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21,800 | Some medical thermometers, especially those for high temperatures, are filled with mercury; they are gradually disappearing. In the United States, non-prescription sale of mercury fever thermometers has been banned since 2003. | https://en.wikipedia.org/wiki?curid=18617142 |
21,801 | Some transit telescopes use a basin of mercury to form a flat and absolutely horizontal mirror, useful in determining an absolute vertical or perpendicular reference. Concave horizontal parabolic mirrors may be formed by rotating liquid mercury on a disk, the parabolic form of the liquid thus formed reflecting and focu... | https://en.wikipedia.org/wiki?curid=18617142 |
21,802 | Liquid mercury is a part of popular secondary reference electrode (called the calomel electrode) in electrochemistry as an alternative to the standard hydrogen electrode. The calomel electrode is used to work out the electrode potential of half cells. Last, but not least, the triple point of mercury, −38.8344 °C, is a ... | https://en.wikipedia.org/wiki?curid=18617142 |
21,803 | In polarography both the dropping mercury electrode and the hanging mercury drop electrode use elemental mercury. This use allows a new uncontaminated electrode to be available for each measurement or each new experiment. | https://en.wikipedia.org/wiki?curid=18617142 |
21,804 | Mercury-containing compounds are also of use in the field of structural biology. Mercuric compounds such as mercury(II) chloride or potassium tetraiodomercurate(II) can be added to protein crystals in an effort to create heavy atom derivatives that can be used to solve the phase problem in X-ray crystallography via iso... | https://en.wikipedia.org/wiki?curid=18617142 |
21,805 | Gaseous mercury is used in mercury-vapor lamps and some "neon sign" type advertising signs and fluorescent lamps. Those low-pressure lamps emit very spectrally narrow lines, which are traditionally used in optical spectroscopy for calibration of spectral position. Commercial calibration lamps are sold for this purpose;... | https://en.wikipedia.org/wiki?curid=18617142 |
21,806 | The Deep Space Atomic Clock (DSAC) under development by the Jet Propulsion Laboratory utilises mercury in a linear ion-trap-based clock. The novel use of mercury allows very compact atomic clocks, with low energy requirements, and is therefore ideal for space probes and Mars missions. | https://en.wikipedia.org/wiki?curid=18617142 |
21,807 | Mercury, as thiomersal, is widely used in the manufacture of mascara. In 2008, Minnesota became the first state in the United States to ban intentionally added mercury in cosmetics, giving it a tougher standard than the federal government. | https://en.wikipedia.org/wiki?curid=18617142 |
21,808 | A study in geometric mean urine mercury concentration identified a previously unrecognized source of exposure (skin care products) to inorganic mercury among New York City residents. Population-based biomonitoring also showed that mercury concentration levels are higher in consumers of seafood and fish meals. | https://en.wikipedia.org/wiki?curid=18617142 |
21,809 | Mercury is effective as an active ingredient in skin whitening compounds used to depigment skin. The Minamata Convention on Mercury limits the concentration of mercury in such whiteners to 1 part per million. However, as of 2022, many commercially sold whitener products continue to exceed that limit, and are considered... | https://en.wikipedia.org/wiki?curid=18617142 |
21,810 | Mercury(II) fulminate is a primary explosive which is mainly used as a primer of a cartridge in firearms. | https://en.wikipedia.org/wiki?curid=18617142 |
21,811 | Many historic applications made use of the peculiar physical properties of mercury, especially as a dense liquid and a liquid metal: | https://en.wikipedia.org/wiki?curid=18617142 |
21,812 | Mercury(I) chloride (also known as calomel or mercurous chloride) has been used in traditional medicine as a diuretic, topical disinfectant, and laxative. Mercury(II) chloride (also known as mercuric chloride or corrosive sublimate) was once used to treat syphilis (along with other mercury compounds), although it is so... | https://en.wikipedia.org/wiki?curid=18617142 |
21,813 | Mercury and most of its compounds are extremely toxic and must be handled with care; in cases of spills involving mercury (such as from certain thermometers or fluorescent light bulbs), specific cleaning procedures are used to avoid exposure and contain the spill. Protocols call for physically merging smaller droplets ... | https://en.wikipedia.org/wiki?curid=18617142 |
21,814 | Mercury can be absorbed through the skin and mucous membranes and mercury vapors can be inhaled, so containers of mercury are securely sealed to avoid spills and evaporation. Heating of mercury, or of compounds of mercury that may decompose when heated, should be carried out with adequate ventilation in order to minimi... | https://en.wikipedia.org/wiki?curid=18617142 |
21,815 | Preindustrial deposition rates of mercury from the atmosphere may be about 4 ng /(1 L of ice deposit). Although that can be considered a natural level of exposure, regional or global sources have significant effects. Volcanic eruptions can increase the atmospheric source by 4–6 times. | https://en.wikipedia.org/wiki?curid=18617142 |
21,816 | Natural sources, such as volcanoes, are responsible for approximately half of atmospheric mercury emissions. The human-generated half can be divided into the following estimated percentages: | https://en.wikipedia.org/wiki?curid=18617142 |
21,817 | The above percentages are estimates of the global human-caused mercury emissions in 2000, excluding biomass burning, an important source in some regions. | https://en.wikipedia.org/wiki?curid=18617142 |
21,818 | Recent atmospheric mercury contamination in outdoor urban air was measured at 0.01–0.02 μg/m. A 2001 study measured mercury levels in 12 indoor sites chosen to represent a cross-section of building types, locations and ages in the New York area. This study found mercury concentrations significantly elevated over outdoo... | https://en.wikipedia.org/wiki?curid=18617142 |
21,819 | Artificial lakes, or reservoirs, may be contaminated with mercury due to the absorption by the water of mercury from submerged trees and soil. | https://en.wikipedia.org/wiki?curid=18617142 |
21,820 | For example, Williston Lake in northern British Columbia, created by the damming of the Peace River in 1968, is still sufficiently contaminated with mercury that it is inadvisable to consume fish from the lake. Permafrost soils have accumulated mercury through atmospheric deposition, and permafrost thaw in cryospheric ... | https://en.wikipedia.org/wiki?curid=18617142 |
21,821 | Mercury also enters into the environment through the improper disposal (e.g., land filling, incineration) of certain products. Products containing mercury include: auto parts, batteries, fluorescent bulbs, medical products, thermometers, and thermostats. Due to health concerns (see below), toxics use reduction efforts ... | https://en.wikipedia.org/wiki?curid=18617142 |
21,822 | Most thermometers now use pigmented alcohol instead of mercury. Mercury thermometers are still occasionally used in the medical field because they are more accurate than alcohol thermometers, though both are commonly being replaced by electronic thermometers and less commonly by galinstan thermometers. Mercury thermome... | https://en.wikipedia.org/wiki?curid=18617142 |
21,823 | Historically, one of the largest releases was from the Colex plant, a lithium isotope separation plant at Oak Ridge, Tennessee. The plant operated in the 1950s and 1960s. Records are incomplete and unclear, but government commissions have estimated that some two million pounds of mercury are unaccounted for. | https://en.wikipedia.org/wiki?curid=18617142 |
21,824 | A serious industrial disaster was the dumping of waste mercury compounds into Minamata Bay, Japan, between 1932 and 1968. It is estimated that over 3,000 people suffered various deformities, severe mercury poisoning symptoms or death from what became known as Minamata disease. | https://en.wikipedia.org/wiki?curid=18617142 |
21,825 | The tobacco plant readily absorbs and accumulates heavy metals such as mercury from the surrounding soil into its leaves. These are subsequently inhaled during tobacco smoking. While mercury is a constituent of tobacco smoke, studies have largely failed to discover a significant correlation between smoking and Hg uptak... | https://en.wikipedia.org/wiki?curid=18617142 |
21,826 | Sediments within large urban-industrial estuaries act as an important sink for point source and diffuse mercury pollution within catchments. A 2015 study of foreshore sediments from the Thames estuary measured total mercury at 0.01 to 12.07 mg/kg with mean of 2.10 mg/kg and median of 0.85 mg/kg (n=351). The highest mer... | https://en.wikipedia.org/wiki?curid=18617142 |
21,827 | Due to the health effects of mercury exposure, industrial and commercial uses are regulated in many countries. The World Health Organization, OSHA, and NIOSH all treat mercury as an occupational hazard, and have established specific occupational exposure limits. Environmental releases and disposal of mercury are regula... | https://en.wikipedia.org/wiki?curid=18617142 |
21,828 | Fish and shellfish have a natural tendency to concentrate mercury in their bodies, often in the form of methylmercury, a highly toxic organic compound of mercury. Species of fish that are high on the food chain, such as shark, swordfish, king mackerel, bluefin tuna, albacore tuna, and tilefish contain higher concentrat... | https://en.wikipedia.org/wiki?curid=18617142 |
21,829 | Some facial creams contain dangerous levels of mercury. Most contain comparatively non-toxic inorganic mercury, but products containing highly toxic organic mercury have been encountered. | https://en.wikipedia.org/wiki?curid=18617142 |
21,830 | Toxic effects include damage to the brain, kidneys and lungs. Mercury poisoning can result in several diseases, including acrodynia (pink disease), Hunter-Russell syndrome, and Minamata disease. | https://en.wikipedia.org/wiki?curid=18617142 |
21,831 | Symptoms typically include sensory impairment (vision, hearing, speech), disturbed sensation and a lack of coordination. The type and degree of symptoms exhibited depend upon the individual toxin, the dose, and the method and duration of exposure. Case–control studies have shown effects such as tremors, impaired cognit... | https://en.wikipedia.org/wiki?curid=18617142 |
21,832 | Research on the treatment of mercury poisoning is limited. Currently available drugs for acute mercurial poisoning include chelators N-acetyl-D, L-penicillamine (NAP), British Anti-Lewisite (BAL), 2,3-dimercapto-1-propanesulfonic acid (DMPS), and dimercaptosuccinic acid (DMSA). In one small study including 11 construct... | https://en.wikipedia.org/wiki?curid=18617142 |
21,833 | 140 countries agreed in the Minamata Convention on Mercury by the United Nations Environment Programme (UNEP) to prevent emissions. The convention was signed on 10 October 2013. | https://en.wikipedia.org/wiki?curid=18617142 |
21,834 | In the United States, the Environmental Protection Agency is charged with regulating and managing mercury contamination. Several laws give the EPA this authority, including the Clean Air Act, the Clean Water Act, the Resource Conservation and Recovery Act, and the Safe Drinking Water Act. Additionally, the Mercury-Cont... | https://en.wikipedia.org/wiki?curid=18617142 |
21,835 | The United States Clean Air Act, passed in 1990, put mercury on a list of toxic pollutants that need to be controlled to the greatest possible extent. Thus, industries that release high concentrations of mercury into the environment agreed to install maximum achievable control technologies (MACT). In March 2005, the EP... | https://en.wikipedia.org/wiki?curid=18617142 |
21,836 | The EPA announced new rules for coal-fired power plants on 22 December 2011. Cement kilns that burn hazardous waste are held to a looser standard than are standard hazardous waste incinerators in the United States, and as a result are a disproportionate source of mercury pollution. | https://en.wikipedia.org/wiki?curid=18617142 |
21,837 | In the European Union, the directive on the Restriction of the Use of Certain Hazardous Substances in Electrical and Electronic Equipment (see RoHS) bans mercury from certain electrical and electronic products, and limits the amount of mercury in other products to less than 1000 ppm. There are restrictions for mercury ... | https://en.wikipedia.org/wiki?curid=18617142 |
21,838 | Norway enacted a total ban on the use of mercury in the manufacturing and import/export of mercury products, effective 1 January 2008. In 2002, several lakes in Norway were found to have a poor state of mercury pollution, with an excess of 1 μg/g of mercury in their sediment. | https://en.wikipedia.org/wiki?curid=18617142 |
21,839 | In 2008, Norway's Minister of Environment Development Erik Solheim said: "Mercury is among the most dangerous environmental toxins. Satisfactory alternatives to Hg in products are | https://en.wikipedia.org/wiki?curid=18617142 |
21,840 | In 2008, Denmark also banned dental mercury amalgam, except for molar masticating surface fillings in permanent (adult) teeth. | https://en.wikipedia.org/wiki?curid=18617142 |
21,841 | The Higgs boson, sometimes called the Higgs particle, is an elementary particle in the Standard Model of particle physics produced by the quantum excitation of the Higgs field, one of the fields in particle physics theory. In the Standard Model, the Higgs particle is a massive scalar boson with zero spin, even (positiv... | https://en.wikipedia.org/wiki?curid=20556903 |
21,842 | The Higgs field is a scalar field, with two neutral and two electrically charged components that form a complex doublet of the weak isospin SU(2) symmetry. Its "Mexican hat-shaped" potential leads it to take a nonzero value "everywhere" (including otherwise empty space), which breaks the weak isospin symmetry of the el... | https://en.wikipedia.org/wiki?curid=20556903 |
21,843 | Both the field and the boson are named after physicist Peter Higgs, who in 1964, along with five other scientists in three teams, proposed the Higgs mechanism, a way that some particles can acquire mass. (All fundamental particles that were known at the time should be massless at very high energies, but fully explainin... | https://en.wikipedia.org/wiki?curid=20556903 |
21,844 | After a 40 year search, a subatomic particle with the expected properties was discovered in 2012 by the ATLAS and CMS experiments at the Large Hadron Collider (LHC) at CERN near Geneva, Switzerland. The new particle was subsequently confirmed to match the expected properties of a Higgs boson. Physicists from two of the... | https://en.wikipedia.org/wiki?curid=20556903 |
21,845 | In the mainstream media, the Higgs boson is sometimes called the ""God particle"" after the 1993 book "The God Particle" by Nobel Laureate Leon Lederman, although the nickname has been criticised by many physicists. | https://en.wikipedia.org/wiki?curid=20556903 |
21,846 | Physicists explain the fundamental particles and forces of our universe in terms of the Standard Model – a widely accepted framework based on quantum field theory that predicts almost all known particles and forces other than gravity with great accuracy. (A separate theory, general relativity, is used for gravity.) In ... | https://en.wikipedia.org/wiki?curid=20556903 |
21,847 | Gauge invariant theories are theories which have a useful feature, that some kinds of changes to the value of certain items don't make any difference to the outcomes or the measurements we make. An example is that changing voltages in an electromagnet by +100 Volts, doesn't cause any change to the magnetic field it pro... | https://en.wikipedia.org/wiki?curid=20556903 |
21,848 | In these kinds of theories, the gauge is an item whose value we can change, the fact that some changes leave the results we measure unchanged means it is a gauge invariant theory, and symmetries are the specific kinds of changes to the gauge, which have this effect of leaving measurements unchanged. (More precisely, th... | https://en.wikipedia.org/wiki?curid=20556903 |
21,849 | Quantum field theories based on gauge invariance had been used with great success in understanding the electromagnetic and strong forces, but by around 1960 all attempts to create a "gauge invariant" theory for the weak force (and its combination with the electromagnetic force, known together as the electroweak interac... | https://en.wikipedia.org/wiki?curid=20556903 |
21,850 | A further problem was that many promising solutions seemed to require extra particles known as Goldstone bosons to exist. But evidence suggested these did not exist either. This meant that either gauge invariance was an incorrect approach, or something unknown was giving the weak force's W and Z bosons their mass, and ... | https://en.wikipedia.org/wiki?curid=20556903 |
21,851 | In the late 1950s, Yoichiro Nambu recognised that spontaneous symmetry breaking, a process where a symmetric system becomes asymmetric, could occur under certain conditions. | https://en.wikipedia.org/wiki?curid=20556903 |
21,852 | Symmetry breaking is when a change that previously didn't change the measured results ("it was originally a "symmetry"") now does change the measured results ("it's now "broken" and no longer a symmetry"). In 1962 physicist Philip Anderson, an expert in condensed matter physics, observed that symmetry breaking played a... | https://en.wikipedia.org/wiki?curid=20556903 |
21,853 | Specifically, Anderson suggested that the Goldstone bosons that would result from symmetry breaking might instead, in some circumstances, be "absorbed" by the massless W and Z bosons. If so, perhaps the Goldstone bosons would not exist, and the W and Z bosons could gain mass, solving both problems at once. Similar beha... | https://en.wikipedia.org/wiki?curid=20556903 |
21,854 | Following the 1963 and early 1964 papers, three groups of researchers independently developed these theories more completely, in what became known as the 1964 PRL symmetry breaking papers. All three groups reached similar conclusions and for all cases, not just some limited cases. They showed that the conditions for el... | https://en.wikipedia.org/wiki?curid=20556903 |
21,855 | The field required for this to happen (which was purely hypothetical at the time) became known as the "Higgs field" (after Peter Higgs, one of the researchers) and the mechanism by which it led to symmetry breaking, known as the "Higgs mechanism". A key feature of the necessary field is that it would take "less" energy... | https://en.wikipedia.org/wiki?curid=20556903 |
21,856 | Although these ideas did not gain much initial support or attention, by 1972 they had been developed into a comprehensive theory and proved capable of giving "sensible" results that accurately described particles known at the time, and which, with exceptional accuracy, predicted several other particles discovered durin... | https://en.wikipedia.org/wiki?curid=20556903 |
21,857 | The Standard Model includes a field of the kind needed to "break" electroweak symmetry and give particles their correct mass. This field, called the "Higgs Field", exists throughout space, and it breaks some symmetry laws of the electroweak interaction, triggering the Higgs mechanism. It therefore causes the W and Z ga... | https://en.wikipedia.org/wiki?curid=20556903 |
21,858 | When the weak force bosons acquire mass, this affects the distance they can freely travel, which becomes very small, also matching experimental findings. | https://en.wikipedia.org/wiki?curid=20556903 |
21,859 | Furthermore, it was later realised that the same field would also explain, in a different way, why other fundamental constituents of matter (including electrons and quarks) have mass. | https://en.wikipedia.org/wiki?curid=20556903 |
21,860 | Unlike all other known fields such as the electromagnetic field, the Higgs field is a scalar field, and has a non-zero average value in vacuum. | https://en.wikipedia.org/wiki?curid=20556903 |
21,861 | There was not yet any direct evidence that the Higgs field existed, but even without direct proof, the accuracy of its predictions led scientists to believe the theory might be true. By the 1980s, the question of whether the Higgs field existed, and therefore whether the entire Standard Model was correct, had come to b... | https://en.wikipedia.org/wiki?curid=20556903 |
21,862 | For many decades, scientists had no way to determine whether the Higgs field existed, because the technology needed for its detection did not exist at that time. If the Higgs field did exist, then it would be unlike any other known fundamental field, but it also was possible that these key ideas, or even the entire Sta... | https://en.wikipedia.org/wiki?curid=20556903 |
21,863 | The existence of the Higgs field became the last unverified part of the Standard Model of particle physics, and for several decades was considered "the central problem in particle physics". | https://en.wikipedia.org/wiki?curid=20556903 |
21,864 | The hypothesised Higgs theory made several key predictions. One crucial prediction was that a matching particle, called the "Higgs boson", should also exist. Proving the existence of the Higgs boson would prove whether the Higgs field existed, and therefore finally prove whether the Standard Model's explanation was cor... | https://en.wikipedia.org/wiki?curid=20556903 |
21,865 | Although the Higgs field would exist everywhere, proving its existence was far from easy. In principle, it can be proved to exist by detecting its excitations, which manifest as Higgs particles (the "Higgs boson"), but these are extremely difficult to produce and detect, due to the energy required to produce them and t... | https://en.wikipedia.org/wiki?curid=20556903 |
21,866 | The importance of this fundamental question led to a 40-year search, and the construction of one of the world's most expensive and complex experimental facilities to date, CERN's Large Hadron Collider, | https://en.wikipedia.org/wiki?curid=20556903 |
21,867 | in an attempt to create Higgs bosons and other particles for observation and study. On 4 July 2012, the discovery of a new particle with a mass between 125 and was announced; physicists suspected that it was the Higgs boson. | https://en.wikipedia.org/wiki?curid=20556903 |
21,868 | Since then, the particle has been shown to behave, interact, and decay in many of the ways predicted for Higgs particles by the Standard Model, as well as having even parity and zero spin, two fundamental attributes of a Higgs boson. This also means it is the first elementary scalar particle discovered in nature. | https://en.wikipedia.org/wiki?curid=20556903 |
21,869 | By March 2013, the existence of the Higgs boson was confirmed, and therefore, the concept of some type of Higgs field throughout space is strongly supported. | https://en.wikipedia.org/wiki?curid=20556903 |
21,870 | The presence of the field, now confirmed by experimental investigation, explains why some fundamental particles have mass, despite the symmetries controlling their interactions implying that they should be massless. It also resolves several other long-standing puzzles, such as the reason for the extremely short distanc... | https://en.wikipedia.org/wiki?curid=20556903 |
21,871 | As of 2018, in-depth research shows the particle continuing to behave in line with predictions for the Standard Model Higgs boson. More studies are needed to verify with higher precision that the discovered particle has all of the properties predicted, or whether, as described by some theories, multiple Higgs bosons ex... | https://en.wikipedia.org/wiki?curid=20556903 |
21,872 | The nature and properties of this field are now being investigated further, using more data collected at the LHC. | https://en.wikipedia.org/wiki?curid=20556903 |
21,873 | Various analogies have been used to describe the Higgs field and boson, including analogies with well-known symmetry-breaking effects such as the rainbow and prism, electric fields, and ripples on the surface of water. | https://en.wikipedia.org/wiki?curid=20556903 |
21,874 | Other analogies based on resistance of macro objects moving through media (such as people moving through crowds, or some objects moving through syrup or molasses) are commonly used but misleading, since the Higgs field does not actually resist particles, and the effect of mass is not caused by resistance. | https://en.wikipedia.org/wiki?curid=20556903 |
21,875 | In the Standard Model, the Higgs boson is a massive scalar boson whose mass must be found experimentally. Its mass has been determined to be . It is the only particle that remains massive even at very high energies. It has zero spin, even (positive) parity, no electric charge, and no colour charge, and it couples to (i... | https://en.wikipedia.org/wiki?curid=20556903 |
21,876 | The Higgs field is a scalar field, with two neutral and two electrically charged components that form a complex doublet of the weak isospin SU(2) symmetry. Unlike any other known quantum field, it has a "Mexican hat-shaped" potential. This shape means that below extremely high energies of about such as those seen durin... | https://en.wikipedia.org/wiki?curid=20556903 |
21,877 | Evidence of the Higgs field and its properties has been extremely significant for many reasons. The importance of the Higgs boson is largely that it is able to be examined using existing knowledge and experimental technology, as a way to confirm and study the entire Higgs field theory. Conversely, proof that the Higgs ... | https://en.wikipedia.org/wiki?curid=20556903 |
21,878 | The Higgs boson validates the Standard Model through the mechanism of mass generation. As more precise measurements of its properties are made, more advanced extensions may be suggested or excluded. As experimental means to measure the field's behaviours and interactions are developed, this fundamental field may be bet... | https://en.wikipedia.org/wiki?curid=20556903 |
21,879 | Related to this, a belief generally exists among physicists that there is likely to be "new" physics beyond the Standard Model, and the Standard Model will at some point be extended or superseded. The Higgs discovery, as well as the many measured collisions occurring at the LHC, provide physicists a sensitive tool to s... | https://en.wikipedia.org/wiki?curid=20556903 |
21,880 | Below an extremely high temperature, electroweak symmetry breaking causes the electroweak interaction to manifest in part as the short-ranged weak force, which is carried by massive gauge bosons. In the history of the universe, electroweak symmetry breaking is believed to have happened at about after the Big Bang, when... | https://en.wikipedia.org/wiki?curid=20556903 |
21,881 | The Higgs field is pivotal in generating the masses of quarks and charged leptons (through Yukawa coupling) and the W and Z gauge bosons (through the Higgs mechanism). | https://en.wikipedia.org/wiki?curid=20556903 |
21,882 | It is worth noting that the Higgs field does not "create" mass out of nothing (which would violate the law of conservation of energy), nor is the Higgs field responsible for the mass of all particles. For example, approximately 99% of the mass of baryons (composite particles such as the proton and neutron), is due inst... | https://en.wikipedia.org/wiki?curid=20556903 |
21,883 | The Higgs field is the only scalar (spin 0) field to be detected; all the other fields in the Standard Model are spin fermions or spin 1 bosons. According to Rolf-Dieter Heuer, director general of CERN when the Higgs boson was discovered, this existence proof of a scalar field is almost as important as the Higgs's rol... | https://en.wikipedia.org/wiki?curid=20556903 |
21,884 | There has been considerable scientific research on possible links between the Higgs field and the inflaton a hypothetical field suggested as the explanation for the expansion of space during the first fraction of a second of the universe (known as the "inflationary epoch"). Some theories suggest that a fundamental scal... | https://en.wikipedia.org/wiki?curid=20556903 |
21,885 | In the Standard Model, there exists the possibility that the underlying state of our universe – known as the "vacuum" – is long-lived, but not completely stable. In this scenario, the universe as we know it could effectively be destroyed by collapsing into a more stable vacuum state. This was sometimes misreported as t... | https://en.wikipedia.org/wiki?curid=20556903 |
21,886 | If measurements of the Higgs boson suggest that our universe lies within a false vacuum of this kind, then it would imply more than likely in many billions of years that the universe's forces, particles, and structures could cease to exist as we know them (and be replaced by different ones), if a true vacuum happened t... | https://en.wikipedia.org/wiki?curid=20556903 |
21,887 | More speculatively, the Higgs field has also been proposed as the energy of the vacuum, which at the extreme energies of the first moments of the Big Bang caused the universe to be a kind of featureless symmetry of undifferentiated, extremely high energy. In this kind of speculation, the single unified field of a Grand... | https://en.wikipedia.org/wiki?curid=20556903 |
21,888 | The relationship (if any) between the Higgs field and the presently observed vacuum energy density of the universe has also come under scientific study. As observed, the present vacuum energy density is extremely close to zero, but the energy densities predicted from the Higgs field, supersymmetry, and other current th... | https://en.wikipedia.org/wiki?curid=20556903 |
21,889 | Particle physicists study matter made from fundamental particles whose interactions are mediated by exchange particles gauge bosons acting as force carriers. At the beginning of the 1960s a number of these particles had been discovered or proposed, along with theories suggesting how they relate to each other, some of w... | https://en.wikipedia.org/wiki?curid=20556903 |
21,890 | One known problem was that gauge invariant approaches, including non-abelian models such as Yang–Mills theory (1954), which held great promise for unified theories, also seemed to predict known massive particles as massless. Goldstone's theorem, relating to continuous symmetries within some theories, also appeared to r... | https://en.wikipedia.org/wiki?curid=20556903 |
21,891 | The Higgs mechanism is a process by which vector bosons can acquire rest mass "without" explicitly breaking gauge invariance, as a byproduct of spontaneous symmetry breaking. Initially, the mathematical theory behind spontaneous symmetry breaking was conceived and published within particle physics by Yoichiro Nambu in ... | https://en.wikipedia.org/wiki?curid=20556903 |
21,892 | These approaches were quickly developed into a full relativistic model, independently and almost simultaneously, by three groups of physicists: by François Englert and Robert Brout in August 1964; by Peter Higgs in October 1964; and by Gerald Guralnik, Carl Hagen, and Tom Kibble (GHK) in November 1964. Higgs also wrote... | https://en.wikipedia.org/wiki?curid=20556903 |
21,893 | independently showed how a Higgs mechanism could be used to break the electroweak symmetry of Sheldon Glashow's unified model for the weak and electromagnetic interactions, | https://en.wikipedia.org/wiki?curid=20556903 |
21,894 | (itself an extension of work by Schwinger), forming what became the Standard Model of particle physics. Weinberg was the first to observe that this would also provide mass terms for the fermions. | https://en.wikipedia.org/wiki?curid=20556903 |
21,895 | At first, these seminal papers on spontaneous breaking of gauge symmetries were largely ignored, because it was widely believed that the (non-Abelian gauge) theories in question were a dead-end, and in particular that they could not be renormalised. In 1971–72, Martinus Veltman and Gerard 't Hooft proved renormalisatio... | https://en.wikipedia.org/wiki?curid=20556903 |
21,896 | The resulting electroweak theory and Standard Model have accurately predicted (among other things) weak neutral currents, three bosons, the top and charm quarks, and with great precision, the mass and other properties of some of these. Many of those involved eventually won Nobel Prizes or other renowned awards. A 1974 ... | https://en.wikipedia.org/wiki?curid=20556903 |
21,897 | The three papers written in 1964 were each recognised as milestone papers during "Physical Review Letters" 50th anniversary celebration. Their six authors were also awarded the 2010 J. J. Sakurai Prize for Theoretical Particle Physics for this work. (A controversy also arose the same year, because in the event of a Nob... | https://en.wikipedia.org/wiki?curid=20556903 |
21,898 | In the paper by Higgs the boson is massive, and in a closing sentence Higgs writes that "an essential feature" of the theory "is the prediction of incomplete multiplets of scalar and vector bosons". (Frank Close comments that 1960s gauge theorists were focused on the problem of massless "vector" bosons, and the implied... | https://en.wikipedia.org/wiki?curid=20556903 |
21,899 | To produce Higgs bosons, two beams of particles are accelerated to very high energies and allowed to collide within a particle detector. Occasionally, although rarely, a Higgs boson will be created fleetingly as part of the collision byproducts. Because the Higgs boson decays very quickly, particle detectors cannot det... | https://en.wikipedia.org/wiki?curid=20556903 |
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