wiki/Evolution%20of%20reptiles | Biology and health sciences | Basics_4 | Biology |
Permian reptiles
Near the end of the Carboniferous, while the terrestrial reptiliomorph labyrinthodonts were still present, the synapsids evolved the first fully terrestrial large vertebrates, the pelycosaurs such as Edaphosaurus. In the mid-Permian period, the climate turned drier, resulting in a change of fauna: The ... | Evolution of reptiles | Wikipedia | 420 | 30600763 | https://en.wikipedia.org/wiki/Evolution%20of%20reptiles | Biology and health sciences | Basics_4 | Biology |
The sister group to Archosauromorpha is Lepidosauromorpha, containing squamates and rhynchocephalians, as well as their fossil relatives. Lepidosauromorpha contained at least one major group of the Mesozoic sea reptiles: the mosasaurs, which emerged during the Cretaceous period. The phylogenetic placement of other main... | Evolution of reptiles | Wikipedia | 387 | 30600763 | https://en.wikipedia.org/wiki/Evolution%20of%20reptiles | Biology and health sciences | Basics_4 | Biology |
The close of the Cretaceous period saw the demise of the Mesozoic era reptilian megafauna. Along with massive amount of volcanic activity at the time, the meteor impact that created the Cretaceous–Paleogene boundary is accepted as the main cause for this mass extinction event. Of the large marine reptiles, only sea tur... | Evolution of reptiles | Wikipedia | 332 | 30600763 | https://en.wikipedia.org/wiki/Evolution%20of%20reptiles | Biology and health sciences | Basics_4 | Biology |
Testudines, or turtles, may have evolved from anaspids, but their exact origin is unknown and heavily debated. Fossils date back to around 220 million years ago and share remarkably similar characteristics. These first turtles retain the same body plan as do all modern testudines and are mostly herbivorous, with some f... | Evolution of reptiles | Wikipedia | 284 | 30600763 | https://en.wikipedia.org/wiki/Evolution%20of%20reptiles | Biology and health sciences | Basics_4 | Biology |
The most recent order of reptiles, squamates, are recognized by having a movable quadrate bone (giving them upper-jaw movement), possessing horny scales and hemipenes. They originate from the early Jurassic and are made up of the three suborders Lacertilia (paraphyletic), Serpentes, and Amphisbaenia. Although they are ... | Evolution of reptiles | Wikipedia | 332 | 30600763 | https://en.wikipedia.org/wiki/Evolution%20of%20reptiles | Biology and health sciences | Basics_4 | Biology |
The first organisms that showed similar characteristics of Crocodilians were the Crurotarsi, who appeared during the early Triassic 250 million years ago. This quickly gave rise to the Eusuchia clade 220 million years ago, which would eventually lead to the order of Crocodilians, the first of which arose about 85 milli... | Evolution of reptiles | Wikipedia | 282 | 30600763 | https://en.wikipedia.org/wiki/Evolution%20of%20reptiles | Biology and health sciences | Basics_4 | Biology |
True gobies were a subfamily, the Gobiinae, of the goby family Gobiidae, although the 5th edition of the Fishes of the World does not subdivide the Gobiidae into subfamilies. They are found in all oceans and a few rivers and lakes, but most live in warm waters. Altogether, the Gobiinae unite about 1149 described speci... | Gobiinae | Wikipedia | 382 | 30607828 | https://en.wikipedia.org/wiki/Gobiinae | Biology and health sciences | Acanthomorpha | Animals |
The larger species are fished for food, in some cases on a commercial scale. Many Gobiinae species are popular aquarium fish. Especially popular are the colorful species, some of which are regularly traded. In general, the interesting behavior and bold habits make most true gobies seem attractive pets. However, their t... | Gobiinae | Wikipedia | 144 | 30607828 | https://en.wikipedia.org/wiki/Gobiinae | Biology and health sciences | Acanthomorpha | Animals |
Aboma
Acentrogobius
Afurcagobius
Akko
Amblyeleotris
Amblygobius
Amoya
Anatirostrum
Ancistrogobius
Antilligobius
Aphia
Arcygobius
Arenigobius
Aruma
Asterropteryx
Aulopareia
Austrolethops
Babka
Barbulifer
Barbuligobius
Bathygobius
Benthophiloides
Benthophilus
Bollmannia
Bryaninops
Buenia
Cabill... | Gobiinae | Wikipedia | 511 | 30607828 | https://en.wikipedia.org/wiki/Gobiinae | Biology and health sciences | Acanthomorpha | Animals |
Psilogobius
Psilotris
Pycnomma
Rhinogobiops
Risor
Robinsichthys
Signigobius
Silhouettea
Siphonogobius
Speleogobius
Stonogobiops
Sueviota
Sufflogobius
Thorogobius
Tigrigobius
Tomiyamichthys
Trimma
Trimmatom
Tryssogobius
Valenciennea
Vanderhorstia
Vanneaugobius
Varicus
Vomerogobius
Wheelerigobius... | Gobiinae | Wikipedia | 108 | 30607828 | https://en.wikipedia.org/wiki/Gobiinae | Biology and health sciences | Acanthomorpha | Animals |
Triglidae, commonly known as gurnards or sea robins, are a family of bottom-feeding scorpaeniform ray-finned fish. The gurnards are distributed in temperate and tropical seas worldwide.
Taxonomy
Triglidae was first described as a family in 1815 by the French polymath and naturalist Constantine Samuel Rafinesque. In 18... | Triglidae | Wikipedia | 485 | 2083108 | https://en.wikipedia.org/wiki/Triglidae | Biology and health sciences | Acanthomorpha | Animals |
Prionotinae Kaup, 1873
Bellator Jordan & Evermann, 1896 (8 species)
Prionotus Lacépède, 1801 (23 species)
Pterygotriglinae Fowler, 1938
Bovitrigla Fowler, 1938 (monotypic)
Pterygotrigla Waite, 1899 (31 species)
Triglinae Rafinesque, 1815
Chelidonichthys Kaup, 1873 (10 species)
Eutrigla Fraser-Brunner, 1938 (mon... | Triglidae | Wikipedia | 496 | 2083108 | https://en.wikipedia.org/wiki/Triglidae | Biology and health sciences | Acanthomorpha | Animals |
Sea robins have three "walking rays" on each side of their body. They are derived from the supportive structures in the pectoral fins, called fin-rays. During development, the fin-rays separate from the rest of the pectoral fin, developing into walking rays. These walking rays have specialized muscle divisions and uniq... | Triglidae | Wikipedia | 452 | 2083108 | https://en.wikipedia.org/wiki/Triglidae | Biology and health sciences | Acanthomorpha | Animals |
Angling
Sea robins can be caught by dropping a variety of baits and lures to the seafloor, where they actively feed. Mackerel is believed to be the most efficient bait for catching sea robins, but crabs, bunker and other fish meat can also be used successfully depending on location. Sea robins can also be caught by lu... | Triglidae | Wikipedia | 119 | 2083108 | https://en.wikipedia.org/wiki/Triglidae | Biology and health sciences | Acanthomorpha | Animals |
Dwarf rabbit refers either (formally) to a rabbit with the dwarfing gene, or (informally) to any small breed of domestic rabbit or specimen thereof, or (colloquially) to any small rabbit. Dwarfism is a genetic condition that may occur in humans and in many animals, including rabbits. True dwarfism is often associated w... | Dwarf rabbit | Wikipedia | 340 | 2083650 | https://en.wikipedia.org/wiki/Dwarf%20rabbit | Biology and health sciences | Rabbits | Animals |
In particle physics, neutral particle oscillation is the transmutation of a particle with zero electric charge into another neutral particle due to a change of a non-zero internal quantum number, via an interaction that does not conserve that quantum number. Neutral particle oscillations were first investigated in 1954... | Neutral particle oscillation | Wikipedia | 506 | 2083830 | https://en.wikipedia.org/wiki/Neutral%20particle%20oscillation | Physical sciences | Particle physics: General | Physics |
In 1968, Bruno Pontecorvo showed that if neutrinos are not considered massless, then (produced in the sun) can transform into some other neutrino species ( or ), to which Homestake detector was insensitive. This explained the deficit in the results of the Homestake experiment. The final confirmation of this solution t... | Neutral particle oscillation | Wikipedia | 467 | 2083830 | https://en.wikipedia.org/wiki/Neutral%20particle%20oscillation | Physical sciences | Particle physics: General | Physics |
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|style="background:white;border-left:1px solid white;border-right:1px solid... | Neutral particle oscillation | Wikipedia | 493 | 2083830 | https://en.wikipedia.org/wiki/Neutral%20particle%20oscillation | Physical sciences | Particle physics: General | Physics |
The general case: considering mixing and decay
If the particle(s) under consideration undergoes decay, then the Hamiltonian describing the system is no longer Hermitian. Since any matrix can be written as a sum of its Hermitian and anti-Hermitian parts, can be written as,
The eigenvalues of are
The suffixes st... | Neutral particle oscillation | Wikipedia | 464 | 2083830 | https://en.wikipedia.org/wiki/Neutral%20particle%20oscillation | Physical sciences | Particle physics: General | Physics |
From the above two quantities, it can be seen that even when there is no CP violation through mixing alone (i.e. ) and neither is there any CP violation through decay alone (i.e. ) and thus the probabilities will still be unequal, provided that
The last terms in the above expressions for probability are thus associat... | Neutral particle oscillation | Wikipedia | 414 | 2083830 | https://en.wikipedia.org/wiki/Neutral%20particle%20oscillation | Physical sciences | Particle physics: General | Physics |
Length scale of the system
Equation () indicates that an appropriate length scale of the system is the oscillation wavelength . We can draw the following inferences:
If , then and oscillation will not be observed. For example, production (say, by radioactive decay) and detection of neutrinos in a laboratory.
If , w... | Neutral particle oscillation | Wikipedia | 500 | 2083830 | https://en.wikipedia.org/wiki/Neutral%20particle%20oscillation | Physical sciences | Particle physics: General | Physics |
Since , condition () is satisfied and there is a mixing between the strangeness eigenstates and giving rise to a long-lived and a short-lived state.
CP violation through decay only
The and have two modes of two pion decay: or . Both of these final states are CP eigenstates of themselves. We can define the branch... | Neutral particle oscillation | Wikipedia | 422 | 2083830 | https://en.wikipedia.org/wiki/Neutral%20particle%20oscillation | Physical sciences | Particle physics: General | Physics |
Dodecanol , or lauryl alcohol, is an organic compound produced industrially from palm kernel oil or coconut oil. It is a fatty alcohol. Sulfate esters of lauryl alcohol, especially sodium lauryl sulfate, are very widely used as surfactants. Sodium lauryl sulfate and the related dodecanol derivatives ammonium lauryl sul... | Dodecanol | Wikipedia | 339 | 2084166 | https://en.wikipedia.org/wiki/Dodecanol | Physical sciences | Alcohols | Chemistry |
{| class="wikitable sortable"
|+Mutual solubility of water and 1-dodecanol (98%, melting point 24 °C), Weight %
|-
!Temperature (°C) !! Solubility of dodecanol in water !! Solubility of water in dodecanol
|-
| 29.5 || 0.04 || 2.87
|-
| 40.0 || 0.05 || 2.85
|-
| 50.2 || 0.09 || 2.69
|-
| 60.5 || 0.15 || 2.96
|-
| 70.5 |... | Dodecanol | Wikipedia | 200 | 2084166 | https://en.wikipedia.org/wiki/Dodecanol | Physical sciences | Alcohols | Chemistry |
A paper bag is a bag made of paper, usually kraft paper. Paper bags can be made either with virgin or recycled fibres to meet customers' demands. Paper bags are commonly used as shopping carrier bags and for packaging of some consumer goods. They carry a wide range of products from groceries, glass bottles, clothing, b... | Paper bag | Wikipedia | 477 | 2086634 | https://en.wikipedia.org/wiki/Paper%20bag | Technology | Containers | null |
In 2018, the “European Paper Bag Day” was established by the platform The Paper Bag, an association of the leading European kraft paper manufacturers and producers of paper bags. The annual action day takes place on 18 October and aims to raise awareness among consumers about paper carrier bags as a sustainable packagi... | Paper bag | Wikipedia | 483 | 2086634 | https://en.wikipedia.org/wiki/Paper%20bag | Technology | Containers | null |
Paper sacks are usually made of Kraft paper, which has the advantage of being soft and strong at the same time. The stretch or elongation increases the energy required to break the material. They can carry and protect products up to 50 kg, and adapt easily to the nature of their contents and to handling constraints. De... | Paper bag | Wikipedia | 425 | 2086634 | https://en.wikipedia.org/wiki/Paper%20bag | Technology | Containers | null |
Construction
Standard brown paper bags are made from kraft paper. Tote-style paper carrier bags, such as those often used by department stores or as gift bags, can be made from any kind of paper, and come in any color. There are two different styles of handles for paper carrier bags: flat handles and cord handles. Pape... | Paper bag | Wikipedia | 300 | 2086634 | https://en.wikipedia.org/wiki/Paper%20bag | Technology | Containers | null |
Paper sack manufacturing
The production of paper sacks is an entirely automatic process. It is divided into two main parts: tube forming and bottom folding. The sack kraft paper used for the production is printed on its way to the tube forming. In the first step of tube forming, paper and film (if applied) can be vent-... | Paper bag | Wikipedia | 485 | 2086634 | https://en.wikipedia.org/wiki/Paper%20bag | Technology | Containers | null |
Paper sacks are available in different sizes and can carry loads up to 50 kg. The capacity is variable, and paper sacks also come in a variety of calipers, basis weights, and treatments.
Single layer
Paper shopping bags, brown paper bags, grocery bags, paper bread bags and other light duty bags have a single layer o... | Paper bag | Wikipedia | 422 | 2086634 | https://en.wikipedia.org/wiki/Paper%20bag | Technology | Containers | null |
Sustainability
The raw material used in papermaking – cellulose fibre extracted from wood – is a renewable and natural resource. However, environmental concerns have been raised about types of wood harvesting, such as clearcutting. Due to their biodegradable characteristics, paper bags degrade in a short period of time... | Paper bag | Wikipedia | 497 | 2086634 | https://en.wikipedia.org/wiki/Paper%20bag | Technology | Containers | null |
Branding and marketing
Paper shopping bags can be used as a vehicle to project the brand image of retailers. Paper is very tactile due to its texture and shape. Its print quality and color reproduction allow for creativity in advertising and development of the brand image. Furthermore, they achieve maximum visibility a... | Paper bag | Wikipedia | 417 | 2086634 | https://en.wikipedia.org/wiki/Paper%20bag | Technology | Containers | null |
The second form of "brown bagging" involves drinking alcohol in places where it is not legal to do so (such as a public park, or a venue without a liquor license) while using a brown paper bag (or a black plastic bag, or other suitably opaque covering) to conceal the bottle or can. While it's usually an open secret tha... | Paper bag | Wikipedia | 500 | 2086634 | https://en.wikipedia.org/wiki/Paper%20bag | Technology | Containers | null |
EUROSAC is the European Federation of multiwall paper sack manufacturers. It was created in 1952 and is headquartered in Paris. It represents over 75% of European paper sack manufacturers. Its members operate in 20 different countries. Sack manufacturers from all continents and bag manufacturers also contribute to the ... | Paper bag | Wikipedia | 210 | 2086634 | https://en.wikipedia.org/wiki/Paper%20bag | Technology | Containers | null |
Ostraciidae or Ostraciontidae is a family of squared, bony fish belonging to the order Tetraodontiformes, closely related to the pufferfishes and filefishes. Fish in the family are known variously as boxfishes, cofferfishes, cowfishes and trunkfishes. It contains about 23 extant species in 6 extant genera.
Taxonomy
Os... | Ostraciidae | Wikipedia | 510 | 2086847 | https://en.wikipedia.org/wiki/Ostraciidae | Biology and health sciences | Acanthomorpha | Animals |
Toxic defences
The various members of this family are able to secrete cationic surfactants through their skin which can act as a chemical defense mechanism. An example of this is pahutoxin, a water-soluble, crystalline chemical toxin that is contained in mucus secreted from the skin of Ostracion lentiginosus and other ... | Ostraciidae | Wikipedia | 345 | 2086847 | https://en.wikipedia.org/wiki/Ostraciidae | Biology and health sciences | Acanthomorpha | Animals |
Ammonium nitrite is a chemical compound with the chemical formula . It is the ammonium salt of nitrous acid. It is composed of ammonium cations and nitrite anions . It is not used in pure isolated form since it is highly unstable and decomposes into water and nitrogen, even at room temperature.
Preparation
Ammonium n... | Ammonium nitrite | Wikipedia | 333 | 2088152 | https://en.wikipedia.org/wiki/Ammonium%20nitrite | Physical sciences | Nitric oxyanions | Chemistry |
Submillimetre astronomy or submillimeter astronomy (see spelling differences) is the branch of observational astronomy that is conducted at submillimetre wavelengths (i.e., terahertz radiation) of the electromagnetic spectrum. Astronomers place the submillimetre waveband between the far-infrared and microwave wavebands... | Submillimetre astronomy | Wikipedia | 451 | 2088221 | https://en.wikipedia.org/wiki/Submillimetre%20astronomy | Physical sciences | Radio astronomy | Astronomy |
The Llano de Chajnantor Observatory site hosts the Atacama Pathfinder Experiment (APEX), the largest submillimetre telescope operating in the southern hemisphere,
and the world's largest ground based astronomy project, the Atacama Large Millimeter Array (ALMA), an interferometer for submillimetre wavelength observation... | Submillimetre astronomy | Wikipedia | 485 | 2088221 | https://en.wikipedia.org/wiki/Submillimetre%20astronomy | Physical sciences | Radio astronomy | Astronomy |
The European Space Agency launched a space-based mission known as the Herschel Space Observatory (formerly called Far Infrared and Sub-millimetre Telescope or FIRST) in 2009. Herschel deployed the largest mirror ever launched into space (until December 2021, with the launch of the near-infrared James Webb Space Telesco... | Submillimetre astronomy | Wikipedia | 158 | 2088221 | https://en.wikipedia.org/wiki/Submillimetre%20astronomy | Physical sciences | Radio astronomy | Astronomy |
In probability theory and statistics, the Poisson distribution (; ) is a discrete probability distribution that expresses the probability of a given number of events occurring in a fixed interval of time if these events occur with a known constant mean rate and independently of the time since the last event. It can als... | Poisson distribution | Wikipedia | 463 | 23009144 | https://en.wikipedia.org/wiki/Poisson%20distribution | Mathematics | Statistics and probability | null |
In 1860, Simon Newcomb fitted the Poisson distribution to the number of stars found in a unit of space.
A further practical application was made by Ladislaus Bortkiewicz in 1898. Bortkiewicz showed that the frequency with which soldiers in the Prussian army were accidentally killed by horse kicks could be well modeled ... | Poisson distribution | Wikipedia | 510 | 23009144 | https://en.wikipedia.org/wiki/Poisson%20distribution | Mathematics | Statistics and probability | null |
On a particular river, overflow floods occur once every 100 years on average. Calculate the probability of = 0, 1, 2, 3, 4, 5, or 6 overflow floods in a 100-year interval, assuming the Poisson model is appropriate.
Because the average event rate is one overflow flood per 100 years, = 1
{| class="wikitable"... | Poisson distribution | Wikipedia | 494 | 23009144 | https://en.wikipedia.org/wiki/Poisson%20distribution | Mathematics | Statistics and probability | null |
In general, if an event occurs on average once per interval ( = 1), and the events follow a Poisson distribution, then In addition, as shown in the table for overflow floods.
Examples that violate the Poisson assumptions
The number of students who arrive at the student union per minute will likely not follow a Poi... | Poisson distribution | Wikipedia | 500 | 23009144 | https://en.wikipedia.org/wiki/Poisson%20distribution | Mathematics | Statistics and probability | null |
Sums of Poisson-distributed random variables
If for are independent, then A converse is Raikov's theorem, which says that if the sum of two independent random variables is Poisson-distributed, then so are each of those two independent random variables.
Maximum entropy
It is a maximum-entropy distribution among th... | Poisson distribution | Wikipedia | 351 | 23009144 | https://en.wikipedia.org/wiki/Poisson%20distribution | Mathematics | Statistics and probability | null |
As a Binomial distribution with infinitesimal time-steps
The Poisson distribution can be derived as a limiting case to the binomial distribution as the number of trials goes to infinity and the expected number of successes remains fixed — see law of rare events below. Therefore, it can be used as an approximation of t... | Poisson distribution | Wikipedia | 264 | 23009144 | https://en.wikipedia.org/wiki/Poisson%20distribution | Mathematics | Statistics and probability | null |
General
If and are independent, then the difference follows a Skellam distribution.
If and are independent, then the distribution of conditional on is a binomial distribution. Specifically, if then More generally, if X1, X2, ..., X are independent Poisson random variables with parameters 1, 2, ..., then
... | Poisson distribution | Wikipedia | 489 | 23009144 | https://en.wikipedia.org/wiki/Poisson%20distribution | Mathematics | Statistics and probability | null |
The marginal distributions are Poisson(θ1) and Poisson(θ2) and the correlation coefficient is limited to the range
A simple way to generate a bivariate Poisson distribution is to take three independent Poisson distributions with means and then set The probability function of the bivariate Poisson distribution is
... | Poisson distribution | Wikipedia | 424 | 23009144 | https://en.wikipedia.org/wiki/Poisson%20distribution | Mathematics | Statistics and probability | null |
Since each observation has expectation so does the sample mean. Therefore, the maximum likelihood estimate is an unbiased estimator of . It is also an efficient estimator since its variance achieves the Cramér–Rao lower bound (CRLB). Hence it is minimum-variance unbiased. Also it can be proven that the sum (and hence ... | Poisson distribution | Wikipedia | 495 | 23009144 | https://en.wikipedia.org/wiki/Poisson%20distribution | Mathematics | Statistics and probability | null |
where is the quantile function (corresponding to a lower tail area p) of the chi-squared distribution with degrees of freedom and is the quantile function of a gamma distribution with shape parameter n and scale parameter 1. This interval is 'exact' in the sense that its coverage probability is never less than the n... | Poisson distribution | Wikipedia | 465 | 23009144 | https://en.wikipedia.org/wiki/Poisson%20distribution | Mathematics | Statistics and probability | null |
Some applications of the Poisson distribution to count data (number of events):
telecommunication: telephone calls arriving in a system,
astronomy: photons arriving at a telescope,
chemistry: the molar mass distribution of a living polymerization,
biology: the number of mutations on a strand of DNA per unit length,... | Poisson distribution | Wikipedia | 426 | 23009144 | https://en.wikipedia.org/wiki/Poisson%20distribution | Mathematics | Statistics and probability | null |
The rate of an event is related to the probability of an event occurring in some small subinterval (of time, space or otherwise). In the case of the Poisson distribution, one assumes that there exists a small enough subinterval for which the probability of an event occurring twice is "negligible". With this assumption ... | Poisson distribution | Wikipedia | 426 | 23009144 | https://en.wikipedia.org/wiki/Poisson%20distribution | Mathematics | Statistics and probability | null |
The name "law of rare events" may be misleading because the total count of success events in a Poisson process need not be rare if the parameter is not small. For example, the number of telephone calls to a busy switchboard in one hour follows a Poisson distribution with the events appearing frequent to the operator, ... | Poisson distribution | Wikipedia | 493 | 23009144 | https://en.wikipedia.org/wiki/Poisson%20distribution | Mathematics | Statistics and probability | null |
During each cellular replication event, the number of mutations is roughly Poisson distributed. For example, the HIV virus has 10,000 base pairs, and has a mutation rate of about 1 per 30,000 base pairs, meaning the number of mutations per replication event is distributed as . (p. 64 )
Other applications in science
... | Poisson distribution | Wikipedia | 503 | 23009144 | https://en.wikipedia.org/wiki/Poisson%20distribution | Mathematics | Statistics and probability | null |
which is mathematically equivalent but numerically stable. The natural logarithm of the Gamma function can be obtained using the lgamma function in the C standard library (C99 version) or R, the gammaln function in MATLAB or SciPy, or the log_gamma function in Fortran 2008 and later.
Some computing languages provide b... | Poisson distribution | Wikipedia | 491 | 23009144 | https://en.wikipedia.org/wiki/Poisson%20distribution | Mathematics | Statistics and probability | null |
The choice of STEP depends on the threshold of overflow. For double precision floating point format the threshold is near e700, so 500 should be a safe STEP.
Other solutions for large values of include rejection sampling and using Gaussian approximation.
Inverse transform sampling is simple and efficient for small v... | Poisson distribution | Wikipedia | 156 | 23009144 | https://en.wikipedia.org/wiki/Poisson%20distribution | Mathematics | Statistics and probability | null |
Railway engineering is a multi-faceted engineering discipline dealing with the design, construction and operation of all types of rail transport systems. It encompasses a wide range of engineering disciplines, including civil engineering, computer engineering, electrical engineering, mechanical engineering, industrial ... | Railway engineering | Wikipedia | 310 | 5235231 | https://en.wikipedia.org/wiki/Railway%20engineering | Technology | Disciplines | null |
The Dvorak technique (developed between 1969 and 1984 by Vernon Dvorak) is a widely used system to estimate tropical cyclone intensity (which includes tropical depression, tropical storm, and hurricane/typhoon/intense tropical cyclone intensities) based solely on visible and infrared satellite images. Within the Dvor... | Dvorak technique | Wikipedia | 415 | 5240327 | https://en.wikipedia.org/wiki/Dvorak%20technique | Physical sciences | Storms | Earth science |
The initial development of this technique occurred in 1969 by Vernon Dvorak, using satellite pictures of tropical cyclones within the northwest Pacific Ocean. The system as it was initially conceived involved pattern matching of cloud features with a development and decay model. As the technique matured through the 1... | Dvorak technique | Wikipedia | 422 | 5240327 | https://en.wikipedia.org/wiki/Dvorak%20technique | Physical sciences | Storms | Earth science |
In a developing cyclone, the technique takes advantage of the fact that cyclones of similar intensity tend to have certain characteristic features, and as they strengthen, they tend to change in appearance in a predictable manner. The structure and organization of the tropical cyclone are tracked over 24 hours to dete... | Dvorak technique | Wikipedia | 289 | 5240327 | https://en.wikipedia.org/wiki/Dvorak%20technique | Physical sciences | Storms | Earth science |
Pattern types
Within the Dvorak satellite strength estimate for tropical cyclones, there are several visual patterns that a cyclone may take on which define the upper and lower bounds on its intensity. The primary patterns used are curved band pattern (T1.0-T4.5), shear pattern (T1.5-T3.5), central dense overcast (CDO)... | Dvorak technique | Wikipedia | 506 | 5240327 | https://en.wikipedia.org/wiki/Dvorak%20technique | Physical sciences | Storms | Earth science |
The National Hurricane Center will often quote Dvorak T-numbers in their tropical cyclone products. The following example is from discussion number 3 of Tropical Depression 24 (eventually Hurricane Wilma) of the 2005 Atlantic hurricane season:
BOTH TAFB AND SAB CAME IN WITH A DVORAK SATELLITE INTENSITY ESTIMATE OF T2.... | Dvorak technique | Wikipedia | 389 | 5240327 | https://en.wikipedia.org/wiki/Dvorak%20technique | Physical sciences | Storms | Earth science |
Benefits and disadvantages
The most significant benefit of the use of the technique is that it has provided a more complete history of tropical cyclone intensity in areas where aircraft reconnaissance is neither possible nor routinely available. Intensity estimates of maximum sustained wind are currently within of w... | Dvorak technique | Wikipedia | 301 | 5240327 | https://en.wikipedia.org/wiki/Dvorak%20technique | Physical sciences | Storms | Earth science |
Gemini is one of the constellations of the zodiac and is located in the northern celestial hemisphere. It was one of the 48 constellations described by the 2nd century AD astronomer Ptolemy, and it remains one of the 88 modern constellations today. Its name is Latin for twins, and it is associated with the twins Casto... | Gemini (constellation) | Wikipedia | 493 | 21533375 | https://en.wikipedia.org/wiki/Gemini%20%28constellation%29 | Physical sciences | Zodiac | Astronomy |
α Gem (Castor) is a sextuple star system 52 light-years from Earth, which appears as a magnitude 1.6 blue-white star to the unaided eye. Two spectroscopic binaries are visible at magnitudes 1.9 and 3.0 with a period of 470 years. A wide-set red dwarf star is also a part of the system; this star is an Algol-type eclipsi... | Gemini (constellation) | Wikipedia | 498 | 21533375 | https://en.wikipedia.org/wiki/Gemini%20%28constellation%29 | Physical sciences | Zodiac | Astronomy |
κ Gem is a binary star 143 light-years from Earth. The primary is a yellow giant of magnitude 3.6; the secondary is of magnitude 8. The two are only divisible in larger amateur instruments because of the discrepancy in brightness.
ν Gem is a double star divisible in binoculars and small amateur telescopes. The primary... | Gemini (constellation) | Wikipedia | 482 | 21533375 | https://en.wikipedia.org/wiki/Gemini%20%28constellation%29 | Physical sciences | Zodiac | Astronomy |
Meteor showers
The Geminids is a bright meteor shower that peaks on December 13–14. It has a maximum rate of approximately 100 meteors per hour, making it one of the richest meteor showers. The Epsilon Geminids peak between October 18 and October 29 and have only been recently confirmed. They overlap with the Orionids,... | Gemini (constellation) | Wikipedia | 448 | 21533375 | https://en.wikipedia.org/wiki/Gemini%20%28constellation%29 | Physical sciences | Zodiac | Astronomy |
H. A. Rey has suggested an alternative to the traditional visualization that connected the stars of Gemini to show twins holding hands. Pollux's torso is represented by the star υ Gem, Pollux's right hand by ι Gem, Pollux's left hand by κ Gem; all three of these stars are of the fourth magnitude. Pollux's pelvis is rep... | Gemini (constellation) | Wikipedia | 498 | 21533375 | https://en.wikipedia.org/wiki/Gemini%20%28constellation%29 | Physical sciences | Zodiac | Astronomy |
Sedimentation is the deposition of sediments. It takes place when particles in suspension settle out of the fluid in which they are entrained and come to rest against a barrier. This is due to their motion through the fluid in response to the forces acting on them: these forces can be due to gravity, centrifugal accele... | Sedimentation | Wikipedia | 483 | 938894 | https://en.wikipedia.org/wiki/Sedimentation | Physical sciences | Other separations | Chemistry |
In geology, the term sedimentation is broadly applied to the entire range of processes that result in the formation of sedimentary rock, from initial formation of sediments by erosion of particles from rock outcrops, through sediment transport and settling, to the lithification of the sediments. However, the term is mo... | Sedimentation | Wikipedia | 444 | 938894 | https://en.wikipedia.org/wiki/Sedimentation | Physical sciences | Other separations | Chemistry |
Modular programming is a software design technique that emphasizes separating the functionality of a program into independent, interchangeable modules, such that each contains everything necessary to execute only one aspect or "concern" of the desired functionality.
A module interface expresses the elements that are p... | Modular programming | Wikipedia | 339 | 939133 | https://en.wikipedia.org/wiki/Modular%20programming | Technology | Software development: General | null |
Modules were not included in the original specification for ALGOL 68 (1968), but were included as extensions in early implementations, ALGOL 68-R (1970) and ALGOL 68C (1970), and later formalized. One of the first languages designed from the start for modular programming was the short-lived Modula (1975), by Niklaus Wi... | Modular programming | Wikipedia | 498 | 939133 | https://en.wikipedia.org/wiki/Modular%20programming | Technology | Software development: General | null |
Modular programming is now widespread, and found in virtually all major languages developed since the 1990s. The relative importance of modules varies between languages, and in class-based object-oriented languages there is still overlap and confusion with classes as a unit of organization and encapsulation, but these ... | Modular programming | Wikipedia | 453 | 939133 | https://en.wikipedia.org/wiki/Modular%20programming | Technology | Software development: General | null |
Conspicuous examples of languages that lack support for modules are C and have been C++ and Pascal in their original form, C and C++ do, however, allow separate compilation and declarative interfaces to be specified using header files. Modules were added to Objective-C in iOS 7 (2013); to C++ with C++20, and Pascal was... | Modular programming | Wikipedia | 455 | 939133 | https://en.wikipedia.org/wiki/Modular%20programming | Technology | Software development: General | null |
This makes modular designed systems, if built correctly, far more reusable than a traditional monolithic design, since all (or many) of these modules may then be reused (without change) in other projects. This also facilitates the "breaking down" of projects into several smaller projects. Theoretically, a modularized s... | Modular programming | Wikipedia | 106 | 939133 | https://en.wikipedia.org/wiki/Modular%20programming | Technology | Software development: General | null |
Messier 7 or M7, also designated NGC 6475 and sometimes known as the Ptolemy Cluster, is an open cluster of stars in the constellation of Scorpius. The cluster is easily detectable with the naked eye, close to the "stinger" of Scorpius. With a declination of −34.8°, it is the southernmost Messier object.
M7 has been k... | Messier 7 | Wikipedia | 435 | 939182 | https://en.wikipedia.org/wiki/Messier%207 | Physical sciences | Notable star clusters | Astronomy |
The Carina Nebula or Eta Carinae Nebula (catalogued as NGC 3372; also known as the Great Carina Nebula) is a large, complex area of bright and dark nebulosity in the constellation Carina, located in the Carina–Sagittarius Arm of the Milky Way galaxy. The nebula is approximately from Earth.
The nebula has within its b... | Carina Nebula | Wikipedia | 410 | 939579 | https://en.wikipedia.org/wiki/Carina%20Nebula | Physical sciences | Notable nebulae | null |
This object is currently the most massive star that can be studied in great detail, because of its location and size. Several other known stars may be more luminous and more massive, but data on them is far less robust. (Caveat: Since examples such as the Pistol Star have been demoted by improved data, one should be sk... | Carina Nebula | Wikipedia | 418 | 939579 | https://en.wikipedia.org/wiki/Carina%20Nebula | Physical sciences | Notable nebulae | null |
The distance to the Homunculus can be derived from its observed angular dimensions and calculated linear size, assuming it is axially symmetric. The most accurate distance obtained using this method is . The largest radius of the bipolar lobes in this model is about 22,000 AU, and the axis is oriented 41° from the line... | Carina Nebula | Wikipedia | 355 | 939579 | https://en.wikipedia.org/wiki/Carina%20Nebula | Physical sciences | Notable nebulae | null |
A small Bok globule in the Keyhole Nebula (at RA 10h44m30s, Dec −59°40') has been photographed by the Hubble Space Telescope and is nicknamed the "Carina Defiant Finger" due to its shape. In Hubble images, light can be seen radiating off the edges of the globule; this is especially visible in the southern tip, where th... | Carina Nebula | Wikipedia | 496 | 939579 | https://en.wikipedia.org/wiki/Carina%20Nebula | Physical sciences | Notable nebulae | null |
WR 25 is a binary system in the central portion of the Carina Nebula, a member of the cluster. The primary is a Wolf–Rayet star, possibly the most luminous star in the galaxy. The secondary is hard to detect but thought to be a luminous OB star.
HD 93129
HD 93129 is a triple star system of O-class stars in Carina. A... | Carina Nebula | Wikipedia | 494 | 939579 | https://en.wikipedia.org/wiki/Carina%20Nebula | Physical sciences | Notable nebulae | null |
The less massive member is an O8 main sequence star of approximately . It moves in its orbit at a speed of over and is considered to be a relativistic binary, which causes the apses of the orbit to change in a predictable way.
Catalogued open clusters in Carina Nebula
, there are eight known open clusters in the Cari... | Carina Nebula | Wikipedia | 144 | 939579 | https://en.wikipedia.org/wiki/Carina%20Nebula | Physical sciences | Notable nebulae | null |
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