Scripps Institution of Oceanography
The Scripps Institution of Oceanography in La Jolla, founded in 1903, is one of the oldest and largest centers for ocean and Earth science research, public service and graduate training in the world. Hundreds of ocean and Earth scientists conduct research with the aid of oceanographic research vessels and shorebased laboratories, its Old Scripps Building is a U. S. National Historic Landmark. SIO is a division of the University of California San Diego; the public explorations center of the institution is the Birch Aquarium at Scripps. Since becoming part of the University of California in 1912, the institution has expanded its scope to include studies of the physics, geology and climate of Earth. Dr. Margaret Leinen took office as Vice Chancellor for Marine Sciences, Director of Scripps Institution of Oceanography, Dean of the Graduate School of Marine Sciences on October 1, 2013. Scripps publishes explorations now, an e-magazine of ocean and earth science. "To seek and communicate scientific understanding of the oceans, atmosphere and other planets for the benefit of society and the environment."
Scripps Institution of Oceanography was founded in 1903 as the Marine Biological Association of San Diego, an independent biological research laboratory. It was proposed and incorporated by a committee of the San Diego Chamber of Commerce, led by local activist and amateur malacologist Fred Baker, together with two colleagues, he recruited University of California Zoology professor William Emerson Ritter to head up the proposed marine biology institution, obtained financial support from local philanthropists E. W. Scripps and his sister Ellen Browning Scripps, they funded the institution for its first decade. It began institutional life in the boathouse of the Hotel del Coronado located on San Diego Bay, it re-located in 1905 to the La Jolla area on the head above La Jolla Cove, in 1907 to its present location. In 1912 Scripps became part of the University of California and was renamed the "Scripps Institution for Biological Research." Since 1916, measurements have been taken daily at its pier.
The name was changed to Scripps Institution of Oceanography in October 1925. During the 1960s, led by Scripps Institution of Oceanography director Roger Revelle, it formed the nucleus for the creation of the University of California, San Diego on a bluff overlooking Scripps Institution; the Old Scripps Building, designed by Irving Gill, was declared a National Historic Landmark in 1982. Architect Barton Myers designed the current Scripps Building for the Institution of Oceanography in 1998; the institution's research programs encompass biological, chemical and geophysical studies of the oceans and earth. Scripps studies the interaction of the oceans with both the atmospheric climate and environmental concerns on terra firma. Related to this research, Scripps offers graduate degrees. Today, the Scripps staff of 1,300 includes 235 faculty, 180 other scientists and some 300 graduate students, with an annual budget of more than $195 million; the institution operates a fleet of three oceanographic research vessels and the research platform R/P FLIP for oceanographic research.
The Integrated Research Themes encompassing the work done by Scripps researchers are: Biodiversity and Conservation California Environment Earth and Planetary Chemistry Earth Through Space and Time Energy and the Environment Environment and Human Health Global Change Global Environmental Monitoring Hazards Ice and Climate Instruments and Innovation Interfaces Marine Life Modeling and Computing Sound and Light in the Sea Waves and Circulation Scripps Oceanography is divided into three research sections, each with its own subdivisions: Biology Center for Marine Biotechnology & Biomedicine Integrative Oceanography Division Marine Biology Research Division Earth Cecil H. and Ida M. Green Institute of Geophysics and Planetary Physics Geosciences Research Division Oceans & Atmosphere Climate, Atmospheric Science & Physical Oceanography Marine Physical Laboratory Scripps owns and operates several research vessels and platforms: RV Roger Revelle RV Sally Ride RV Robert Gordon Sproul RP FlipCurrent and previous vessels larger than 50 ft 1906–????
– RV Loma 1907–1917 – RV Alexander Agassiz 1918–1918 – RV Ellen Browning 1925–1936 – RV Scripps 1937–1955 – RV E. W. Scripps 1955–1965 – RV Stranger 1947–1956 – RV Crest 1947–1969 – RV Horizon 1948–1965 – RV Paolina-T 1951–1965 – RV Spencer F. Baird 1955–1969 – T-441 1956–1962 – RV Orca 1959–1963 – RV Hugh M. Smith 1959–1970 – RV Argo 1962–1976 – RV Alexander Agassiz 1962–present – RP FLIP 1962–1974 – RV Oconostota 1965–1980 – RV Alpha Helix (Transferred to University of Alaska, Fairbanks in 1980 1965–???? – RV Ellen B. Scripps 1966–1992 – RV Thomas Washington 1969–2014 – RV Melville 1973–???? – RV Gianna 1978–2015 – RV New Horizon 1984–present – RV Robert Gordon Sproul 1995–present – RV Roger Revelle 2016–present – RV Sally Ride Birch Aquarium at Scripps, the public exploration center for the institution, features a Hall of Fishes with more than 60 tanks of Pacific fishes and invertebrates from the cold waters of the Pacific Northwest to the tropical waters of Mexico and the IndoPacific, a 13,000-gallon local shark and ray exhibit, interactive tide pools, interactive science exhibits.
In 2014, the institution and
Europe is a continent located in the Northern Hemisphere and in the Eastern Hemisphere. It is bordered by the Arctic Ocean to the north, the Atlantic Ocean to the west and the Mediterranean Sea to the south, it comprises the westernmost part of Eurasia. Since around 1850, Europe is most considered to be separated from Asia by the watershed divides of the Ural and Caucasus Mountains, the Ural River, the Caspian and Black Seas and the waterways of the Turkish Straits. Although the term "continent" implies physical geography, the land border is somewhat arbitrary and has been redefined several times since its first conception in classical antiquity; the division of Eurasia into two continents reflects East-West cultural and ethnic differences which vary on a spectrum rather than with a sharp dividing line. The geographic border does not follow political boundaries, with Turkey and Kazakhstan being transcontinental countries. A strict application of the Caucasus Mountains boundary places two comparatively small countries and Georgia, in both continents.
Europe covers 2 % of the Earth's surface. Politically, Europe is divided into about fifty sovereign states of which the Russian Federation is the largest and most populous, spanning 39% of the continent and comprising 15% of its population. Europe had a total population of about 741 million as of 2016; the European climate is affected by warm Atlantic currents that temper winters and summers on much of the continent at latitudes along which the climate in Asia and North America is severe. Further from the sea, seasonal differences are more noticeable than close to the coast. Europe, in particular ancient Greece, was the birthplace of Western civilization; the fall of the Western Roman Empire in 476 AD and the subsequent Migration Period marked the end of ancient history and the beginning of the Middle Ages. Renaissance humanism, exploration and science led to the modern era. Since the Age of Discovery started by Portugal and Spain, Europe played a predominant role in global affairs. Between the 16th and 20th centuries, European powers controlled at various times the Americas all of Africa and Oceania and the majority of Asia.
The Age of Enlightenment, the subsequent French Revolution and the Napoleonic Wars shaped the continent culturally and economically from the end of the 17th century until the first half of the 19th century. The Industrial Revolution, which began in Great Britain at the end of the 18th century, gave rise to radical economic and social change in Western Europe and the wider world. Both world wars took place for the most part in Europe, contributing to a decline in Western European dominance in world affairs by the mid-20th century as the Soviet Union and the United States took prominence. During the Cold War, Europe was divided along the Iron Curtain between NATO in the West and the Warsaw Pact in the East, until the revolutions of 1989 and fall of the Berlin Wall. In 1949 the Council of Europe was founded, following a speech by Sir Winston Churchill, with the idea of unifying Europe to achieve common goals, it includes all European states except for Belarus and Vatican City. Further European integration by some states led to the formation of the European Union, a separate political entity that lies between a confederation and a federation.
The EU originated in Western Europe but has been expanding eastward since the fall of the Soviet Union in 1991. The currency of most countries of the European Union, the euro, is the most used among Europeans. In classical Greek mythology, Europa was a Phoenician princess; the word Europe is derived from her name. The name contains the elements εὐρύς, "wide, broad" and ὤψ "eye, countenance", hence their composite Eurṓpē would mean "wide-gazing" or "broad of aspect". Broad has been an epithet of Earth herself in the reconstructed Proto-Indo-European religion and the poetry devoted to it. There have been attempts to connect Eurṓpē to a Semitic term for "west", this being either Akkadian erebu meaning "to go down, set" or Phoenician'ereb "evening, west", at the origin of Arabic Maghreb and Hebrew ma'arav. Michael A. Barry, professor in Princeton University's Near Eastern Studies Department, finds the mention of the word Ereb on an Assyrian stele with the meaning of "night, sunset", in opposition to Asu " sunrise", i.e. Asia.
The same naming motive according to "cartographic convention" appears in Greek Ἀνατολή. Martin Litchfield West stated that "phonologically, the match between Europa's name and any form of the Semitic word is poor." Next to these hypotheses there is a Proto-Indo-European root *h1regʷos, meaning "darkness", which produced Greek Erebus. Most major world languages use words derived from Europa to refer to the continent. Chinese, for example, uses the word Ōuzhōu. In some Turkic languages the Persian name Frangistan is used casually in referring to much of Europe, besides official names such as Avrupa or Evropa; the prevalent definition of Europe as a geographical term has been in use since the mid-19th century. Europe is taken to be bounded by large bodies of water
Seawater, or salt water, is water from a sea or ocean. On average, seawater in the world's oceans has a salinity of about 3.5%. This means that every kilogram of seawater has 35 grams of dissolved salts. Average density at the surface is 1.025 kg/L. Seawater is denser than both fresh water and pure water because the dissolved salts increase the mass by a larger proportion than the volume; the freezing point of seawater decreases as salt concentration increases. At typical salinity, it freezes at about −2 °C; the coldest seawater recorded was in 2010, in a stream under an Antarctic glacier, measured −2.6 °C. Seawater pH is limited to a range between 7.5 and 8.4. However, there is no universally accepted reference pH-scale for seawater and the difference between measurements based on different reference scales may be up to 0.14 units. Although the vast majority of seawater has a salinity of between 31 g/kg and 38 g/kg, 3.1-3.8%, seawater is not uniformly saline throughout the world. Where mixing occurs with fresh water runoff from river mouths, near melting glaciers or vast amounts of precipitation, seawater can be less saline.
The most saline open sea is the Red Sea, where high rates of evaporation, low precipitation and low river run-off, confined circulation result in unusually salty water. The salinity in isolated bodies of water can be greater still - about ten times higher in the case of the Dead Sea. Several salinity scales were used to approximate the absolute salinity of seawater. A popular scale was the "Practical Salinity Scale" where salinity was measured in "practical salinity units"; the current standard for salinity is the "Reference Salinity" scale with the salinity expressed in units of "g/kg". The density of surface seawater ranges from about 1020 to 1029 kg/m3, depending on the temperature and salinity. At a temperature of 25 °C, salinity of 35 g/kg and 1 atm pressure, the density of seawater is 1023.6 kg/m3. Deep in the ocean, under high pressure, seawater can reach a density of higher; the density of seawater changes with salinity. Brines generated by seawater desalination plants can have salinities up to 120 g/kg.
The density of typical seawater brine of 120 g/kg salinity at 25 °C and atmospheric pressure is 1088 kg/m3. Seawater pH is limited to the range 7.5 to 8.4. The speed of sound in seawater is about 1,500 m/s, varies with water temperature and pressure; the thermal conductivity of seawater is a salinity of 35 g/kg. The thermal conductivity decreases with increasing salinity and increases with increasing temperature. Seawater contains more dissolved ions than all types of freshwater. However, the ratios of solutes differ dramatically. For instance, although seawater contains about 2.8 times more bicarbonate than river water, the percentage of bicarbonate in seawater as a ratio of all dissolved ions is far lower than in river water. Bicarbonate ions constitute 48% of river water solutes but only 0.14% for seawater. Differences like these are due to the varying residence times of seawater solutes; the most abundant dissolved ions in seawater are sodium, magnesium and calcium. Its osmolarity is about 1000 mOsm/l.
Small amounts of other substances are found, including amino acids at concentrations of up to 2 micrograms of nitrogen atoms per liter, which are thought to have played a key role in the origin of life. Research in 1957 by the Scripps Institution of Oceanography sampled water in both pelagic and neritic locations in the Pacific Ocean. Direct microscopic counts and cultures were used, the direct counts in some cases showing up to 10 000 times that obtained from cultures; these differences were attributed to the occurrence of bacteria in aggregates, selective effects of the culture media, the presence of inactive cells. A marked reduction in bacterial culture numbers was noted below the thermocline, but not by direct microscopic observation. Large numbers of spirilli-like forms were seen by microscope but not under cultivation; the disparity in numbers obtained by the two methods is well known in other fields. In the 1990s, improved techniques of detection and identification of microbes by probing just small snippets of DNA, enabled researchers taking part in the Census of Marine Life to identify thousands of unknown microbes present only in small numbers.
This revealed a far greater diversity than suspected, so that a litre of seawater may hold more than 20,000 species. Mitchell Sogin from the Marine Biological Laboratory feels that "the number of different kinds of bacteria in the oceans could eclipse five to 10 million."Bacteria are found at all depths in the water column, as well as in the sediments, some being aerobic, others anaerobic. Most are free-swimming, but some exist as symbionts within other organisms – examples of these being bioluminescent bacteria. Cyanobacteria played an important role in the evolution of ocean processes, enabling the development of stromatolites and oxygen in the atmosphere; some bacteria interact with diatoms, form a critical link in the cycling of silicon in the ocean. One anaerobic species, Thiomargarita namibiensis, plays an important part in the breakdown of hydrogen sulfide eruptions from diatomaceous sediments off the Namibian coast, generated by high rates of phytoplankton
International Atomic Energy Agency
The International Atomic Energy Agency is an international organization that seeks to promote the peaceful use of nuclear energy, to inhibit its use for any military purpose, including nuclear weapons. The IAEA was established as an autonomous organisation on 29 July 1957. Though established independently of the United Nations through its own international treaty, the IAEA Statute, the IAEA reports to both the United Nations General Assembly and Security Council; the IAEA has its headquarters in Austria. The IAEA has two "Regional Safeguards Offices" which are located in Toronto, in Tokyo, Japan; the IAEA has two liaison offices which are located in New York City, United States, in Geneva, Switzerland. In addition, the IAEA has laboratories and research centers located in Seibersdorf, Austria, in Monaco and in Trieste, Italy; the IAEA serves as an intergovernmental forum for scientific and technical co-operation in the peaceful use of nuclear technology and nuclear power worldwide. The programs of the IAEA encourage the development of the peaceful applications of nuclear energy and technology, provide international safeguards against misuse of nuclear technology and nuclear materials, promote nuclear safety and nuclear security standards and their implementation.
The IAEA and its former Director General, Mohamed ElBaradei, were jointly awarded the Nobel Peace Prize on 7 October 2005. The IAEA's current Director General is Yukiya Amano. In 1953, the President of the United States, Dwight D. Eisenhower, proposed the creation of an international body to both regulate and promote the peaceful use of atomic power, in his Atoms for Peace address to the UN General Assembly. In September 1954, the United States proposed to the General Assembly the creation of an international agency to take control of fissile material, which could be used either for nuclear power or for nuclear weapons; this agency would establish a kind of "nuclear bank." The United States called for an international scientific conference on all of the peaceful aspects of nuclear power. By November 1954, it had become clear that the Soviet Union would reject any international custody of fissile material if the United States did not agree to a disarmament first, but that a clearing house for nuclear transactions might be possible.
From 8 to 20 August 1955, the United Nations held the International Conference on the Peaceful Uses of Atomic Energy in Geneva, Switzerland. In October 1957, a Conference on the IAEA Statute was held at the Headquarters of the United Nations to approve the founding document for the IAEA, negotiated in 1955–1957 by a group of twelve countries; the Statute of the IAEA was approved on 23 October 1956 and came into force on 29 July 1957. Former US Congressman W. Sterling Cole served as the IAEA's first Director General from 1957 to 1961. Cole served only one term, after which the IAEA was headed by two Swedes for nearly four decades: the scientist Sigvard Eklund held the job from 1961 to 1981, followed by former Swedish Foreign Minister Hans Blix, who served from 1981 to 1997. Blix was succeeded as Director General by Mohamed ElBaradei of Egypt, who served until November 2009. Beginning in 1986, in response to the nuclear reactor explosion and disaster near Chernobyl, the IAEA increased its efforts in the field of nuclear safety.
The same happened after the 2011 Fukushima disaster in Japan. Both the IAEA and its Director General, ElBaradei, were awarded the Nobel Peace Prize in 2005. In ElBaradei's acceptance speech in Oslo, he stated that only one percent of the money spent on developing new weapons would be enough to feed the entire world, that, if we hope to escape self-destruction nuclear weapons should have no place in our collective conscience, no role in our security. On 2 July 2009, Yukiya Amano of Japan was elected as the Director General for the IAEA, defeating Abdul Samad Minty of South Africa and Luis E. Echávarri of Spain. On 3 July 2009, the Board of Governors voted to appoint Yukiya Amano "by acclamation," and IAEA General Conference in September 2009 approved, he took office on 1 December 2009. The IAEA's mission is guided by the interests and needs of Member States, strategic plans and the vision embodied in the IAEA Statute. Three main pillars -- or areas of work -- underpin the IAEA's mission: Security.
The IAEA as an autonomous organisation is not under direct control of the UN, but the IAEA does report to both the UN General Assembly and Security Council. Unlike most other specialised international agencies, the IAEA does much of its work with the Security Council, not with the United Nations Economic and Social Council; the structure and functions of the IAEA are defined by the IAEA Statute. The IAEA has three main bodies: the Board of Governors, the General Conference, the Secretariat; the IAEA exists to pursue the "safe and peaceful uses of nuclear sciences and technology". The IAEA executes this mission with three main functions: the inspection of existing nuclear facilities to ensure their peaceful use, providing information and developing standards to ensure the safety and security of nuclear facilities, as a hub for the various fields of science involved in the peaceful applications of nuclear technology; the IAEA recognises knowledge as the nuclear energy industry's most valuable asset and resource, without which the industry cannot operate safely and economically.
Following the IAEA General Conference since 2002 resolutions the Nuclear Knowledge Management, a formal programme was established to address Member States' priorities in the 21st century. In 2004, the IAEA developed a Progr
Properties of water
Water is a polar inorganic compound, at room temperature a tasteless and odorless liquid, nearly colorless apart from an inherent hint of blue. It is by far the most studied chemical compound and is described as the "universal solvent" and the "solvent of life", it is the most abundant substance on Earth and the only common substance to exist as a solid and gas on Earth's surface. It is the third most abundant molecule in the universe. Water molecules form hydrogen bonds with each other and are polar; this polarity allows it to dissociate ions in salts and bond to other polar substances such as alcohols and acids, thus dissolving them. Its hydrogen bonding causes its many unique properties, such as having a solid form less dense than its liquid form, a high boiling point of 100 °C for its molar mass, a high heat capacity. Water is amphoteric, meaning that it can exhibit properties of an acid or a base, depending on the pH of the solution that it is in. Related to its amphoteric character, it undergoes self-ionization.
The product of the activities, or the concentrations of H+ and OH− is a constant, so their respective concentrations are inversely proportional to each other. Water is the chemical substance with chemical formula H2O. Water is a odorless liquid at ambient temperature and pressure. Liquid water has weak absorption bands at wavelengths of around 750 nm which cause it to appear to have a blue colour; this can be observed in a water-filled bath or wash-basin whose lining is white. Large ice crystals, as in glaciers appear blue. Unlike other analogous hydrides of the oxygen family, water is a liquid under standard conditions due to hydrogen bonding; the molecules of water are moving in relation to each other, the hydrogen bonds are continually breaking and reforming at timescales faster than 200 femtoseconds. However, these bonds are strong enough to create many of the peculiar properties of water, some of which make it integral to life. Within the Earth's atmosphere and surface, the liquid phase is the most common and is the form, denoted by the word "water".
The solid phase of water is known as ice and takes the structure of hard, amalgamated crystals, such as ice cubes, or loosely accumulated granular crystals, like snow. Aside from common hexagonal crystalline ice, other crystalline and amorphous phases of ice are known; the gaseous phase of water is known as water vapor. Visible steam and clouds are formed from minute droplets of water suspended in the air. Water forms a supercritical fluid; the critical temperature is 647 K and the critical pressure is 22.064 MPa. In nature this only occurs in hostile conditions. A example of occurring supercritical water is in the hottest parts of deep water hydrothermal vents, in which water is heated to the critical temperature by volcanic plumes and the critical pressure is caused by the weight of the ocean at the extreme depths where the vents are located; this pressure is reached at a depth of about 2200 meters: much less than the mean depth of the ocean. Water has a high specific heat capacity of 4.1814 J/ at 25 °C – the second highest among all the heteroatomic species, as well as a high heat of vaporization, both of which are a result of the extensive hydrogen bonding between its molecules.
These two unusual properties allow water to moderate Earth's climate by buffering large fluctuations in temperature. Most of the additional energy stored in the climate system since 1970 has accumulated in the oceans; the specific enthalpy of fusion of water is 333.55 kJ/kg at 0 °C: the same amount of energy is required to melt ice as to warm ice from −160 °C up to its melting point or to heat the same amount of water by about 80 °C. Of common substances, only that of ammonia is higher; this property confers resistance to melting on the ice of glaciers and drift ice. Before and since the advent of mechanical refrigeration, ice was and still is in common use for retarding food spoilage; the specific heat capacity of ice at −10 °C is 2.03 J/ and the heat capacity of steam at 100 °C is 2.08 J/. The density of water is about 1 gram per cubic centimetre: this relationship was used to define the gram; the density varies with temperature, but not linearly: as the temperature increases, the density rises to a peak at 3.98 °C and decreases.
This unusual negative thermal expansion below 4 °C is observed in molten silica. Regular, hexagonal ice is less dense than liquid water—upon freezing, the density of water decreases by about 9%. Other substances that expand on freezing are silicon, gallium (melting point of 303 K |, germanium and bismuth. Pure silicon has a negative coefficient of thermal expansion for temperatures between about 18 and 120 kelvins; these effects are due to the reduction of thermal motion with cooling, which allows water molecules to form more hydrogen bonds that prevent the molecules from coming close to each other. While below 4 °C the breakage of hydrogen bonds due to freezing allows water molecules to pack closer despite the increase in the thermal motion, above 4 °C water expands as the temperature increases. Water near the boiling point is ab
Deuterium is one of two stable isotopes of hydrogen. The nucleus of deuterium, called a deuteron, contains one proton and one neutron, whereas the far more common protium has no neutron in the nucleus. Deuterium has a natural abundance in Earth's oceans of about one atom in 6420 of hydrogen, thus deuterium accounts for 0.0156% of all the occurring hydrogen in the oceans, while protium accounts for more than 99.98%. The abundance of deuterium changes from one kind of natural water to another; the deuterium isotope's name is formed from the Greek deuteros, meaning "second", to denote the two particles composing the nucleus. Deuterium was named in 1931 by Harold Urey; when the neutron was discovered in 1932, this made the nuclear structure of deuterium obvious, Urey won the Nobel Prize in 1934. Soon after deuterium's discovery and others produced samples of "heavy water" in which the deuterium content had been concentrated. Deuterium is destroyed in the interiors of stars faster. Other natural processes are thought to produce only an insignificant amount of deuterium.
Nearly all deuterium found in nature was produced in the Big Bang 13.8 billion years ago, as the basic or primordial ratio of hydrogen-1 to deuterium has its origin from that time. This is the ratio found in the gas giant planets, such as Jupiter. However, other astronomical bodies are found to have different ratios of deuterium to hydrogen-1; this is thought to be a result of natural isotope separation processes that occur from solar heating of ices in comets. Like the water cycle in Earth's weather, such heating processes may enrich deuterium with respect to protium; the analysis of deuterium/protium ratios in comets found results similar to the mean ratio in Earth's oceans. This reinforces theories; the deuterium/protium ratio of the comet 67P/Churyumov-Gerasimenko, as measured by the Rosetta space probe, is about three times that of earth water. This figure is the highest yet measured in a comet. Deuterium/protium ratios thus continue to be an active topic of research in both astronomy and climatology.
Deuterium is represented by the chemical symbol D. Since it is an isotope of hydrogen with mass number 2, it is represented by 2H. IUPAC allows 2H, although 2H is preferred. A distinct chemical symbol is used for convenience because of the isotope's common use in various scientific processes, its large mass difference with protium confers non-negligible chemical dissimilarities with protium-containing compounds, whereas the isotope weight ratios within other chemical elements are insignificant in this regard. In quantum mechanics the energy levels of electrons in atoms depend on the reduced mass of the system of electron and nucleus. For the hydrogen atom, the role of reduced mass is most seen in the Bohr model of the atom, where the reduced mass appears in a simple calculation of the Rydberg constant and Rydberg equation, but the reduced mass appears in the Schrödinger equation, the Dirac equation for calculating atomic energy levels; the reduced mass of the system in these equations is close to the mass of a single electron, but differs from it by a small amount about equal to the ratio of mass of the electron to the atomic nucleus.
For hydrogen, this amount is about 1837/1836, or 1.000545, for deuterium it is smaller: 3671/3670, or 1.0002725. The energies of spectroscopic lines for deuterium and light hydrogen therefore differ by the ratios of these two numbers, 1.000272. The wavelengths of all deuterium spectroscopic lines are shorter than the corresponding lines of light hydrogen, by a factor of 1.000272. In astronomical observation, this corresponds to a blue Doppler shift of 0.000272 times the speed of light, or 81.6 km/s. The differences are much more pronounced in vibrational spectroscopy such as infrared spectroscopy and Raman spectroscopy, in rotational spectra such as microwave spectroscopy because the reduced mass of the deuterium is markedly higher than that of protium. In nuclear magnetic resonance spectroscopy, deuterium has a different NMR frequency and is much less sensitive. Deuterated solvents are used in protium NMR to prevent the solvent from overlapping with the signal, although deuterium NMR on its own right is possible.
Deuterium is thought to have played an important role in setting the number and ratios of the elements that were formed in the Big Bang. Combining thermodynamics and the changes brought about by cosmic expansion, one can calculate the fraction of protons and neutrons based on the temperature at the point that the universe cooled enough to allow formation of nuclei; this calculation indicates seven protons for every neutron at the beginning of nucleogenesis, a ratio that would remain stable after nucleogenesis was over. This fraction was in favor of protons primarily because the lower mass of the proton favored their production; as the universe expanded, it cooled. Free neutrons and protons are less stable than helium nuclei, the protons and neutrons had a strong energetic reason to form helium-4. However, forming helium-4 requires the intermediate step of forming deuterium. Through much of the few minutes after the big bang during which nucleosynthesis could have occurred
Thermodynamic temperature is the absolute measure of temperature and is one of the principal parameters of thermodynamics. Thermodynamic temperature is defined by the third law of thermodynamics in which the theoretically lowest temperature is the null or zero point. At this point, absolute zero, the particle constituents of matter have minimal motion and can become no colder. In the quantum-mechanical description, matter at absolute zero is in its ground state, its state of lowest energy. Thermodynamic temperature is also called absolute temperature, for two reasons: one, proposed by Kelvin, that it does not depend on the properties of a particular material; the International System of Units specifies a particular scale for thermodynamic temperature. It uses the kelvin scale for measurement and selects the triple point of water at 273.16 K as the fundamental fixing point. Other scales have been in use historically; the Rankine scale, using the degree Fahrenheit as its unit interval, is still in use as part of the English Engineering Units in the United States in some engineering fields.
ITS-90 gives a practical means of estimating the thermodynamic temperature to a high degree of accuracy. The temperature of a body at rest is a measure of the mean of the energy of the translational and rotational motions of matter's particle constituents, such as molecules and subatomic particles; the full variety of these kinetic motions, along with potential energies of particles, occasionally certain other types of particle energy in equilibrium with these, make up the total internal energy of a substance. Internal energy is loosely called the heat energy or thermal energy in conditions when no work is done upon the substance by its surroundings, or by the substance upon the surroundings. Internal energy may be stored in a number of ways within a substance, each way constituting a "degree of freedom". At equilibrium, each degree of freedom will have on average the same energy: k B T / 2 where k B is the Boltzmann constant, unless that degree of freedom is in the quantum regime; the internal degrees of freedom may be in the quantum regime at room temperature, but the translational degrees of freedom will be in the classical regime except at low temperatures and it may be said that, for most situations, the thermodynamic temperature is specified by the average translational kinetic energy of the particles.
Temperature is a measure of the random submicroscopic motions and vibrations of the particle constituents of matter. These motions comprise the internal energy of a substance. More the thermodynamic temperature of any bulk quantity of matter is the measure of the average kinetic energy per classical degree of freedom of its constituent particles. "Translational motions" are always in the classical regime. Translational motions are ordinary, whole-body movements in three-dimensional space in which particles move about and exchange energy in collisions. Figure 1 below shows translational motion in gases. Thermodynamic temperature's null point, absolute zero, is the temperature at which the particle constituents of matter are as close as possible to complete rest. Zero kinetic energy remains in a substance at absolute zero. Throughout the scientific world where measurements are made in SI units, thermodynamic temperature is measured in kelvins. Many engineering fields in the U. S. however, measure thermodynamic temperature using the Rankine scale.
By international agreement, the unit kelvin and its scale are defined by two points: absolute zero, the triple point of Vienna Standard Mean Ocean Water. Absolute zero, the lowest possible temperature, is defined as being 0 K and −273.15 °C. The triple point of water is defined as being 273.16 K and 0.01 °C. This definition does three things: It fixes the magnitude of the kelvin unit as being 1 part in 273.16 parts the difference between absolute zero and the triple point of water. Temperatures expressed in kelvins are converted to degrees Rankine by multiplying by 1.8. Temperatures expressed in degrees Rankine are converted to kelvins by dividing by 1.8. Although the kelvin and Celsius scales are defined using absolute zero and the triple point of water, it is impractical to use this definition at temperatures that are different from the triple point of water. ITS-90 is designed to represent the thermodynamic temperature as as possible throughout its range. Many different thermometer designs are required to cover the entire range.
These include helium vapor pressure thermometers, helium gas thermometers, standard platinum resistance thermometers and monochromatic radiation thermometers. For some types of thermometer the relationship between the property observed and temperature, is close to linear, so for most purposes a linear scale is sufficient, without point-by-point calibration