title: Introduction to quantum mechanics

text: By the dawn of the 20th century, the evidence required a model of the atom with a diffuse cloud of negatively charged [[electron]]s surrounding a small, dense, positively charged [[Atomic nucleus|nucleus]]. These properties suggested a model in which electrons circle the nucleus like planets orbiting a star. However, it was also known that the atom in this model would be unstable: according to classical theory, orbiting electrons are undergoing centripetal acceleration, and should therefore give off electromagnetic radiation, the loss of energy also causing them to spiral toward the nucleus, colliding with it in a fraction of a second.


title: Introduction to quantum mechanics

text: A second, related puzzle was the [[emission spectrum]] of atoms. When a gas is heated, it gives off light only at discrete frequencies. For example, the visible light given off by [[hydrogen]] consists of four different colors, as shown in the picture below. The intensity of the light at different frequencies is also different. By contrast, white light consists of a continuous emission across the whole range of visible frequencies. By the end of the nineteenth century, a simple rule known as [[Balmer series|Balmer's formula]] showed how the frequencies of the different lines related to each other, though without explaining why this was, or making any prediction about the intensities. The formula also predicted some additional spectral lines in ultraviolet and infrared light that had not been observed at the time. These lines were later observed experimentally, raising confidence in the value of the formula.


title: Introduction to quantum mechanics

text: In 1885 the Swiss mathematician [[Johann Balmer]] discovered that each wavelength (lambda) in the visible spectrum of hydrogen is related to some integer by the equation


title: Introduction to quantum mechanics

text: In 1888 [[Johannes Rydberg]] generalized and greatly increased the explanatory utility of Balmer's formula. He predicted that is related to two integers and according to what is now known as the [[Rydberg formula]]:


title: Introduction to quantum mechanics

text: Rydberg's formula accounts for the four visible wavelengths of hydrogen by setting and . It also predicts additional wavelengths in the emission spectrum: for and for , the emission spectrum should contain certain ultraviolet wavelengths, and for and , it should also contain certain infrared wavelengths. Experimental observation of these wavelengths came two decades later: in 1908 [[Louis Paschen]] found some of the predicted infrared wavelengths, and in 1914 [[Theodore Lyman IV|Theodore Lyman]] found some of the predicted ultraviolet wavelengths.


title: Introduction to quantum mechanics

text: Both Balmer and Rydberg's formulas involve integers: in modern terms, they imply that some property of the atom is quantized. Understanding exactly what this property was, and why it was quantized, was a major part of the development of quantum mechanics, as shown in the rest of this article.


title: Introduction to quantum mechanics

text: In 1913 [[Niels Bohr]] proposed [[Bohr model|a new model of the atom]] that included quantized electron orbits: electrons still orbit the nucleus much as planets orbit around the sun, but they are permitted to inhabit only certain orbits, not to orbit at any arbitrary distance. When an atom emitted (or absorbed) energy, the electron did not move in a continuous trajectory from one orbit around the nucleus to another, as might be expected classically. Instead, the electron would jump instantaneously from one orbit to another, giving off the emitted light in the form of a photon. The possible energies of photons given off by each element were determined by the differences in energy between the orbits, and so the emission spectrum for each element would contain a number of lines.


title: Introduction to quantum mechanics

text: Starting from only one simple assumption about the rule that the orbits must obey, the Bohr model was able to relate the observed spectral lines in the emission spectrum of hydrogen to previously known constants. In Bohr's model, the electron was not allowed to emit energy continuously and crash into the nucleus: once it was in the closest permitted orbit, it was stable forever. Bohr's model did not explain why the orbits should be quantized in that way, nor was it able to make accurate predictions for atoms with more than one electron, or to explain why some spectral lines are brighter than others.


title: Introduction to quantum mechanics

text: Some fundamental assumptions of the Bohr model were soon proven wrong—but the key result that the discrete lines in emission spectra are due to some property of the electrons in atoms being quantized is correct. The way that the electrons actually behave is strikingly different from Bohr's atom, and from what we see in the world of our everyday experience; this modern quantum mechanical model of the atom is discussed [[#Application to the hydrogen atom|below]].


title: Introduction to quantum mechanics

text: where is an integer and and are the [[Planck constant]] and Planck reduced constant respectively. Starting from this assumption, [[Coulomb's law]] and the equations of [[uniform circular motion|circular motion]] show that an electron with units of angular momentum orbits a proton at a distance given by


title: Introduction to quantum mechanics

text: where is the [[Coulomb constant]], is the mass of an electron, and is the [[elementary charge|charge on an electron]].


title: Introduction to quantum mechanics

text: Thus Bohr's assumption that angular momentum is quantized means that an electron can inhabit only certain orbits around the nucleus and that it can have only certain energies. A consequence of these constraints is that the electron does not crash into the nucleus: it cannot continuously emit energy, and it cannot come closer to the nucleus than "a" (the Bohr radius).


title: Introduction to quantum mechanics

text: An electron loses energy by jumping instantaneously from its original orbit to a lower orbit; the extra energy is emitted in the form of a photon. Conversely, an electron that absorbs a photon gains energy, hence it jumps to an orbit that is farther from the nucleus.


title: Introduction to quantum mechanics

text: Each photon from glowing atomic hydrogen is due to an electron moving from a higher orbit, with radius , to a lower orbit, . The energy of this photon is the difference in the energies and of the electron:


title: Introduction to quantum mechanics

text: Since Planck's equation shows that the photon's energy is related to its wavelength by , the wavelengths of light that can be emitted are given by


title: Introduction to quantum mechanics

text: This equation has the same form as the [[Rydberg formula]], and predicts that the constant should be given by


title: Introduction to quantum mechanics

text: Therefore, the Bohr model of the atom can predict the emission spectrum of hydrogen in terms of fundamental constants. However, it was not able to make accurate predictions for multi-electron atoms, or to explain why some spectral lines are brighter than others.


title: Introduction to quantum mechanics

text: Just as light has both wave-like and particle-like properties, [[de Broglie hypothesis|matter also has wave-like properties]].


title: Introduction to quantum mechanics

text: Matter behaving as a wave was first demonstrated experimentally for electrons: a beam of electrons can exhibit [[diffraction]], just like a beam of light or a water wave. Similar wave-like phenomena were later shown for atoms and even molecules.


title: Introduction to quantum mechanics

text: The wavelength, "λ", associated with any object is related to its momentum, "p", through the [[Planck constant]], "h":


title: Introduction to quantum mechanics

text: The relationship, called the de Broglie hypothesis, holds for all types of matter: all matter exhibits properties of both particles and waves.


title: Introduction to quantum mechanics

text: The concept of wave–particle duality says that neither the classical concept of "particle" nor of "wave" can fully describe the behavior of quantum-scale objects, either photons or matter. Wave–particle duality is an example of the [[complementarity (physics)|principle of complementarity]] in quantum physics. An elegant example of wave-particle duality, the double-slit experiment, is discussed in the section below.


title: Introduction to quantum mechanics

text: [[Image:Single slit and double slit2.jpg|left|upright=1.5|thumb|The diffraction pattern produced when light is shone through one slit (top) and the interference pattern produced by two slits (bottom). The much more complex pattern from two slits, with its small-scale interference fringes, demonstrates the wave-like propagation of light.]]


title: Introduction to quantum mechanics

text: In the double-slit experiment, as originally performed by [[Thomas Young (scientist)|Thomas Young]] in 1803, and then [[Augustin Fresnel]] a decade later, a beam of light is directed through two narrow, closely spaced slits, producing an [[interference (wave propagation)|interference pattern]] of light and dark bands on a screen. If one of the slits is covered up, one might naïvely expect that the intensity of the fringes due to interference would be halved everywhere. In fact, a much simpler pattern is seen, a [[diffraction|diffraction pattern]] diametrically opposite the open slit. The same behavior can be demonstrated in water waves, and so the double-slit experiment was seen as a demonstration of the wave nature of light.


title: Introduction to quantum mechanics

text: Variations of the double-slit experiment have been performed using electrons, atoms, and even large molecules, and the same type of interference pattern is seen. Thus it has been demonstrated that all [[matter]] possesses both particle and wave characteristics.


title: Introduction to quantum mechanics

text: Even if the source intensity is turned down, so that only one particle (e.g. photon or electron) is passing through the apparatus at a time, the same interference pattern develops over time. The quantum particle acts as a wave when passing through the double slits, but as a particle when it is detected. This is a typical feature of quantum complementarity: a quantum particle acts as a wave in an experiment to measure its wave-like properties, and like a particle in an experiment to measure its particle-like properties. The point on the detector screen where any individual particle shows up is the result of a random process. However, the distribution pattern of many individual particles mimics the diffraction pattern produced by waves.


title: Introduction to quantum mechanics

text: De Broglie expanded the [[Bohr model of the atom]] by showing that an electron in orbit around a nucleus could be thought of as having wave-like properties. In particular, an [[electron]] is observed only in situations that permit a [[standing wave]] around a [[atomic nucleus|nucleus]]. An example of a standing wave is a violin string, which is fixed at both ends and can be made to vibrate. The waves created by a stringed instrument appear to oscillate in place, moving from crest to trough in an up-and-down motion. The wavelength of a standing wave is related to the length of the vibrating object and the boundary conditions. For example, because the violin string is fixed at both ends, it can carry standing waves of wavelengths formula_17, where "l" is the length and "n" is a positive integer. De Broglie suggested that the allowed electron orbits were those for which the circumference of the orbit would be an integer number of wavelengths. The electron's wavelength, therefore, determines that only Bohr orbits of certain distances from the nucleus are possible. In turn, at any distance from the nucleus smaller than a certain value, it would be impossible to establish an orbit. The minimum possible distance from the nucleus is called the Bohr radius.


title: Introduction to quantum mechanics

text: De Broglie's treatment of quantum events served as a starting point for Schrödinger when he set out to construct a wave equation to describe quantum-theoretical events.


title: Introduction to quantum mechanics

text: In 1922, [[Otto Stern]] and [[Walther Gerlach]] shot silver atoms through an [[Homogeneity and heterogeneity|inhomogeneous]] [[magnetic field]]. Relative to its northern pole, pointing up, down, or somewhere in between, in classical mechanics, a magnet thrown through a magnetic field may be deflected a small or large distance upwards or downwards. The atoms that Stern and Gerlach shot through the magnetic field acted similarly. However, while the magnets could be deflected variable distances, the atoms would always be deflected a constant distance either up or down. This implied that the property of the atom that corresponds to the magnet's orientation must be quantized, taking one of two values (either up or down), as opposed to being chosen freely from any angle.


title: Introduction to quantum mechanics

text: [[Ralph Kronig]] originated the theory that particles such as atoms or electrons behave as if they rotate, or "spin", about an axis. Spin would account for the missing [[magnetic moment]], and allow two electrons in the same orbital to occupy distinct [[quantum state]]s if they "spun" in opposite directions, thus satisfying the [[Pauli exclusion principle|exclusion principle]]. The quantum number represented the sense (positive or negative) of spin.


title: Introduction to quantum mechanics

text: The choice of the orientation of the magnetic field used in the Stern–Gerlach experiment is arbitrary. In the animation shown here, the field is vertical and so the atoms are deflected either up or down. If the magnet is rotated a quarter turn, the atoms are deflected either left or right. Using a vertical field shows that the spin along the vertical axis is quantized, and using a horizontal field shows that the spin along the horizontal axis is quantized.


title: Introduction to quantum mechanics

text: If instead of hitting a detector screen, one of the beams of atoms coming out of the Stern–Gerlach apparatus is passed into another (inhomogeneous) magnetic field oriented in the same direction, all of the atoms are deflected the same way in this second field. However, if the second field is oriented at 90° to the first, then half of the atoms are deflected one way and half the other so that the atom's spin about the horizontal and vertical axes are independent of each other. However, if one of these beams (e.g. the atoms that were deflected up then left) is passed into a third magnetic field, oriented the same way as the first, half of the atoms go one way and half the other, even though they all went in the same direction originally. The action of measuring the atoms' spin concerning a horizontal field has changed their spin concerning a vertical field.


title: Introduction to quantum mechanics

text: In 1925, [[Werner Heisenberg]] attempted to solve one of the problems that the Bohr model left unanswered, explaining the intensities of the different lines in the hydrogen emission spectrum. Through a series of mathematical analogies, he wrote out the quantum-mechanical analog for the classical computation of intensities. Shortly afterward, Heisenberg's colleague [[Max Born]] realized that Heisenberg's method of calculating the probabilities for transitions between the different energy levels could best be expressed by using the mathematical concept of [[Matrix (mathematics)|matrices]].


title: Introduction to quantum mechanics

text: In the same year, building on de Broglie's hypothesis, [[Erwin Schrödinger]] developed the equation that describes the behavior of a quantum-mechanical wave. The mathematical model, called the [[Schrödinger equation]] after its creator, is central to quantum mechanics, defines the permitted stationary states of a quantum system, and describes how the quantum state of a physical system changes in time. The wave itself is described by a mathematical function known as a "[[wave function]]". Schrödinger said that the wave function provides the "means for predicting the probability of measurement results".


title: Introduction to quantum mechanics

text: Schrödinger was able to calculate the energy levels of hydrogen by treating a hydrogen atom's [[electron]] as a classical wave, moving in a well of the electrical potential created by the proton. This calculation accurately reproduced the energy levels of the Bohr model.


title: Introduction to quantum mechanics

text: In May 1926, Schrödinger proved that Heisenberg's [[matrix mechanics]] and his own [[Schrödinger equation|wave mechanics]] made the same predictions about the properties and behavior of the electron; mathematically, the two theories had an underlying common form. Yet the two men disagreed on the interpretation of their mutual theory. For instance, Heisenberg accepted the theoretical prediction of jumps of electrons between orbitals in an atom, but Schrödinger hoped that a theory based on continuous wave-like properties could avoid what he called (as paraphrased by [[Wilhelm Wien]]) "this nonsense about quantum jumps". In the end, Heisenberg's approach won out, and quantum jumps were confirmed.


title: Introduction to quantum mechanics

text: Bohr, Heisenberg, and others tried to explain what these experimental results and mathematical models really mean. Their description, known as the Copenhagen interpretation of quantum mechanics, aimed to describe the nature of reality that was being probed by the measurements and described by the mathematical formulations of quantum mechanics.


title: Introduction to quantum mechanics

text: Suppose it is desired to measure the position and speed of an object—for example, a car going through a radar speed trap. It can be assumed that the car has a definite position and speed at a particular moment in time. How accurately these values can be measured depends on the quality of the measuring equipment. If the precision of the measuring equipment is improved, it provides a result closer to the true value. It might be assumed that the speed of the car and its position could be operationally defined and measured simultaneously, as precisely as might be desired.


title: Introduction to quantum mechanics

text: In 1927, Heisenberg proved that this last assumption is not correct. Quantum mechanics shows that certain pairs of physical properties, for example, position and speed, cannot be simultaneously measured, nor defined in operational terms, to arbitrary precision: the more precisely one property is measured, or defined in operational terms, the less precisely can the other. This statement is known as the [[uncertainty principle]]. The uncertainty principle is not only a statement about the accuracy of our measuring equipment but, more deeply, is about the conceptual nature of the measured quantities—the assumption that the car had simultaneously defined position and speed does not work in quantum mechanics. On a scale of cars and people, these uncertainties are negligible, but when dealing with atoms and electrons they become critical.


title: Introduction to quantum mechanics

text: Heisenberg gave, as an illustration, the measurement of the position and momentum of an electron using a photon of light. In measuring the electron's position, the higher the frequency of the photon, the more accurate is the measurement of the position of the impact of the photon with the electron, but the greater is the disturbance of the electron. This is because from the impact with the photon, the electron absorbs a random amount of energy, rendering the measurement obtained of its [[momentum]] increasingly uncertain (momentum is velocity multiplied by mass), for one is necessarily measuring its post-impact disturbed momentum from the collision products and not its original momentum (momentum which should be simultaneously measured with position). With a photon of lower frequency, the disturbance (and hence uncertainty) in the momentum is less, but so is the accuracy of the measurement of the position of the impact.


title: Introduction to quantum mechanics

text: At the heart of the uncertainty principle is a fact that for any mathematical analysis in the position and velocity domains, achieving a sharper (more precise) curve in the position domain can only be done at the expense of a more gradual (less precise) curve in the speed domain, and vice versa. More sharpness in the position domain requires contributions from more frequencies in the speed domain to create the narrower curve, and vice versa. It is a fundamental tradeoff inherent in any such related or [[Complementarity (physics)|complementary]] measurements, but is only really noticeable at the smallest (Planck) scale, near the size of [[elementary particles]].


title: Introduction to quantum mechanics

text: The uncertainty principle shows mathematically that the product of the uncertainty in the position and [[momentum]] of a particle (momentum is velocity multiplied by mass) could never be less than a certain value, and that this value is related to [[Planck's constant]].


title: Introduction to quantum mechanics

text: "Wave function collapse" means that a measurement has forced or converted a quantum (probabilistic or potential) state into a definite measured value. This phenomenon is only seen in quantum mechanics rather than classical mechanics.


title: Introduction to quantum mechanics

text: For example, before a photon actually "shows up" on a detection screen it can be described only with a set of probabilities for where it might show up. When it does appear, for instance in the [[Charge-coupled device|CCD]] of an electronic camera, the time and space where it interacted with the device are known within very tight limits. However, the photon has disappeared in the process of being captured (measured), and its quantum [[wave function]] has disappeared with it. In its place, some macroscopic physical change in the detection screen has appeared, e.g., an exposed spot in a sheet of photographic film, or a change in electric potential in some cell of a CCD.


title: Introduction to quantum mechanics

text: Because of the [[uncertainty principle]], statements about both the position and momentum of particles can assign only a [[probability]] that the position or momentum has some numerical value. Therefore, it is necessary to formulate clearly the difference between the state of something indeterminate, such as an electron in a probability cloud, and the state of something having a definite value. When an object can definitely be "pinned-down" in some respect, it is said to possess an [[eigenstate]].


title: Introduction to quantum mechanics

text: In the Stern–Gerlach experiment discussed [[#Spin|above]], the spin of the atom about the vertical axis has two eigenstates: up and down. Before measuring it, we can only say that any individual atom has an equal probability of being found to have spin up or spin down. The measurement process causes the wave function to collapse into one of the two states.


title: Introduction to quantum mechanics

text: The eigenstates of spin about the vertical axis are not simultaneously eigenstates of spin about the horizontal axis, so this atom has an equal probability of being found to have either value of spin about the horizontal axis. As described in the section [[#Spin|above]], measuring the spin about the horizontal axis can allow an atom that was spun up to spin down: measuring its spin about the horizontal axis collapses its wave function into one of the eigenstates of this measurement, which means it is no longer in an eigenstate of spin about the vertical axis, so can take either value.


title: Introduction to quantum mechanics

text: In 1924, [[Wolfgang Pauli]] proposed a new quantum degree of freedom (or [[quantum number]]), with two possible values, to resolve inconsistencies between observed molecular spectra and the predictions of quantum mechanics. In particular, the [[hydrogen spectrum|spectrum of atomic hydrogen]] had a [[Doublet (physics)|doublet]], or pair of lines differing by a small amount, where only one line was expected. Pauli formulated his "exclusion principle", stating, "There cannot exist an atom in such a quantum state that two electrons within [it] have the same set of quantum numbers."


title: Introduction to quantum mechanics

text: A year later, [[George Eugene Uhlenbeck|Uhlenbeck]] and [[Samuel Goudsmit|Goudsmit]] identified Pauli's new degree of freedom with the property called [[spin (physics)|spin]] whose effects were observed in the Stern–Gerlach experiment.


title: Introduction to quantum mechanics

text: Bohr's model of the atom was essentially a planetary one, with the electrons orbiting around the nuclear "sun". However, the uncertainty principle states that an electron cannot simultaneously have an exact location and velocity in the way that a planet does. Instead of classical orbits, electrons are said to inhabit "[[atomic orbital]]s". An orbital is the "cloud" of possible locations in which an electron might be found, a distribution of probabilities rather than a precise location. Each orbital is three dimensional, rather than the two-dimensional orbit, and is often depicted as a three-dimensional region within which there is a 95 percent probability of finding the electron.


title: Introduction to quantum mechanics

text: Schrödinger was able to calculate the energy levels of hydrogen by treating a hydrogen atom's [[electron]] as a wave, represented by the "[[wave function]]" , in an [[electric potential]] [[potential well|well]], , created by the proton. The solutions to Schrödinger's equation are distributions of probabilities for electron positions and locations. Orbitals have a range of different shapes in three dimensions. The energies of the different orbitals can be calculated, and they accurately match the energy levels of the Bohr model.


title: Introduction to quantum mechanics

text: The collective name for these properties is the [[quantum state]] of the electron. The quantum state can be described by giving a number to each of these properties; these are known as the electron's [[quantum numbers]]. The quantum state of the electron is described by its wave function. The Pauli exclusion principle demands that no two electrons within an atom may have the same values of all four numbers. [[File:Atomic orbitals spdf m-eigenstates.png|right|thumb|upright=1.5|The shapes of atomic orbitals. Rows: 1"s", 2"p", 3"d" and 4"f". From left to right formula_20. The colors show the phase of the wave function.]]


title: Introduction to quantum mechanics

text: The first property describing the orbital is the [[principal quantum number]], , which is the same as in Bohr's model. denotes the energy level of each orbital. The possible values for are integers:


title: Introduction to quantum mechanics

text: The next quantum number, the [[azimuthal quantum number]], denoted , describes the shape of the orbital. The shape is a consequence of the [[angular momentum]] of the orbital. The angular momentum represents the resistance of a spinning object to speeding up or slowing down under the influence of external force. The azimuthal quantum number represents the orbital angular momentum of an electron around its nucleus. The possible values for are integers from 0 to (where is the principal quantum number of the electron):


title: Introduction to quantum mechanics

text: The shape of each orbital is usually referred to by a letter, rather than by its azimuthal quantum number. The first shape (=0) is denoted by the letter (a [[mnemonic]] being ""s"phere"). The next shape is denoted by the letter and has the form of a dumbbell. The other orbitals have more complicated shapes (see [[atomic orbital]]), and are denoted by the letters , , , etc.


title: Introduction to quantum mechanics

text: The third quantum number, the [[magnetic quantum number]], describes the [[magnetic moment]] of the electron, and is denoted by (or simply "m"). The possible values for are integers from to (where is the azimuthal quantum number of the electron):


title: Introduction to quantum mechanics

text: The magnetic quantum number measures the component of the angular momentum in a particular direction. The choice of direction is arbitrary; conventionally the z-direction is chosen.


title: Introduction to quantum mechanics

text: The fourth quantum number, the [[spin quantum number]] (pertaining to the "orientation" of the electron's spin) is denoted , with values + or −.


title: Introduction to quantum mechanics

text: It is the underlying structure and symmetry of atomic orbitals, and the way that electrons fill them, that leads to the organization of the [[periodic table]]. The way the atomic orbitals on different atoms combine to form [[molecular orbital]]s determines the structure and strength of chemical bonds between atoms.


title: Introduction to quantum mechanics

text: In 1928, [[Paul Dirac]] extended the [[Pauli equation]], which described spinning electrons, to account for [[special relativity]]. The result was a theory that dealt properly with events, such as the speed at which an electron orbits the nucleus, occurring at a substantial fraction of the [[speed of light]]. By using the simplest [[electromagnetic interaction]], Dirac was able to predict the value of the magnetic moment associated with the electron's spin and found the experimentally observed value, which was too large to be that of a spinning charged sphere governed by [[classical physics]]. He was able to solve for the [[hydrogen spectrum|spectral lines of the hydrogen atom]] and to reproduce from physical first principles [[Arnold Sommerfeld|Sommerfeld]]'s successful formula for the [[fine structure]] of the hydrogen spectrum.


title: Introduction to quantum mechanics

text: Dirac's equations sometimes yielded a negative value for energy, for which he proposed a novel solution: he posited the existence of an [[antielectron]] and a dynamical vacuum. This led to the many-particle [[quantum field theory]].


title: Introduction to quantum mechanics

text: The Pauli exclusion principle says that two electrons in one system cannot be in the same state. Nature leaves open the possibility, however, that two electrons can have both states "superimposed" over each of them. Recall that the wave functions that emerge simultaneously from the double slits arrive at the detection screen in a state of superposition. Nothing is certain until the superimposed waveforms "collapse". At that instant, an electron shows up somewhere in accordance with the probability that is the square of the absolute value of the sum of the complex-valued amplitudes of the two superimposed waveforms. The situation there is already very abstract. A concrete way of thinking about entangled photons, photons in which two contrary states are superimposed on each of them in the same event, is as follows:


title: Introduction to quantum mechanics

text: Imagine that we have two color-coded states of photons: one state labeled "blue" and another state labeled "red". Let the superposition of the red and the blue state appear (in imagination) as a "purple" state. We consider a case in which two photons are produced as the result of one single atomic event. Perhaps they are produced by the excitation of a crystal that characteristically absorbs a photon of a certain frequency and emits two photons of half the original frequency. In this case, the photons are interconnected via their shared origin in a single atomic event. This setup results in superimposed states of the photons. So the two photons come out "purple." If the experimenter now performs some experiment that determines whether one of the photons is either "blue" or "red", then that experiment changes the photon involved from one having a superposition of "blue" and "red" characteristics to a photon that has only one of those characteristics. The problem that Einstein had with such an imagined situation was that if one of these photons had been kept bouncing between mirrors in a laboratory on earth, and the other one had traveled halfway to the nearest star when its twin was made to reveal itself as either blue or red, that meant that the distant photon now had to lose its "purple" status too. So whenever it might be investigated after its twin had been measured, it would necessarily show up in the opposite state to whatever its twin had revealed.


title: Introduction to quantum mechanics

text: In trying to show that quantum mechanics was not a complete theory, Einstein started with the theory's prediction that two or more particles that have interacted in the past can appear strongly correlated when their various properties are later measured. He sought to explain this seeming interaction classically, through their common past, and preferably not by some "spooky action at a distance". The argument is worked out in a famous paper, Einstein, Podolsky, and Rosen (1935; abbreviated EPR) setting out what is now called the [[EPR paradox]]. Assuming what is now usually called [[local realism]], EPR attempted to show from quantum theory that a particle has both position and momentum simultaneously, while according to the [[Copenhagen interpretation]], only one of those two properties actually exists and only at the moment that it is being measured. EPR concluded that quantum theory is incomplete in that it refuses to consider physical properties that objectively exist in nature. (Einstein, Podolsky, & Rosen 1935 is currently Einstein's most cited publication in physics journals.) In the same year, [[Erwin Schrödinger]] used the word "entanglement" and declared: "I would not call that "one" but rather "the" characteristic trait of quantum mechanics." Ever since Irish physicist John Stewart Bell theoretically and experimentally [[Bell's theorem|disproved the "hidden variables" theory]] of Einstein, Podolsky, and Rosen, most physicists have accepted entanglement as a real phenomenon. However, there is some minority dispute. The [[Bell inequalities]] are the most powerful challenge to Einstein's claims.


title: Introduction to quantum mechanics

text: The idea of quantum field theory began in the late 1920s with British physicist [[Paul Dirac]], when he attempted to [[quantization (physics)|quantize]] the energy of the [[electromagnetic field]]; just like in quantum mechanics the energy of an electron in the hydrogen atom was quantized. Quantization is a procedure for constructing a quantum theory starting from a classical theory.


title: Introduction to quantum mechanics

text: "[[Merriam-Webster]]" defines a "field" in physics as "a region or space in which a given effect (such as [[magnetism]]) exists". Other effects that manifest themselves as fields are [[gravitation]] and [[static electricity]]. In 2008, physicist [[Richard Hammond (physicist)|Richard Hammond]] wrote:


title: Introduction to quantum mechanics

text: Sometimes we distinguish between quantum mechanics (QM) and quantum field theory (QFT). QM refers to a system in which the number of particles is fixed, and the fields (such as the electromechanical field) are continuous classical entities. QFT ... goes a step further and allows for the creation and annihilation of particles ...


title: Introduction to quantum mechanics

text: He added, however, that "quantum mechanics" is often used to refer to "the entire notion of quantum view".


title: Introduction to quantum mechanics

text: In 1931, Dirac proposed the existence of particles that later became known as [[antimatter]]. Dirac shared the [[Nobel Prize in Physics]] for 1933 with [[Erwin Schrödinger|Schrödinger]] "for the discovery of new productive forms of [[atomic theory]]".


title: Introduction to quantum mechanics

text: On its face, quantum field theory allows infinite numbers of particles and leaves it up to the theory itself to predict how many and with which probabilities or numbers they should exist. When developed further, the theory often contradicts observation, so that its creation and annihilation operators can be empirically tied down. Furthermore, empirical conservation laws such as that of [[Mass–energy equivalence|mass–energy]] suggest certain constraints on the mathematical form of the theory, which are mathematically speaking finicky. The latter fact makes quantum field theories difficult to handle, but has also led to further restrictions on admissible forms of the theory; the complications are mentioned below under the rubric of [[renormalization]].


title: Introduction to quantum mechanics

text: Quantum electrodynamics (QED) is the name of the quantum theory of the [[electromagnetic force]]. Understanding QED begins with understanding [[electromagnetism]]. Electromagnetism can be called "electrodynamics" because it is a dynamic interaction between electrical and [[magnetic force]]s. Electromagnetism begins with the [[electric charge]].


title: Introduction to quantum mechanics

text: Electric charges are the sources of and create, [[electric field]]s. An electric field is a field that exerts a force on any particles that carry electric charges, at any point in space. This includes the electron, proton, and even [[quark]]s, among others. As a force is exerted, electric charges move, a current flows, and a magnetic field is produced. The changing magnetic field, in turn, causes [[electric current]] (often moving electrons). The physical description of interacting [[charged particle]]s, electrical currents, electrical fields, and magnetic fields is called electromagnetism.


title: Introduction to quantum mechanics

text: In 1928 [[Paul Dirac]] produced a relativistic quantum theory of electromagnetism. This was the progenitor to modern quantum electrodynamics, in that it had essential ingredients of the modern theory. However, the problem of unsolvable infinities developed in this [[relativistic quantum theory]]. Years later, [[renormalization]] largely solved this problem. Initially viewed as a provisional, suspect procedure by some of its originators, renormalization eventually was embraced as an important and self-consistent tool in QED and other fields of physics. Also, in the late 1940s [[Feynman diagram|Feynman's diagrams]] depicted all possible interactions on a given event. The diagrams showed in particular that the electromagnetic force is the exchange of photons between interacting particles.


title: Introduction to quantum mechanics

text: The [[Lamb shift]] is an example of a quantum electrodynamics prediction that has been experimentally verified. It is an effect whereby the quantum nature of the electromagnetic field makes the energy levels in an atom or ion deviate slightly from what they would otherwise be. As a result, spectral lines may shift or split.


title: Introduction to quantum mechanics

text: Similarly, within a freely propagating electromagnetic wave, the current can also be just an abstract [[displacement current]], instead of involving charge carriers. In QED, its full description makes essential use of short-lived [[virtual particles]]. There, QED again validates an earlier, rather mysterious concept.


title: Introduction to quantum mechanics

text: In the 1960s [[physicist]]s realized that QED broke down at extremely high energies. From this inconsistency the [[Standard Model]] of particle physics was discovered, which remedied the higher energy breakdown in theory. It is another extended quantum field theory that unifies the electromagnetic and [[weak interaction]]s into one theory. This is called the [[electroweak theory]].


title: Introduction to quantum mechanics

text: Additionally, the Standard Model contains a high energy unification of the electroweak theory with the [[strong force]], described by [[quantum chromodynamics]]. It also postulates a connection with [[gravity]] as yet another [[gauge theory]], but the connection is as of 2015 still poorly understood. The theory's successful prediction of the [[Higgs particle]] to explain inertial mass was confirmed by the [[Large Hadron Collider]], and thus the Standard model is now considered the basic and more or less complete description of [[particle physics]] as we know it.


title: Introduction to quantum mechanics

text: The physical measurements, equations, and predictions pertinent to quantum mechanics are all consistent and hold a very high level of confirmation. However, the question of what these abstract models say about the underlying nature of the real world has received competing answers. These interpretations are widely varying and sometimes somewhat abstract. For instance, the [[Copenhagen interpretation]] states that before a measurement, statements about a particle's properties are completely meaningless, while in the [[Many-worlds interpretation]] describes the existence of a [[multiverse]] made up of every possible universe.


title: Introduction to quantum mechanics

text: Applications of quantum mechanics include the [[laser]], the [[transistor]], the [[electron microscope]], and [[Magnetic Resonance Imaging|magnetic resonance imaging]]. A special class of quantum mechanical applications is related to [[macroscopic quantum phenomena]] such as superfluid helium and superconductors. The study of semiconductors led to the invention of the [[diode]] and the [[transistor]], which are indispensable for modern [[electronics]].


title: Introduction to quantum mechanics

text: In even the simple [[light switch]], [[quantum tunneling]] is absolutely vital, as otherwise the electrons in the [[electric current]] could not penetrate the potential barrier made up of a layer of oxide. [[Flash memory]] chips found in [[USB flash drive|USB drives]] also use quantum tunneling, to erase their memory cells.


title: Introduction to quantum mechanics

text: The following titles, all by working physicists, attempt to communicate quantum theory to laypeople, using a minimum of technical apparatus.


title: Clare Torry

text: Clare H. Torry (born 29 November 1947) is a British singer, well known for writing and performing the wordless vocals on the song "The Great Gig in the Sky" by the group Pink Floyd on their 1973 album "The Dark Side of the Moon". She also covered the Dolly Parton single "Love Is Like a Butterfly" for the opening titles of the BBC TV series "Butterflies", which ran for four series between 1978 and 1983.


title: Clare Torry

text: Clare Torry was born in November 1947 in Marylebone to Geoffrey Napier Torry (1916-1979), who combined careers as Lieutenant-Commander in the Fleet Air Arm and as a Flight Lieutenant in the RAF, and his wife Dorothy W. Singer (1916-2017), who was the secretary to six BBC Directors-General.


title: Clare Torry

text: By the end of the 1960s Torry had started a career as a performer, mainly singing covers of popular songs. In 1973 Alan Parsons booked her to provide vocals in a session at Abbey Road Studios, where Pink Floyd were recording their album "The Dark Side of the Moon", on an instrumental composed by Richard Wright which was to be called "The Great Gig in the Sky". On 4 November 1973, Torry sang "The Great Gig in the Sky" at the Rainbow Theatre in London. She sang it with Pink Floyd again at their 1990 concert at Knebworth, and with Roger Waters at some of his 1980s solo shows. She also contributed to Waters' 1986 soundtrack "When the Wind Blows" and to his 1987 album "Radio K.A.O.S.".


title: Clare Torry

text: Torry has also performed as a session singer (singing on a number of 1970s UK TV adverts) and as a live backing vocalist with Kevin Ayers, Olivia Newton-John, Shriekback, The Alan Parsons Project (for which she also sang lead vocal on one track on their 1979 "Eve" album), Procol Harum mainman Gary Brooker, Matthew Fisher, Cerrone, Meat Loaf (a duet on the song "Nowhere Fast", and the hit single "Modern Girl"), Johnny Mercer and Doctors of Madness.


title: Clare Torry

text: She performed the Dolly Parton song "Love Is Like a Butterfly" as the theme music to the 1970s Wendy Craig/Geoffrey Palmer, Carla Laine sitcom "Butterflies". The song was released as a single in 1981. Torry also released the song "Love for Living" in 1969, which was produced by Ronnie Scott and Robin Gibb.


title: Clare Torry

text: Torry sang backing vocals on the track "The War Song" from Culture Club's "Waking Up with the House on Fire" album in 1984, as well as on the track "Yellowstone Park" on the Tangerine Dream album "Le Parc" the following year. Her voice can also be heard singing "Love to Love You Baby" (originally by Donna Summer) during the opening scene of the cult BBC "Play for Today" production of "Abigail's Party" in 1977.


title: Clare Torry

text: Torry is also credited on the 1987 album "En Dejlig Torsdag" ("A Lovely Thursday") by the Danish pop rock band TV-2, where she sings in a fashion similar to that on "The Great Gig in the Sky" at the end of the tracks "Stjernen I Mit Liv" ("The Star in my Life") and "I Baronessens Seng" ("In the Bed of the Baroness").


title: Clare Torry

text: On 20 October 2010, Torry was presented with a BASCA Gold Badge Award in recognition of her unique contribution to music.


title: Clare Torry

text: In 2004, she sued Pink Floyd and EMI for songwriting royalties on the basis that her contribution to "The Great Gig in the Sky" constituted co-authorship with keyboardist Richard Wright. Originally, she was paid the standard flat fee of £30 for Sunday studio work (the equivalent of £400 in 2022). In 2005, an out-of-court settlement was reached in Torry's favour, although the terms of the settlement were not disclosed. All releases after 2005 carry an additional credit for "Vocal composition by Clare Torry" for the "Great Gig in the Sky" segment of the booklet or liner notes.


title: Clare Torry

text: In February 2006, Torry released "Heaven in the Sky", a collection of her early pop recordings from the 1960s and 1970s. In 2011, Torry released a collaboration with musician and composer John Fyffe.


title: Arnhem

text: Arnhem ( ; ; South Guelderish: "Èrnem") is a city and municipality situated in the eastern part of the Netherlands about 55 km south east of Utrecht. It is the capital of the province of Gelderland, located on both banks of the rivers Nederrijn and Sint-Jansbeek, which was the source of the city's development. Arnhem had a population of 163.972 on 1 December 2021, which made it one of the larger cities of the Netherlands. The municipality is part of the Arnhem–Nijmegen metropolitan area, which has a combined number of 774,506 inhabitants on 31 January 2022.


title: Arnhem

text: Arnhem is home to the Hogeschool van Arnhem en Nijmegen, ArtEZ Institute of the Arts, Netherlands Open Air Museum, Airborne Museum 'Hartenstein', Royal Burgers' Zoo, NOC*NSF and National Sports Centre Papendal. The north corner of the municipality is part of the Hoge Veluwe National Park. It is approximately in area, consisting of heathlands, sand dunes, and woodlands.


title: Arnhem

text: The oldest archeological findings of human activity around Arnhem are two firestones of about 70,000 years ago. These come from the Stone Age, when the Neanderthals lived in this part of Europe. In Schuytgraaf, remnants of a hunters camp from around 5000 BC have been discovered. In Schaarsbergen, twelve grave mounds were found from 2400 BC, which brought the so-called Neolithic Revolution to the area of Arnhem, which meant the rise of the farmers.


title: Arnhem

text: The earliest settlement in Arnhem dates from 1500 BC, of which traces have been found on the Hoogkamp, where the Van Goyenstraat is currently located. In the inner city, around the Sint-Jansbeek, traces of settlement have been found from around 700 BC, while the first traces south of the Rhine have been found dating to around 500 BC, in the "Schuytgraaf".


title: Arnhem

text: Though the early tracks of settlements did show that the early residents of Arnhem descended from the forests on the hills, Arnhem was not built on the banks of the river Rhine, but a little higher along the Sint-Jansbeek. Arnhem arose on the location where the road between Nijmegen and Utrecht and Zutphen split. Seven streams provided the city with water, and only when the flow of the Rhine was changed in 1530, was the city located on the river.


title: Arnhem

text: Arnhem was first mentioned as such in 893 as "Arneym" or "Arentheym". In 1233, Count Otto II of Guelders from Zutphen, conferred city rights on the town, which had belonged to the abbey of Prüm, settled in, and fortified it. Arnhem entered the Hanseatic League in 1443. In 1473, it was captured by Charles the Bold of Burgundy.


title: Arnhem

text: In 1514, Charles of Egmond, duke of Guelders, took it from the dukes of Burgundy; in 1543, it fell to the emperor Charles V. As capital of the so-called "Kwartier van Veluwe" it joined the Union of Utrecht during the Eighty Years' War in 1579. After its capture from the Spanish forces by Dutch and English troops in 1585 the city became part of the Republic of the Seven United Provinces of the Netherlands. The French occupied the town from 1672 to 1674.


title: Arnhem

text: In the early 19th century, the former fortifications were almost completely dismantled, to give space for town expansion. The "Sabelspoort" (Sabresgate) is the only remaining part of the medieval walls.


title: Arnhem

text: In the 19th century, Arnhem was a genteel resort town famous for its picturesque beauty. It was known as "het Haagje van het oosten" (The Little Hague of the East), mainly because a number of rich former sugar barons or planters from the Indies settled there, as they did in The Hague. Even now the city is famous for its parks and greenery. The urbanization in the north on hilly terrain is also quite unusual for the Netherlands.


title: Arnhem

text: In the Second World War (1939–1945), during Operation Market Garden (September 1944), the British 1st Airborne Division, under the command of Major-General Roy Urquhart, and the Polish 1st Independent Parachute Brigade were given the task of securing the bridge at Arnhem.


title: Arnhem

text: Glider infantry and paratrooper units were landed into the area on 17 September and later. The bulk of the force was dropped rather far from the bridge and never met their objective. A small element of the British 1st Airborne, the 2nd Parachute Battalion under Lieutenant Colonel John D. Frost, managed to make its way as far as the bridge but was unable to secure both sides. The British troops encountered stiff resistance from the German 9th and 10th SS Panzer Divisions, which had been stationed in and around the city.


title: Arnhem

text: The British force at the bridge eventually ran out of ammunition and was captured on 21 September, and a full withdrawal of the remaining forces was made on 26 September. These events were dramatized in the 1977 movie "A Bridge Too Far". (The bridge scenes in the movie were shot in Deventer, where a similar bridge over the IJssel was available, as the area around Arnhem bridge had changed too much to represent WWII-era Arnhem). As a tribute, the rebuilt bridge was renamed 'John Frost Bridge' after the commander of the paratroopers. The official commemoration is 17 September.


title: Arnhem

text: The current bridge is the third almost-identical bridge built at the same spot. The Dutch Army destroyed the first bridge when the German Army invaded the Netherlands in 1940. The second bridge was destroyed by the United States Army Air Forces shortly after the 1944 battle.


title: Arnhem

text: A second battle of Arnhem took place in April 1945 when the city was liberated by the British 49th (West Riding) Infantry Division fighting as part of the First Canadian Army. The inhabitants of the city, who had been forcibly evacuated by the Germans during and after the battle, returned in the summer of 1945. The reconstruction of Arnhem took until 1969 to finally be completed.


title: Arnhem

text: Just outside Arnhem, in the town of Oosterbeek the Commonwealth War Graves Commission built the Arnhem Oosterbeek War Cemetery which contains the graves of most of those killed during the September landings, and many of those killed in later fighting in the area.


title: Arnhem

text: The municipality of Arnhem consists of the city of Arnhem and the following surrounding suburbs and former villages:


title: Arnhem

text: Arnhem consists of three districts ("stadsdelen") and 24 neighbourhoods ("wijken"). Each neighbourhood has a number which corresponds to its postal code.


title: Arnhem

text: The outlying areas of the following villages are bordering the municipality of Arnhem directly, which means among others that in many a case a considerable number of their inhabitants originate from Arnhem.


title: Arnhem

text: The city lies a few kilometers from the border with Germany, and to some extent the westernmost villages in the municipality of Elten, Germany, function as dormitories for people who work in the Dutch city of Arnhem in part due to the immigration of Dutch people from the region that were attracted by the lower house pricing just across the border.


title: Arnhem

text: Arnhem features the same climate (Cfb, oceanic climate) as all of the Netherlands; however, its location on the foothills of the Veluwe, the largest forest in the Netherlands, contributes to some higher precipitation values.


title: Arnhem

text: The "Grote Kerk" (St. Eusebius' Church), built 1452–1560, lost most of its tower during World War II, of which a part has been reconstructed to a modern design and opened in 1964. Officially the tower is not part of the church and is owned by the municipality.


title: Arnhem

text: The house of Maarten van Rossum, a general serving Duke Charles van Gelre, has been the town hall since 1830: The satyrs in its Renaissance ornamentation earned it the name "Duivelshuis" (devil's house). The Netherlands Open Air Museum is located outside the city. It includes antique houses, farms, factories, and windmills from different parts of the Netherlands. Two other windmills stand in Arnhem itself, De Hoop and De Kroon.


title: Arnhem

text: The Royal Burgers' Zoo in Arnhem is one of the biggest and most-visited zoos in the Netherlands, featuring an underwater walkthrough, desert, mangrove, and rainforest. The GelreDome, the home of Vitesse Arnhem, the city's Eredivisie team in football, is a unique facility that features a retractable roof and a slide-out grass pitch. The concept has been fully duplicated since then by the Veltins-Arena in Gelsenkirchen, Germany, and State Farm Stadium in Glendale, Arizona, U.S., and partially by the Sapporo Dome in Japan (which has a sliding pitch but a fixed roof).


title: Arnhem

text: The KEMA Toren (formerly known as "SEP Control Tower") is the highest structure of the town. It is a 140-m-high TV tower.


title: Arnhem

text: The National Sports Centre Papendal is the national sports development centre of the Netherlands, located in Arnhem. The first event held at Papendal was the 1980 Summer Paralympics, from 21 June to 5 July. However the site was formally adopted and developed from 1993, after the merger of the Dutch National Olympic Committee (NOC) and the Nederlandse Sport Federatie (NSF).


title: Arnhem

text: NOC*NSF have 90 affiliated national sports organizations, representing about 2700 individual sports clubs. Papendal is also the training location of football club Vitesse Arnhem, and the club's youth development system. Supporting facilities include a conference centre and hotel.


title: Arnhem

text: In preparation for the 2012 Summer Olympics, in 2011 the facility built a replica of the proposed BMX racing track at the London Velopark venue. The track will host the second event on the 2011 UCI BMX World Championships, on 27 and 28 May 2011.


title: Arnhem

text: Since January 2013 Sports Centre Papendal officially split from NOC * NSF and thus as organization demerges. This split offers Sports Centre Papendal many commercial benefits. There are facilities for various sports, including athletics, cycling and more.


title: Arnhem

text: Sport in the city is principally focussed on its association football club Vitesse Arnhem and its stadium the GelreDome built for the UEFA Euro 2000. The club has enjoyed some success in the Eredivisie and has featured in the UEFA Cup competition. Their best result in the Eredivisie was third place in 1997–98. The club won the KNVB Cup in 2016–17.


title: Arnhem

text: Introdans is a dance company based in the city of Arnhem. In 2009 the Ministry of Education, Culture and Science designated Introdans part of the basic national infrastructure. In 2016 was the Giro d'Italia in Arnhem.


title: Arnhem

text: Arnhem has had a main central railway station since 1845 – Arnhem Centraal railway station, which is serviced by several intercity lines and the Intercity-Express to Düsseldorf and further on to Frankfurt.


title: Arnhem

text: Until 2016, there were also NS International trains to other destinations abroad, with some coaches going as far as Moscow.


title: Arnhem

text: The intercity lines provide direct connections to Utrecht, Nijmegen and Zutphen. It is also the terminus for several local railway services. Arnhem has three other stations, namely Arnhem Velperpoort (since 1953), Arnhem Presikhaaf (since 1969) and Arnhem Zuid (since 2005).


title: Arnhem

text: KLM operates a bus from the train station to Schiphol Airport for its customers. Arnhem is unique in the Netherlands with its trolleybus system.


title: Adzuki bean

text: "Vigna angularis", also known as the adzuki bean , azuki bean, aduki bean, red bean, or red mung bean, is an annual vine widely cultivated throughout East Asia for its small (approximately long) bean. The cultivars most familiar in East Asia have a uniform red color, but there are also white, black, gray, and variously mottled varieties.


title: Adzuki bean

text: The wild ancestor of cultivated adzuki bean is probably "Vigna angularis" var. "nipponensis", which is distributed across Japan, Korea, China, Nepal and Bhutan. Speciation between "Vigna angularis" var. "nipponensis" and "Vigna angularis" var. "angularis" occurred around years ago. Archaeologists estimate it was domesticated around 3000 BC. However, adzuki beans (as well as soybeans) dating from 3000 BC to 2000 BC are indicated to still be largely within the wild size range. Enlarged seeds occurred during the later Bronze Age or Iron Age, periods with plough use. Domestication of adzuki beans resulted in a trade-off between yield and seed size. Cultivated adzuki beans have fewer but longer pods, fewer but larger seeds, a shorter stature, and also a smaller overall seed yield than wild forms. The exact place of domestication is not known; multiple domestication origins in East Asia have been suggested.


title: Adzuki bean

text: In Japan, the adzuki bean was one of the first crops subjected to scientific plant breeding. Important breeding traits are yield, pureness of the bean colour, and the maturing time. Separate cultivars with smaller seeds and higher biomass are bred for fodder production and as green manure. Locally adapted cultivars are available in China, Japan, Korea, and Taiwan. More than 300 cultivars/landraces/breeding lines are registered in Japan. Moreover, China (Institute of Crop Germplasm Resources (CAAS), Beijing, more than 3700 accessions) and Japan (Tokachi Agricultural Experiment Station, Hokkaido, about 2500 accessions) accommodate large germplasm collections of adzuki bean.


title: Adzuki bean

text: Weed forms of adzuki bean frequently occur in Japan. The wide spread of weed forms is due to adaptation to human-disturbed habitats, escapes of old cultivars, and natural establishment from derivatives of hybrids between cultivars and wild forms. In contrast to wild forms, the weed forms of adzuki bean are used as a substitute for the cultivated form and consumed as sweet beans, especially if cultivated adzuki beans are attacked by pests. However, in cultivated gardens the weed form is recognized as contamination and lowers the seed quality of adzuki cultivars.


title: Adzuki bean

text: The name "adzuki" is a transliteration of the native Japanese アヅキ, as it was spelled according to historical kana orthography. The name is also transliterated as "azuki", reflecting the modern spelling アズキ, or less commonly as "aduki", according to an alternate system of romanization. All are meant to represent the same Modern Japanese pronunciation, "azuki".


title: Adzuki bean

text: Japanese also has a Chinese loanword, , which means "small bean", its counterpart being the soybean. It is common to write in kanji but pronounce it as "azuki" ', an example of '. In China, the corresponding name () still is used in botanical or agricultural parlance, however, in everyday Chinese, the more common terms are ' () and ' (), both meaning "red bean", because almost all Chinese cultivars are uniformly red. In English the beans are often described as "red beans" in the context of Chinese cuisine, especially in reference to red bean paste, but the term is not otherwise used as other beans are also red in color. In normal contexts, "red cowpeas" have been used to refer to this bean. In Korean, adzuki beans are called ' () and it contrasts with ' (, "bean"), rather than being considered a type of it. ' ("beans") without qualifiers usually means soybeans. In Vietnamese it is called ' (literally: red bean). In some parts of India, the beans are referred to as "red chori". In Punjabi it is called ' and is a common ingredient of chaat. In Marathi, it is known as ' (), literally meaning 'red cowpea'. In Iraq its name is "" () meaning "red cowpeas".


title: Adzuki bean

text: The adzuki bean is mainly cultivated in China ( ha), Japan ( ha), South Korea ( ha), and Taiwan ( ha) (data published 2006). The bean is also grown commercially in the US, South America, and India, as well as New Zealand, Congo, and Angola. In Japan, the adzuki bean is the second most important legume after the soy bean; its 1998 annual yield of this crop was around 100,000 tons. With a consumption of about 140,000 t/year (data published 2006), Japan is also the most important importer of adzuki beans. The imports are received from China, Korea, Colombia, Taiwan, US, Thailand, and Canada.


title: Adzuki bean

text: The bean yields per area spread over a broad range due to differing cultivation intensity. Amounts of 4 to 8 dt/ha are reported, but in Japan and China yields between 20 and 30 dt/ha are reached.


title: Adzuki bean

text: Optimal temperature range for adzuki bean growth is between 15 °C and 30 °C. The crop is not frost-hardy and needs soil temperatures above 6–10 °C (30–34 °C optimal) for germination. Hot temperatures stimulate vegetative growth and are therefore less favorable for pea production. The adzuki bean is usually not irrigated. Annual rainfall ranges from 500 to 1750 mm in areas where the bean is grown. The plant can withstand drought but severe reduction in yield is expected. The cultivation of the adzuki bean is possible on preferably well drained soils with pH 5–7.5. Fertilizer application differs widely depending on expected yield but is generally similar to soybean. Due to nodulation with rhizobia, nitrogen fixation of up to 100 kg/ha is possible.


title: Adzuki bean

text: The sowing of the peas is in 2–3 cm depth in rows 30–90 cm apart and 10–45 cm within the row. Rarely seeds are sown by broadcast. The amount of seeds ranges between 8–70 kg/ha. Growth of the crop is slow, therefore weed control is crucial mainly between germination and flowering. Cultivation systems differ largely among different countries. In China adzuki bean is often grown in intercrops with maize, sorghum and millet while in Japan the bean is grown in crop rotations. Harvest of the peas should not be done as long as moisture content of the seed is higher than 16%.


title: Adzuki bean

text: Fungal and bacterial diseases of the adzuki bean are powdery mildew, brown stem rot, and bacterial blight. Furthermore, pests such as the adzuki pod worm, Japanese butterbur borer, and cutworm attack the crop. The bean weevil is an important storage pest.


title: Adzuki bean

text: The description of the adzuki bean can vary between authors because there are both wild and cultivated forms of the plant.


title: Adzuki bean

text: The adzuki bean is an annual, rarely biennial bushy erect or twining herb usually between 30 and 90 centimeters high. There exist climbing or prostrate forms of the plant. The stem is normally green and sparsely pilose.


title: Adzuki bean

text: The adzuki bean has a taproot type of root system that can reach a depth of 40–50 cm from the point of seed germination.


title: Adzuki bean

text: The leaves of the adzuki bean are trifoliate, pinnate and arranged alternately along the stem on a long petiole. Leaflets are ovate and about 5–10 cm long and 5–8 cm wide.


title: Adzuki bean

text: Adzuki flowers are papilionaceous and bright yellow. The inflorescence is an axillary false raceme consisting of six to ten (two to twenty) flowers.


title: Adzuki bean

text: Adzuki pods are smooth, cylindrical and thin-walled. The colour of the pods is green turning white to grey as they mature. The size is between 5–13 cm × 0.5 cm with 2 to 14 seeds per pod. Pod shatter during seed ripening and harvesting might be a difficulty under certain conditions.


title: Adzuki bean

text: The seeds are smooth and subcylindric with a length of 5.0-9.1 mm, width of 4.0-6.3 mm, thickness of 4.1-6.0 mm. The thousand kernel weight is between 50 and 200 g. There are many different seed colours from maroon to blue-black mottled with straw.


title: Adzuki bean

text: The emergence of the seedlings is hypogeal and takes 7–20 days. Compared to other pulses the growth of the plant is slow. Normally the adzuki plant reaches maturity between 80 and 120 days depending on the cultivar and the environmental conditions. Flowering lasts 30–40 days. Commonly the plant self-pollinates but cross-pollination also exists.


title: Adzuki bean

text: In East Asian cuisine, the adzuki bean is commonly sweetened before eating. In particular, it is often boiled with sugar, producing red bean paste, a very common ingredient in all of these cuisines. It also is common to add flavoring to the bean paste, such as chestnut. Red bean paste is used in many Chinese dishes, such as tangyuan, zongzi, mooncakes, baozi, and red bean ice. It also serves as a filling in Japanese sweets such as anpan, dorayaki, imagawayaki, manjū, monaka, anmitsu, taiyaki, and daifuku. A more liquid version, using adzuki beans boiled with sugar and a pinch of salt, produces a sweet dish called hong dou tang. Some East Asian cultures enjoy red bean paste as a filling or topping for various kinds of waffles, pastries, baked buns, or biscuits.


title: Adzuki bean

text: Traditionally in Japan, rice with adzuki beans (赤飯; "sekihan") is cooked for auspicious occasions. Adzuki beans are used in amanattō and ice cream with the whole bean or as paste.


title: Adzuki bean

text: Cooked adzuki beans are 66% water, 25% carbohydrates, including 7% dietary fiber, 8% protein, and contain negligible fat (table). In a 100-gram reference amount, cooked beans provide of food energy, a moderate to high content (10% or more of the Daily Value, DV) of the B vitamin folate (30% DV), and several dietary minerals (11% to 27% DV, table).


title: Kombu

text: Konbu (from ) is edible kelp mostly from the family Laminariaceae and is widely eaten in East Asia. It may also be referred to as dasima () or haidai ().


title: Kombu

text: Kelp features in the diets of many civilizations, including Chinese and Icelandic; however, the largest consumers of kelp are the Japanese, who have incorporated kelp and seaweed into their diets for over 1,500 years.


title: Kombu

text: There are about eighteen edible species in Laminariaceae and most of them, but not all, are called kombu. Confusingly, species of Laminariaceae have multiple names in biology and in fisheries science. In the following list, fisheries science synonyms are in parentheses, and Japanese names follow them.


title: Kombu

text: In Old Japanese, edible seaweed was generically called ""me"" (cf. wakame, arame) and kanji such as "軍布", 海藻 or "和布" were applied to transcribe the word. Especially, kombu was called "hirome" (from "hiroi", wide) or "ebisume" (from "ebisu"). Sometime later the names "konfu" and "kofu" appeared respectively in two editions of Iroha Jiruishō in 12th–13th century.


title: Kombu

text: Various theories have been claimed for the origin of the name kombu, with the following two predominant today.


title: Kombu

text: One is that it originated from the on'yomi (Sino-Japanese reading) of the Chinese name 昆布 (kūnbù). The kanji itself already could be seen in "Shōsōin Monjo" (8th century) and "Shoku Nihongi" (797) in Japan, and furthermore trace back in China, as early as 3rd century, to the book "Wupu Bencao" (around 239). Li Shizhen wrote the following in his "Bencao Gangmu" (1596):


title: Kombu

text: Another possibility to explain the association arises because descriptions of kūnbù in Chinese documents are vague and inconsistent, and it is impossible to identify to which seaweed the term might have applied. For instance, Chen Cangqi (681–757) noted: "kūnbù is produced in the South China Sea; its leaf is like a hand and the size is the same as a silver grass and a reed, is of red purple; the thin part of leaf is seaweed", which is similar to wakame, arame, kurome, or kajime ("Ecklonia cava"). The difficulty is that, at least in that time, kombu was not produced either in the East nor in the South China Sea. Moreover, following Zhang Yxi, Li Shizhen classified kūnbù and haidai (stands for kombu in Chinese) as different things, and this classification continues in China today.


title: Kombu

text: The Erya (3rd–2nd century BC) noted that "Qūan resembles 綸 (lace, cord or rope). This is in the East China Sea." The Wupu Bencao (3rd century) mentions it as "Gūanbù, alias kūnbù". Tao Hongjing (456–536) noted kūnbù is edible. As previously mentioned, however, kūnbù can not be identified with kombu. Zhang Yuxi referred to haidai in the book "Jiayou buzhu Shen Nong bencao" (嘉祐補註神農本草; 1060).


title: Kombu

text: Although archaeological evidence of seaweed is hard to find because of its easy decomposition, some plant remains of wakame seaweed are found in some ruins of the Jōmon Period which leads to the supposition that kombu was also eaten at that time. As to surviving documents, the letters 軍布 (in Sino-Japanese reading 軍 is gun/kun; 布 is fu/pu/bu) appeared in Man'yōshū and wood strips from Fujiwara-kyō, and may have indicated kombu. The "Shoku Nihongi" (797) reports: in 797 of Emishi (Ainu or Tohoku region people) stated they had been offering up kombu, which grew there, as tribute to the Yamato court every year without fail. The Engishiki (927) also reports that kombu had been offered up by Mutsu.


title: Kombu

text: During the Muromachi period, a newly developed drying technique allowed kombu to be stored for more than a few days, and it became an important export from the Tohoku area. By the Edo period, as Hokkaidō was colonized and shipment routes were organized, the use of "kombu" became widespread throughout Japan. Traditional Okinawan cuisine relies heavily on "kombu" as a part of the diet; this practice began in the Edo period. Okinawa uses more "kombu" per household than any other prefecture. In the 20th century, a way to cultivate kombu was discovered and it became cheap and readily available.


title: Kombu

text: In 1867, the word "kombu" first appeared in an English-language publication—"A Japanese and English Dictionary" by James Curtis Hepburn.


title: Kombu

text: Umami, a basic taste, was first scientifically identified in 1908 by Kikunae Ikeda through his experimentation with "kombu". He found that glutamic acid was responsible for the palatability of the "dashi" broth created from "kombu", and was a distinct sensation from sweet, sour, bitter, and salty tastes. Ikeda named the newly-discovered taste "umami" (うま味), from the Japanese word "umai" (うまい, "delicious").


title: Kombu

text: Since the 1960s, dried "kombu" has been exported from Japan to many countries. It was available initially at Asian, and especially Japanese, food shops and restaurants, and can be found in supermarkets, health-food stores, and other nonspecializing suppliers.


title: Kombu

text: Kombu is sold dried ("dashi konbu") or pickled in vinegar ("su konbu") or as a dried shred ("oboro konbu", "tororo konbu" or "shiraga konbu"). It may also be eaten fresh in "sashimi".


title: Kombu

text: Kombu is used extensively in Japanese cuisines as one of the three main ingredients needed to make "dashi", a soup stock. "Konbu dashi" is made by putting either whole dried or powdered kombu in cold water and heating it to near-boiling. The softened kombu is commonly eaten after cooking or is sliced and used to make "tsukudani", a dish that is simmered in soy sauce and "mirin".


title: Kombu

text: Kombu may be pickled with sweet-and-sour flavoring, cut into small strips about 5 or 6 cm long and 2 cm wide. These are often eaten as a snack with green tea. It is often included when cooking beans, putatively to add nutrients and improve their digestibility.


title: Kombu

text: "Konbu-cha" or "kobu-cha" () is a tea made by infusing kombu in hot water. What Americans call kombucha is called "kōcha kinoko" in Japan.


title: Kombu

text: "Kombu" is a good source of glutamic acid, an amino acid responsible for umami (the Japanese word used for a basic taste identified in 1908). Several foodstuffs in addition to "kombu" provide glutamic acid or glutamates.


title: Kombu

text: "Kombu" contains extremely high levels of iodine. While this element is essential for normal growth and development, the levels in kombu can cause overdoses; it has been blamed for thyroid problems after drinking large amounts of soy milk in which "kombu" was an additive.


title: Kombu

text: It is also a source of dietary fiber. Algae including kombu also contain entire families of obscure enzymes that break down complex sugars that are normally indigestible to the human gut (thus gas-causing), including the well-studied alpha-galactosidase and beta-galactosidase.


title: Kombu

text: Genetically manipulated "E. coli" bacteria can digest "kombu" into ethanol, making it a possible maritime biofuel source.


title: Oksana Baiul

text: Oksana Serhiyivna Baiul-Farina (; born 16 November 1977) is a Ukrainian retired competitive figure skater. She is the 1993 world champion and the 1994 Olympic champion in ladies' singles.


title: Oksana Baiul

text: Baiul is the first and only skater representing Ukraine to win gold at the Winter Olympics. She is also the first Olympic champion of independent Ukraine in any sport.


title: Oksana Baiul

text: After winning the gold medal in 1994, Baiul decided to turn professional in order to tour in the United States and have a career based on her skating. She followed one of her coaches to Connecticut. Later, she also became involved in a variety of TV appearances, and benefit skates. She has lived in the United States since 1994. In 1997 she published two books, a memoir about her life and one on skating.


title: Oksana Baiul

text: Baiul was born on 16 November 1977 in Dnipro, Ukrainian SSR, Soviet Union, an industrial city famous for manufacturing Soviet missiles. Her parents divorced when she was two years old, and her father, Sergey Baiul—who died in 2006—disappeared shortly after. No one is certain whether he deserted his family or was pressured to leave town when he and his wife divorced. She was raised by her mother, Marina, a French teacher, and her maternal grandparents. In addition to having Ukraine ancestry, she is of Russian descent through her maternal grandfather.


title: Oksana Baiul

text: Her grandfather died in 1987, and her grandmother in 1988. In 1991, her mother, who had been very healthy, died suddenly of ovarian cancer, when Baiul was 13. Her father appeared at her mother's funeral, but Baiul wanted nothing to do with him. She lived with the wife of her coach, Stanislav Koritek, who had moved to Canada, and then with friends.


title: Oksana Baiul

text: After moving to Odesa in mid-1992, Baiul lived chiefly in a dormitory. Her expenses were covered by the state because of her promise in skating. In 1993, she lived a month with coach Galina Zmievskaya between the European and World championships.


title: Oksana Baiul

text: After the 1994 Winter Olympics, Baiul moved to the United States and started living in Simsbury, Connecticut. It is the location of the International Skating Center of Connecticut. In the late 1990s, she followed her coach, Valentyn Nikolayev, to Richmond, Virginia, where she lived for several years before moving to Cliffside Park, New Jersey. After residing there for 14 years, Baiul moved to Pennsylvania in March 2012, settling in Upper Makefield Township, Bucks County.


title: Oksana Baiul

text: In January 1997 (three years after winning the gold medal), Baiul was arrested for driving under the influence of alcohol after crashing her car into a tree in Bloomfield, Connecticut. The charges were dropped after she met the terms of probation and completed an alcohol education program. Her drinking problem worsened, however. In May 1997 she entered an alcohol rehabilitation program for two and a half months. In a 2004 interview, she said she had been sober for six years, saying "This is more important than Olympic gold."


title: Oksana Baiul

text: Baiul was raised as a Russian Orthodox Christian. As a child, she heard rumors that her maternal grandmother was Jewish. In 2003, years after her father left the family, she phoned her old rink in Dnipro to ask for assistance in locating him. Assuming it was a prank, they hung up twice. Eventually Baiul convinced them of her identity. The rink manager helped her reunite with her father Sergey Baiul in September 2003, when she was 25 years old.


title: Oksana Baiul

text: He confirmed that her Romanian maternal grandmother was Jewish. According to Orthodox Judaism, her mother and Baiul would also be classified as Jewish by blood. Baiul decided to identify as Jewish because of the custom of matrilineality in Judaism. In 2005, she said, "Being Jewish, that feels good. It feels natural, like a second skin".


title: Oksana Baiul

text: As a child, Baiul was interested in ballet, but was told she did not have the right body type. Her grandmother took her to skating lessons, saying it was ballet on skates. Her grandfather was also supportive of her skating, which she began at age three in Dnipro. He believed that she could be a future prima ballerina and that skating was a fine training ground for dance. Baiul pursued ballet, but ultimately chose ice skating. As she trained, her mother paid for her training expenses, including lessons, costumes, and equipment. By the age of five, she was studying with Stanislav Koritek, a prominent Ukrainian coach.


title: Oksana Baiul

text: She was coached by Koritek until he was offered a coaching job in Toronto, Ontario, in March 1992. He accepted due to lack of support for the sport in Ukraine as it struggled economically after the collapse of the Soviet Union. In August 1992, his father, Alfred Koritek, vice-president of the Ukrainian skating federation, called coach Galina Zmievskaya on Baiul's behalf. She took her on as a student, arranging for the girl to move to her home in Odesa. Zmievskaya welcomed her into her circle of elite skaters, and provided her shelter in her family's cramped three-room apartment in the city. Under Zmievskaya's training, Baiul made rapid progress. Her other coach in Odesa was Valentyn Nikolayev. She represented FSC "Ukraine" (Odesa, Dnipro).


title: Oksana Baiul

text: Baiul began competing and took the silver medal at the 1993 European Championships in Helsinki, finishing second to Surya Bonaly of France.


title: Oksana Baiul

text: Prior to the 1993 World Championships in Prague, Baiul had crashed into the boards and displaced disks in her back and neck. At the event, she stopped practicing and consulted a Czech doctor. She competed in skates with crooked blades because it was too late to try a new pair. Ranked second in the short program and first in the free skate, she finished ahead of Bonaly and became world champion at age 15.


title: Oksana Baiul

text: In 1994, Baiul won the silver medal at the European Championships in Copenhagen, again finishing second to Bonaly. At the 1994 Winter Olympics, she was second to American Nancy Kerrigan after the short program of Ladies' singles. During a practice session before the long program, she collided with Germany's Tanja Szewczenko, sustaining a wrenched lower back and a cut on her right shin, which required three stitches.


title: Oksana Baiul

text: She received two Olympic-approved pain-killing injections of anaesthetics in her lower back and shoulder, which enabled her to compete in the free skate. She won the free skate over Kerrigan by the slimmest of margins, and so won the gold medal. It was a controversial win that was defended by the referee, who said that Baiul had skated in an artistic and engaging style while Kerrigan skated cautiously. She won the Olympic gold medal at the age of 16 years and 101 days, becoming one of the youngest figure skating Olympic champions. Kerrigan placed second and Chen Lu from China placed third. Baiul was announced as the winner after Surya Bonaly and Katarina Witt completed their respective programs out of medal competition. In addition to her Olympic title, Ukraine named her in 1994 as a Merited Master of Sports.


title: Oksana Baiul

text: Despite their status as Olympic champions, Baiul and Viktor Petrenko faced difficulties in Odesa, as did fellow Ukrainians across the country. The country was struggling economically. and conditions at their rink in Odesa had deteriorated severely. The government could not extend financial support for figure skating following the breakup of the Soviet Union. Lacking a working ice resurfacer, coaches and skaters often had to resurface the rink ice by hand.


title: Oksana Baiul

text: Such conditions influenced Baiul's decision to turn professional after the 1994 Winter Olympics, although she was only 16 years old. Zmievskaya negotiated a very profitable contract for her to tour the United States following the Olympics and earn money with her sport. In May 1994, at age 16, Baiul signed an agreement with the American talent agency William Morris Endeavor.


title: Oksana Baiul

text: "Except myself, nearly all the figure skaters on the bus were grown-ups, and it was full of alcohol. Most of the skaters were Russians and Americans, and they all drank. That's when I tried it. I was very young, with no one to teach me the right. I thought it was the norm, 'cause as a teenager you don't want to break away from the majority."


title: Oksana Baiul

text: Following the Olympics, Baiul was plagued by physical ailments that affected her skating ability. She required arthroscopic knee surgery in the summer of 1994, after which she was advised by her doctor not to return to the ice for two months. Due to the million-dollar touring contract, Baiul ignored the doctor's recommendations. She resumed skating in two weeks and returned to performing in six. Her jumping ability became hindered.


title: Oksana Baiul

text: In 1994, Zmievskaya was asked to lead the coaching staff at Simsbury, Connecticut's newly built International Skating Center. Both Baiul and Viktor Petrenko followed her there to train with her.


title: Oksana Baiul

text: Baiul portrayed Clara and Dorothy Gale in the CBS productions of "The Nutcracker on Ice" and "The Wizard of Oz on Ice", respectively. In May 1997, she was dropped from the "Champions on Ice" tour due to concerns about her drinking.


title: Oksana Baiul

text: She decided to part ways with Zmievskaya the same year. Baiul had completed a rehab program and, in August 1998, she began training under Natalia Linichuk at the University of Delaware's skating center. She has continued to skate professionally from time to time, including an engagement with the touring show "Broadway on Ice."


title: Oksana Baiul

text: In December 2006, Baiul traveled to Russia and skated at the Red Square ice rink in Moscow, alongside champions from Russia, China, France, and other countries. In February 2007, she collaborated with Saule Rachmedova, a renowned ballet dancer, to bring together Ice Theatre of New York and couture fashion for the debut of fashion designer Levi Okunov's "Winter Collection." The following month, she appeared on MTV's "Total Request Live".


title: Oksana Baiul

text: Baiul had a role in the skating stage musical, "Cold as Ice." The story explores six skaters from Canada, Russia, and the United States preparing for national championships and the Olympics while dealing with demanding coaches, stage mothers, stage coaches, and other trials. The story was conceived and written by former skater Frank D'Agostino. A full stage version of "Cold As Ice" was produced and presented by the Gateway Playhouse in May 2007.


title: Oksana Baiul

text: On 8 March 2009, and again on 14 March 2010, Baiul made guest appearances at the Kate Wollman Skating Rink at Prospect Park in Brooklyn, New York, as part of its annual show. She also took part in meet-and-greet sessions with skating students after each performance.


title: Oksana Baiul

text: Baiul has her own line of clothing and jewelry. In November 2005, she appeared on the Bravo television program "Celebrity Poker Showdown". She was also part of the celebrity panel of judges (along with Steve Garvey and Jonny Moseley) on the ABC show "Master of Champions", which aired briefly in 2006.


title: Oksana Baiul

text: In November 2011, her manager (and future husband), Carlo Farina, discovered accounting and collection discrepancies in her account at William Morris Endeavor. After collecting $9.5 million from the company, Baiul filed a lawsuit in November 2012 in Los Angeles for an additional $1 million in compensatory damages and more in punitive damages. She sued NBCUniversal in February 2013 for their alleged illicit promotional use of her likeness. Having withdrawn the November case, she filed a broader lawsuit in New York in October 2013.


title: Oksana Baiul

text: In January 2015, Baiul publicly accused her former coaches Galina Zmievskaya, Viktor Petrenko, and their manager, Joseph Lemire, of fraud, claiming they 'have been stealing money' from her for more than a decade. In addition, she accused Lemire of fraudulent attempts to represent her in multiple court proceedings in Ukraine against the state, concerning various assets.


title: Oksana Baiul

text: As of January 2015, Baiul is married to her manager, Carlo Farina. She now uses the name Oksana Baiul-Farina. They reside in Las Vegas with their daughter, Sophia (born 2015).


title: Oksana Baiul

text: On 27 March 2010, Baiul skated at a figure skating exhibition for One Step Closer HIV AIDS. Directed and produced by Tim David, the benefit was for the AIDS Resource Foundation for Children. Baiul performed her signature "Swan Lake" program and was part of the meet-and-greet after the show.


title: Oksana Baiul

text: Baiul supports the Tikva Children's Home Charity, which works to aid the Jewish children of Odesa. In addition, she supports and is a member of the International Museum of Women. This celebrates the lives of women around the world. Baiul also created a program to donate sled dogs to underprivileged Inuit children.'


title: VirusTotal

text: VirusTotal is a website created by the Spanish security company Hispasec Sistemas. Launched in June 2004, it was acquired by Google in September 2012. The company's ownership switched in January 2018 to Chronicle, a subsidiary of Google.


title: VirusTotal

text: VirusTotal aggregates many antivirus products and online scan engines called Contributors. In November, 2018, the Cyber National Mission Force, a unit subordinate to the U.S. Cyber Command became a Contributor. The aggregated data from these Contributors allows a user to check for viruses that the user's own antivirus software may have missed, or to verify against any false positives. Files up to 650 MB can be uploaded to the website, or sent via email (max. 32MB). Anti-virus software vendors can receive copies of files that were flagged by other scans but passed by their own engine, to help improve their software and, by extension, VirusTotal's own capability. Users can also scan suspect URLs and search through the VirusTotal dataset. VirusTotal uses the Cuckoo sandbox for dynamic analysis of malware.


title: VirusTotal

text: VirusTotal's Windows Uploader was an application that integrates into the Explorer's (right-click) contextual menu, listed under "Send To > Virus Total". The application also launches manually for submitting a URL or a program that is currently running in the OS.


title: VirusTotal

text: VirusTotal stores the name and various hashes for each scanned file. Already scanned files can be identified by their known (e.g., VT default) SHA256 hash without uploading complete files. The SHA256 query URL has the form codice_1. File uploads are normally limited to 128 MB. In 2017 VirusTotal discontinued support of the Windows Uploader.


title: VirusTotal

text: Same as the Windows app you upload the file (via the app's UI or context menu) then you will be given back a result. The Mac OS X app can be downloaded from their website. However, you need to compile and build the app for Linux using the same core (provided in their repository) used in the Mac OS X application. Already scanned files can be identified by their known (e.g., VT default) SHA256 hash without uploading complete files.


title: VirusTotal

text: There are several browser extensions available, such as "VT4Browsers" for Mozilla Firefox, and Google Chrome and "vtExplorer" for Internet Explorer. They allow the user to download files directly with VirusTotal's web application prior to storing them in the computer, as well as scanning URLs.


title: VirusTotal

text: The service also offers an Android App that employs the public API to search any installed application for VirusTotal's previously scanned ones and show its status. Any application not previously scanned can be submitted, but an API key must be provided and other restrictions to public API usage may apply (see #Public API).


title: VirusTotal

text: VirusTotal provides as a free service a public API that allows for automation of some of its online features such as ""upload and scan files, submit and scan URLs, access finished scan reports and make automatic comments on URLs and samples"". Some restrictions apply for requests made through the public API, such as requiring an individual API key freely obtained by online signing up, low priority scan queue, limited number of requests per time frame, etc.


title: VirusTotal

text: Files uploaded to VirusTotal may be shared freely with anti-malware companies and will also be retained in a store. The VirusTotal "About Page" states under "VirusTotal and confidentiality":


title: VirusTotal

text: Files and URLs sent to VirusTotal will be shared with antivirus vendors and security companies so as to help them in improving their services and products. We do this because we believe it will eventually lead to a safer Internet and better end-user protection.


title: VirusTotal

text: By default any file/URL submitted to VirusTotal which is detected by at least one scanner is freely sent to all those scanners that do not detect the resource. Additionally, all files and URLs enter a private store that may be accessed by premium (mainly security/antimalware companies/organizations) VirusTotal users so as to improve their security products and services.


title: Sylvia Browne

text: Sylvia Celeste Browne ("née" Shoemaker; October 19, 1936 – November 20, 2013) was an American author who claimed to be a medium with psychic abilities. She appeared regularly on television and radio, including on "The Montel Williams Show" and "Larry King Live", and hosted an hour-long online radio show on Hay House Radio.


title: Sylvia Browne

text: Browne frequently made pronouncements that were later found to be false, including those related to missing persons. She was also a convicted criminal, having faced theft charges in 1992. Despite the considerable negative publicity, she maintained a large following until her death in 2013.


title: Sylvia Browne

text: Sylvia Browne grew up in Kansas City, Missouri, the daughter of William Lee and Celeste (née Coil) Shoemaker. Her father held several different jobs, working at times in mail delivery, jewelry sales, and as a vice president of a major freight line. Browne was raised mostly as a Catholic, and was said to have an Episcopalian mother, a Lutheran maternal grandmother, Jewish father, and relatives from all these faiths.<ref name="CNN0103/06"></ref>


title: Sylvia Browne

text: Browne claimed she started seeing visions at the age of five, and that her grandmother, who she claimed was also a psychic medium, helped her understand what they meant. Browne also claimed her great-uncle was a psychic medium and was "rabid about UFOs".


title: Sylvia Browne

text: Browne started to give psychic readings in 1974. In 1986, she founded a "Gnostic Christian" church in Campbell, California, known as the Society of Novus Spiritus. She was also head of the Sylvia Browne Corporation and Sylvia Browne Enterprises. In a 2010 interview, Browne's business manager said that her businesses earned $3 million a year.


title: Sylvia Browne

text: Browne claimed to have observed Heaven and angels. She also professed the ability to speak with a spirit guide named "Francine", and to perceive a wide range of "vibrational frequencies".


title: Sylvia Browne

text: Browne authored some 40 books on paranormal topics, some of which appeared on "The New York Times" Best Seller list. Many of these books were acknowledged as resulting from collaborations with other writers such as Lindsay Harrison and Chris Dufresne.


title: Sylvia Browne

text: Browne was a frequent guest on U.S. television and radio programs, including "Larry King Live", "The Montel Williams Show", "That's Incredible!", and "Coast to Coast AM". During these appearances, she usually discussed her claimed abilities with the host and then performed readings for audience members or callers. On certain occasions she was paired with other guests, including skeptics, often leading to debate about the authenticity of Browne's psychic abilities. Browne hosted her own hour-long online radio show on Hay House Radio, where she performed readings and discussed paranormal issues.


title: Sylvia Browne

text: Browne appeared in a 1991 episode of "". In the segment "Ghosts R Us", she portrayed herself in a recreation of events that purportedly took place in a haunted Toys R Us store. Browne also appeared as herself on the CBS television soap opera "The Young and the Restless" in December 2006.


title: Sylvia Browne

text: Browne made many public pronouncements which were subsequently proven false. Among the more notable incidents were the following:


title: Sylvia Browne

text: In 2000, "Brill's Content" examined ten recent "Montel Williams" episodes that highlighted Browne's work as a psychic detective, spanning 35 cases. In 21 cases, the information predicted by Browne was too vague to be verified. Of the remaining 14, law enforcement officials or family members stated Browne had played no useful role.


title: Sylvia Browne

text: In 2010, the "Skeptical Inquirer" published a detailed three-year study by Ryan Shaffer and Agatha Jadwiszczok that examined Browne's predictions about missing persons and murder cases. Despite her repeated claims to be more than 85% correct, the study reported that "Browne has not even been mostly correct in a single case." The study compared Browne's televised statements about 115 cases with newspaper reports and found that in the 25 cases where the actual outcome was known, she was completely wrong in every one. In the rest, where the final outcome was unknown, her predictions could not be substantiated. The study concluded that the media outlets that repeatedly promoted Browne's work had no visible concern about whether she was untrustworthy or harmed people.


title: Sylvia Browne

text: On January 2, 2006, an explosion at Sago mine in West Virginia trapped several miners underground. The following day, Browne was a guest on the radio program "Coast to Coast AM" with George Noory. At the start of the broadcast, it was believed that twelve of thirteen miners trapped by the disaster had been found alive and, when Noory asked Browne if the reported lack of noise from inside the mine might have led her to think the men had died, she replied, "No; I knew they were going to be found." Later in the program, it was discovered that the earlier news reports had been in error; Browne said, "I don't think there's anybody alive, maybe one ... I just don't think they are alive", adding, subsequently, that she "didn't believe that they were alive ... I did believe that they were gone."


title: Sylvia Browne

text: Browne cultivated a large following. In 2007, she had a four-year waiting list for readings by telephone. That same year, hundreds of people joined Browne on a cruise, each paying thousands of dollars for psychic readings. Many of her books became staples on "The New York Times" Best Seller list.


title: Sylvia Browne

text: Browne attracted media attention seven years after her death, when social media users claimed that a prediction in her books ("End of Days" and "Prophecy: What the Future Holds For You") referred to the COVID-19 pandemic (she claimed "a severe pneumonia-like illness" would spread "around" 2020). News coverage of the alleged similarity appeared in March 2020, and was picked up by celebrities with large social media platforms such as Kim Kardashian. Investigator Benjamin Radford and others dismissed the one-paragraph prediction as too generic, and actually more akin to the 2003 SARS epidemic, than to COVID-19. Radford said that as Browne had produced predictions by the thousands, "the fact that this one happened to possibly, maybe, be partly right is meaningless."