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Giant-impact hypothesis Darwin's hypothesis was that a molten Moon had been spun from the Earth because of centrifugal forces, and this became the dominant academic explanation. Using Newtonian mechanics, he calculated that the Moon had orbited much more closely in the past and was drifting away from the Earth. This drifting was later confirmed by American and Soviet experiments, using laser ranging targets placed on the Moon. Nonetheless, Darwin's calculations could not resolve the mechanics required to trace the Moon backward to the surface of the Earth. In 1946, Reginald Aldworth Daly of Harvard University challenged Darwin's explanation, adjusting it to postulate that the creation of the Moon was caused by an impact rather than centrifugal forces. Little attention was paid to Professor Daly's challenge until a conference on satellites in 1974, during which the idea was reintroduced and later published and discussed in "Icarus" in 1975 by Drs. William K. Hartmann and Donald R. Davis. Their models suggested that, at the end of the planet formation period, several satellite-sized bodies had formed that could collide with the planets or be captured. They proposed that one of these objects may have collided with the Earth, ejecting refractory, volatile-poor dust that could coalesce to form the Moon. This collision could potentially explain the unique geological and geochemical properties of the Moon. A similar approach was taken by Canadian astronomer Alastair G. W. Cameron and American astronomer William R | https://en.wikipedia.org/wiki?curid=51143 |
Giant-impact hypothesis Ward, who suggested that the Moon was formed by the tangential impact upon Earth of a body the size of Mars. It is hypothesised that most of the outer silicates of the colliding body would be vaporised, whereas a metallic core would not. Hence, most of the collisional material sent into orbit would consist of silicates, leaving the coalescing Moon deficient in iron. The more volatile materials that were emitted during the collision probably would escape the Solar System, whereas silicates would tend to coalesce. The name of the hypothesised protoplanet is derived from the mythical Greek titan Theia , who gave birth to the Moon goddess Selene. This designation was proposed initially by the English geochemist Alex N. Halliday in 2000 and has become accepted in the scientific community. According to modern theories of planet formation, Theia was part of a population of Mars-sized bodies that existed in the Solar System 4.5 billion years ago. One of the attractive features of the giant-impact hypothesis is that the formation of the Moon and Earth align; during the course of its formation, the Earth is thought to have experienced dozens of collisions with planet-sized bodies. The Moon-forming collision would have been only one such "giant impact" but certainly the last significant impactor event. The Late Heavy Bombardment by much smaller asteroids occurred later - approximately 3.9 billion years ago. Astronomers think the collision between Earth and Theia happened at about 4.4 to 4.45 bya; about 0 | https://en.wikipedia.org/wiki?curid=51143 |
Giant-impact hypothesis 1 billion years after the Solar System began to form. In astronomical terms, the impact would have been of moderate velocity. Theia is thought to have struck the Earth at an oblique angle when the Earth was nearly fully formed. Computer simulations of this "late-impact" scenario suggest an impact angle of about 45° and an initial impactor velocity below 4 km/s. However, oxygen isotope abundance in lunar rock suggests "vigorous mixing" of Theia and Earth, indicating a steep impact angle. Theia's iron core would have sunk into the young Earth's core, and most of Theia's mantle accreted onto the Earth's mantle. However, a significant portion of the mantle material from both Theia and the Earth would have been ejected into orbit around the Earth (if ejected with velocities between orbital velocity and escape velocity) or into individual orbits around the Sun (if ejected at higher velocities). The material in orbits around the Earth quickly coalesced into the Moon (possibly within less than a month, but in no more than a century). The material in orbits around the sun stayed on its Kepler orbits, which are stable in space, and was thus likely to hit the earth-moon system sometime later (because the Earth-Moon system's Kepler orbit around the sun also remains stable). Estimates based on computer simulations of such an event suggest that some twenty percent of the original mass of Theia would have ended up as an orbiting ring of debris around the Earth, and about half of this matter coalesced into the Moon | https://en.wikipedia.org/wiki?curid=51143 |
Giant-impact hypothesis The Earth would have gained significant amounts of angular momentum and mass from such a collision. Regardless of the speed and tilt of the Earth's rotation before the impact, it would have experienced a day some five hours long after the impact, and the Earth's equator and the Moon's orbit would have become coplanar. Not all of the ring material need have been swept up right away: the thickened crust of the Moon's far side suggests the possibility that a second moon about 1,000 km in diameter formed in a Lagrange point of the Moon. The smaller moon may have remained in orbit for tens of millions of years. As the two moons migrated outward from the Earth, solar tidal effects would have made the Lagrange orbit unstable, resulting in a slow-velocity collision that "pancaked" the smaller moon onto what is now the far side of the Moon, adding material to its crust. Lunar magma cannot pierce through the thick crust of the far side, causing lesser lunar maria, while the near side has a thin crust displaying the large maria visible from Earth. In 2001, a team at the Carnegie Institution of Washington reported that the rocks from the Apollo program carried an isotopic signature that was identical with rocks from Earth, and were different from almost all other bodies in the Solar System. In 2014, a team in Germany reported that the Apollo samples had a slightly different isotopic signature from Earth rocks. The difference was slight, but statistically significant | https://en.wikipedia.org/wiki?curid=51143 |
Giant-impact hypothesis One possible explanation is that Theia formed near the Earth. This empirical data showing close similarity of composition can only be explained by the standard giant-impact hypothesis as an extremely unlikely coincidence, where the two bodies prior to collision somehow had a similar composition. However, in science, a very low probability of a situation points toward an error in theory, so effort has been focused on modifying the theory in order to better explain this fact that the Earth and Moon are composed of nearly the same type of rock. In 2007, researchers from the California Institute of Technology showed that the likelihood of Theia having an identical isotopic signature as the Earth was very small (less than 1 percent). They proposed that in the aftermath of the giant impact, while the Earth and the proto-lunar disc were molten and vaporised, the two reservoirs were connected by a common silicate vapor atmosphere and that the Earth– Moon system became homogenised by convective stirring while the system existed in the form of a continuous fluid. Such an "equilibration" between the post-impact Earth and the proto-lunar disc is the only proposed scenario that explains the isotopic similarities of the Apollo rocks with rocks from the Earth's interior. For this scenario to be viable, however, the proto-lunar disc would have to endure for about 100 years. Work is ongoing to determine whether or not this is possible | https://en.wikipedia.org/wiki?curid=51143 |
Giant-impact hypothesis According to research (2012) to explain similar compositions of Earth and the Moon based on simulations at the University of Bern by physicist Andreas Reufer and his colleagues, Theia collided directly with Earth instead of barely swiping it. The collision speed may have been higher than originally assumed, and this higher velocity may have totally destroyed Theia. According to this modification, the composition of Theia is not so restricted, making a composition of up to 50% water ice possible. One effort (2018) to homogenise the products of the collision was to energise the primary body by way of a greater pre-collision rotational speed. This way, more material from the primary body would be spun off to form the moon. Further computer modelling determined that the observed result could be obtained by having the pre-Earth body spinning very rapidly, so much so that it formed a new celestial object which was given the name 'synestia'. This is an unstable state that could have been generated by yet another collision to get the rotation spinning fast enough. Further modelling of this transient structure has shown that the primary body spinning as a doughnut-shaped object (the synestia) existed for about a century (a very short time) before it cooled down and gave birth to the Earth and the Moon | https://en.wikipedia.org/wiki?curid=51143 |
Giant-impact hypothesis Another model (2019) to explain the similarity of the Earth and moon's composition posits that shortly after the Earth formed, it was covered by a sea of hot magma, while the impacting object was likely made of solid material. Modelling suggests that this would lead to the impact heating the magma much more than solids from the impacting object, leading to more material being ejected from the proto-Earth, so that about 80% of the moon-forming debris originated from the proto-Earth. Many prior models had suggested 80% of the moon coming from the impactor. Indirect evidence for the giant impact scenario comes from rocks collected during the Apollo Moon landings, which show oxygen isotope ratios nearly identical to those of Earth. The highly anorthositic composition of the lunar crust, as well as the existence of KREEP-rich samples, suggest that a large portion of the Moon once was molten; and a giant impact scenario could easily have supplied the energy needed to form such a magma ocean. Several lines of evidence show that if the Moon has an iron-rich core, it must be a small one. In particular, the mean density, moment of inertia, rotational signature, and magnetic induction response of the Moon all suggest that the radius of its core is less than about 25% the radius of the Moon, in contrast to about 50% for most of the other terrestrial bodies | https://en.wikipedia.org/wiki?curid=51143 |
Giant-impact hypothesis Appropriate impact conditions satisfying the angular momentum constraints of the Earth-Moon system yield a Moon formed mostly from the mantles of the Earth and the impactor, while the core of the impactor accretes to the Earth. It is noteworthy that the Earth has the highest density of all the planets in the Solar System; the absorption of the core of the impactor body explains this observation, given the proposed properties of the early Earth and Theia. Comparison of the zinc isotopic composition of lunar samples with that of Earth and Mars rocks provides further evidence for the impact hypothesis. Zinc is strongly fractionated when volatilised in planetary rocks, but not during normal igneous processes, so zinc abundance and isotopic composition can distinguish the two geological processes. Moon rocks contain more heavy isotopes of zinc, and overall less zinc, than corresponding igneous Earth or Mars rocks, which is consistent with zinc being depleted from the Moon through evaporation, as expected for the giant impact origin. Collisions between ejecta escaping Earth's gravity and asteroids would have left impact heating signatures in stony meteorites; analysis based on assuming the existence of this effect has been used to date the impact event to 4.47 billion years ago, in agreement with the date obtained by other means | https://en.wikipedia.org/wiki?curid=51143 |
Giant-impact hypothesis Warm silica-rich dust and abundant SiO gas, products of high velocity (> 10 km/s) impacts between rocky bodies, have been detected by the Spitzer Space Telescope around the nearby (29 pc distant) young (~12 My old) star HD172555 in the Beta Pictoris moving group. A belt of warm dust in a zone between 0.25AU and 2AU from the young star HD 23514 in the Pleiades cluster appears similar to the predicted results of Theia's collision with the embryonic Earth, and has been interpreted as the result of planet-sized objects colliding with each other. A similar belt of warm dust was detected around the star BD+20°307 (HIP 8920, SAO 75016). This lunar origin hypothesis has some difficulties that have yet to be resolved. For example, the giant-impact hypothesis implies that a surface magma ocean would have formed following the impact. Yet there is no evidence that the Earth ever had such a magma ocean and it is likely there exists material that has never been processed in a magma ocean. A number of compositional inconsistencies need to be addressed. If the Moon was formed by such an impact, it is possible that other inner planets also may have been subjected to comparable impacts. A moon that formed around Venus by this process would have been unlikely to escape. If such a moon-forming event had occurred there, a possible explanation of why the planet does not have such a moon might be that a second collision occurred that countered the angular momentum from the first impact | https://en.wikipedia.org/wiki?curid=51143 |
Giant-impact hypothesis Another possibility is that the strong tidal forces from the Sun would tend to destabilise the orbits of moons around close-in planets. For this reason, if Venus's slow rotation rate began early in its history, any satellites larger than a few kilometers in diameter would likely have spiraled inwards and collided with Venus. Simulations of the chaotic period of terrestrial planet formation suggest that impacts like those hypothesised to have formed the Moon were common. For typical terrestrial planets with a mass of 0.5 to 1 Earth masses, such an impact typically results in a single moon containing 4% of the host planet's mass. The inclination of the resulting moon's orbit is random, but this tilt affects the subsequent dynamic evolution of the system. For example, some orbits may cause the moon to spiral back into the planet. Likewise, the proximity of the planet to the star will also affect the orbital evolution. The net effect is that it is more likely for impact-generated moons to survive when they orbit more distant terrestrial planets and are aligned with the planetary orbit. It has once been postulated that Mercury may be an ex-satellite of Venus (see History of Solar System formation and evolution hypotheses), though this has been refuted. In 2004, Princeton University mathematician Edward Belbruno and astrophysicist J. Richard Gott III proposed that Theia coalesced at the or Lagrangian point relative to Earth (in about the same orbit and about 60° ahead or behind), similar to a trojan asteroid | https://en.wikipedia.org/wiki?curid=51143 |
Giant-impact hypothesis Two-dimensional computer models suggest that the stability of Theia's proposed trojan orbit would have been affected when its growing mass exceeded a threshold of approximately 10% of the Earth's mass (the mass of Mars). In this scenario, gravitational perturbations by planetesimals caused Theia to depart from its stable Lagrangian location, and subsequent interactions with proto-Earth led to a collision between the two bodies. In 2008, evidence was presented that suggests that the collision may have occurred later than the accepted value of 4.53 Gya, at approximately 4.48 Gya. A 2014 comparison of computer simulations with elemental abundance measurements in the Earth's mantle indicated that the collision occurred approximately 95 My after the formation of the Solar System. It has been suggested that other significant objects may have been created by the impact, which could have remained in orbit between the Earth and Moon, stuck in Lagrangian points. Such objects may have stayed within the Earth–Moon system for as long as 100 million years, until the gravitational tugs of other planets destabilised the system enough to free the objects. A study published in 2011 suggested that a subsequent collision between the Moon and one of these smaller bodies caused the notable differences in physical characteristics between the two hemispheres of the Moon | https://en.wikipedia.org/wiki?curid=51143 |
Giant-impact hypothesis This collision, simulations have supported, would have been at a low enough velocity so as not to form a crater; instead, the material from the smaller body would have spread out across the Moon (in what would become its far side), adding a thick layer of highlands crust. The resulting mass irregularities would subsequently produce a gravity gradient that resulted in tidal locking of the Moon so that today, only the near side remains visible from Earth. However, mapping by the GRAIL mission has ruled out this scenario. In 2019, a team at the University of Münster reported that the molybdenum isotopic composition of Earth's core originates from the outer Solar System, likely bringing water to Earth. One possible explanation is that Theia originated in the outer Solar System. Other mechanisms that have been suggested at various times for the Moon's origin are that the Moon was spun off from the Earth's molten surface by centrifugal force; that it was formed elsewhere and was subsequently captured by the Earth's gravitational field; or that the Earth and the Moon formed at the same time and place from the same accretion disk. None of these hypotheses can account for the high angular momentum of the Earth–Moon system. Another hypothesis attributes the formation of the Moon to the impact of a large asteroid with the Earth much later than previously thought, creating the satellite primarily from debris from Earth | https://en.wikipedia.org/wiki?curid=51143 |
Giant-impact hypothesis In this hypothesis, the formation of the Moon occurs 60–140 million years after the formation of the Solar System. Previously, the age of the Moon had been thought to be 4.527 ± 0.010 billion years. The impact in this scenario would have created a magma ocean on Earth and the proto-Moon with both bodies sharing a common plasma metal vapor atmosphere. The shared metal vapor bridge would have allowed material from the Earth and proto-Moon to exchange and equilibrate into a more common composition. Yet another hypothesis proposes that the Moon and the Earth have formed together instead of separately like the giant-impact hypothesis suggests. This model, published in 2012 by Robin M. Canup, suggests that the Moon and the Earth formed from a massive collision of two planetary bodies, each larger than Mars, which then re-collided to form what we now call Earth. After the re-collision, Earth was surrounded by a disk of material, which accreted to form the Moon. This hypothesis could explain facts that others do not. Academic articles Non-academic books | https://en.wikipedia.org/wiki?curid=51143 |
Power number The power number "N" (also known as Newton number) is a commonly used dimensionless number relating the resistance force to the inertia force. The power-number has different specifications according to the field of application. E.g., for stirrers the power number is defined as: with | https://en.wikipedia.org/wiki?curid=51332 |
Interpretations of quantum mechanics An interpretation of quantum mechanics is an attempt to explain how the mathematical theory of quantum mechanics "corresponds" to reality. Although quantum mechanics has held up to rigorous and extremely precise tests in an extraordinarily broad range of experiments (not one prediction from quantum mechanics is found to be contradicted by experiments), there exist a number of contending schools of thought over their interpretation. These views on interpretation differ on such fundamental questions as whether quantum mechanics is deterministic or stochastic, which elements of quantum mechanics can be considered real, and what is the nature of measurement, among other matters. Despite nearly a century of debate and experiment, no consensus has been reached among physicists and philosophers of physics concerning which interpretation best "represents" reality. The definition of quantum theorists' terms, such as "wave functions" and "matrix mechanics", progressed through many stages. For instance, Erwin Schrödinger originally viewed the electron's wave function as its charge density smeared across space, whereas Max Born reinterpreted the absolute square value of the wave function as the electron's probability density distributed across space | https://en.wikipedia.org/wiki?curid=54738 |
Interpretations of quantum mechanics The views of several early pioneers of quantum mechanics, such as Niels Bohr and Werner Heisenberg, are often grouped together as the "Copenhagen interpretation", though physicists and historians of physics have argued that this terminology obscures differences between the views so designated. While Copenhagen-type ideas were never universally embraced, challenges to a perceived Copenhagen orthodoxy gained increasing attention in the 1950s with the pilot-wave interpretation of David Bohm and the many-worlds interpretation of Hugh Everett III. Moreover, the strictly formalist position, shunning interpretation, has been challenged by proposals for falsifiable experiments that might one day distinguish among interpretations, as by measuring an AI consciousness or via quantum computing. The physicist N. David Mermin once quipped, "New interpretations appear every year. None ever disappear." As a rough guide to development of the mainstream view during the 1990s to 2000s, consider the "snapshot" of opinions collected in a poll by Schlosshauer et al. at the "Quantum Physics and the Nature of Reality" conference of July 2011. The authors reference a similarly informal poll carried out by Max Tegmark at the "Fundamental Problems in Quantum Theory" conference in August 1997 | https://en.wikipedia.org/wiki?curid=54738 |
Interpretations of quantum mechanics The main conclusion of the authors is that "the Copenhagen interpretation still reigns supreme", receiving the most votes in their poll (42%), besides the rise to mainstream notability of the many-worlds interpretations: More or less, all interpretations of quantum mechanics share two qualities: Two qualities vary among interpretations: In philosophy of science, the distinction of knowledge versus reality is termed "epistemic" versus "ontic". A general law is a "regularity" of outcomes (epistemic), whereas a causal mechanism may "regulate" the outcomes (ontic). A phenomenon can receive interpretation either ontic or epistemic. For instance, indeterminism may be attributed to limitations of human observation and perception (epistemic), or may be explained as a real existing "maybe" encoded in the universe (ontic). Confusing the epistemic with the ontic, like if one were to presume that a general law actually "governs" outcomes—and that the statement of a regularity has the role of a causal mechanism—is a category mistake. In a broad sense, scientific theory can be viewed as offering scientific realism—approximately true description or explanation of the natural world—or might be perceived with antirealism. A realist stance seeks the epistemic and the ontic, whereas an antirealist stance seeks epistemic but not the ontic. In the 20th century's first half, antirealism was mainly logical positivism, which sought to exclude unobservable aspects of reality from scientific theory | https://en.wikipedia.org/wiki?curid=54738 |
Interpretations of quantum mechanics Since the 1950s, antirealism is more modest, usually instrumentalism, permitting talk of unobservable aspects, but ultimately discarding the very question of realism and posing scientific theory as a tool to help humans make predictions, not to attain metaphysical understanding of the world. The instrumentalist view is carried by the famous quote of David Mermin, "Shut up and calculate", often misattributed to Richard Feynman. Other approaches to resolve conceptual problems introduce new mathematical formalism, and so propose alternative theories with their interpretations. An example is Bohmian mechanics, whose empirical equivalence with the three standard formalisms—Schrödinger's wave mechanics, Heisenberg's matrix mechanics, and Feynman's path integral formalism—has been demonstrated. As well as the mainstream interpretations discussed below, a number of other interpretations have been proposed which have not made a significant scientific impact for whatever reason. These range from proposals by mainstream physicists to the more occult ideas of quantum mysticism. The current usage of realism and completeness originated in the 1935 paper in which Einstein and others proposed the EPR paradox. In that paper the authors proposed the concepts "element of reality" and the "completeness of a physical theory" | https://en.wikipedia.org/wiki?curid=54738 |
Interpretations of quantum mechanics They characterised element of reality as a quantity whose value can be predicted with certainty before measuring or otherwise disturbing it, and defined a complete physical theory as one in which every element of physical reality is accounted for by the theory. In a semantic view of interpretation, an interpretation is complete if every element of the interpreting structure is present in the mathematics. Realism is also a property of each of the elements of the maths; an element is real if it corresponds to something in the interpreting structure. For example, in some interpretations of quantum mechanics (such as the many-worlds interpretation) the ket vector associated to the system state is said to correspond to an element of physical reality, while in other interpretations it is not. Determinism is a property characterizing state changes due to the passage of time, namely that the state at a future instant is a function of the state in the present (see time evolution). It may not always be clear whether a particular interpretation is deterministic or not, as there may not be a clear choice of a time parameter. Moreover, a given theory may have two interpretations, one of which is deterministic and the other not. Local realism has two aspects: A precise formulation of local realism in terms of a local hidden-variable theory was proposed by John Bell | https://en.wikipedia.org/wiki?curid=54738 |
Interpretations of quantum mechanics Bell's theorem, combined with experimental testing, restricts the kinds of properties a quantum theory can have, the primary implication being that quantum mechanics cannot satisfy both the principle of locality and counterfactual definiteness. Regardless of Einstein's concerns about interpretation issues, Dirac and other quantum notables embraced the technical advances of the new theory while devoting little or no attention to interpretational aspects. The Copenhagen interpretation is the "standard" interpretation of quantum mechanics formulated by Niels Bohr and Werner Heisenberg while collaborating in Copenhagen around 1927. Bohr and Heisenberg extended the probabilistic interpretation of the wavefunction proposed originally by Max Born. The Copenhagen interpretation rejects questions like "where was the particle before I measured its position?" as meaningless. The measurement process randomly picks out exactly one of the many possibilities allowed for by the state's wave function in a manner consistent with the well-defined probabilities that are assigned to each possible state. According to the interpretation, the interaction of an observer or apparatus that is external to the quantum system is the cause of wave function collapse, thus according to Paul Davies, "reality is in the observations, not in the electron". In general, after a measurement (click of a Geiger counter or a trajectory in a spark or bubble chamber) it ceases to be relevant unless subsequent experimental observations can be performed | https://en.wikipedia.org/wiki?curid=54738 |
Interpretations of quantum mechanics Quantum informational approaches have attracted growing support. They subdivide into two kinds. The state is not an objective property of an individual system but is that information, obtained from a knowledge of how a system was prepared, which can be used for making predictions about future measurements. ...A quantum mechanical state being a summary of the observer's information about an individual physical system changes both by dynamical laws, and whenever the observer acquires new information about the system through the process of measurement. The existence of two laws for the evolution of the state vector...becomes problematical only if it is believed that the state vector is an objective property of the system...The "reduction of the wavepacket" does take place in the consciousness of the observer, not because of any unique physical process which takes place there, but only because the state is a construct of the observer and not an objective property of the physical system. The essential idea behind relational quantum mechanics, following the precedent of special relativity, is that different observers may give different accounts of the same series of events: for example, to one observer at a given point in time, a system may be in a single, "collapsed" eigenstate, while to another observer at the same time, it may be in a superposition of two or more states | https://en.wikipedia.org/wiki?curid=54738 |
Interpretations of quantum mechanics Consequently, if quantum mechanics is to be a complete theory, relational quantum mechanics argues that the notion of "state" describes not the observed system itself, but the relationship, or correlation, between the system and its observer(s). The state vector of conventional quantum mechanics becomes a description of the correlation of some "degrees of freedom" in the observer, with respect to the observed system. However, it is held by relational quantum mechanics that this applies to all physical objects, whether or not they are conscious or macroscopic. Any "measurement event" is seen simply as an ordinary physical interaction, an establishment of the sort of correlation discussed above. Thus the physical content of the theory has to do not with objects themselves, but the relations between them. An independent relational approach to quantum mechanics was developed in analogy with David Bohm's elucidation of special relativity, in which a detection event is regarded as establishing a relationship between the quantized field and the detector. The inherent ambiguity associated with applying Heisenberg's uncertainty principle is subsequently avoided. Quantum Bayesianism (also called QBism) is an interpretation of quantum mechanics that takes an agent's actions and experiences as the central concerns of the theory. This interpretation is distinguished by its use of a subjective Bayesian account of probabilities to understand the quantum mechanical Born rule as a normative addition to good decision-making | https://en.wikipedia.org/wiki?curid=54738 |
Interpretations of quantum mechanics QBism draws from the fields of quantum information and Bayesian probability and aims to eliminate the interpretational conundrums that have beset quantum theory. QBism deals with common questions in the interpretation of quantum theory about the nature of wavefunction superposition, quantum measurement, and entanglement. According to QBism, many, but not all, aspects of the quantum formalism are subjective in nature. For example, in this interpretation, a quantum state is not an element of reality—instead it represents the degrees of belief an agent has about the possible outcomes of measurements. For this reason, some philosophers of science have deemed QBism a form of anti-realism. The originators of the interpretation disagree with this characterization, proposing instead that the theory more properly aligns with a kind of realism they call "participatory realism", wherein reality consists of "more" than can be captured by any putative third-person account of it. The many-worlds interpretation is an interpretation of quantum mechanics in which a universal wavefunction obeys the same deterministic, reversible laws at all times; in particular there is no (indeterministic and irreversible) wavefunction collapse associated with measurement | https://en.wikipedia.org/wiki?curid=54738 |
Interpretations of quantum mechanics The phenomena associated with measurement are claimed to be explained by decoherence, which occurs when states interact with the environment producing entanglement, repeatedly "splitting" the universe into mutually unobservable alternate histories—effectively distinct universes within a greater multiverse. The consistent histories interpretation generalizes the conventional Copenhagen interpretation and attempts to provide a natural interpretation of quantum cosmology. The theory is based on a consistency criterion that allows the history of a system to be described so that the probabilities for each history obey the additive rules of classical probability. It is claimed to be consistent with the Schrödinger equation. According to this interpretation, the purpose of a quantum-mechanical theory is to predict the relative probabilities of various alternative histories (for example, of a particle). The ensemble interpretation, also called the statistical interpretation, can be viewed as a minimalist interpretation. That is, it claims to make the fewest assumptions associated with the standard mathematics. It takes the statistical interpretation of Born to the fullest extent. The interpretation states that the wave function does not apply to an individual systemfor example, a single particlebut is an abstract statistical quantity that only applies to an ensemble (a vast multitude) of similarly prepared systems or particles | https://en.wikipedia.org/wiki?curid=54738 |
Interpretations of quantum mechanics In the words of Einstein: The most prominent current advocate of the ensemble interpretation is Leslie E. Ballentine, professor at Simon Fraser University, author of the text book "Quantum Mechanics, A Modern Development". An experiment illustrating the ensemble interpretation is provided in Akira Tonomura's Video clip 1. The de Broglie–Bohm theory of quantum mechanics (also known as the pilot wave theory) is a theory by Louis de Broglie and extended later by David Bohm to include measurements. Particles, which always have positions, are guided by the wavefunction. The wavefunction evolves according to the Schrödinger wave equation, and the wavefunction never collapses. The theory takes place in a single space-time, is non-local, and is deterministic. The simultaneous determination of a particle's position and velocity is subject to the usual uncertainty principle constraint. The theory is considered to be a hidden-variable theory, and by embracing non-locality it satisfies Bell's inequality. The measurement problem is resolved, since the particles have definite positions at all times. Collapse is explained as phenomenological. Quantum Darwinism is a theory meant to explain the emergence of the classical world from the quantum world as due to a process of Darwinian natural selection induced by the environment interacting with the quantum system; where the many possible quantum states are selected against in favor of a stable pointer state | https://en.wikipedia.org/wiki?curid=54738 |
Interpretations of quantum mechanics It was proposed in 2003 by Wojciech Zurek and a group of collaborators including Ollivier, Poulin, Paz and Blume-Kohout. The development of the theory is due to the integration of a number of Zurek’s research topics pursued over the course of twenty-five years including: pointer states, einselection and decoherence. The transactional interpretation of quantum mechanics (TIQM) by John G. Cramer is an interpretation of quantum mechanics inspired by the Wheeler–Feynman absorber theory. It describes the collapse of the wave function as resulting from a time-symmetric transaction between a possibility wave from the source to the receiver (the wave function) and a possibility wave from the receiver to source (the complex conjugate of the wave function). This interpretation of quantum mechanics is unique in that it not only views the wave function as a real entity, but the complex conjugate of the wave function, which appears in the Born rule for calculating the expected value for an observable, as also real. An entirely classical derivation and interpretation of Schrödinger's wave equation by analogy with Brownian motion was suggested by Princeton University professor Edward Nelson in 1966. Similar considerations had previously been published, for example by R. Fürth (1933), I. Fényes (1952), and Walter Weizel (1953), and are referenced in Nelson's paper. More recent work on the stochastic interpretation has been done by M. Pavon. An alternative stochastic interpretation was developed by Roumen Tsekov | https://en.wikipedia.org/wiki?curid=54738 |
Interpretations of quantum mechanics Objective collapse theories differ from the Copenhagen interpretation by regarding both the wave function and the process of collapse as ontologically objective (meaning these exist and occur independent of the observer). In objective theories, collapse occurs either randomly ("spontaneous localization") or when some physical threshold is reached, with observers having no special role. Thus, objective-collapse theories are realistic, indeterministic, no-hidden-variables theories. Standard quantum mechanics does not specify any mechanism of collapse; QM would need to be extended if objective collapse is correct. The requirement for an extension to QM means that objective collapse is more of a theory than an interpretation. Examples include In his treatise "The Mathematical Foundations of Quantum Mechanics", John von Neumann deeply analyzed the so-called measurement problem. He concluded that the entire physical universe could be made subject to the Schrödinger equation (the universal wave function). He also described how measurement could cause a collapse of the wave function. This point of view was prominently expanded on by Eugene Wigner, who argued that human experimenter consciousness (or maybe even dog consciousness) was critical for the collapse, but he later abandoned this interpretation | https://en.wikipedia.org/wiki?curid=54738 |
Interpretations of quantum mechanics Variations of the consciousness causes collapse interpretation include: Other physicists have elaborated their own variations of the consciousness causes collapse interpretation; including: Quantum logic can be regarded as a kind of propositional logic suitable for understanding the apparent anomalies regarding quantum measurement, most notably those concerning composition of measurement operations of complementary variables. This research area and its name originated in the 1936 paper by Garrett Birkhoff and John von Neumann, who attempted to reconcile some of the apparent inconsistencies of classical boolean logic with the facts related to measurement and observation in quantum mechanics. Modal interpretations of quantum mechanics were first conceived of in 1972 by B. van Fraassen, in his paper "A formal approach to the philosophy of science." However, this term now is used to describe a larger set of models that grew out of this approach. The Stanford Encyclopedia of Philosophy describes several versions: Several theories have been proposed which modify the equations of quantum mechanics to be symmetric with respect to time reversal. (E.g. see Wheeler-Feynman time-symmetric theory). This creates retrocausality: events in the future can affect ones in the past, exactly as events in the past can affect ones in the future | https://en.wikipedia.org/wiki?curid=54738 |
Interpretations of quantum mechanics In these theories, a single measurement cannot fully determine the state of a system (making them a type of hidden-variables theory), but given two measurements performed at different times, it is possible to calculate the exact state of the system at all intermediate times. The collapse of the wavefunction is therefore not a physical change to the system, just a change in our knowledge of it due to the second measurement. Similarly, they explain entanglement as not being a true physical state but just an illusion created by ignoring retrocausality. The point where two particles appear to "become entangled" is simply a point where each particle is being influenced by events that occur to the other particle in the future. Not all advocates of time-symmetric causality favour modifying the unitary dynamics of standard quantum mechanics. Thus a leading exponent of the two-state vector formalism, Lev Vaidman, states that the two-state vector formalism dovetails well with Hugh Everett's many-worlds interpretation. BST theories resemble the many worlds interpretation; however, "the main difference is that the BST interpretation takes the branching of history to be a feature of the topology of the set of events with their causal relationships... rather than a consequence of the separate evolution of different components of a state vector." In MWI, it is the wave functions that branches, whereas in BST, the space-time topology itself branches | https://en.wikipedia.org/wiki?curid=54738 |
Interpretations of quantum mechanics BST has applications to Bell's theorem, quantum computation and quantum gravity. It also has some resemblance to hidden-variable theories and the ensemble interpretation: particles in BST have multiple well defined trajectories at the microscopic level. These can only be treated stochastically at a coarse grained level, in line with the ensemble interpretation. The most common interpretations are summarized in the table below. The values shown in the cells of the table are not without controversy, for the precise meanings of some of the concepts involved are unclear and, in fact, are themselves at the center of the controversy surrounding the given interpretation. For another table comparing interpretations of quantum theory, see reference. No experimental evidence exists that distinguishes among these interpretations. To that extent, the physical theory stands, and is consistent with itself and with reality; difficulties arise only when one attempts to "interpret" the theory. Nevertheless, designing experiments which would test the various interpretations is the subject of active research. Most of these interpretations have variants. For example, it is difficult to get a precise definition of the Copenhagen interpretation as it was developed and argued about by many people. Although interpretational opinions are openly and widely discussed today, that was not always the case | https://en.wikipedia.org/wiki?curid=54738 |
Interpretations of quantum mechanics A notable exponent of a tendency of silence was Paul Dirac who once wrote: "The interpretation of quantum mechanics has been dealt with by many authors, and I do not want to discuss it here. I want to deal with more fundamental things." This position is not uncommon among practitioners of quantum mechanics. Others, like Nico van Kampen and Willis Lamb, have openly criticized non-orthodox interpretations of quantum mechanics. Almost all authors below are professional physicists. | https://en.wikipedia.org/wiki?curid=54738 |
Geophysics () is a subject of natural science concerned with the physical processes and physical properties of the Earth and its surrounding space environment, and the use of quantitative methods for their analysis. The term "geophysics" sometimes refers only to geological applications: Earth's shape; its gravitational and magnetic fields; its internal structure and composition; its dynamics and their surface expression in plate tectonics, the generation of magmas, volcanism and rock formation. However, modern geophysics organizations and pure scientists use a broader definition that includes the water cycle including snow and ice; fluid dynamics of the oceans and the atmosphere; electricity and magnetism in the ionosphere and magnetosphere and solar-terrestrial relations; and analogous problems associated with the Moon and other planets. Although geophysics was only recognized as a separate discipline in the 19th century, its origins date back to ancient times. The first magnetic compasses were made from lodestones, while more modern magnetic compasses played an important role in the history of navigation. The first seismic instrument was built in 132 AD. Isaac Newton applied his theory of mechanics to the tides and the precession of the equinox; and instruments were developed to measure the Earth's shape, density and gravity field, as well as the components of the water cycle | https://en.wikipedia.org/wiki?curid=54962 |
Geophysics In the 20th century, geophysical methods were developed for remote exploration of the solid Earth and the ocean, and geophysics played an essential role in the development of the theory of plate tectonics. is applied to societal needs, such as mineral resources, mitigation of natural hazards and environmental protection. In Exploration geophysics, geophysical survey data are used to analyze potential petroleum reservoirs and mineral deposits, locate groundwater, find archaeological relics, determine the thickness of glaciers and soils, and assess sites for environmental remediation. is a highly interdisciplinary subject, and geophysicists contribute to every area of the Earth sciences. To provide a clearer idea of what constitutes geophysics, this section describes phenomena that are studied in physics and how they relate to the Earth and its surroundings. In Geophysics, principles of Physics are applied to study the "Interior" of the Earth. Depending on the problem under study, one has to decide which method should be applied. e.g. for ground water surveys, Electrical method is helpful. For mineral deposits, one can adopt Gravity and/or Magnetic surveys. For Oil & Natural Gas, one has to carry out Gravity, Magnetic surveys to get rough idea about structure of rock formations. If the desired structure is existing, for detailed study of rock formations, one has to carry out Seismic and/or Magneto-telluric surveys | https://en.wikipedia.org/wiki?curid=54962 |
Geophysics The gravitational pull of the Moon and Sun give rise to two high tides and two low tides every lunar day, or every 24 hours and 50 minutes. Therefore, there is a gap of 12 hours and 25 minutes between every high tide and between every low tide. Gravitational forces make rocks press down on deeper rocks, increasing their density as the depth increases. Measurements of gravitational acceleration and gravitational potential at the Earth's surface and above it can be used to look for mineral deposits (see gravity anomaly and gravimetry). The surface gravitational field provides information on the dynamics of tectonic plates. The geopotential surface called the geoid is one definition of the shape of the Earth. The geoid would be the global mean sea level if the oceans were in equilibrium and could be extended through the continents (such as with very narrow canals). The Earth is cooling, and the resulting heat flow generates the Earth's magnetic field through the geodynamo and plate tectonics through mantle convection. The main sources of heat are the primordial heat and radioactivity, although there are also contributions from phase transitions. Heat is mostly carried to the surface by thermal convection, although there are two thermal boundary layers – the core-mantle boundary and the lithosphere – in which heat is transported by conduction. Some heat is carried up from the bottom of the mantle by mantle plumes. The heat flow at the Earth's surface is about , and it is a potential source of geothermal energy | https://en.wikipedia.org/wiki?curid=54962 |
Geophysics Seismic waves are vibrations that travel through the Earth's interior or along its surface. The entire Earth can also oscillate in forms that are called normal modes or free oscillations of the Earth. Ground motions from waves or normal modes are measured using seismographs. If the waves come from a localized source such as an earthquake or explosion, measurements at more than one location can be used to locate the source. The locations of earthquakes provide information on plate tectonics and mantle convection. Recording of seismic waves from controlled sources provide information on the region that the waves travel through. If the density or composition of the rock changes, waves are reflected. Reflections recorded using Reflection Seismology can provide a wealth of information on the structure of the earth up to several kilometers deep and are used to increase our understanding of the geology as well as to explore for oil and gas. Changes in the travel direction, called refraction, can be used to infer the deep structure of the Earth. Earthquakes pose a risk to humans. Understanding their mechanisms, which depend on the type of earthquake (e.g., intraplate or deep focus), can lead to better estimates of earthquake risk and improvements in earthquake engineering. Although we mainly notice electricity during thunderstorms, there is always a downward electric field near the surface that averages 120 volts per meter | https://en.wikipedia.org/wiki?curid=54962 |
Geophysics Relative to the solid Earth, the atmosphere has a net positive charge due to bombardment by cosmic rays. A current of about 1800 amperes flows in the global circuit. It flows downward from the ionosphere over most of the Earth and back upwards through thunderstorms. The flow is manifested by lightning below the clouds and sprites above. A variety of electric methods are used in geophysical survey. Some measure spontaneous potential, a potential that arises in the ground because of man-made or natural disturbances. Telluric currents flow in Earth and the oceans. They have two causes: electromagnetic induction by the time-varying, external-origin geomagnetic field and motion of conducting bodies (such as seawater) across the Earth's permanent magnetic field. The distribution of telluric current density can be used to detect variations in electrical resistivity of underground structures. Geophysicists can also provide the electric current themselves (see induced polarization and electrical resistivity tomography). Electromagnetic waves occur in the ionosphere and magnetosphere as well as in Earth's outer core. Dawn chorus is believed to be caused by high-energy electrons that get caught in the Van Allen radiation belt. Whistlers are produced by lightning strikes. Hiss may be generated by both. Electromagnetic waves may also be generated by earthquakes (see seismo-electromagnetics) | https://en.wikipedia.org/wiki?curid=54962 |
Geophysics In the highly conductive liquid iron of the outer core, magnetic fields are generated by electric currents through electromagnetic induction. Alfvén waves are magnetohydrodynamic waves in the magnetosphere or the Earth's core. In the core, they probably have little observable effect on the Earth's magnetic field, but slower waves such as magnetic Rossby waves may be one source of geomagnetic secular variation. Electromagnetic methods that are used for geophysical survey include transient electromagnetics, magnetotellurics, surface nuclear magnetic resonance and electromagnetic seabed logging. The Earth's magnetic field protects the Earth from the deadly solar wind and has long been used for navigation. It originates in the fluid motions of the outer core. The magnetic field in the upper atmosphere gives rise to the auroras. The Earth's field is roughly like a tilted dipole, but it changes over time (a phenomenon called geomagnetic secular variation). Mostly the geomagnetic pole stays near the geographic pole, but at random intervals averaging 440,000 to a million years or so, the polarity of the Earth's field reverses. These geomagnetic reversals, analyzed within a Geomagnetic Polarity Time Scale, contain 184 polarity intervals in the last 83 million years, with change in frequency over time, with the most recent brief complete reversal of the Laschamp event occurring 41,000 years ago during the last glacial period | https://en.wikipedia.org/wiki?curid=54962 |
Geophysics Geologists observed geomagnetic reversal recorded in volcanic rocks, through magnetostratigraphy correlation (see natural remanent magnetization) and their signature can be seen as parallel linear magnetic anomaly stripes on the seafloor. These stripes provide quantitative information on seafloor spreading, a part of plate tectonics. They are the basis of magnetostratigraphy, which correlates magnetic reversals with other stratigraphies to construct geologic time scales. In addition, the magnetization in rocks can be used to measure the motion of continents. Radioactive decay accounts for about 80% of the Earth's internal heat, powering the geodynamo and plate tectonics. The main heat-producing isotopes are potassium-40, uranium-238, uranium-235, and thorium-232. Radioactive elements are used for radiometric dating, the primary method for establishing an absolute time scale in geochronology. Unstable isotopes decay at predictable rates, and the decay rates of different isotopes cover several orders of magnitude, so radioactive decay can be used to accurately date both recent events and events in past geologic eras. Radiometric mapping using ground and airborne gamma spectrometry can be used to map the concentration and distribution of radioisotopes near the Earth's surface, which is useful for mapping lithology and alteration. Fluid motions occur in the magnetosphere, atmosphere, ocean, mantle and core. Even the mantle, though it has an enormous viscosity, flows like a fluid over long time intervals | https://en.wikipedia.org/wiki?curid=54962 |
Geophysics This flow is reflected in phenomena such as isostasy, post-glacial rebound and mantle plumes. The mantle flow drives plate tectonics and the flow in the Earth's core drives the geodynamo. Geophysical fluid dynamics is a primary tool in physical oceanography and meteorology. The rotation of the Earth has profound effects on the Earth's fluid dynamics, often due to the Coriolis effect. In the atmosphere it gives rise to large-scale patterns like Rossby waves and determines the basic circulation patterns of storms. In the ocean they drive large-scale circulation patterns as well as Kelvin waves and Ekman spirals at the ocean surface. In the Earth's core, the circulation of the molten iron is structured by Taylor columns. Waves and other phenomena in the magnetosphere can be modeled using magnetohydrodynamics. The physical properties of minerals must be understood to infer the composition of the Earth's interior from seismology, the geothermal gradient and other sources of information. Mineral physicists study the elastic properties of minerals; their high-pressure phase diagrams, melting points and equations of state at high pressure; and the rheological properties of rocks, or their ability to flow. Deformation of rocks by creep make flow possible, although over short times the rocks are brittle. The viscosity of rocks is affected by temperature and pressure, and in turn determines the rates at which tectonic plates move. Water is a very complex substance and its unique properties are essential for life | https://en.wikipedia.org/wiki?curid=54962 |
Geophysics Its physical properties shape the hydrosphere and are an essential part of the water cycle and climate. Its thermodynamic properties determine evaporation and the thermal gradient in the atmosphere. The many types of precipitation involve a complex mixture of processes such as coalescence, supercooling and supersaturation. Some precipitated water becomes groundwater, and groundwater flow includes phenomena such as percolation, while the conductivity of water makes electrical and electromagnetic methods useful for tracking groundwater flow. Physical properties of water such as salinity have a large effect on its motion in the oceans. The many phases of ice form the cryosphere and come in forms like ice sheets, glaciers, sea ice, freshwater ice, snow, and frozen ground (or permafrost). The Earth is roughly spherical, but it bulges towards the Equator, so it is roughly in the shape of an ellipsoid (see Earth ellipsoid). This bulge is due to its rotation and is nearly consistent with an Earth in hydrostatic equilibrium. The detailed shape of the Earth, however, is also affected by the distribution of continents and ocean basins, and to some extent by the dynamics of the plates. Evidence from seismology, heat flow at the surface, and mineral physics is combined with the Earth's mass and moment of inertia to infer models of the Earth's interior – its composition, density, temperature, pressure | https://en.wikipedia.org/wiki?curid=54962 |
Geophysics For example, the Earth's mean specific gravity () is far higher than the typical specific gravity of rocks at the surface (), implying that the deeper material is denser. This is also implied by its low moment of inertia (, compared to for a sphere of constant density). However, some of the density increase is compression under the enormous pressures inside the Earth. The effect of pressure can be calculated using the Adams–Williamson equation. The conclusion is that pressure alone cannot account for the increase in density. Instead, we know that the Earth's core is composed of an alloy of iron and other minerals. Reconstructions of seismic waves in the deep interior of the Earth show that there are no S-waves in the outer core. This indicates that the outer core is liquid, because liquids cannot support shear. The outer core is liquid, and the motion of this highly conductive fluid generates the Earth's field. Earth's inner core, however, is solid because of the enormous pressure. Reconstruction of seismic reflections in the deep interior indicate some major discontinuities in seismic velocities that demarcate the major zones of the Earth: inner core, outer core, mantle, lithosphere and crust. The mantle itself is divided into the upper mantle, transition zone, lower mantle and "D′′" layer. Between the crust and the mantle is the Mohorovičić discontinuity. The seismic model of the Earth does not by itself determine the composition of the layers | https://en.wikipedia.org/wiki?curid=54962 |
Geophysics For a complete model of the Earth, mineral physics is needed to interpret seismic velocities in terms of composition. The mineral properties are temperature-dependent, so the geotherm must also be determined. This requires physical theory for thermal conduction and convection and the heat contribution of radioactive elements. The main model for the radial structure of the interior of the Earth is the preliminary reference Earth model (PREM). Some parts of this model have been updated by recent findings in mineral physics (see post-perovskite) and supplemented by seismic tomography. The mantle is mainly composed of silicates, and the boundaries between layers of the mantle are consistent with phase transitions. The mantle acts as a solid for seismic waves, but under high pressures and temperatures it deforms so that over millions of years it acts like a liquid. This makes plate tectonics possible. If a planet's magnetic field is strong enough, its interaction with the solar wind forms a magnetosphere. Early space probes mapped out the gross dimensions of the Earth's magnetic field, which extends about 10 Earth radii towards the Sun. The solar wind, a stream of charged particles, streams out and around the terrestrial magnetic field, and continues behind the magnetic tail, hundreds of Earth radii downstream. Inside the magnetosphere, there are relatively dense regions of solar wind particles called the Van Allen radiation belts. Geophysical measurements are generally at a particular time and place | https://en.wikipedia.org/wiki?curid=54962 |
Geophysics Accurate measurements of position, along with earth deformation and gravity, are the province of geodesy. While geodesy and geophysics are separate fields, the two are so closely connected that many scientific organizations such as the American Geophysical Union, the Canadian Geophysical Union and the International Union of Geodesy and encompass both. Absolute positions are most frequently determined using the global positioning system (GPS). A three-dimensional position is calculated using messages from four or more visible satellites and referred to the 1980 Geodetic Reference System. An alternative, optical astronomy, combines astronomical coordinates and the local gravity vector to get geodetic coordinates. This method only provides the position in two coordinates and is more difficult to use than GPS. However, it is useful for measuring motions of the Earth such as nutation and Chandler wobble. Relative positions of two or more points can be determined using very-long-baseline interferometry. Gravity measurements became part of geodesy because they were needed to related measurements at the surface of the Earth to the reference coordinate system. Gravity measurements on land can be made using gravimeters deployed either on the surface or in helicopter flyovers. Since the 1960s, the Earth's gravity field has been measured by analyzing the motion of satellites. Sea level can also be measured by satellites using radar altimetry, contributing to a more accurate geoid | https://en.wikipedia.org/wiki?curid=54962 |
Geophysics In 2002, NASA launched the Gravity Recovery and Climate Experiment (GRACE), wherein two twin satellites map variations in Earth's gravity field by making measurements of the distance between the two satellites using GPS and a microwave ranging system. Gravity variations detected by GRACE include those caused by changes in ocean currents; runoff and ground water depletion; melting ice sheets and glaciers. Satellites in space have made it possible to collect data from not only the visible light region, but in other areas of the electromagnetic spectrum. The planets can be characterized by their force fields: gravity and their magnetic fields, which are studied through geophysics and space physics. Measuring the changes in acceleration experienced by spacecraft as they orbit has allowed fine details of the gravity fields of the planets to be mapped. For example, in the 1970s, the gravity field disturbances above lunar maria were measured through lunar orbiters, which led to the discovery of concentrations of mass, mascons, beneath the Imbrium, Serenitatis, Crisium, Nectaris and Humorum basins. emerged as a separate discipline only in the 19th century, from the intersection of physical geography, geology, astronomy, meteorology, and physics. However, many geophysical phenomena – such as the Earth's magnetic field and earthquakes – have been investigated since the ancient era. The magnetic compass existed in China back as far as the fourth century BC. It was used as much for feng shui as for navigation on land | https://en.wikipedia.org/wiki?curid=54962 |
Geophysics It was not until good steel needles could be forged that compasses were used for navigation at sea; before that, they could not retain their magnetism long enough to be useful. The first mention of a compass in Europe was in 1190 AD. In circa 240 BC, Eratosthenes of Cyrene deduced that the Earth was round and measured the circumference of Earth with great precision. He developed a system of latitude and longitude. Perhaps the earliest contribution to seismology was the invention of a seismoscope by the prolific inventor Zhang Heng in 132 AD. This instrument was designed to drop a bronze ball from the mouth of a dragon into the mouth of a toad. By looking at which of eight toads had the ball, one could determine the direction of the earthquake. It was 1571 years before the first design for a seismoscope was published in Europe, by Jean de la Hautefeuille. It was never built. One of the publications that marked the beginning of modern science was William Gilbert's "De Magnete" (1600), a report of a series of meticulous experiments in magnetism. Gilbert deduced that compasses point north because the Earth itself is magnetic. In 1687 Isaac Newton published his "Principia", which not only laid the foundations for classical mechanics and gravitation but also explained a variety of geophysical phenomena such as the tides and the precession of the equinox. The first seismometer, an instrument capable of keeping a continuous record of seismic activity, was built by James Forbes in 1844. | https://en.wikipedia.org/wiki?curid=54962 |
High-energy astronomy High energy astronomy is the study of astronomical objects that release electromagnetic radiation of highly energetic wavelengths. It includes X-ray astronomy, gamma-ray astronomy, and extreme UV astronomy, as well as studies of neutrinos and cosmic rays. The physical study of these phenomena is referred to as high-energy astrophysics. Astronomical objects commonly studied in this field may include black holes, neutron stars, active galactic nuclei, supernovae, supernova remnants, and gamma ray bursts. Some space and ground-based telescopes that have studied high energy astronomy include the following: | https://en.wikipedia.org/wiki?curid=55233 |
Timeline of knowledge about the interstellar and intergalactic medium Timeline of knowledge about the interstellar medium and intergalactic medium | https://en.wikipedia.org/wiki?curid=58934 |
List of biologists This is a list of notable biologists with a biography in Wikipedia. It includes zoologists, botanists, ornithologists, entomologists, malacologists, naturalists and other specialities. | https://en.wikipedia.org/wiki?curid=59018 |
Soil science Sometimes terms which refer to branches of soil science, such as pedology (formation, chemistry, morphology, and classification of soil) and edaphology (how soils interact with living things, especially plants), are used as if synonymous with soil science. The diversity of names associated with this discipline is related to the various associations concerned. Indeed, engineers, agronomists, chemists, geologists, physical geographers, ecologists, biologists, microbiologists, silviculturists, sanitarians, archaeologists, and specialists in regional planning, all contribute to further knowledge of soils and the advancement of the soil sciences. Soil scientists have raised concerns about how to preserve soil and arable land in a world with a growing population, possible future water crisis, increasing per capita food consumption, and land degradation. Soil occupies the pedosphere, one of Earth's spheres that the geosciences use to organize the Earth conceptually. This is the conceptual perspective of pedology and edaphology, the two main branches of soil science. Pedology is the study of soil in its natural setting. Edaphology is the study of soil in relation to soil-dependent uses. Both branches apply a combination of soil physics, soil chemistry, and soil biology. Due to the numerous interactions between the biosphere, atmosphere and hydrosphere that are hosted within the pedosphere, more integrated, less soil-centric concepts are also valuable | https://en.wikipedia.org/wiki?curid=59413 |
Soil science Many concepts essential to understanding soil come from individuals not identifiable strictly as soil scientists. This highlights the interdisciplinary nature of soil concepts. Dependence on and curiosity about soil, exploring the diversity and dynamics of this resource continues to yield fresh discoveries and insights. New avenues of soil research are compelled by a need to understand soil in the context of climate change, greenhouse gases, and carbon sequestration. Interest in maintaining the planet's biodiversity and in exploring past cultures has also stimulated renewed interest in achieving a more refined understanding of soil. Most empirical knowledge of soil in nature comes from soil survey efforts. Soil survey, or soil mapping, is the process of determining the soil types or other properties of the soil cover over a landscape, and mapping them for others to understand and use. It relies heavily on distinguishing the individual influences of the five classic soil forming factors. This effort draws upon geomorphology, physical geography, and analysis of vegetation and land-use patterns. Primary data for the soil survey are acquired by field sampling and supported by remote sensing. As of 2006, the World Reference Base for Soil Resources, via its Land & Water Development division, is the pre-eminent soil classification system. It replaces the previous FAO soil classification. The WRB borrows from modern soil classification concepts, including USDA soil taxonomy | https://en.wikipedia.org/wiki?curid=59413 |
Soil science The classification is based mainly on soil morphology as an expression pedogenesis. A major difference with USDA soil taxonomy is that soil climate is not part of the system, except insofar as climate influences soil profile characteristics. Many other classification schemes exist, including vernacular systems. The structure in vernacular systems are either nominal, giving unique names to soils or landscapes, or descriptive, naming soils by their characteristics such as red, hot, fat, or sandy. Soils are distinguished by obvious characteristics, such as physical appearance (e.g., color, texture, landscape position), performance (e.g., production capability, flooding), and accompanying vegetation. A vernacular distinction familiar to many is classifying texture as heavy or light. Light soil content and better structure, take less effort to turn and cultivate. Contrary to popular belief, light soils do not weigh less than heavy soils on an air dry basis nor do they have more porosity. Contemporaries Friedrich Albert Fallou, the German founder of modern soil science, and Vasily Dokuchaev, the Russian founder of modern soil science, are both credited with being among the first to identify soil as a resource whose distinctness and complexity deserved to be separated conceptually from geology and crop production and treated as a whole. As a founding father of soil science Fallou has primacy in time | https://en.wikipedia.org/wiki?curid=59413 |
Soil science Fallou was working on the origins of soil before Dokuchaev was born, however Dokuchaev's work was more extensive and is considered to be the more significant to modern soil theory than Fallou's. Previously, soil had been considered a product of chemical transformations of rocks, a dead substrate from which plants derive nutritious elements. Soil and bedrock were in fact equated. Dokuchaev considers the soil as a natural body having its own genesis and its own history of development, a body with complex and multiform processes taking place within it. The soil is considered as different from bedrock. The latter becomes soil under the influence of a series of soil-formation factors (climate, vegetation, country, relief and age). According to him, soil should be called the "daily" or outward horizons of rocks regardless of the type; they are changed naturally by the common effect of water, air and various kinds of living and dead organisms. A 1914 encyclopedic definition: "the different forms of earth on the surface of the rocks, formed by the breaking down or weathering of rocks". serves to illustrate the historic view of soil which persisted from the 19th century. Dokuchaev's late 19th century soil concept developed in the 20th century to one of soil as earthy material that has been altered by living processes. A corollary concept is that soil without a living component is simply a part of earth's outer layer | https://en.wikipedia.org/wiki?curid=59413 |
Soil science Further refinement of the soil concept is occurring in view of an appreciation of energy transport and transformation within soil. The term is popularly applied to the material on the surface of the Earth's moon and Mars, a usage acceptable within a portion of the scientific community. Accurate to this modern understanding of soil is Nikiforoff's 1959 definition of soil as the "excited skin of the sub aerial part of the earth's crust". Academically, soil scientists tend to be drawn to one of five areas of specialization: microbiology, pedology, edaphology, physics, or chemistry. Yet the work specifics are very much dictated by the challenges facing our civilization's desire to sustain the land that supports it, and the distinctions between the sub-disciplines of soil science often blur in the process. professionals commonly stay current in soil chemistry, soil physics, soil microbiology, pedology, and applied soil science in related disciplines One interesting effort drawing in soil scientists in the USA is the Soil Quality Initiative. Central to the Soil Quality Initiative is developing indices of soil health and then monitoring them in a way that gives us long term (decade-to-decade) feedback on our performance as stewards of the planet. The effort includes understanding the functions of soil microbiotic crusts and exploring the potential to sequester atmospheric carbon in soil organic matter | https://en.wikipedia.org/wiki?curid=59413 |
Soil science The concept of soil quality, however, has not been without its share of controversy and criticism, including critiques by Nobel Laureate Norman Borlaug and World Food Prize Winner Pedro Sanchez. A more traditional role for soil scientists has been to map soils. Most every area in the United States now has a published soil survey, which includes interpretive tables as to how soil properties support or limit activities and uses. An internationally accepted soil taxonomy allows uniform communication of soil characteristics and soil functions. National and international soil survey efforts have given the profession unique insights into landscape scale functions. The landscape functions that soil scientists are called upon to address in the field seem to fall roughly into six areas: There are also practical applications of soil science that might not be apparent from looking at a published soil survey. Depression storage capacity, in soil science, is the ability of a particular area of land to retain water in its pits and depressions, thus preventing it from flowing. Depression storage capacity, along with infiltration capacity, is one of the main factors involved in Horton overland flow, whereby water volume surpasses both infiltration and depression storage capacity and begins to flow horizontally across land, possibly leading to flooding and soil erosion. The study of land's depression storage capacity is important in the fields of geology, ecology, and especially hydrology. | https://en.wikipedia.org/wiki?curid=59413 |
Triboluminescence is an optical phenomenon in which light is generated when a material is mechanically pulled apart, ripped, scratched, crushed, or rubbed (see tribology). The phenomenon is not fully understood, but appears to be caused by the separation and reunification of static electrical charges. The term comes from the Greek τρίβειν ("to rub"; see tribology) and the Latin "lumen" (light). can be observed when breaking sugar crystals and peeling adhesive tapes. "Triboluminescence" is often used as a synonym for "fractoluminescence" (a term sometimes used when referring only to light emitted from fractured crystals). differs from piezoluminescence in that a piezoluminescent material emits light when it is deformed, as opposed to broken. These are examples of mechanoluminescence, which is luminescence resulting from any mechanical action on a solid. The Uncompahgre Ute Indians from Central Colorado are one of the first documented groups of people in the world credited with the application of mechanoluminescence involving the use of quartz crystals to generate light. The Ute constructed special ceremonial rattles made from buffalo rawhide which they filled with clear quartz crystals collected from the mountains of Colorado and Utah. When the rattles were shaken at night during ceremonies, the friction and mechanical stress of the quartz crystals impacting together produced flashes of light visible through the translucent buffalo hide | https://en.wikipedia.org/wiki?curid=60875 |
Triboluminescence The first recorded observation is attributed to English scholar Francis Bacon when he recorded in his 1620 "Novum Organum" that "It is well known that all sugar, whether candied or plain, if it be hard, will sparkle when broken or scraped in the dark." The scientist Robert Boyle also reported on some of his work on triboluminescence in 1663. In the late 1790s, sugar production began to produce more refined sugar crystals. These crystals were formed into a large solid cone for transport and sale. This solid cone of sugar had to be broken into usable chunks using a device known as sugar nips. People began to notice that as sugar was "nipped" in low light, tiny bursts of light were visible. A historically important instance of triboluminescence occurred in Paris in 1675. Astronomer Jean-Felix Picard observed that his barometer was glowing in the dark as he carried it. His barometer consisted of a glass tube that was partially filled with mercury. Whenever the mercury slid down the glass tube, the empty space above the mercury would glow. While investigating this phenomenon, researchers discovered that static electricity could cause low-pressure air to glow. This discovery revealed the possibility of electric lighting. Materials scientists have not yet arrived at a full understanding of the effect, but the current theory of triboluminescence — based upon crystallographic, spectroscopic, and other experimental evidence — is that upon fracture of asymmetrical materials, charge is separated | https://en.wikipedia.org/wiki?curid=60875 |
Triboluminescence When the charges recombine, the electrical discharge ionizes the surrounding air, causing a flash of light. Research further suggests that crystals which display triboluminescence must lack symmetry (thus being anisotropic in order to permit charge separation) and be poor conductors. However, there are substances which break this rule, and which do not possess asymmetry, yet display triboluminescence anyway, such as hexakis(antipyrine)terbium iodide. It is thought that these materials contain impurities, which make the substance locally asymmetric. The biological phenomenon of triboluminescence is conditioned by recombination of free radicals during mechanical activation. A diamond may begin to glow while being rubbed. This occasionally happens to diamonds while a facet is being ground or the diamond is being sawn during the cutting process. Diamonds may fluoresce blue or red. Some other minerals, such as quartz, are triboluminescent, emitting light when rubbed together. Ordinary Pressure-sensitive tape ("Scotch tape") displays a glowing line where the end of the tape is being pulled away from the roll. In 1953, Soviet scientists observed that unpeeling a roll of tape in a vacuum produced X-rays. The mechanism of X-ray generation was studied further in 2008. Similar X-Ray emissions have also been observed with metals. Also, when sugar crystals are crushed, tiny electrical fields are created, separating positive and negative charges that then create sparks while trying to reunite | https://en.wikipedia.org/wiki?curid=60875 |
Triboluminescence Wint-O-Green Life Savers work especially well for creating such sparks, because wintergreen oil (methyl salicylate) is fluorescent and converts ultraviolet light into blue light. is a biological phenomenon observed in mechanical deformation and contact electrization of epidermal surface of osseous and soft tissues, at chewing food, at friction in joints of vertebrae, during sexual intercourse, and during blood circulation. "Fractoluminescence" is often used as a synonym for triboluminescence. It is the emission of light from the fracture (rather than rubbing) of a crystal, but fracturing often occurs with rubbing. Depending upon the atomic and molecular composition of the crystal, when the crystal fractures a charge separation can occur making one side of the fractured crystal positively charged and the other side negatively charged. Like in triboluminescence, if the charge separation results in a large enough electric potential, a discharge across the gap and through the bath gas between the interfaces can occur. The potential at which this occurs depends upon the dielectric properties of the bath gas. The emission of electromagnetic radiation (EMR) during plastic deformation and crack propagation in metals and rocks has been studied. The EMR emissions from metals and alloys have also been explored and confirmed. Molotskii presented a dislocation mechanism for this type of EMR emission | https://en.wikipedia.org/wiki?curid=60875 |
Triboluminescence Recently, Srilakshmi and Misra reported an additional phenomenon of secondary EMR during plastic deformation and crack propagation in uncoated and metal-coated metals and alloys. EMR during the micro-plastic deformation and crack propagation from several metals and alloys and transient magnetic field generation during necking in ferromagnetic metals were reported by Misra (1973–75), which have been confirmed and explored by several researchers. Tudik and Valuev (1980) were able to measure the EMR frequency during tensile fracture of iron and aluminum in the region 1014¬¬ Hz by using photomultipliers. Srilakshmi and Misra (2005a) also reported an additional phenomenon of secondary electromagnetic radiation in uncoated and metal-coated metals and alloys. If a solid material is subjected to stresses of large amplitudes, which can cause plastic deformation and fracture, emissions such as thermal, acoustic, ions, exo-emissions occur. With the discovery of new materials and advancement in instrumentation to measure effects of EMR, crack formation and fracture; the EMR emissions effect becomes important. In a moderate vacuum, peeling tape generated x-rays sufficient to x-ray a human finger. The study of deformation is essential for the development of new materials. Deformation in metals depends on temperature, type of stress applied, strain rate, oxidation and corrosion | https://en.wikipedia.org/wiki?curid=60875 |
Triboluminescence Deformation induced EMR can be divided into three categories: effects in ionic crystal materials; effects in rocks and granites; and, effects in metals and alloys. EMR emission depends on the orientation of the grains in individual crystals since material properties are different in differing directions. Amplitude of EMR pulse increases as long as the crack continues to grow as new atomic bonds are broken and it leads to EMR. The Pulse starts to decay as cracking halts. Observations from experiments showed that emitted EMR signals contain mixed frequency components. Most widely tensile test method is used to characterize the mechanical properties of materials. From any complete tensile test record, one can obtain important information about the material's elastic properties, the character and extent of plastic deformation, yield and tensile strengths and toughness. The information which can be obtained from one test justifies the extensive use of tensile test in engineering materials research. Therefore, investigations of EMR emissions are mainly based on the tensile test of the specimens. From experiments, it can be shown that tensile crack formation excites more intensive EMR than shear cracking, increasing the elasticity, strength and loading rate during uniaxial loading increases amplitude. Poisson's ratio is a key parameter for EMR characterization during triaxial compression | https://en.wikipedia.org/wiki?curid=60875 |
Triboluminescence If the Poisson's ratio is lower, it is harder for the material to strain transversally and hence higher is the probability of new fractures. Mechanism of plastic deformation is very important for safe operation of any component under dynamic conditions. This EMR can be utilized in developing sensors/smart materials. This technique can be implemented in powder metallurgy technique also. EMR is one of these emissions which accompany large deformation. If an element can be identified which gives maximum EMR response with minimum mechanical stimulus then it can be incorporated into main material and thus set new trends in the development of smart material. The deformation induced EMR can serve as a strong tool for failure detection and prevention. Orel V.E. invented the device to measure EMR whole blood and lymphocytes in laboratory diagnostics. | https://en.wikipedia.org/wiki?curid=60875 |
Photoconductivity is an optical and electrical phenomenon in which a material becomes more electrically conductive due to the absorption of electromagnetic radiation such as visible light, ultraviolet light, infrared light, or gamma radiation. When light is absorbed by a material such as a semiconductor, the number of free electrons and electron holes increases and raises its electrical conductivity. To cause excitation, the light that strikes the semiconductor must have enough energy to raise electrons across the band gap, or to excite the impurities within the band gap. When a bias voltage and a load resistor are used in series with the semiconductor, a voltage drop across the load resistors can be measured when the change in electrical conductivity of the material varies the current through the circuit. Classic examples of photoconductive materials include : When a photoconductive material is connected as part of a circuit, it functions as a resistor whose resistance depends on the light intensity. In this context, the material is called a photoresistor (also called "light-dependent resistor" or "photoconductor"). The most common application of photoresistors is as photodetectors, i.e. devices that measure light intensity. Photoresistors are not the "only" type of photodetector—other types include charge-coupled devices (CCDs), photodiodes and phototransistors—but they are among the most common | https://en.wikipedia.org/wiki?curid=60885 |
Photoconductivity Some photodetector applications in which photoresistors are often used include camera light meters, street lights, clock radios, infrared detectors, nanophotonic systems and low-dimensional photo-sensors devices. Some materials exhibit deterioration in photoconductivity upon exposure to illumination. One prominent example is hydrogenated amorphous silicon (a-Si:H) in which a metastable reduction in photoconductivity is observable (see Staebler–Wronski effect). Other materials that were reported to exhibit negative photoconductivity include molybdenum disulfide, graphene, indium arsenide nanowires, and metal nanoparticles. In 2016 it was demonstrated that in some photoconductive material a magnetic order can exist. One prominent example is CHNH(Mn:Pb)I. In this material a light induced magnetization melting was also demonstrated thus could be used in magneto optical devices and data storage. | https://en.wikipedia.org/wiki?curid=60885 |
Radio-frequency induction or RF induction is the use of a radio frequency magnetic field to transfer energy by means of electromagnetic induction in the near field. A radio-frequency alternating current is passed through a coil of wire that acts as the transmitter, and a second coil or conducting object, magnetically coupled to the first coil, acts as the receiver. | https://en.wikipedia.org/wiki?curid=60994 |
Division (biology) Division is a taxonomic rank in biological classification that is used differently in zoology and in botany. In botany and mycology, "division" refers to a rank equivalent to phylum. The use of either term is allowed under the International Code of Botanical Nomenclature, and both are commonly used in scientific literature. The main Divisions of land plants, in the order in which they probably evolved, are the Marchantiophyta (liverworts), Anthocerotophyta (hornworts), Bryophyta (mosses), Filicophyta (ferns), Sphenophyta (horsetails), Cycadophyta (cycads), Ginkgophyta (ginkgo)s, Pinophyta (conifers), Gnetophyta (gnetophytes), and the Magnoliophyta (Angiosperms, flowering plants). The flowering plants now dominate terrestrial ecosystems, comprising 80% of vascular plant species. In zoology, the term "division" is applied to an optional rank subordinate to the infraclass and superordinate to the cohort. A widely used classification (e.g. Carroll 1988) recognises teleost fishes as a Division Teleostei within Class Actinopterygii (the ray-finned fishes). Less commonly (as in Milner 1988), living tetrapods are ranked as Divisions Amphibia and Amniota within the clade of vertebrates with fleshy limbs (Sarcopterygii). | https://en.wikipedia.org/wiki?curid=61889 |
Pfizer Inc. () is an American multinational pharmaceutical corporation headquartered in New York City. It is one of the world's largest pharmaceutical companies. It is listed on the New York Stock Exchange, and its shares have been a component of the Dow Jones Industrial Average since 2004. ranked No. 57 on the 2018 Fortune 500 list of the largest United States corporations by total revenue. On December 19, 2018, announced a joint merger of their consumer healthcare division with UK pharma giant GlaxoSmithKline; the British company will maintain a controlling share (listed at 68%). The company developed and produces medicines and vaccines for a wide range of medical disciplines, including immunology, oncology, cardiology, endocrinology, and neurology. Its products include the blockbuster drug Lipitor (atorvastatin), used to lower LDL blood cholesterol; Lyrica (pregabalin) for neuropathic pain and fibromyalgia; Diflucan (fluconazole), an oral antifungal medication; Zithromax (azithromycin), an antibiotic; Viagra (sildenafil) for erectile dysfunction; and Celebrex (also Celebra, celecoxib), an anti-inflammatory drug. In 2016, Inc. was expected to merge with Allergan to create the Ireland-based "plc" in a deal that would have been worth $160 billion. The merger was called off in April 2016, however, because of new rules from the United States Treasury against tax inversions, a method of avoiding taxes by merging with a foreign company | https://en.wikipedia.org/wiki?curid=62304 |
Pfizer The company has made the second-largest pharmaceutical settlement with the United States Department of Justice. In 1849, was founded in New York City by German-American Charles and his cousin Charles F. Erhart from Ludwigsburg, Germany. They launched the chemicals business, Charles and Company, from a building at the intersection of Harrison Avenue and Bartlett Street in Williamsburg, Brooklyn, where they produced an antiparasitic called santonin. This was an immediate success, although it was the production of citric acid that led to Pfizer's growth in the 1880s. continued to buy property to expand its lab and factory. Pfizer's original administrative headquarters was at 81 Maiden Lane in Manhattan. By 1906, sales totaled $3.4 million. World War I caused a shortage of calcium citrate, which imported from Italy for the manufacture of citric acid, and the company began a search for an alternative supply. chemists learned of a fungus that ferments sugar to citric acid, and they were able to commercialize production of citric acid from this source in 1919. The company developed expertise in fermentation technology as a result. These skills were applied to the mass production of the antibiotic penicillin during World War II in response to the need to treat injured Allied soldiers; most of the penicillin that went ashore with the troops on D-Day was made by Pfizer. Penicillin became very inexpensive in the 1940s, and searched for new antibiotics with greater profit potential | https://en.wikipedia.org/wiki?curid=62304 |
Pfizer They discovered Terramycin (oxytetracycline) in 1950, and this changed the company from a manufacturer of fine chemicals to a research-based pharmaceutical company. developed a drug discovery program focused on in vitro synthesis in order to augment its research in fermentation technology. The company also established an animal health division in 1959 with an farm and research facility in Terre Haute, Indiana. By the 1950s, had established offices in Belgium, Brazil, Canada, Cuba, Mexico, Panama, Puerto Rico, and the United Kingdom. In 1960, the company moved its medical research laboratory operations out of New York City to a new facility in Groton, Connecticut. In 1980, they launched Feldene (piroxicam), a prescription anti-inflammatory medication that became Pfizer's first product to reach one billion dollars in total sales. During the 1980s and 1990s, Corporation growth was sustained by the discovery and marketing of Zoloft, Lipitor, Norvasc, Zithromax, Aricept, Diflucan, and Viagra. In this decade, grew by mergers, including those with Warner–Lambert (2000), Pharmacia (2003), and Wyeth (2009). In 2003, the company acquired Esperion Therapeutics for $1.3 billion (later selling the unit in 2008), protecting Lipitor from ETC-216. In 2004, announced it would acquire Meridica for $125 million. In 2005, the company acquired Vicuron Pharmaceuticals for $1.9 billion, Idun for just less than $300 million and finally Angiosyn for $527 million | https://en.wikipedia.org/wiki?curid=62304 |
Pfizer On June 26, 2006, announced it would sell its Consumer Healthcare unit (manufacturer of Listerine, Nicorette, Visine, Sudafed and Neosporin) to Johnson & Johnson for $16.6 billion. Development of torcetrapib, a drug that increases production of HDL, or "good cholesterol", which reduces LDL thought to be correlated to heart disease, was cancelled in December 2006. During a Phase III clinical trial involving 15,000 patients, more deaths occurred in the group that took the medicine than expected, and a sixty percent increase in mortality was seen among patients taking the combination of torcetrapib and Lipitor versus Lipitor alone. Lipitor alone was not implicated in the results, but lost nearly $1 billion developing the failed drug and the market value of the company plummeted afterwards. That same year, the company also announced it would acquire PowerMed and Rivax. In September 2009, pleaded guilty to the illegal marketing of the arthritis drug Bextra for uses unapproved by the U.S. Food and Drug Administration (FDA), and agreed to a $2.3 billion settlement, the largest health care fraud settlement at that time. A July 2010 article in "BusinessWeek" reported that was seeing more success in its battle against makers of counterfeit prescription drugs by pursuing civil lawsuits rather than criminal prosecution. has hired customs and narcotics experts from all over the globe to track down fakes and assemble evidence that can be used to pursue civil suits for trademark infringement. Since 2007, has spent $3 | https://en.wikipedia.org/wiki?curid=62304 |
Pfizer 3 million on investigations and legal fees and recovered about $5.1 million, with another $5 million tied up in ongoing cases. On May 6, 2013, told The Associated Press it would begin selling Viagra directly to patients via its website. acquired Warner–Lambert in 2000 for $111.8 billion, at the time, created the second largest pharmaceutical company in the world. Warner–Lambert was founded as a Philadelphia drug store in 1856 by William R. Warner. Inventing a tablet-coating process gained Warner a place in the Smithsonian Institution. Parke–Davis was founded in Detroit in 1866 by Hervey Parke and George Davis. Warner–Lambert took over Parke–Davis in 1976, and acquired Wilkinson Sword in 1993 and Agouron Pharmaceuticals in 1999. In 2002, merged with Pharmacia. The merger was again driven in part by the desire to acquire full rights to a product, this time Celebrex (celecoxib), the COX-2 selective inhibitor previously jointly marketed by Searle (acquired by Pharmacia) and Pfizer. In the ensuing years, carried out a massive restructuring that resulted in numerous site closures and the loss of jobs including Terre Haute, Indiana; Holland, Michigan; Groton, Connecticut; Brooklyn, New York; Sandwich, UK; and Puerto Rico. Pharmacia had been formed by a series of mergers and acquisitions from its predecessors, including Searle, Upjohn and SUGEN. In April 1888, Searle was founded in Omaha, Nebraska by Gideon Daniel Searle. In 1908, the company was incorporated in Chicago, Illinois | https://en.wikipedia.org/wiki?curid=62304 |
Pfizer In 1941, the company established headquarters in Skokie, Illinois. It was acquired by the Monsanto Company, headquartered in St. Louis, Missouri, in 1985. The Upjohn Company was a pharmaceutical manufacturing firm founded in 1886 in Kalamazoo, Michigan, by Dr. William E. Upjohn, a graduate of the University of Michigan medical school. The company was originally formed to make friable pills, which were designed to be easily digested. Greenstone was founded in 1993 by Upjohn as a generics division. In 1995, Upjohn merged with Pharmacia, to form Pharmacia & Upjohn. Pharmacia was created in April 2000 through the merger of Pharmacia & Upjohn with the Monsanto Company and its G.D. Searle unit. The merged company was based in Peapack, New Jersey. The agricultural division was spun off from Pharmacia, as Monsanto, in preparation for the close of the acquisition by Pfizer. SUGEN, a company focused on protein kinase inhibitors, was founded in 1991 in Redwood City, California, and acquired by Pharmacia in 1999. The company pioneered the use of ATP-mimetic small molecules to block signal transduction. After the merger, the SUGEN site was shut down in 2003, with the loss of over 300 jobs, and several programs were transferred to Pfizer. These included sunitinib (Sutent), which was approved for human use by the FDA in January 2006, passed $1 billion in annual revenues for in 2010. A related compound, SU11654 (Toceranib), was also approved for canine tumors, and the ALK inhibitor Crizotinib also grew out of a SUGEN program | https://en.wikipedia.org/wiki?curid=62304 |
Pfizer In 2003, the new made Greenstone (originally established as a division of Upjohn) its generic division, and focused on selling authorized generics of Pfizer's products. In 2008, announced 275 job cuts at the Kalamazoo manufacturing facility. Kalamazoo was previously the world headquarters for the Upjohn Company. On January 26, 2009, after more than a year of talks between the two companies, agreed to buy pharmaceuticals rival Wyeth for a combined US$68 billion in cash, shares and loans, including some US$22.5 billion lent by five major Wall Street banks. The deal cemented Pfizer's position as the largest pharmaceutical company in the world, with the merged company generating over US$20 billion in cash each year, and was the largest corporate merger since AT&T and BellSouth's US$70 billion deal in March 2006. The combined company was expected to save US$4 billion annually through streamlining; however, as part of the deal, both companies must repatriate billions of dollars in revenue from foreign sources to the United States, which will result in higher tax costs. The acquisition was completed on October 15, 2009, making Wyeth a wholly owned subsidiary of Pfizer. The merger was broadly criticized. Harvard Business School's Gary Pisano told The Wall Street Journal, "the record of big mergers and acquisitions in Big Pharma has just not been good. There's just been an enormous amount of shareholder wealth destroyed | https://en.wikipedia.org/wiki?curid=62304 |
Pfizer " Analysts said at the time, "The Warner–Lambert and Pharmacia mergers do not appear to have achieved gains for shareholders, so it is unclear who benefits from the Wyeth–merger to many critics." In October 2010, agreed to buy King Pharmaceuticals for $3.6 billion in cash or $14.25 per share: an approximately 40% premium over King's closing share price October 11, 2010. In February 2011, it was announced that was to close its UK research and development facility (formerly also a manufacturing plant) in Sandwich, Kent, which at the time employed 2,400 people. However, as of 2014, has a reduced presence at the site; it also has a UK research unit in Cambridge. On September 4, 2012, the FDA approved a pill for a rare type of leukemia. The medicine, called Bosulif, treats chronic myelogenous leukemia (CML), a blood and bone marrow disease that usually affects older adults. In July 2014, the company announced it would acquire Innopharma for $225 million, plus up to $135 million in milestone payments, in a deal that expanded Pfizer's range of generic and injectable drugs. On January 5, 2015, the company announced it would acquire a controlling interest in Redvax for an undisclosed sum. This deal expanded the company's vaccine portfolio targeting human cytomegalovirus. In March 2015, the company announced it would restart its collaboration with Eli Lilly surrounding the phase III trial of Tanezumab. is expected to receive an upfront sum of $200 million | https://en.wikipedia.org/wiki?curid=62304 |
Pfizer In June 2015, the company acquired two meningitis drugs from GlaxoSmithKline—Nimenrix and Mencevax—for around $130 million, expanding the company's meningococcal disease portfolio of drugs. In May 2016, the company announced it would acquire Anacor Pharmaceuticals for $5.2 billion, expanding the companies portfolio in both inflammation and immunology drugs areas. On their final trading day, Anacor shares traded for $99.20 each, giving Anacor a market capitalisation of $4.5 billion. In August, the company made a $40 million bid for the assets of the now bankrupt BIND Therapeutics through the U.S. Bankruptcy Court. The same month, the company announced it would acquire Bamboo Therapeutics for $645 million, expanding the company's gene therapy offerings. Later, in August, the company announced the acquisition of cancer drug-maker - Medivation - for $14 billion. On Medivation's final day of trading, its shares were valued at $81.44 each, giving an effective market capitalisation of $13.52 billion. Two days later, announced it would acquire AstraZenecas small-molecule antibiotics business for $1.575 billion merging it into its "Essential Medicines" business In the same month the company licensed the anti-CTLA4 monoclonal antibody, ONC-392, from OncoImmune. In May 2019 the company announced it would acquire Therachon for $810 million, expanding its rare disease portfolio through Theracons recombinant human fibroblast growth factor receptor 3 compound, aimed at treating conditions such as achondroplasia | https://en.wikipedia.org/wiki?curid=62304 |
Pfizer In June, announced it would acquire Array Biopharma for $10.6 billion boosting its oncology pipeline. Plans to spin out Zoetis, the Agriculture Division of and later Animal Health, were announced in 2012. filed for registration of a Class A stock with the U.S. Securities and Exchange Commission on August 13, 2012. Zoetis's IPO on February 1, 2013, sold 86.1 million shares for US$2.2 billion. retained 414 million Class B shares, giving it an 83% controlling stake in the firm. The offering's lead underwriters were JPMorgan Chase, Bank of America, Merrill Lynch, and Morgan Stanley. Most of the money raised through the IPO was used to pay off existing debt. In April 2014, it was reported that had reignited a $100 billion takeover bid for the UK-based AstraZeneca, sparking political controversy in the UK, as well as in the US. On May 19, 2014, a "final offer" of £55 a share was rejected by the AstraZeneca board, which said the bid was too low and imposed too many risks. If successful, the takeover—the biggest in British history—would have made the world's largest drug company. Hopes for a renewed bid later in the year were dashed when signed a major cancer drug deal with Merck KGaA, selling its sharing rights to develop an experimental immunotherapy drug for a fee of $850 million. In February 2015, and Hospira agreed that would acquire Hospira for $15.2 billion, a deal in which Hospira shareholders would receive $90 in cash for each share they owned. News of the deal sent Hospira share prices up from $63.43 to $87 | https://en.wikipedia.org/wiki?curid=62304 |
Pfizer 43 on a volume of 60.7 million shares. Including debt, the deal is valued at around $17 billion. Hospira is the largest producer of generic injectable pharmaceuticals in the world. On the final day of trading, Hospira shares traded for $89.96 each, giving a market capitalisation of $15.56 billion. On November 23, 2015, and Allergan, plc announced their intention to merge for an approximate sum of $160 billion, making it the largest pharmaceutical deal ever, and the third largest corporate merger in history. As part of the deal, the CEO, Ian Read, was to remain as CEO and chairman of the new company, to be called "plc", with Allergan's CEO, Brent Saunders, becoming president and chief operating officer. As part of the deal, Allergan shareholders would receive 11.3 shares of the company, with shareholders receiving one. The terms proposed that the merged company would maintain Allergan's Irish domicile, resulting in the new company being subject to corporation tax at the Irish rate of 12.5%--considerably lower than the 35% rate that paid at the time. The deal was to constitute a reverse merger, whereby Allergan acquired Pfizer, with the new company then changing its name to "Pfizer, plc". The deal was expected to be completed in the second half of 2016, subject to certain conditions: US and EU approval, approval from both sets of shareholders, and the completion of Allergan's divestiture of its generics division to Teva Pharmaceuticals (expected in the first quarter of 2016) | https://en.wikipedia.org/wiki?curid=62304 |
Pfizer On April 6, 2016, and Allergan announced they would be calling off the merger after the Obama administration introduced new laws intended to limit corporate tax inversions (the extent to which companies could move their headquarters overseas in order to reduce the amount of taxes they pay). In 2018 announced it would reorganise its business into three separate units; a higher-margin innovative medicines division, a lower-margin, off-patent drug division, and a consumer healthcare division, with a view to focussing on higher margin therapies. In October 2017, reports emerged that were undertaking a strategic review of their Consumer Healthcare division, with possible results ranging from a partial or complete spin-off or a direct sale with the divestment expected to raise in the region of $15 billion for one of the largest Over-the-Counter businesses in the world. Reckitt Benckiser expressed interest in bidding for the division earlier in October with Sanofi, Johnson & Johnson, Procter & Gamble and GlaxoSmithKline also being linked with bids for the business. On March 22, Reckitt Benckiser pulled out of the deal, a day later GlaxoSmithKline also pulled out. In December 2018, GlaxoSmithKline announced that it, along with Pfizer, had reached an agreement to merge and combine their consumer healthcare divisions into a single entity. The combined entity would have sales of around £9.8 billon ($12.7 billion), with GSK maintaining a 68% controlling stake in the joint venture. would own the remaining 32% shareholding | https://en.wikipedia.org/wiki?curid=62304 |
Pfizer The deal builds on an earlier 2018 deal where GSK bought out Novartis' stake in the GSK-Novartis consumer healthcare joint business. In late July 2019, the company announced that it would spin off and merge its off-patent medicine division, Upjohn, with Mylan, forming a brand new pharmaceutical business with sales of around $20 billion. The new combined business will have a portfolio of drugs and brands including the Epi-Pen, Viagra, Lipitor and Celebrex. The deal will be structured as an all-stock, Reverse Morris Trust transaction: is organised into nine principal operating divisions: Primary Care, Specialty Care, Oncology, Emerging Markets, Established Products, Consumer Healthcare, Nutrition, Animal Health, and Capsugel. In May 2015, and a Bar-Ilan University laboratory announced a partnership based on the development of medical DNA nanotechnology. Pfizer's research and development activities are organised into two principal groups: the PharmaTherapeutics Research & Development Group, which focuses on the discovery of small molecules and related modalities; and the BioTherapeutics Research & Development Group, which focuses on large-molecule research, including vaccines. In 2007, invested $8.1 billion in research and development, the largest R&D investment in the pharmaceutical industry. has R&D facilities in the following locations: In 2007, announced plans to close or sell the Loughbeg API facility, located at Loughbeg, Ringaskiddy, Cork, Ireland by mid to end of 2008 | https://en.wikipedia.org/wiki?curid=62304 |
Pfizer In 2007, announced plans to completely close the Ann Arbor, Nagoya and Amboise Research facilities by the end of 2008, eliminating 2,160 jobs and idling the $300 million Michigan facility, which in recent years had seen expansion worth millions of dollars. On June 18, 2007, announced it would move the Animal Health Research (VMRD) division based in Sandwich, England, to Kalamazoo, Michigan. On February 1, 2011, announced the closure of the Research and Development centre in Sandwich, with the loss of 2,400 jobs. subsequently announced it would be maintaining a significant presence at Sandwich, with around 650 staff continuing to be based at the site. On September 1, 2011, announced it had agreed to a 10-year lease of more than 180,000 square feet of research space from MIT in a building to be constructed just north of the MIT campus in Cambridge, Massachusetts. The space will house Pfizer's Cardiovascular, Metabolic and Endocrine Disease Research Unit and its Neuroscience Research Unit; anticipated moving into the space once it was completed in late 2013. As of 2013, products in Pfizer's development pipeline included dimebon and tanezumab. In 2018, announced that it would end its work on research into treatments for Alzheimer's disease and Parkinsonism (a symptom of Parkinson's disease and other conditions). The company stated that approximately 300 researchers would lose their jobs as a result | https://en.wikipedia.org/wiki?curid=62304 |
Pfizer As of 2017, split its business into two primary segments: (1) innovative health, which includes branded drugs and vaccines, and (2) essential health. In 2016, innovative health generated $29.2 billion in revenue and essential health generated $23.6 billion. Key current and products include: In addition to marketing branded pharmaceuticals, is involved in the manufacture and sale of generics. In the US it does this through its Greenstone subsidiary, which it acquired as part of the acquisition of Pharmacia. also has a licensing deal in place with Aurobindo, which grants the former access to a variety of oral solid generic products. Key historical generics include: has long been known within the industry as one of the more aggressive marketers of their products. Access to Wyeth internal documents has revealed marketing strategies used to promote Neurontin for off-label use. In 1993, the U.S. Food and Drug Administration (FDA) approved gabapentin (Neurontin, Pfizer) only for treatment of seizures. Warner–Lambert, which merged with in 2000, used activities not usually associated with sales promotion, including continuing medical education and research, sponsored articles about the drug for the medical literature, and alleged suppression of unfavorable study results, to promote gabapentin. Within 5 years the drug was being widely used for the off-label treatment of pain and psychiatric conditions | https://en.wikipedia.org/wiki?curid=62304 |
Pfizer Warner–Lambert admitted to charges that it violated FDA regulations by promoting the drug for pain, psychiatric conditions, migraine, and other unapproved uses, and paid $430 million to resolve criminal and civil health care liability charges. A recent Cochrane review concluded that gabapentin is ineffective in migraine prophylaxis. The American Academy of Neurology rates it as having unproven efficacy, while the Canadian Headache Society and the European Federation of Neurological Societies rate its use as being supported by moderate and low-quality evidence, respectively. In September 2009, agreed to pay $2.3 billion to settle civil and criminal allegations that it had illegally marketed four drugs—Bextra, Geodon, Zyvox, and Lyrica—for non-approved uses; it was Pfizer's fourth such settlement in a decade. The payment included $1.3 billion in criminal penalties for felony violations of the Food, Drug and Cosmetic Act, and $1 billion to settle allegations it had illegally promoted the drugs for uses that were not approved by the U.S. Food and Drug Administration (FDA) and caused false claims to be submitted to Federal and State programs. The criminal fine was the largest ever assessed in the United States up to that time. has entered an extensive corporate integrity agreement with the Office of Inspector General and will be required to make substantial structural reforms within the company, and maintain the website (codice_1) to track the company's post marketing commitments | https://en.wikipedia.org/wiki?curid=62304 |
Pfizer had to also put a searchable database of all payments to physicians the company had made on the website by March 31, 2010. Peter Rost was vice president in charge of the endocrinology division at Pharmacia before and during its acquisition by Pfizer. During that time he raised concerns internally about kickbacks and off-label marketing of Genotropin, Pharmacia's human growth hormone drug. reported the Pharmacia marketing practices to the FDA and Department of Justice; Rost was unaware of this and filed an FCA lawsuit against Pfizer. kept him on, but isolated him until the FCA suit was unsealed in 2005. The Justice Department declined to intervene, and fired him, and he filed a wrongful termination suit against Pfizer. won a summary dismissal of the case, with the court ruling that the evidence showed had decided to fire Rost prior to learning of his whistleblower activities. A "whistleblower suit" was filed in 2005 against Wyeth, which was acquired by in 2009, alleging that the company illegally marketed their drug Rapamune. Wyeth is targeted in the suit for off-label marketing, targeting specific doctors and medical facilities to increase sales of Rapamune, trying to get current transplant patients to change from their current transplant drugs to Rapamune and for specifically targeting African-Americans. According to the whistleblowers, Wyeth also provided doctors and hospitals with kickbacks to prescribe the drug in the form of grants, donations and other money | https://en.wikipedia.org/wiki?curid=62304 |
Pfizer In 2013, the company pleaded guilty to criminal mis-branding violations under the Food, Drug and Cosmetic Act. By August 2014 it had paid $491 million in civil and criminal penalties. According to "Harper's Magazine" publisher John MacArthur, withdrew "between $400,000 and a million dollars" worth of ads from their magazine following an unflattering article on depression medication. is party to a number of lawsuits stemming from its pharmaceutical products as well as the practices of various companies it has merged with or acquired. acquired Quigley in 1968, and the division sold asbestos-containing insulation products until the early 1970s. Asbestos victims and have been negotiating a settlement deal that calls for to pay $430 million to 80 percent of existing plaintiffs. It will also place an additional $535 million into an asbestos settlement trust that will compensate future plaintiffs as well as the remaining 20 percent of current plaintiffs with claims against and Quigley. The compensation deal is worth $965 million all up. Of that $535 million, $405 million is in a 40-year note from Pfizer, while $100 million will come from insurance policies. purchased Shiley in 1979 at the onset of its Convexo-Concave valve ordeal, involving the Bjork–Shiley heart valve. Approximately 500 people died when defective valves failed and, in 1994, the United States ruled against for ~$200 million. In 1996, an outbreak of measles, cholera, and bacterial meningitis occurred in Nigeria | https://en.wikipedia.org/wiki?curid=62304 |
Pfizer representatives and personnel from a contract research organization (CRO) traveled to Kano, Nigeria to set up a clinical trial and administer an experimental antibiotic, trovafloxacin, to approximately 200 children. Local Kano officials report that more than 50 children died in the experiment, while many others developed mental and physical deformities. The nature and frequency of both fatalities and other adverse outcomes were similar to those historically found among pediatric patients treated for meningitis in sub-Saharan Africa. In 2001, families of the children, as well as the governments of Kano and Nigeria, filed lawsuits regarding the treatment. According to the news program "Democracy Now!", "[r]esearchers did not obtain signed consent forms, and medical personnel said did not tell parents their children were getting the experimental drug." The lawsuits also accuse of using the outbreak to perform unapproved human testing, as well as allegedly under-dosing a control group being treated with traditional antibiotics in order to skew the results of the trial in favor of Trovan. While the specific facts of the case remain in dispute, both Nigerian medical personnel and at least one physician have stated that the trial was conducted without regulatory approval. In 2007, published a Statement of Defense letter | https://en.wikipedia.org/wiki?curid=62304 |
Pfizer The letter states that the drug's oral form was safer and easier to administer, that Trovan had been used safely in over 5000 Americans prior to the Nigerian trial, that mortality in the patients treated by was lower than that observed historically in African meningitis epidemics, and that no unusual side effects, unrelated to meningitis, were observed after 4 weeks. In June 2010, the US Supreme Court rejected Pfizer's appeal against a ruling allowing lawsuits by the Nigerian families to proceed. In December 2010, WikiLeaks released US diplomatic cables, which indicate that had hired investigators to find evidence of corruption against Nigerian attorney general Aondoakaa to persuade him to drop legal action. "Washington Post" reporter Joe Stephens, who helped break the story in 2000, called these actions "dangerously close to blackmail." In response, the company has released a press statement describing the allegations as "preposterous" and stating that they acted in good faith. Aondoakka, who had allegedly demanded bribes from in return for a settlement of the case, was declared unfit for office and had his U.S. visa revoked in association with corruption charges in 2010. A scientist claims she was infected by a genetically modified virus while working for Pfizer. In her federal lawsuit she says she has been intermittently paralyzed by the Pfizer-designed virus | https://en.wikipedia.org/wiki?curid=62304 |
Pfizer "McClain, of Deep River, suspects she was inadvertently exposed, through work by a former colleague in 2002 or 2003, to an engineered form of the lentivirus, a virus similar to the one that can lead to acquired immune deficiency syndrome, also known as AIDS." The court found that McClain failed to demonstrate that her illness was caused by exposure to the lentivirus, but also that violated whistleblower laws. Health insurance company Blue Cross Blue Shield (BCBS) filed a lawsuit against for reportedly illegally marketing their drugs Bextra, Geodon and Lyrica. BCBS is reporting that used "kickbacks" and wrongly persuaded doctors to prescribe the drugs. FiercePharma reported that "According to the suit, the drugmaker not only handed out those "misleading" materials on off-label uses, but sent doctors on Caribbean junkets and paid them $2,000 honoraria in return for their listening to lectures about Bextra. More than 5,000 healthcare professionals were entertained at meetings in Bahamas, Virgin Islands, and across the U.S., the suit alleges." The case was settled in 2014 for $325M. Controversy arose over the drug "Celebrex". Brigham Young University (BYU) said that a professor of chemistry, Dr. Daniel L. Simmons, discovered an enzyme in the 1990s that would later lead towards the development of Celebrex. BYU was originally seeking 15% royalty on sales, which would equate to $9.7 billion | https://en.wikipedia.org/wiki?curid=62304 |
Pfizer The court filings show that a research agreement was made with Monsanto, whose pharmaceutical business was later acquired by Pfizer, to develop a better aspirin. The enzyme that Dr. Simmons claims to have discovered would induce pain and inflammation while causing gastrointestinal problems, which Celebrex is used to reduce those issues. A battle ensued, lasting over six years, because BYU claimed that did not give him credit or compensation while claims it had met all obligations regarding the Monsanto agreement. This culminated in a $450 million amicable settlement without going to trial. said it would take a $450 million charge against first quarter earnings to settle. was discussed as part of the Kelo v. New London case that was decided by U.S. Supreme Court in 2005. In February 1998 announced it would build a research facility in New London, Connecticut, and local planners, hoping to promote economic development and build on the influx of jobs the planned facility would bring to the town, created a plan that included seizing property to redevelop it under eminent domain, and local residents sued to stop the seizure. The case went to the Supreme Court, and with regard to Pfizer, the court cited a prior decision that said: "The record clearly demonstrates that the development plan was not intended to serve the interests of Pfizer, Inc | https://en.wikipedia.org/wiki?curid=62304 |
Pfizer , or any other private entity, but rather, to revitalize the local economy by creating temporary and permanent jobs, generating a significant increase in tax revenue, encouraging spin-off economic activities and maximizing public access to the waterfront”. The Supreme Court allowed the eminent domain to proceed. opened the facility in 2001 but abandoned it in 2009, angering residents of the town. Between 2002 and 2008, reduced its greenhouse emissions by 20%, and committed to reducing emissions by an additional 20% by 2012. In 2012 the company was named to the Carbon Disclosure Project's Carbon Leadership Index in recognition of its efforts to reduce greenhouse gas emissions. has inherited Wyeth's liabilities in the American Cyanamid site in Bridgewater, New Jersey. This site is highly toxic and an EPA declared Superfund site. has since attempted to remediate this land in order to clean and develop it for future profits and potential public uses. The Sierra Club and the Edison Wetlands Association have come out in opposition to the cleanup plan, arguing that the area is subject to flooding, which could cause pollutants to leach. The EPA considers the plan the most reasonable from considerations of safety and cost-effectiveness, arguing that an alternative plan involving trucking contaminated soil off site could expose cleanup workers. The EPA's position is backed by the environmental watchdog group CRISIS | https://en.wikipedia.org/wiki?curid=62304 |
Pfizer In June 2002, a chemical explosion at the Groton plant injured seven people and caused the evacuation of over 100 homes in the surrounding area. is a leading member of the U.S. Global Leadership Coalition, a Washington D.C.-based coalition of over 400 major companies and NGOs that advocates for a larger International Affairs Budget, which funds American diplomatic, humanitarian, and development efforts abroad. is one of the single largest lobbying interests in United States politics. For example, in the first 9 months of 2009 spent over $16.3 million on lobbying US congressional lawmakers, making them the sixth largest lobbying interest in the US (following Pharmaceutical Research and Manufacturers of America (PhRMA), which ranked fourth but also represents many of their interests). A spokeswoman for said the company “wanted to make sure our voice is heard in this conversation” in regards to the company's expenditure of $25 million in 2010 to lobby health care reform. According to U.S. State Department cables released by the whistleblower site WikiLeaks, "lobbied against New Zealand getting a free trade agreement with the United States because it objected to New Zealand's restrictive drug buying rules and tried to get rid of New Zealand's former health minister, Helen Clark, in 1990. In an example of the revolving door between government and industry in the United States, Scott Gotlieb, who resigned as the US FDA Commissioner in April 2019, joined the board of directors three months later, in July | https://en.wikipedia.org/wiki?curid=62304 |
Pfizer Since 2004, has received a 100% rating every year on the Corporate Equality Index, released by the Human Rights Campaign Foundation. In 2012, Pfizer's Canadian division, which then employed 2,890 people, was named one of Montreal's Top 15 Employers, the only research-based pharmaceutical company to receive this honor. In 2010, Ian Read took over as CEO from Jeff Kindler. In 2019, Ian Read left the CEO role and became executive chairman, with COO Albert Bouria taking the CEO role. makes the anti-fungal drug fluconazole available free of charge to governmental and non-governmental organizations (NGOs) in developing countries with a greater than 1% prevalence of HIV/AIDS. The company has also pledged to provide up to 740 million doses of its anti-pneumococcal vaccine at discounted rates to infants and young children in 41 developing countries in association with the GAVI Alliance. In 2012, and the Gates Foundation announced a joint effort to provide affordable access to Pfizer's long-lasting injectable contraceptive, medroxyprogesterone acetate, to three million women in developing countries. | https://en.wikipedia.org/wiki?curid=62304 |
Pharmacia was a pharmaceutical and biotechnological company in Sweden that merged with the American pharmaceutical company Upjohn in 1995. company was founded in 1911 in Stockholm, Sweden by pharmacist Gustav Felix Grönfeldt at the "Elgen" Pharmacy. The company is named after the Greek word φαρμακεία, transliterated "pharmakeia", which means 'sorcery'. In the company's early days, much of its profits were derived from the "miracle medicine" Phospho-Energon. During World War II, Swedish chemist Björn Ingelman (who worked for Arne Tiselius at Uppsala university) researched various uses for the polysaccharide dextran. Together with the medical researcher Anders Grönwall, he discovered that dextran could be used as a replacement for blood plasma in blood transfusions, for which there could be a large need in wartime. Pharmacia, which then was still a small company, was contacted in 1943 and its CEO Elis Göth was very interested. The product Macrodex, a dextran solution, was launched four years later. Dextran-based products were to play a significant role in the further expansion of Pharmacia. In 1951, the company moved to Uppsala, Sweden, to get closer to the scientists with whom they cooperated, and Ingelman became its head of research. In 1959, pioneered gel filtration with its Sephadex products. These were also based on dextran and discoveries in Tiselius' department, this time by Jerker Porath and Per Flodin. In 1967 Fine Chemicals was established in Uppsala | https://en.wikipedia.org/wiki?curid=62313 |
Pharmacia In 1986 Fine Chemicals acquired LKB-produkter AB and changed name to Biotech. Biotech expanded their role in the "biotech revolution" through its acquisition of PL Laboratories from Pabst Brewery offering a line of recombinant DNA specialty research chemicals. Sold to private interests in the 1990s, was first merged with "Kabi Vitrum" to form Kabi with headquarters in Uppsala. In 1993, Kabi bought Farmitalia, an Italian company that had developed doxorubicin, a chemotherapeutic. In 1995 the company merged with the American pharmaceutical company Upjohn, becoming known as & Upjohn and moved its headquarters to London. In 1998, the company was divided into two business area. The pharmaceutical business became & Upjohn. The scientific instruments groups which sold chromatography resin, purification equipment, molecular biology reagents and electrophoresis products was purchased by Amersham in 1998 and was named Amersham Biotech. They later changed the name to Amersham Biosciences and ran their radio chemical and reagents business along with the highly profitable chromatography business. The Logo Drop remained as a highly recognized brand. Amersham Biosciences was sold to GE Healthcare in April 1998 to be come GE Healthcare Life Sciences. GE is currently divesting the life sciences arm selling the $2B+ business to Danaher for $21B and is expected to close in Q4 of 2019. The following is an illustration of the company's mergers, acquisitions, spin-offs and historical predecessors: | https://en.wikipedia.org/wiki?curid=62313 |
Environmental science is an interdisciplinary academic field that integrates physical, biological and information sciences (including ecology, biology, physics, chemistry, plant science, zoology, mineralogy, oceanography, limnology, soil science, geology and physical geography, and atmospheric science) to the study of the environment, and the solution of environmental problems. emerged from the fields of natural history and medicine during the Enlightenment. Today it provides an integrated, quantitative, and interdisciplinary approach to the study of environmental systems. Environmental studies incorporates more of the social sciences for understanding human relationships, perceptions and policies towards the environment. Environmental engineering focuses on design and technology for improving environmental quality in every aspect. Environmental scientists study subjects like the understanding of earth processes, evaluating alternative energy systems, pollution control and mitigation, natural resource management, and the effects of global climate change. Environmental issues almost always include an interaction of physical, chemical, and biological processes. Environmental scientists bring a systems approach to the analysis of environmental problems. Key elements of an effective environmental scientist include the ability to relate space, and time relationships as well as quantitative analysis | https://en.wikipedia.org/wiki?curid=64919 |
Environmental science came alive as a substantive, active field of scientific investigation in the 1960s and 1970s driven by (a) the need for a multi-disciplinary approach to analyze complex environmental problems, (b) the arrival of substantive environmental laws requiring specific environmental protocols of investigation and (c) the growing public awareness of a need for action in addressing environmental problems. Events that spurred this development included the publication of Rachel Carson's landmark environmental book "Silent Spring" along with major environmental issues becoming very public, such as the 1969 Santa Barbara oil spill, and the Cuyahoga River of Cleveland, Ohio, "catching fire" (also in 1969), and helped increase the visibility of environmental issues and create this new field of study. In common usage, "environmental science" and "ecology" are often used interchangeably, but technically, ecology refers only to the study of organisms and their interactions with each other and their environment. Ecology could be considered a subset of environmental science, which also could involve purely chemical or public health issues (for example) ecologists would be unlikely to study. In practice, there is considerable overlap between the work of ecologists and other environmental scientists | https://en.wikipedia.org/wiki?curid=64919 |
Environmental science The National Center for Education Statistics in the United States defines an academic program in environmental science as follows: A program that focuses on the application of biological, chemical, and physical principles to the study of the physical environment and the solution of environmental problems, including subjects such as abating or controlling environmental pollution and degradation; the interaction between human society and the natural environment; and natural resources management. Includes instruction in biology, chemistry, physics, geosciences, climatology, statistics, and mathematical modeling. Atmospheric sciences focus on the Earth's atmosphere, with an emphasis upon its interrelation to other systems. Atmospheric sciences can include studies of meteorology, greenhouse gas phenomena, atmospheric dispersion modeling of airborne contaminants, sound propagation phenomena related to noise pollution, and even light pollution. Taking the example of the global warming phenomena, physicists create computer models of atmospheric circulation and infra-red radiation transmission, chemists examine the inventory of atmospheric chemicals and their reactions, biologists analyze the plant and animal contributions to carbon dioxide fluxes, and specialists such as meteorologists and oceanographers add additional breadth in understanding the atmospheric dynamics. Ecology is the study of the interactions between organisms and their environment | https://en.wikipedia.org/wiki?curid=64919 |
Environmental science Ecologists might investigate the relationship between a population of organisms and some physical characteristic of their environment, such as concentration of a chemical; or they might investigate the interaction between two populations of different organisms through some symbiotic or competitive relationship. For example, an interdisciplinary analysis of an ecological system which is being impacted by one or more stressors might include several related environmental science fields. In an estuarine setting where a proposed industrial development could impact certain species by water and air pollution, biologists would describe the flora and fauna, chemists would analyze the transport of water pollutants to the marsh, physicists would calculate air pollution emissions and geologists would assist in understanding the marsh soils and bay muds. Environmental chemistry is the study of chemical alterations in the environment. Principal areas of study include soil contamination and water pollution. The topics of analysis include chemical degradation in the environment, multi-phase transport of chemicals (for example, evaporation of a solvent containing lake to yield solvent as an air pollutant), and chemical effects upon biota. As an example study, consider the case of a leaking solvent tank which has entered the habitat soil of an endangered species of amphibian. As a method to resolve or understand the extent of soil contamination and subsurface transport of solvent, a computer model would be implemented | https://en.wikipedia.org/wiki?curid=64919 |
Environmental science Chemists would then characterize the molecular bonding of the solvent to the specific soil type, and biologists would study the impacts upon soil arthropods, plants, and ultimately pond-dwelling organisms that are the food of the endangered amphibian. Geosciences include environmental geology, environmental soil science, volcanic phenomena and evolution of the Earth's crust. In some classification systems this can also include hydrology, including oceanography. As an example study, of soils erosion, calculations would be made of surface runoff by soil scientists. Fluvial geomorphologists would assist in examining sediment transport in overland flow. Physicists would contribute by assessing the changes in light transmission in the receiving waters. Biologists would analyze subsequent impacts to aquatic flora and fauna from increases in water turbidity. In the U.S. the National Environmental Policy Act (NEPA) of 1969 set forth requirements for analysis of major projects in terms of specific environmental criteria. Numerous state laws have echoed these mandates, applying the principles to local-scale actions. The upshot has been an explosion of documentation and study of environmental consequences before the fact of development actions | https://en.wikipedia.org/wiki?curid=64919 |
Environmental science One can examine the specifics of environmental science by reading examples of Environmental Impact Statements prepared under NEPA such as: "Wastewater treatment expansion options discharging into the San Diego/Tijuana Estuary", "Expansion of the San Francisco International Airport", "Development of the Houston, Metro Transportation system", "Expansion of the metropolitan Boston MBTA transit system", and "Construction of Interstate 66 through Arlington, Virginia". In England and Wales the Environment Agency (EA), formed in 1996, is a public body for protecting and improving the environment and enforces the regulations listed on the communities and local government site. (formerly the office of the deputy prime minister). The agency was set up under the Environment Act 1995 as an independent body and works closely with UK Government to enforce the regulations. | https://en.wikipedia.org/wiki?curid=64919 |
Inverted repeat An inverted repeat (or IR) is a single stranded sequence of nucleotides followed downstream by its reverse complement. The intervening sequence of nucleotides between the initial sequence and the reverse complement can be any length including zero. When the intervening length is zero, the composite sequence is a palindromic sequence. For example, is an inverted repeat sequence. Both inverted repeats and direct repeats constitute types of nucleotide sequences that occur repetitively. These repeated DNA sequences often range from a pair of nucleotides to a whole gene, while the proximity of the repeat sequences varies between widely dispersed and simple tandem arrays. The short tandem repeat sequences may exist as just a few copies in a small region to thousands of copies dispersed all over the genome of most eukaryotes. Repeat sequences with about 10–100 base pairs are known as minisatellites, while shorter repeat sequences having mostly 2–4 base pairs are known as microsatellites. The most common repeats include the dinucleotide repeats, which have the bases AC on one DNA strand, and GT on the complementary strand. Some elements of the genome with unique sequences function as exons, introns and regulatory DNA. Though the most familiar loci of the repetitive sequences are the centromere, and the telomere, a large portion of the repeated sequences in the genome are found among the noncoding DNA. Inverted repeats have a number of important biological functions | https://en.wikipedia.org/wiki?curid=65132 |
Inverted repeat They define the boundaries in transposons and indicate regions capable of self-complementary base pairing (regions within a single sequence which can base pair with each other). These properties play an important role in genome instability and contribute not only to cellular evolution and genetic diversity but also to mutation and disease. In order to study these effects in detail, a number of programs and databases have been developed to assist in discovery and annotation of inverted repeats in various genomes. Beginning with this initial sequence: The complement created by base pairing is: The reverse complement is: And, the inverted repeat sequence is: "nnnnnn" represents any number of intervening nucleotides. A direct repeat occurs when a sequence is repeated with the same pattern downstream. There is no inversion and no reverse complement associated with a direct repeat. The nucleotide sequence written in bold characters signifies the repeated sequence. It may or may not have intervening nucleotides. Linguistically, a typical direct repeat is comparable to saying "bye-bye". An inverted repeat sequence with "no" intervening nucleotides between the initial sequence and its downstream reverse complement is a palindrome. EXAMPLE: Step 1: start with an inverted repeat: Step 2: remove intervening nucleotides: This resulting sequence is palindromic because it is the reverse complement of itself | https://en.wikipedia.org/wiki?curid=65132 |
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