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81-476: The APEX telescope is a modified ALMA (Atacama Large Millimeter Array) prototype antenna and is at the site of the ALMA observatory. APEX is designed to work at sub-millimetre wavelengths, in the 0.2 to 1.5 mm range — between infrared light and radio waves — and to find targets that ALMA will be able to study in greater detail. Submillimetre astronomy provides a window into the cold, dusty and distant Universe, but

162-513: A negative quantity. A system with a truly negative temperature is not colder than absolute zero. Rather, a system with a negative temperature is hotter than any system with a positive temperature, in the sense that if a negative-temperature system and a positive-temperature system come in contact, heat flows from the negative to the positive-temperature system. Most familiar systems cannot achieve negative temperatures because adding energy always increases their entropy . However, some systems have

243-404: A cooled ideal gas reach their minimum value. The fundamental particles of nature have minimum vibrational motion, retaining only quantum mechanical, zero-point energy -induced particle motion. The theoretical temperature is determined by extrapolating the ideal gas law ; by international agreement, absolute zero is taken as 0 kelvin ( International System of Units ), which is −273.15 degrees on

324-797: A joint project between the two observatories with participation by Canada and Spain (the latter became a member of ESO later). A series of resolutions and agreements led to the choice of "Atacama Large Millimeter Array", or ALMA, as the name of the new array in March 1999 and the signing of the ALMA Agreement on 25 February 2003, between the North American and European parties. ("Alma" means "soul" in Spanish and "learned" or "knowledgeable" in Arabic.) Following mutual discussions over several years,

405-730: A large angular size, such as molecular clouds and nearby galaxies. The antennae forming the Atacama Compact Array, four 12-meter antennae and twelve 7-meter antennae, were produced and delivered by Japan. In 2013, the Atacama Compact Array was named the Morita Array after Professor Koh-ichiro Morita, a member of the Japanese ALMA team and designer of the ACA, who died on 7 May 2012 in Santiago. In August 2013, workers at

486-536: A maximum amount of energy that they can hold, and as they approach that maximum energy their entropy actually begins to decrease. Because temperature is defined by the relationship between energy and entropy, such a system's temperature becomes negative, even though energy is being added. As a result, the Boltzmann factor for states of systems at negative temperature increases rather than decreases with increasing state energy. Therefore, no complete system, i.e. including

567-402: A subtotal of fifty antennae, that compose the main array. The participating East Asian countries are contributing 16 antennae (four 12-meter diameter and twelve 7-meter diameter antennae) in the form of the Atacama Compact Array (ACA), which is part of the enhanced ALMA. By using smaller antennae than the main ALMA array, larger fields of view can be imaged at a given frequency using ACA. Placing

648-475: A young (100,000-1,000,000-year-old) system, so the new data spurred renewed theories of protoplanetary development. One theory suggests that the faster accretion rate might be due to the complex magnetic field of the protoplanetary disc. ALMA participated in the Event Horizon Telescope project, which produced the first direct image of a black hole , published in 2019. ALMA participated in

729-500: Is an international partnership amongst Europe , the United States , Canada , Japan , South Korea , Taiwan , and Chile . Costing about US$ 1.4 billion, it is the most expensive ground-based telescope in operation. ALMA began scientific observations in the second half of 2011 and the first images were released to the press on 3 October 2011. The array has been fully operational since March 2013. The initial ALMA array

810-776: Is awaiting additional measurements . The Atacama Large Millimeter/submillimeter Array (ALMA), an international astronomy facility, is a partnership of Europe, North America and East Asia in cooperation with the Republic of Chile. ALMA is funded in Europe by the European Southern Observatory (ESO), in North America by the U.S. National Science Foundation (NSF) in cooperation with the National Research Council of Canada (NRC) and

891-542: Is called the Fermi energy . The Fermi temperature is defined as this maximum energy divided by the Boltzmann constant, and is on the order of 80,000 K for typical electron densities found in metals. For temperatures significantly below the Fermi temperature, the electrons behave in almost the same way as at absolute zero. This explains the failure of the classical equipartition theorem for metals that eluded classical physicists in

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972-597: Is composed of 66 high-precision antennae, and operates at wavelengths of 3.6 to 0.32 millimeters (31 to 1000 GHz). The array has much higher sensitivity and higher resolution than earlier submillimeter telescopes such as the single-dish James Clerk Maxwell Telescope or existing interferometer networks such as the Submillimeter Array or the Institut de Radio Astronomie Millimétrique (IRAM) Plateau de Bure facility. The antennae can be moved across

1053-407: Is not required; endothermic reactions can proceed spontaneously if the T Δ S term is large enough. Moreover, the slopes of the derivatives of Δ G and Δ H converge and are equal to zero at T  = 0. This ensures that Δ G and Δ H are nearly the same over a considerable range of temperatures and justifies the approximate empirical Principle of Thomsen and Berthelot, which states that

1134-459: Is roughly the radius of Earth. In 2021, University of Bremen physicists achieved a BEC with a temperature of only 38 picokelvin , the current coldest temperature record. Absolute, or thermodynamic , temperature is conventionally measured in kelvin ( Celsius -scaled increments) and in the Rankine scale ( Fahrenheit -scaled increments) with increasing rarity. Absolute temperature measurement

1215-435: Is that the entropy of a perfect crystal approaches a constant value. An adiabat is a state with constant entropy, typically represented on a graph as a curve in a manner similar to isotherms and isobars. The Nernst postulate identifies the isotherm T = 0 as coincident with the adiabat S = 0, although other isotherms and adiabats are distinct. As no two adiabats intersect, no other adiabat can intersect

1296-455: Is the entropy . In such a circumstance, pure substances can (ideally) form perfect crystals with no structural imperfections as T → 0. Max Planck 's strong form of the third law of thermodynamics states the entropy of a perfect crystal vanishes at absolute zero. The original Nernst heat theorem makes the weaker and less controversial claim that the entropy change for any isothermal process approaches zero as T → 0: The implication

1377-463: Is to use two custom 28-wheel self-loading heavy haulers . The vehicles were made by Scheuerle Fahrzeugfabrik  [ de ] in Germany and are 10 m wide, 20 m long and 6 m high, weighing 130 tonnes. They are powered by twin turbocharged 500 kW Diesel engines . The transporters, which feature a driver's seat designed to accommodate an oxygen tank to aid breathing

1458-568: Is uniquely determined by a multiplicative constant which specifies the size of the degree , so the ratios of two absolute temperatures, T 2 / T 1 , are the same in all scales. The most transparent definition of this standard comes from the Maxwell–Boltzmann distribution . It can also be found in Fermi–Dirac statistics (for particles of half-integer spin ) and Bose–Einstein statistics (for particles of integer spin). All of these define

1539-474: The COVID-19 pandemic . It also delayed the cycle 8 proposal submission deadline and suspended public visits to the site. On October 29, 2022, ALMA suspended observations due to a cyber attack. Observations were restarted 48 days later, on December 16, 2022. Absolute zero Absolute zero is the lowest limit of the thermodynamic temperature scale; a state at which the enthalpy and entropy of

1620-551: The Celsius scale, and equals −459.67 degrees on the Fahrenheit scale ( United States customary units or imperial units ). The Kelvin and Rankine temperature scales set their zero points at absolute zero by definition. It is commonly thought of as the lowest temperature possible, but it is not the lowest enthalpy state possible, because all real substances begin to depart from the ideal gas when cooled as they approach

1701-477: The Debye model , the specific heat and entropy of a pure crystal are proportional to T , while the enthalpy and chemical potential are proportional to T (Guggenheim, p. 111). These quantities drop toward their T  = 0 limiting values and approach with zero slopes. For the specific heats at least, the limiting value itself is definitely zero, as borne out by experiments to below 10 K. Even

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1782-488: The National Astronomical Observatory of Japan (NAOJ). The Joint ALMA Observatory (JAO) provides the unified leadership and management of the construction, commissioning and operation of ALMA. Its current director since February 2018 is Sean Dougherty . The ALMA regional centre (ARC) has been designed as an interface between user communities of the major contributors of the ALMA project and

1863-835: The National Science Council of Taiwan (NSC) and in East Asia by the National Institutes of Natural Sciences of Japan (NINS) in cooperation with the Academia Sinica (AS) in Taiwan. ALMA construction and operations are led on behalf of Europe by ESO, on behalf of North America by the National Radio Astronomy Observatory (NRAO), which is managed by Associated Universities, Inc (AUI) and on behalf of East Asia by

1944-695: The Onsala Space Observatory (OSO, 13%), and the European Organisation for Astronomical Research in the Southern Hemisphere ESO (32%). It is now a sole project of the MPIfR, hosted and operated by ESO on behalf of the MPIfR. Submillimetre astronomy is a relatively unexplored frontier in astronomy and reveals a Universe that cannot be seen in the more familiar visible or infrared light. It is ideal for studying

2025-557: The SMA in Hawaii has set the world-record in angular resolution: 28.6 micro-arcseconds All ESO and Swedish APEX data are stored in the ESO archive. These data follow the standard ESO archive rules, i.e., they become publicly available one year after they have been delivered to the principal investigator of the project. APEX, the largest submillimetre-wavelength single-dish telescope operating in

2106-476: The Very Large Array since 2002. General Dynamics C4 Systems and its SATCOM Technologies division was contracted by Associated Universities, Inc. to provide twenty-five of the 12 m antennae, while European manufacturer Thales Alenia Space provided the other twenty-five principal antennae (in the largest-ever European industrial contract in ground-based astronomy). Japan's Mitsubishi Electric

2187-548: The coldest temperatures achieved on Earth at the time and his achievement earned him the Nobel Prize in 1913. Kamerlingh Onnes would continue to study the properties of materials at temperatures near absolute zero, describing superconductivity and superfluids for the first time. The average temperature of the universe today is approximately 2.73 K (−270.42 °C; −454.76 °F), based on measurements of cosmic microwave background radiation. Standard models of

2268-426: The future expansion of the universe predict that the average temperature of the universe is decreasing over time. This temperature is calculated as the mean density of energy in space; it should not be confused with the mean electron temperature (total energy divided by particle count) which has increased over time. Absolute zero cannot be achieved, although it is possible to reach temperatures close to it through

2349-423: The instrumentation page . To operate at the shorter sub-millimetre wavelengths, APEX presents a surface of exceedingly high quality. After a series of high precision adjustments, the surface of the primary mirror can be adjusted with remarkable precision. Over the 12 m diameter of the antenna, the rms deviation from the perfect parabola is less than 17 thousandths of a millimetre. This is smaller than one fifth of

2430-481: The "cold Universe": light at these wavelengths shines from vast cold clouds in interstellar space, at temperatures only a few tens of degrees above absolute zero. Astronomers use this light to study the chemical and physical conditions in these molecular clouds — the dense regions of gas and cosmic dust where new stars are being born. Seen in visible light, these regions of the Universe are often dark and obscured due to

2511-592: The 5,000 m (16,000 ft) elevation Chajnantor plateau – near the Llano de Chajnantor Observatory and the Atacama Pathfinder Experiment . This location was chosen for its high elevation and low humidity , factors which are crucial to reduce noise and decrease signal attenuation due to Earth's atmosphere. ALMA provides insight on star birth during the early Stelliferous era and detailed imaging of local star and planet formation. ALMA

Atacama Pathfinder Experiment - Misplaced Pages Continue

2592-543: The ALMA Project received a proposal from the National Astronomical Observatory of Japan (NAOJ) whereby Japan would provide the ACA (Atacama Compact Array) and three additional receiver bands for the large array, to form Enhanced ALMA. Further discussions between ALMA and NAOJ led to the signing of a high-level agreement on 14 September 2004 that makes Japan an official participant in Enhanced ALMA, to be known as

2673-642: The Atacama Large Millimeter/submillimeter Array (ALMA) for the first time, that detailed the distribution of HCN , HNC , H 2 CO , and dust inside the comae of comets C/2012 F6 (Lemmon) and C/2012 S1 (ISON) . An image of the protoplanetary disc surrounding HL Tauri (a very young T Tauri star in the constellation Taurus ) was made public in 2014, showing a series of concentric bright rings separated by gaps, indicating protoplanet formation. As of 2014 , most theories did not expect planetary formation in such

2754-437: The Atacama Large Millimeter/submillimeter Array. A groundbreaking ceremony was held on November 6, 2003 and the ALMA logo was unveiled. During an early stage of the planning of ALMA, it was decided to employ ALMA antennae designed and constructed by known companies in North America, Europe, and Japan, rather than using one single design. This was mainly for political reasons. Although very different approaches have been chosen by

2835-572: The JAO. Activates for operating the ARC have also divided into the three main regions involved (Europe, North America and East Asia). The European ARC (led by ESO ) has been further subdivided into ARC-nodes located across Europe in Bonn-Bochum-Cologne, Bologna, Ondřejov, Onsala , IRAM (Grenoble), Leiden and JBCA (Manchester). The core purpose of the ARC is to assist the user community with

2916-459: The T ;= 0 isotherm. Consequently no adiabatic process initiated at nonzero temperature can lead to zero temperature (≈ Callen, pp. 189–190). A perfect crystal is one in which the internal lattice structure extends uninterrupted in all directions. The perfect order can be represented by translational symmetry along three (not usually orthogonal ) axes . Every lattice element of

2997-695: The antennae closer together enables the imaging of sources of larger angular extent. The ACA works together with the main array in order to enhance the latter's wide-field imaging capability. ALMA has its conceptual roots in three astronomical projects: the Millimeter Array (MMA) of the United States, the Large Southern Array (LSA) of Europe, and the Large Millimeter Array (LMA) of Japan. The first step toward

3078-533: The average thickness of a human hair. The APEX telescope is made up of three "receiver" cabins: Cassegrain, Nasmyth A, and Nasmyth B. Atacama Large Millimeter Array The Atacama Large Millimeter/submillimeter Array ( ALMA ) is an astronomical interferometer of 66 radio telescopes in the Atacama Desert of northern Chile , which observe electromagnetic radiation at millimeter and submillimeter wavelengths . The array has been constructed on

3159-462: The change of state to liquid, and then to solid; and the sum of the enthalpy of vaporization (gas to liquid) and enthalpy of fusion (liquid to solid) exceeds the ideal gas's change in enthalpy to absolute zero. In the quantum-mechanical description, matter at absolute zero is in its ground state , the point of lowest internal energy . The laws of thermodynamics indicate that absolute zero cannot be reached using only thermodynamic means, because

3240-412: The claimed detection of phosphine , a biomarker, in the air of Venus. As no known non-biological source of phosphine on Venus could produce phosphine in the concentrations detected, this would have indicated the presence of biological organisms in the atmosphere of Venus. Later reanalyses cast doubt on the detection, although later analyses confirmed the results. The detection remains controversial, and

3321-573: The cold of freezing water" was published by George Martine in 1740. This close approximation to the modern value of −273.15 °C for the zero of the air thermometer was further improved upon in 1779 by Johann Heinrich Lambert , who observed that −270 °C (−454.00 °F; 3.15 K) might be regarded as absolute cold. Values of this order for the absolute zero were not, however, universally accepted about this period. Pierre-Simon Laplace and Antoine Lavoisier , in their 1780 treatise on heat, arrived at values ranging from 1,500 to 3,000 below

Atacama Pathfinder Experiment - Misplaced Pages Continue

3402-522: The creation of what would become ALMA came in 1997, when the National Radio Astronomy Observatory (NRAO) and the European Southern Observatory (ESO) agreed to pursue a common project that merged the MMA and LSA. The merged array combined the sensitivity of the LSA with the frequency coverage and superior site of the MMA. ESO and NRAO worked together in technical, science, and management groups to define and organise

3483-652: The desert plateau over distances from 150 m to 16 km, which will give ALMA a powerful variable "zoom", similar in its concept to that employed at the centimeter-wavelength Very Large Array (VLA) site in New Mexico, United States . The high sensitivity is mainly achieved through the large numbers of antenna dishes that make up the array. The telescopes were provided by the European, North American and East Asian partners of ALMA. The American and European partners each provided twenty-five 12-meter diameter antennae, for

3564-411: The dust, but they shine brightly in the millimetre and submillimetre part of the spectrum. This wavelength range is also ideal for studying some of the earliest and most distant galaxies in the Universe, whose light has been redshifted into these longer wavelengths. APEX science goals include studying the formation of stars, planets, and galaxies, including very distant galaxies in the early Universe, and

3645-879: The early 20th century. With a better theoretical understanding of absolute zero, scientists were eager to reach this temperature in the lab. By 1845, Michael Faraday had managed to liquefy most gases then known to exist, and reached a new record for lowest temperatures by reaching −130 °C (−202 °F; 143 K). Faraday believed that certain gases, such as oxygen, nitrogen, and hydrogen , were permanent gases and could not be liquefied. Decades later, in 1873 Dutch theoretical scientist Johannes Diderik van der Waals demonstrated that these gases could be liquefied, but only under conditions of very high pressure and very low temperatures. In 1877, Louis Paul Cailletet in France and Raoul Pictet in Switzerland succeeded in producing

3726-426: The electromagnetic modes, can have negative temperatures, since there is no highest energy state, so that the sum of the probabilities of the states would diverge for negative temperatures. However, for quasi-equilibrium systems (e.g. spins out of equilibrium with the electromagnetic field) this argument does not apply, and negative effective temperatures are attainable. On 3 January 2013, physicists announced that for

3807-427: The entropy is thus, as T decreases, Δ G and Δ H approach each other (so long as Δ S is bounded). Experimentally, it is found that all spontaneous processes (including chemical reactions ) result in a decrease in G as they proceed toward equilibrium . If Δ S and/or T are small, the condition Δ G  < 0 may imply that Δ H  < 0, which would indicate an exothermic reaction. However, this

3888-511: The equilibrium state to which a system proceeds is the one that evolves the greatest amount of heat , i.e., an actual process is the most exothermic one (Callen, pp. 186–187). One model that estimates the properties of an electron gas at absolute zero in metals is the Fermi gas . The electrons, being fermions , must be in different quantum states, which leads the electrons to get very high typical velocities , even at absolute zero. The maximum energy that electrons can have at absolute zero

3969-637: The faint signals from space are heavily absorbed by water vapour in the Earth's atmosphere. Chajnantor was chosen as the location for such a telescope because the region is one of the driest on the planet and is more than 750 m higher than the observatories on Mauna Kea and 2400 m higher than the Very Large Telescope (VLT) on Cerro Paranal. APEX was a collaboration between the Max Planck Institute for Radio Astronomy (MPIfR) (55%),

4050-464: The field of star formation and astrochemistry, are the discovery of a new interstellar molecule and the detection of light emitted at 0.2 mm from CO molecules, as well as light coming from a charged molecule composed of two forms of hydrogen. Recent APEX observations lead to the first ever discovery of hydrogen peroxide in space, the first image of a dusty disc closely encircling a massive baby star, providing direct evidence that massive stars form in

4131-517: The first droplets of liquid air at −195 °C (−319.0 °F; 78.1 K). This was followed in 1883 by the production of liquid oxygen −218 °C (−360.4 °F; 55.1 K) by the Polish professors Zygmunt Wróblewski and Karol Olszewski . Scottish chemist and physicist James Dewar and Dutch physicist Heike Kamerlingh Onnes took on the challenge to liquefy the remaining gases, hydrogen and helium . In 1898, after 20 years of effort, Dewar

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4212-605: The first gaseous condensate was produced by Eric Cornell and Carl Wieman at the University of Colorado at Boulder NIST - JILA lab, using a gas of rubidium atoms cooled to 170 nanokelvin ( 1.7 × 10  K ). In 2003, researchers at the Massachusetts Institute of Technology (MIT) achieved a temperature of 450 ± 80 picokelvin ( 4.5 × 10  K ) in a BEC of sodium atoms. The associated black-body (peak emittance) wavelength of 6.4 megameters

4293-507: The first three antennae were transported one-by-one to the Array Operations Site. At the end of 2009, a team of ALMA astronomers and engineers successfully linked three antennae at the 5,000-metre (16,000 ft) elevation observing site thus finishing the first stage of assembly and integration of the fledgling array. Linking three antennae allows corrections of errors that can arise when only two antennae are used, thus paving

4374-488: The first time they had created a quantum gas made up of potassium atoms with a negative temperature in motional degrees of freedom. One of the first to discuss the possibility of an absolute minimal temperature was Robert Boyle . His 1665 New Experiments and Observations touching Cold , articulated the dispute known as the primum frigidum . The concept was well known among naturalists of the time. Some contended an absolute minimum temperature occurred within earth (as one of

4455-403: The four classical elements ), others within water, others air, and some more recently within nitre . But all of them seemed to agree that, "There is some body or other that is of its own nature supremely cold and by participation of which all other bodies obtain that quality." The question of whether there is a limit to the degree of coldness possible, and, if so, where the zero must be placed,

4536-588: The freezing point of water, and thought that in any case it must be at least 600 below. John Dalton in his Chemical Philosophy gave ten calculations of this value, and finally adopted −3,000 °C as the natural zero of temperature. From 1787 to 1802, it was determined by Jacques Charles (unpublished), John Dalton , and Joseph Louis Gay-Lussac that, at constant pressure, ideal gases expanded or contracted their volume linearly ( Charles's law ) by about 1/273 parts per degree Celsius of temperature's change up or down, between 0° and 100° C. This suggested that

4617-638: The future as the scale of the array continues to increase. The target of the observation was a pair of colliding galaxies with dramatically distorted shapes, known as the Antennae Galaxies . Although ALMA did not observe the entire galaxy merger, the result is the best submillimeter-wavelength image ever made of the Antennae Galaxies, showing the clouds of dense cold gas from which new stars form, which cannot be seen using visible light. On 11 August 2014, astronomers released studies, using

4698-678: The help of the other Japanese, Taiwanese, and Chilean partners. ALMA is the largest and most expensive ground-based astronomical project, costing between US$ 1.4 and 1.5 billion. (However, various space astronomy projects including the Hubble Space Telescope , the James Webb Space Telescope , and several major planet probes have cost considerably more). The complex was built primarily by European, U.S., Japanese, and Canadian companies and universities . Three prototype antennae have undergone evaluation at

4779-427: The late 19th century. A Bose–Einstein condensate (BEC) is a state of matter of a dilute gas of weakly interacting bosons confined in an external potential and cooled to temperatures very near absolute zero. Under such conditions, a large fraction of the bosons occupy the lowest quantum state of the external potential, at which point quantum effects become apparent on a macroscopic scale . This state of matter

4860-458: The less detailed Einstein model shows this curious drop in specific heats. In fact, all specific heats vanish at absolute zero, not just those of crystals. Likewise for the coefficient of thermal expansion . Maxwell's relations show that various other quantities also vanish. These phenomena were unanticipated. Since the relation between changes in Gibbs free energy ( G ), the enthalpy ( H ) and

4941-487: The physical conditions of molecular clouds. Its first results proved the telescope lives up to the ambitions of the scientists by providing access to the "cold Universe" with unprecedented sensitivity and image quality. No fewer than 26 articles based on early science with APEX were published in July 2006 in a special issue of the research journal Astronomy and Astrophysics . Among the many new findings published then, most in

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5022-479: The preparation of observing proposals, ensure observing programs meet their scientific goals efficiently, run a help-desk for submitting proposals and observing programs, delivering the data to principal investigators, maintenance of the ALMA data archive, assistance with the calibration of data and providing user feedback. The Atacama Compact Array, ACA, is a subset of 16 closely separated antennae that will greatly improve ALMA's ability to study celestial objects with

5103-442: The principles on which this scale was constructed that its zero was placed at −273 °C, at almost precisely the same point as the zero of the air thermometer, where the air volume would reach "nothing". This value was not immediately accepted; values ranging from −271.1 °C (−455.98 °F) to −274.5 °C (−462.10 °F), derived from laboratory measurements and observations of astronomical refraction , remained in use in

5184-489: The providers, each of the antenna designs appears to be able to meet ALMA's stringent requirements. The components designed and manufactured across Europe were transported by specialist aerospace and astrospace logistics company Route To Space Alliance, 26 in total which were delivered to Antwerp for onward shipment to Chile. ALMA was initially a 50-50 collaboration between the National Radio Astronomy Observatory and European Southern Observatory (ESO) and later extended with

5265-596: The relative numbers of particles in a system as decreasing exponential functions of energy (at the particle level) over kT , with k representing the Boltzmann constant and T representing the temperature observed at the macroscopic level. Temperatures that are expressed as negative numbers on the familiar Celsius or Fahrenheit scales are simply colder than the zero points of those scales. Certain systems can achieve truly negative temperatures; that is, their thermodynamic temperature (expressed in kelvins) can be of

5346-618: The same way as their smaller brethren, and the first direct measurements of the size and brightness of regions of star-birth in a very distant galaxy. APEX is also involved in the Global mm- VLBI Network and in the Event Horizon Telescope (EHT). The EHT project produced the first direct image of a black hole . The detection in May 2012 of the quasar 3C 279 at 1.3 mm wavelength on the 9386 km baseline between APEX and

5427-500: The southern hemisphere, has a suite of instruments for astronomers to use in their observations, a major one being LABOCA, the Large APEX Bolometer Camera. LABOCA uses an array of extremely sensitive micro-calorimeters — known as bolometers — to detect submillimetre light. With almost 300 elements, at the time of commissioning in 2007 LABOCA has been the largest bolometer camera in the world. To be able to detect

5508-530: The spring of the air was reduced to nothing. He used a scale that marked the boiling point of water at +73 and the melting point of ice at + 51 + 1 ⁄ 2 , so that the zero was equivalent to about −240 on the Celsius scale. Amontons held that the absolute zero cannot be reached, so never attempted to compute it explicitly. The value of −240 °C, or "431 divisions [in Fahrenheit's thermometer] below

5589-577: The structure is in its proper place, whether it is a single atom or a molecular grouping. For substances that exist in two (or more) stable crystalline forms, such as diamond and graphite for carbon , there is a kind of chemical degeneracy . The question remains whether both can have zero entropy at T  = 0 even though each is perfectly ordered. Perfect crystals never occur in practice; imperfections, and even entire amorphous material inclusions, can and do get "frozen in" at low temperatures, so transitions to more stable states do not occur. Using

5670-412: The telescope went on strike to demand better pay and working conditions. This is one of the first strikes to affect an astronomical observatory. The work stoppage began after the observatory failed to reach an agreement with the workers' union. After 17 days an agreement was reached providing for reduced schedules and higher pay for work done at high altitude. In March 2020, ALMA was shut down due to

5751-713: The temperature of the substance being cooled approaches the temperature of the cooling agent asymptotically . Even a system at absolute zero, if it could somehow be achieved, would still possess quantum mechanical zero-point energy, the energy of its ground state at absolute zero; the kinetic energy of the ground state cannot be removed. Scientists and technologists routinely achieve temperatures close to absolute zero, where matter exhibits quantum effects such as superconductivity , superfluidity , and Bose–Einstein condensation . At temperatures near 0 K (−273.15 °C; −459.67 °F), nearly all molecular motion ceases and Δ S  = 0 for any adiabatic process , where S

5832-619: The thin high-altitude air, place the antennae precisely on the pads. The first vehicle was completed and tested in July 2007. Both transporters were delivered to the ALMA Operations Support Facility (OSF) in Chile on 15 February 2008. On 7 July 2008, an ALMA transporter moved an antenna for the first time, from inside the antenna assembly building (Site Erection Facility) to a pad outside the building for testing (holographic surface measurements). During Autumn 2009,

5913-418: The tiny temperature changes caused by the faint submillimetre radiation, the bolometers are cooled to a fraction of a degree above absolute zero (300  millikelvins — minus 272.85 degrees Celsius). LABOCA's high sensitivity, together with its wide field of view (11 arcminutes , one third of the diameter of the full Moon), make it an invaluable tool for imaging the submillimetre Universe. APEX first light

5994-535: The volume of a gas cooled at about −273 °C would reach zero. After James Prescott Joule had determined the mechanical equivalent of heat, Lord Kelvin approached the question from an entirely different point of view, and in 1848 devised a scale of absolute temperature that was independent of the properties of any particular substance and was based on Carnot 's theory of the Motive Power of Heat and data published by Henri Victor Regnault . It followed from

6075-471: The way for precise, high-resolution imaging. With this key step, commissioning of the instrument began 22 January 2010. On 28 July 2011, the first European antenna for ALMA arrived at the Chajnantor plateau, 5,000 meters above sea level, to join 15 antennae already in place from the other international partners. This was the number of antennae specified for ALMA to begin its first science observations, and

6156-626: Was achieved in May 2004 using the SEST Imaging Bolometer Array (SIMBA) that had been moved to APEX after the decommissioning of the SEST and the first radio pointing model was compiled. At the time of the inauguration in 2005, APEX was equipped with state-of-the-art sub-millimetre spectrometers developed by MPIfR's Division for Sub-Millimetre Technology and followed by the first facility receiver built at Chalmers University (OSO). For more information about APEX instruments, consult

6237-588: Was contracted to assemble NAOJ's 16 antennae. The antennae were delivered to the site from December 2008 to September 2013. Transporting the 115  tonne antennae from the Operations Support Facility at 2900 m altitude to the site at 5000 m, or moving antennae around the site to change the array size, presents enormous challenges; as portrayed in the television documentary Monster Moves: Mountain Mission . The solution chosen

6318-458: Was first addressed by the French physicist Guillaume Amontons in 1703, in connection with his improvements in the air thermometer . His instrument indicated temperatures by the height at which a certain mass of air sustained a column of mercury—the pressure, or "spring" of the air varying with temperature. Amontons therefore argued that the zero of his thermometer would be that temperature at which

6399-515: Was first predicted by Satyendra Nath Bose and Albert Einstein in 1924–1925. Bose first sent a paper to Einstein on the quantum statistics of light quanta (now called photons ). Einstein was impressed, translated the paper from English to German and submitted it for Bose to the Zeitschrift für Physik , which published it. Einstein then extended Bose's ideas to material particles (or matter) in two other papers. Seventy years later, in 1995,

6480-529: Was the first to liquefy hydrogen, reaching a new low-temperature record of −252 °C (−421.6 °F; 21.1 K). However, Kamerlingh Onnes, his rival, was the first to liquefy helium, in 1908, using several precooling stages and the Hampson–Linde cycle . He lowered the temperature to the boiling point of helium −269 °C (−452.20 °F; 4.15 K). By reducing the pressure of the liquid helium, he achieved an even lower temperature, near 1.5 K. These were

6561-470: Was therefore an important milestone for the project. In October 2012, 43 of the 66 antennae had been set up. By the summer of 2011, sufficient telescopes were operational during the extensive program of testing prior to the Early Science phase for the first images to be captured. These early images gave a first glimpse of the potential of the new array that will produce much better quality images in

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