A temperature is a numerical measure of hot and cold. Its measurement is by detection of heat radiation, particle velocity, kinetic energy, or most commonly, by the bulk behavior of a thermometric material. It may becalibrated in any of various temperature scales, Celsius, Fahrenheit, Kelvin, etc.
Measurements with a small thermometer, or by detection of heat radiation, can show that the temperature of a body of material can vary from time to time and from place to place within it. If changes happen too fast, or with too small a spacing, within a body, it may be impossible to define its temperature. Thus the concept of temperature in general has an empirical content.
Within a body that exchanges no energy or matter with its surroundings, temperature tends to become spatially uniform as time passes. When a path permeable only to heat is open between two bodies, energy always transfers spontaneously as heat from a hotter body to a colder one. The transfer rate depends on the nature of the path. If they are connected by a path permeable only to heat, and no heat flows between them, then the two bodies are equally hot. If changes are slow and spatially smooth enough to allow consistent comparisons of their hotness with other bodies that are respectively in their own states of internal thermodynamic equilibrium, they obey the Zeroth law of thermodynamics and then they have well defined and equal temperatures. Then thermodynamics provides a fundamental physical definition of temperature, on an absolute scale, relying on the second law of thermodynamics.
The kinetic theory offers a valuable but limited account of the behavior of the materials of macroscopic systems. It indicates theabsolute temperature as proportional to the average kinetic energy of the random microscopic motions of their constituent microscopic particles such as electrons, atoms, and molecules.
The coldest theoretical temperature is called absolute zero. It can be approached but not reached in any actual physical system. It is denoted by 0 K on the Kelvin scale, −273.15 °C on the Celsius scale, and −459.67 °F on the Fahrenheit scale. In matter at absolute zero, the motions of microscopic constituents are minimal.
Use in science
Many things depend on temperature, such as
- physical properties of materials including the phase(solid, liquid, gaseous or plasma), density, solubility,vapor pressure, electrical conductivity
- rate and extent to which chemical reactions occur
- the amount and properties of thermal radiation emitted from the surface of an object
- speed of sound is a function of the square root of the absolute temperature
Temperature scales differ in two ways: the point chosen as zero degrees, and the magnitudes of incremental units or degrees on the scale.
The Celsius scale (°C) is used for common temperature measurements in most of the world. It is an empirical scale. It developed by a historical progress, which led to its zero point 0°C being defined by the freezing point of water, with additional degrees defined so that 100°C was the boiling point of water, both at sea-level atmospheric pressure. Because of the 100 degree interval, it is called a centigrade scale. Since the standardization of the kelvin in the International System of Units, it has subsequently been redefined in terms of the equivalent fixing points on the Kelvin scale, and so that a temperature increment of one degree celsius is the same as an increment of one kelvin, though they differ by an additive offset of 273.15.
The United States commonly uses the Fahrenheit scale, on which water freezes at 32 °F and boils at 212 °F at sea-level atmospheric pressure.
Many scientific measurements use the kelvin temperature scale (unit symbol K), named in honor of the Scottish physicist who first defined it. It is a thermodynamic or absolute temperature scale. Its zero point, 0K, is defined to coincide with coldest physically-possible temperature (called absolute zero). Its degrees are defined through thermodynamics. The temperature of absolute zero occurs at 0K = -273.15°C (or −459.67 °F), and the freezing point of water at sea-level atmospheric pressure occurs at 273.15K = 0°C.
The International System of Units (SI) defines a scale and unit for the kelvin or thermodynamic temperature by using the reliably reproducible temperature of the triple point of water as a second reference point (the first reference point being 0 K at absolute zero). The triple point is a singular state with its own unique and invariant temperature and pressure, along with, for a fixed mass of water in a vessel of fixed volume, an autonomically and stably self-determining partition into three mutually contacting phases, vapour, liquid, and solid, dynamically depending only on the total internal energy of the mass of water. For historical reasons, the triple point temperature of water is fixed at 273.16 units of the measurement increment.
Thermodynamic approach to temperature
Temperature is one of the principal quantities in the study of thermodynamics.
Kinds of temperature scale
There is a variety of kinds of temperature scale. It may be convenient to classify them as empirically and theoretically based. Empirical temperature scales are historically older, while theoretically based scales arose in the middle of the nineteenth century.
Empirically based scales
Empirically based temperature scales rely directly on measurements of simple physical properties of materials. For example, the length of a column of mercury, confined in a glass-walled capillary tube, is dependent largely on temperature, and is the basis of the very useful mercury-in-glass thermometer. Such scales are valid only within convenient ranges of temperature. For example, above the boiling point of mercury, a mercury-in-glass thermometer is impracticable. Most materials expand with temperature increase, but some materials, such as water, contract with temperature increase over some specific range, and then they are hardly useful as thermometric materials. A material is of no use as a thermometer near one of its phase-change temperatures, for example its boiling-point.
In spite of these restrictions, most generally used practical thermometers are of the empirically based kind. Especially, it was used for calorimetry, which contributed greatly to the discovery of thermodynamics. Nevertheless, empirical thermometry has serious drawbacks when judged as a basis for theoretical physics. Empirically based thermometers, beyond their base as simple direct measurements of ordinary physical properties of thermometric materials, can be re-calibrated, by use of theoretical physical reasoning, and this can extend their range of adequacy.
Theoretically based scales
Theoretically based temperature scales are based directly on theoretical arguments, especially those of thermodynamics, of kinetic theory, and of quantum mechanics. They rely on theoretical properties of idealized devices and materials. They are more or less comparable with practically feasible physical devices and materials. Theoretically based temperature scales are used to provide calibrating standards for practical empirically based thermometers.
The accepted fundamental thermodynamic temperature scale is the Kelvin scale, based on an ideal cyclic process envisaged for a Carnot heat engine.
An ideal material on which a temperature scale can be based is the ideal gas. The pressure exerted by a fixed volume and mass of an ideal gas is directly proportional to its temperature. Some natural gases show so nearly ideal properties over suitable temperature ranges that they can be used for thermometry; this was important during the development of thermodynamics, and is still of practical importance today. The ideal gas thermometer is, however, not theoretically perfect for thermodynamics. This is because the entropy of an ideal gas at its absolute zero of temperature is not a positive semi-definite quantity, which puts the gas in violation of the third law of thermodynamics. The physical reason is that the ideal gas law, exactly read, refers to the limit of infinitely high temperature and zero pressure.
Measurement of the spectrum of electromagnetic radiation from an ideal three-dimensional black body can provide an accurate temperature measurement because the frequency of maximum spectral radiance of black-body radiation is directly proportional to the temperature of the black body; this is known as Wien's displacement law, and has a theoretical explanation in Planck's lawand the Bose–Einstein law.
Measurement of the spectrum of noise-power produced by an electrical resistor can also provide an accurate temperature measurement. The resistor has two terminals and is in effect a one-dimensional body. The Bose-Einstein law for this case indicates that the noise-power is directly proportional to the temperature of the resistor and to the value of its resistance and to the noise band-width. In a given frequency band, the noise-power has equal contributions from every frequency, and is calledJohnson noise. If the value of the resistance is known then the temperature can be found.
If molecules, or atoms, or electrons, are emitted from a material and their velocities are measured, the spectrum of their velocities often nearly obeys a theoretical law called the Maxwell–Boltzmann distribution, which gives a well-founded measurement of temperatures for which the law holds. There have not yet been successful experiments of this same kind that directly use the Fermi–Dirac distribution for thermometry, but perhaps that will be achieved in future.
Absolute thermodynamic scale
The Kelvin scale is called absolute for two reasons. One is Kelvin's, that its formal character is independent of the properties of particular materials. The other reason is that its zero is in a sense absolute, in that it indicates absence of microscopic classical motion of the constituent particles of matter, so that they have a limiting specific heat of zero for zero temperature, according to the third law of thermodynamics. Nevertheless, a Kelvin temperature has a definite numerical value, that has been arbitrarily chosen by tradition. This numerical value also depends on the properties of water, which has a gas–liquid–solid triple point that can be reliably reproduced as a standard experimental phenomenon. The choice of this triple point is also arbitrary and by convention. The Kelvin scale is also called the thermodynamic scale.
Definition of the Kelvin scale
The thermodynamic definition of temperature is due to Kelvin.
It is framed in terms of an idealized device called a Carnot engine, imagined to define a continuous cycle of states of its working body. The cycle is imagined to run so slowly that at each point of the cycle the working body is in a state of thermodynamic equilibrium. There are four limbs in such a Carnot cycle. The engine consists of four bodies. The main one is called the working body. Two of them are called heat reservoirs, so large that their respective non-deformation variables are not changed by transfer of energy as heat through a wall permeable only to heat to the working body. The fourth body is able to exchange energy with the working body only through adiabatic work; it may be called the work reservoir. The substances and states of the two heat reservoirs should be chosen so that they are not in thermal equilibrium with one another. This means that they must be at different fixed temperatures, one, labeled here with the number 1, hotter than the other, labeled here with the number 2. This can be tested by connecting the heat reservoirs successively to an auxiliary empirical thermometric body that starts each time at a convenient fixed intermediate temperature. The thermometric body should be composed of a material that has a strictly monotonic relation between its chosen empirical thermometric variable and the amount of adiabatic isochoric work done on it. In order to settle the structure and sense of operation of the Carnot cycle, it is convenient to use such a material also for the working body; because most materials are of this kind, this is hardly a restriction of the generality of this definition. The Carnot cycle is considered to start from an initial condition of the working body that was reached by the completion of a reversible adiabatic compression. From there, the working body is initially connected by a wall permeable only to heat to the heat reservoir number 1, so that during the first limb of the cycle it expands and does work on the work reservoir. The second limb of the cycle sees the working body expand adiabatically and reversibly, with no energy exchanged as heat, but more energy being transferred as work to the work reservoir. The third limb of the cycle sees the working body connected, through a wall permeable only to heat, to the heat reservoir 2, contracting and accepting energy as work from the work reservoir. The cycle is closed by reversible adiabatic compression of the working body, with no energy transferred as heat, but energy being transferred to it as work from the work reservoir.
With this set-up, the four limbs of the reversible Carnot cycle are characterized by amounts of energy transferred, as work from the working body to the work reservoir, and as heat from the heat reservoirs to the working body. The amounts of energy transferred as heat from the heat reservoirs are measured through the changes in the non-deformation variable of the working body, with reference to the previously known properties of that body, the amounts of work done on the work reservoir, and the first law of thermodynamics. The amounts of energy transferred as heat respectively from reservoir 1 and from reservoir 2 may then be denoted respectively Q1 and Q2. Then the absolute or thermodynamic temperatures, T1 and T2, of the reservoirs are defined so that to be such that
Kelvin's original work postulating absolute temperature was published in 1848. It was based on the work of Carnot, before the formulation of the first law of thermodynamics. Kelvin wrote in his 1848 paper that his scale was absolute in the sense that it was defined "independently of the properties of any particular kind of matter." His definitive publication, which sets out the definition just stated, was printed in 1853, a paper read in 1851.
This definition rests on the physical assumption that there are readily available walls permeable only to heat. In his detailed definition of a wall permeable only to heat, Carathéodory includes several ideas. The non-deformation state variable of a closed system is represented as a real number. A state of thermal equilibrium between two closed systems connected by a wall permeable only to heat means that a certain mathematical relation holds between the state variables, including the respective non-deformation variables, of those two systems (that particular mathematical relation is regarded by Buchdahl as a preferred statement of the zeroth law of thermodynamics). Also, referring to thermal contact equilibrium, "whenever each of the systems S1 and S2 is made to reach equilibrium with a third system S3 under identical conditions, the systems S1 and S2 are in mutual equilibrium." It may viewed as a re-statement of the principle stated by Maxwell in the words: "All heat is of the same kind." This physical idea is also expressed by Bailyn as a possible version of the zeroth law of thermodynamics: "All diathermal walls are equivalent." Thus the present definition of thermodynamic temperature rests on the zeroth law of thermodynamics. Explicitly, this present definition of thermodynamic temperature also rests on the first law of thermodynamics, for the determination of amounts of energy transferred as heat.
Implicitly for this definition, the second law of thermodynamics provides information that establishes the virtuous character of the temperature so defined. It provides that any working substance that complies with the requirement stated in this definition will lead to the same ratio of thermodynamic temperatures, which in this sense is universal, or absolute. The second law of thermodynamics also provides that the thermodynamic temperature defined in this way is positive, because this definition requires that the heat reservoirs not be in thermal equilibrium with one another, and the cycle can be imagined to operate only in one sense if net work is to be supplied to the work reservoir.
Numerical details are settled by making one of the heat reservoirs a cell at the triple point of water, which is defined to have an absolute temperature of 273.16 K. The zeroth law of thermodynamics allows this definition to be used to measure the absolute or thermodynamic temperature of an arbitrary body of interest, by making the other heat reservoir have the same temperature as the body of interest.
Temperature an intensive variable
In thermodynamic terms, temperature is an intensive variable because it is equal to a differential coefficient of one extensive variable with respect to another, for a given body. It thus has the dimensions of a ratio of two extensive variables. In thermodynamics, two bodies are often considered as connected by contact with a common wall, which has some specific permeability properties. Such specific permeability can be referred to a specific intensive variable. An example is a diathermic wall that is permeable only to heat; the intensive variable for this case is temperature. When the two bodies have been in contact for a very long time, and have settled to a permanent steady state, the relevant intensive variables are equal in the two bodies; for a diathermal wall, this statement is sometimes called the zeroth law of thermodynamics.
In particular, when the body is described by stating its internal energy U, an extensive variable, as a function of its entropy S, also an extensive variable, and other state variables V, N, with U = U (S, V, N), then the temperature is equal to the partial derivative of the internal energy with respect to the entropy:
Likewise, when the body is described by stating its entropy S as a function of its internal energy U, and other state variablesV, N, with S = S (U, V, N), then the reciprocal of the temperature is equal to the partial derivative of the entropy with respect to the internal energy:
The above definition, equation (1), of the absolute temperature is due to Kelvin. It refers to systems closed to transfer of matter, and has special emphasis on directly experimental procedures. A presentation of thermodynamics by Gibbs starts at a more abstract level and deals with systems open to the transfer of matter; in this development of thermodynamics, the equations (2) and (3) above are actually alternative definitions of temperature.
Temperature local when local thermodynamic equilibrium prevails
Real world bodies are often not in thermodynamic equilibrium and not homogeneous. For study by methods of classical irreversible thermodynamics, a body is usually spatially and temporally divided conceptually into 'cells' of small size. If classical thermodynamic equilibrium conditions for matter are fulfilled to good approximation in such a 'cell', then it is homogeneous and a temperature exists for it. If this is so for every 'cell' of the body, then local thermodynamic equilibrium is said to prevail throughout the body.
It makes good sense, for example, to say of the extensive variable U, or of the extensive variable S, that it has a density per unit volume, or a quantity per unit mass of the system, but it makes no sense to speak of density of temperature per unit volume or quantity of temperature per unit mass of the system. On the other hand, it makes no sense to speak of the internal energy at a point, while when local thermodynamic equilibrium prevails, it makes good sense to speak of the temperature at a point. Consequently, temperature can vary from point to point in a medium that is not in global thermodynamic equilibrium, but in which there is local thermodynamic equilibrium.
Thus, when local thermodynamic equilibrium prevails in a body, temperature can be regarded as a spatially varying local property in that body, and this is because temperature is an intensive variable.
Kinetic theory approach to temperature
A more thorough account of this is below at Theoretical foundation.
Kinetic theory provides a microscopic explanation of temperature, based on macroscopic systems' being composed of many microscopic particles, such as molecules and ions of various species, the particles of a species being all alike. It explains macroscopic phenomena through the classical mechanics of the microscopic particles. The equipartition theorem of kinetic theory asserts that each classical degree of freedom of a freely moving particle has an average kinetic energy of kBT/2 wherekB denotes Boltzmann's constant. The translational motion of the particle has three degrees of freedom, so that, except at very low temperatures where quantum effects predominate, the average translational kinetic energy of a freely moving particle in a system with temperature T will be 3kBT/2.
It is possible to measure the average kinetic energy of constituent microscopic particles if they are allowed to escape from the bulk of the system. The spectrum of velocities has to be measured, and the average calculated from that. It is not necessarily the case that the particles that escape and are measured have the same velocity distribution as the particles that remain in the bulk of the system, but sometimes a good sample is possible.
Molecules, such as oxygen (O2), have more degrees of freedom than single spherical atoms: they undergo rotational and vibrational motions as well as translations. Heating results in an increase in temperature due to an increase in the average translational kinetic energy of the molecules. Heating will also cause, through equipartitioning, the energy associated with vibrational and rotational modes to increase. Thus a diatomic gas will require more energy input to increase its temperature by a certain amount, i.e. it will have a greater heat capacity than a monatomic gas.
The process of cooling involves removing internal energy from a system. When no more energy can be removed, the system is at absolute zero, though this cannot be achieved experimentally. Absolute zero is the null point of the thermodynamic temperature scale, also called absolute temperature. If it were possible to cool a system to absolute zero, all classical motion of its particles would cease and they would be at complete rest in this classical sense. Microscopically in the description of quantum mechanics, however, matter still has zero-point energy even at absolute zero, because of the uncertainty principle.
Temperature is a measure of a quality of a state of a material The quality may be regarded as a more abstract entity than any particular temperature scale that measures it, and is called hotness by some writers. The quality of hotness refers to the state of material only in a particular locality, and in general, apart from bodies held in a steady state of thermodynamic equilibrium, hotness varies from place to place. It is not necessarily the case that a material in a particular place is in a state that is steady and nearly homogeneous enough to allow it to have a well-defined hotness or temperature. Hotness may be represented abstractly as a one-dimensional manifold. Every valid temperature scale has its own one-to-one map into the hotness manifold.
When two systems in thermal contact are at the same temperature no heat transfers between them. When a temperature difference does exist heat flows spontaneously from the warmer system to the colder system until they are in thermal equilibrium. Heat transfer occurs by conduction or by thermal radiation.
Experimental physicists, for example Galileo and Newton, found that there are indefinitely many empirical temperature scales. Nevertheless, the zeroth law of thermodynamics says that they all measure the same quality.
Temperature for bodies in thermodynamic equilibrium
For experimental physics, hotness means that, when comparing any two given bodies in their respective separate thermodynamic equilibria, any two suitably given empirical thermometers with numerical scale readings will agree as to which is the hotter of the two given bodies, or that they have the same temperature. This does not require the two thermometers to have a linear relation between their numerical scale readings, but it does require that the relation between their numerical readings shall be strictly monotonic. A definite sense of greater hotness can be had, independently of calorimetry, ofthermodynamics, and of properties of particular materials, from Wien's displacement law of thermal radiation: the temperature of a bath of thermal radiation is proportional, by a universal constant, to the frequency of the maximum of its frequency spectrum; this frequency is always positive, but can have values that tend to zero. Thermal radiation is initially defined for a cavity in thermodynamic equilibrium. These physical facts justify a mathematical statement that hotness exists on an ordered one-dimensional manifold. This is a fundamental character of temperature and thermometers for bodies in their own thermodynamic equilibrium.
Except for a system undergoing a first-order phase change such as the melting of ice, as a closed system receives heat, without change in its volume and without change in external force fields acting on it, its temperature rises. For a system undergoing such a phase change so slowly that departure from thermodynamic equilibrium can be neglected, its temperature remains constant as the system is supplied with latent heat. Conversely, a loss of heat from a closed system, without phase change, without change of volume, and without change in external force fields acting on it, decreases its temperature.
Temperature for bodies in a steady state but not in thermodynamic equilibrium
While for bodies in their own thermodynamic equilibrium states, the notion of temperature requires that all empirical thermometers must agree as to which of two bodies is the hotter or that they are at the same temperature, this requirement is not safe for bodies that are in steady states though not in thermodynamic equilibrium. It can then well be that different empirical thermometers disagree about which is the hotter, and if this is so, then at least one of the bodies does not have a well defined absolute thermodynamic temperature. Nevertheless, any one given body and any one suitable empirical thermometer can still support notions of empirical, non-absolute, hotness and temperature, for a suitable range of processes. This is a matter for study in non-equilibrium thermodynamics.
Temperature for bodies not in a steady state
When a body is not in a steady state, then the notion of temperature becomes even less safe than for a body in a steady state not in thermodynamic equilibrium. This is also a matter for study in non-equilibrium thermodynamics.
Thermodynamic equilibrium axiomatics
For axiomatic treatment of thermodynamic equilibrium, since the 1930s, it has become customary to refer to a zeroth law of thermodynamics. The customarily stated minimalist version of such a law postulates only that all bodies, which when thermally connected would be in thermal equilibrium, should be said to have the same temperature by definition, but by itself does not establish temperature as a quantity expressed as a real number on a scale. A more physically informative version of such a law views empirical temperature as a chart on a hotness manifold. While the zeroth law permits the definitions of many different empirical scales of temperature, the second law of thermodynamics selects the definition of a single preferred, absolute temperature, unique up to an arbitrary scale factor, whence called the thermodynamic temperature. If internal energy is considered as a function of the volume and entropy of a homogeneous system in thermodynamic equilibrium, thermodynamic absolute temperature appears as the partial derivative of internal energy with respect the entropy at constant volume. Its natural, intrinsic origin or null point is absolute zero at which the entropy of any system is at a minimum. Although this is the lowest absolute temperature described by the model, the third law of thermodynamics postulates that absolute zero cannot be attained by any physical system.
When a sample is heated, meaning it receives thermal energy from an external source, some of the introduced heat is converted into kinetic energy, the rest to other forms of internal energy, specific to the material. The amount converted into kinetic energy causes the temperature of the material to rise. The introduced heat () divided by the observed temperature change is the heat capacity (C) of the material.
If heat capacity is measured for a well defined amount of substance, the specific heat is the measure of the heat required to increase the temperature of such a unit quantity by one unit of temperature. For example, to raise the temperature of water by one kelvin (equal to one degree Celsius) requires 4186 joules per kilogram (J/kg)..
Temperature measurement using modern scientific thermometers and temperature scales goes back at least as far as the early 18th century, when Gabriel Fahrenheitadapted a thermometer (switching to mercury) and a scale both developed by Ole Christensen Rømer. Fahrenheit's scale is still in use in the United States for non-scientific applications.
Temperature is measured with thermometers that may be calibrated to a variety oftemperature scales. In most of the world (except for Belize, Myanmar, Liberia and theUnited States), the Celsius scale is used for most temperature measuring purposes. Most scientists measure temperature using the Celsius scale and thermodynamic temperature using the Kelvin scale, which is the Celsius scale offset so that its null point is 0K = −273.15°C, or absolute zero. Many engineering fields in the U.S., notably high-tech and US federal specifications (civil and military), also use the Kelvin and Celsius scales. Other engineering fields in the U.S. also rely upon the Rankine scale (a shifted Fahrenheit scale) when working in thermodynamic-related disciplines such ascombustion.
For everyday applications, it is often convenient to use the Celsius scale, in which 0°Ccorresponds very closely to the freezing point of water and 100°C is its boiling point at sea level. Because liquid droplets commonly exist in clouds at sub-zero temperatures, 0°C is better defined as the melting point of ice. In this scale a temperature difference of 1 degree Celsius is the same as a 1kelvin increment, but the scale is offset by the temperature at which ice melts (273.15 K).
By international agreement the Kelvin and Celsius scales are defined by two fixing points: absolute zero and the triple pointof Vienna Standard Mean Ocean Water, which is water specially prepared with a specified blend of hydrogen and oxygen isotopes. Absolute zero is defined as precisely 0K and −273.15°C. It is the temperature at which all classical translational motion of the particles comprising matter ceases and they are at complete rest in the classical model. Quantum-mechanically, however, zero-point motion remains and has an associated energy, the zero-point energy. Matter is in its ground state, and contains no thermal energy. The triple point of water is defined as 273.16K and 0.01°C. This definition serves the following purposes: it fixes the magnitude of the kelvin as being precisely 1 part in 273.16 parts of the difference between absolute zero and the triple point of water; it establishes that one kelvin has precisely the same magnitude as one degree on the Celsius scale; and it establishes the difference between the null points of these scales as being 273.15K (0K = −273.15°C and273.16K = 0.01°C).
In the United States, the Fahrenheit scale is widely used. On this scale the freezing point of water corresponds to 32 °F and the boiling point to 212 °F. The Rankine scale, still used in fields of chemical engineering in the U.S., is an absolute scale based on the Fahrenheit increment.
The following table shows the temperature conversion formulas for conversions to and from the Celsius scale.
|from Celsius||to Celsius|
|Fahrenheit||[°F] = [°C] × 9⁄5 + 32||[°C] = ([°F] − 32) × 5⁄9|
|Kelvin||[K] = [°C] + 273.15||[°C] = [K] − 273.15|
|Rankine||[°R] = ([°C] + 273.15) × 9⁄5||[°C] = ([°R] − 491.67) × 5⁄9|
|Delisle||[°De] = (100 − [°C]) × 3⁄2||[°C] = 100 − [°De] × 2⁄3|
|Newton||[°N] = [°C] × 33⁄100||[°C] = [°N] × 100⁄33|
|Réaumur||[°Ré] = [°C] × 4⁄5||[°C] = [°Ré] × 5⁄4|
|Rømer||[°Rø] = [°C] × 21⁄40 + 7.5||[°C] = ([°Rø] − 7.5) × 40⁄21|
The field of plasma physics deals with phenomena of electromagnetic nature that involve very high temperatures. It is customary to express temperature in electronvolts (eV) or kiloelectronvolts (keV), where 1 eV = 11605K. In the study of QCD matter one routinely encounters temperatures of the order of a few hundred MeV, equivalent to about 1012K.
Historically, there are several scientific approaches to the explanation of temperature: the classical thermodynamic description based on macroscopic empirical variables that can be measured in a laboratory; the kinetic theory of gases which relates the macroscopic description to the probability distribution of the energy of motion of gas particles; and a microscopic explanation based on statistical physics and quantum mechanics. In addition, rigorous and purely mathematical treatments have provided an axiomatic approach to classical thermodynamics and temperature. Statistical physics provides a deeper understanding by describing the atomic behavior of matter, and derives macroscopic properties from statistical averages of microscopic states, including both classical and quantum states. In the fundamental physical description, using natural units, temperature may be measured directly in units of energy. However, in the practical systems of measurement for science, technology, and commerce, such as the modern metric system of units, the macroscopic and the microscopic descriptions are interrelated by the Boltzmann constant, a proportionality factor that scales temperature to the microscopic mean kinetic energy.
The microscopic description in statistical mechanics is based on a model that analyzes a system into its fundamental particles of matter or into a set of classical or quantum-mechanical oscillators and considers the system as a statistical ensemble ofmicrostates. As a collection of classical material particles, temperature is a measure of the mean energy of motion, called kinetic energy, of the particles, whether in solids, liquids, gases, or plasmas. The kinetic energy, a concept of classical mechanics, is half the mass of a particle times its speed squared. In this mechanical interpretation of thermal motion, the kinetic energies of material particles may reside in the velocity of the particles of their translational or vibrational motion or in the inertia of their rotational modes. In monatomic perfect gases and, approximately, in most gases, temperature is a measure of the mean particle kinetic energy. It also determines the probability distribution function of the energy. In condensed matter, and particularly in solids, this purely mechanical description is often less useful and the oscillator model provides a better description to account for quantum mechanical phenomena. Temperature determines the statistical occupation of the microstates of the ensemble. The microscopic definition of temperature is only meaningful in the thermodynamic limit, meaning for large ensembles of states or particles, to fulfill the requirements of the statistical model.
In the context of thermodynamics, the kinetic energy is also referred to as thermal energy. The thermal energy may be partitioned into independent components attributed to the degrees of freedom of the particles or to the modes of oscillators in athermodynamic system. In general, the number of these degrees of freedom that are available for the equipartitioning of energy depend on the temperature, i.e. the energy region of the interactions under consideration. For solids, the thermal energy is associated primarily with the vibrations of its atoms or molecules about their equilibrium position. In an ideal monatomic gas, the kinetic energy is found exclusively in the purely translational motions of the particles. In other systems, vibrational and rotationalmotions also contribute degrees of freedom.
Kinetic theory of gases
Maxwell and Boltzmann developed a kinetic theory that yields a fundamental understanding of temperature in gases. This theory also explains the ideal gas law and the observed heat capacity of monatomic (or'noble') gases.
The ideal gas law is based on observed empirical relationships between pressure (p), volume (V), and temperature (T), and was recognized long before the kinetic theory of gases was developed (see Boyle's andCharles's laws). The ideal gas law states:
This relationship gives us our first hint that there is an absolute zero on the temperature scale, because it only holds if the temperature is measured on an absolute scale such as Kelvins. The ideal gas law allows one to measure temperature on this absolute scale using the gas thermometer. The temperature in kelvins can be defined as the pressure in pascals of one mole of gas in a container of one cubic meter, divided by the gas constant.
Although it is not a particularly convenient device, the gas thermometer provides an essential theoretical basis by which all thermometers can be calibrated. As a practical matter it is not possible to use a gas thermometer to measure absolute zero temperature since the gases tend to condense into a liquid long before the temperature reaches zero. It is possible, however, to extrapolate to absolute zero by using the ideal gas law, as shown in the figure.
The kinetic theory assumes that pressure is caused by the force associated with individual atoms striking the walls, and that all energy is translational kinetic energy. Using a sophisticated symmetry argument, Boltzmann deduced what is now called theMaxwell–Boltzmann probability distribution function for the velocity of particles in an ideal gas. From that probability distributionfunction, the average kinetic energy, Ek (per particle), of a monatomic ideal gas is:
where the Boltzmann constant, k, is the Avogadro number divided by the ideal gas constant, and vrms is the root-mean-square speed. Thus the ideal gas law states that internal energy is directly proportional to temperature. This direct proportionality between temperature and internal energy is a special case of the equipartition theorem, and holds only in the classical limit of an ideal gas. It does not hold for most substances, although it is true that temperature is a monotonic (non-decreasing) function of internal energy.
Zeroth law of thermodynamics
When two otherwise isolated bodies are connected together by a rigid physical path impermeable to matter, there is spontaneous transfer of energy as heat from the hotter to the colder of them. Eventually they reach a state of mutual thermal equilibrium, in which heat transfer has ceased, and the bodies' respective state variables have settled to become unchanging.
One statement of the zeroth law of thermodynamics is that if two systems are each in thermal equilibrium with a third system, then they are also in thermal equilibrium with each other.
This statement helps to define temperature but it does not, by itself, complete the definition. An empirical temperature is a numerical scale for the hotness of a thermodynamic system. Such hotness may be defined as existing on a one-dimensional manifold, stretching between hot and cold. Sometimes the zeroth law is stated to include the existence of a unique universal hotness manifold, and of numerical scales on it, so as to provide a complete definition of empirical temperature. To be suitable for empirical thermometry, a material must have a monontonic relation between hotness and some easily measured state variable, such as pressure or volume, when all other relevant coordinates are fixed. An exceptionally suitable system is theideal gas, which can provide a temperature scale that matches the absolute Kelvin scale. The Kelvin scale is defined on the basis of the second law of thermodynamics.
Second law of thermodynamics
In the previous section certain properties of temperature were expressed by the zeroth law of thermodynamics. It is also possible to define temperature in terms of the second law of thermodynamics which deals with entropy. Entropy is often thought of as a measure of the disorder in a system. The second law states that any process will result in either no change or a net increase in the entropy of the universe. This can be understood in terms of probability.
For example, in a series of coin tosses, a perfectly ordered system would be one in which either every toss comes up heads or every toss comes up tails. This means that for a perfectly ordered set of coin tosses, there is only one set of toss outcomes possible: the set in which 100% of tosses come up the same. On the other hand, there are multiple combinations that can result in disordered or mixed systems, where some fraction are heads and the rest tails. A disordered system can be 90% heads and 10% tails, or it could be 98% heads and 2% tails, et cetera. As the number of coin tosses increases, the number of possible combinations corresponding to imperfectly ordered systems increases. For a very large number of coin tosses, the combinations to ~50% heads and ~50% tails dominates and obtaining an outcome significantly different from 50/50 becomes extremely unlikely. Thus the system naturally progresses to a state of maximum disorder or entropy.
It has been previously stated that temperature governs the transfer of heat between two systems and it was just shown that the universe tends to progress so as to maximize entropy, which is expected of any natural system. Thus, it is expected that there is some relationship between temperature and entropy. To find this relationship, the relationship between heat, work and temperature is first considered. A heat engine is a device for converting thermal energy into mechanical energy, resulting in the performance of work, and analysis of the Carnot heat engine provides the necessary relationships. The work from a heat engine corresponds to the difference between the heat put into the system at the high temperature, qH and the heat ejected at the low temperature, qC. The efficiency is the work divided by the heat put into the system or:
where wcy is the work done per cycle. The efficiency depends only on qC/qH. Because qC and qH correspond to heat transfer at the temperatures TC and TH, respectively, qC/qH should be some function of these temperatures:
Carnot's theorem states that all reversible engines operating between the same heat reservoirs are equally efficient. Thus, a heat engine operating between T1 and T3 must have the same efficiency as one consisting of two cycles, one between T1 andT2, and the second between T2 and T3. This can only be the case if:
Since the first function is independent of T2, this temperature must cancel on the right side, meaning f(T1,T3) is of the formg(T1)/g(T3) (i.e. f(T1,T3) = f(T1,T2)f(T2,T3) = g(T1)/g(T2)· g(T2)/g(T3) = g(T1)/g(T3)), where g is a function of a single temperature. A temperature scale can now be chosen with the property that:
Substituting Equation 4 back into Equation 2 gives a relationship for the efficiency in terms of temperature:
Notice that for TC = 0 K the efficiency is 100% and that efficiency becomes greater than 100% below 0 K. Since an efficiency greater than 100% violates the first law of thermodynamics, this implies that 0 K is the minimum possible temperature. In fact the lowest temperature ever obtained in a macroscopic system was 20 nK, which was achieved in 1995 at NIST. Subtracting the right hand side of Equation 5 from the middle portion and rearranging gives:
where the negative sign indicates heat ejected from the system. This relationship suggests the existence of a state function, S, defined by:
where the subscript indicates a reversible process. The change of this state function around any cycle is zero, as is necessary for any state function. This function corresponds to the entropy of the system, which was described previously. Rearranging Equation 6 gives a new definition for temperature in terms of entropy and heat:
For a system, where entropy S(E) is a function of its energy E, the temperature T is given by:
i.e. the reciprocal of the temperature is the rate of increase of entropy with respect to energy.
Definition from statistical mechanics
Statistical mechanics defines temperature based on a system's fundamental degrees of freedom. Eq.(10) is the defining relation of temperature. Eq. (9) can be derived from the principles underlying the fundamental thermodynamic relation.
Generalized temperature from single particle statistics
It is possible to extend the definition of temperature even to systems of few particles, like in a quantum dot. The generalized temperature is obtained by considering time ensembles instead of configuration space ensembles given in statistical mechanics in the case of thermal and particle exchange between a small system of fermions (N even less than 10) with a single/double occupancy system. The finite quantum grand canonical ensemble, obtained under the hypothesis of ergodicity and orthodicity, allows to express the generalized temperature from the ratio of the average time of occupation 1 and 2 of the single/double occupancy system:
where EF is the Fermi energy which tends to the ordinary temperature when N goes to infinity.
On the empirical temperature scales, which are not referenced to absolute zero, a negative temperature is one below the zero-point of the scale used. For example, dry ice has a sublimation temperature of −78.5°C which is equivalent to −109.3°F. On the absolute Kelvin scale, however, this temperature is 194.6 K. On the absolute scale of thermodynamic temperature no material can exhibit a temperature smaller than or equal to 0 K, both of which are forbidden by the third law of thermodynamics.
In the quantum mechanical description of electron and nuclear spin systems that have a limited number of possible states, and therefore a discrete upper limit of energy they can attain, it is possible to obtain a negative temperature, which is numerically indeed less than absolute zero. However, this is not the macroscopic temperature of the material, but instead the temperature of only very specific degrees of freedom, that are isolated from others and do not exchange energy by virtue of the equipartition theorem.
A negative temperature is experimentally achieved with suitable radio frequency techniques that cause a population inversion of spin states from the ground state. As the energy in the system increases upon population of the upper states, the entropy increases as well, as the system becomes less ordered, but attains a maximum value when the spins are evenly distributed among ground and excited states, after which it begins to decrease, once again achieving a state of higher order as the upper states begin to fill exclusively. At the point of maximum entropy, the temperature function shows the behavior of a singularity, because the slope of the entropy function decreases to zero at first and then turns negative. Since temperature is the inverse of the derivative of the entropy, the temperature formally goes to infinity at this point, and switches to negative infinity as the slope turns negative. At energies higher than this point, the spin degree of freedom therefore exhibits formally a negative thermodynamic temperature. As the energy increases further by continued population of the excited state, the negative temperature approaches zero asymptotically. As the energy of the system increases in the population inversion, a system with a negative temperature is not colder than absolute zero, but rather it has a higher energy than at positive temperature, and may be said to be in fact hotter at negative temperatures. When brought into contact with a system at a positive temperature, energy will be transferred from the negative temperature regime to the positive temperature region.
Examples of temperature
Peak emittance wavelength
of black-body radiation
(precisely by definition)
|0 K||−273.15 °C||cannot be defined|
|100 pK||−273.149999999900 °C||29,000 km|
|450 pK||−273.14999999955 °C||6,400 km|
(precisely by definition)
|0.001 K||−273.149 °C||
(radio, FM band)
(precisely by definition)
|273.16 K||0.01 °C||
(long wavelength I.R.)
|Water's boiling point[A]||373.1339 K||99.9839 °C||
(mid wavelength I.R.)
|Incandescent lamp[B]||2500 K||≈2,200 °C||
|Sun's visible surface[D]||5,778 K||5,505 °C||
|28 kK||28,000 °C||
(far ultraviolet light)
|Sun's core[E]||16 MK||16 million °C||0.18 nm (X-rays)|
|350 MK||350 million °C||
Sandia National Labs'
|2 GK||2 billion °C||
Core of a high-mass
star on its last day[E]
|3 GK||3 billion °C||
Merging binary neutron
|350 GK||350 billion °C||
|1 TK||1 trillion °C||
|10 TK||10 trillion °C||
Universe 5.391×10−44 s
after the Big Bang[E]
|1.417×1032 K||1.417×1032 °C||
- A For Vienna Standard Mean Ocean Water at one standard atmosphere (101.325 kPa) when calibrated strictly per the two-point definition of thermodynamic temperature.
- B The 2500 K value is approximate. The 273.15 K difference between K and °C is rounded to 300 K to avoid false precision in the Celsius value.
- C For a true black-body (which tungsten filaments are not). Tungsten filaments' emissivity is greater at shorter wavelengths, which makes them appear whiter.
- D Effective photosphere temperature. The 273.15 K difference between K and °C is rounded to 273 K to avoid false precision in the Celsius value.
- E The 273.15 K difference between K and °C is without the precision of these values.
- F For a true black-body (which the plasma was not). The Z machine's dominant emission originated from 40 MK electrons (soft x–ray emissions) within the plasma.
- Scale of temperature
- Atmospheric temperature
- Color temperature
- Dry-bulb temperature
- Heat conduction
- Heat convection
- ISO 1
- Instrumental temperature record
- Maxwell's demon
- Orders of magnitude (temperature)
- Outside air temperature
- Planck temperature
- Rankine scale
- Relativistic heat conduction
- Satellite temperature measurements
- Stagnation temperature
- Sea Surface Temperature
- Thermal radiation
- Thermodynamic (absolute) temperature
- Body temperature (thermoregulation)
- Virtual temperature
- Wet Bulb Globe Temperature
- Wet-bulb temperature
Notes and references
- Middleton, W.E.K. (1966), pp. 89–105.
- Truesdell, C.A. (1980), Sections 11 B, 11H, pages 306–310, 320-332.
- Quinn, T.J. (1983).
- Quinn, T.J. (1983), pp. 61–83.
- Schooley, J.F. (1986), pp. 115–138.
- Adkins, C.J. (1968/1983), pp. 119–120.
- Buchdahl, H.A. (1966), pp. 137–138.
- Tschoegl, N.W. (2000), p.88.
- Quinn, T.J. (1983), pp. 98–107.
- Schooley, J.F. (1986), pp. 138–143.
- Zeppenfeld, M., Englert, B.G.U., Glöckner, R., Prehn, A., Mielenz, M., Sommer, C., van Buuren, L.D., Motsch, M., Rempe, G. (2012).
- Miller, J. (2013).
- Thomson, W. (Lord Kelvin) (1848).
- Thomson, W. (Lord Kelvin) (1851).
- Partington, J.R. (1949), pp. 175–177.
- Roberts, J.K., Miller, A.R. (1928/1960), pp. 321–322.
- Buchdahl, H.A (1986). On the redundancy of the zeroth law of thermodynamics, J. Phys. A, Math. Gen., 19: L561–L564.
- C. Carathéodory (1909). "Untersuchungen über die Grundlagen der Thermodynamik". Mathematische Annalen67: 355–386. doi:10.1007/BF01450409. A partly reliable translation is to be found at Kestin, J. (1976). The Second Law of Thermodynamics, Dowden, Hutchinson & Ross, Stroudsburg PA.
- Maxwell, J.C. (1871). Theory of Heat, Longmans, Green, and Co., London, p. 57.
- Bailyn, M. (1994). A Survey of Thermodynamics, American Institute of Physics Press, New York, ISBN 0-88318-797-3, page 24.
- Quinn, T.J. (1983). Temperature, Academic Press, London, ISBN0-12-569680-9, pp. 160–162.
- Tisza, L. (1966). Generalized Thermodynamics, M.I.T. Press, Cambridge MA, pp. 47,57.
- Münster, A. (1970), Classical Thermodynamics, translated by E.S. Halberstadt, Wiley–Interscience, London,ISBN 0-471-62430-6, pp. 49, 69.
- Bailyn, M. (1994). A Survey of Thermodynamics, American Institute of Physics Press, New York, ISBN 0-88318-797-3, pp. 14–15, 214.
- Callen, H.B. (1960/1985), Thermodynamics and an Introduction to Thermostatistics, (first edition 1960), second edition 1985, John Wiley & Sons, New York, ISBN 0–471–86256–8, pp. 146–148.
- Kondepudi, D., Prigogine, I. (1998). Modern Thermodynamics. From Heat Engines to Dissipative Structures, John Wiley, Chichester, ISBN 0-471-97394-7, pp. 115–116.
- Tisza, L. (1966). Generalized Thermodynamics, M.I.T. Press, Cambridge MA, p. 58.
- Milne, E.A. (1929). The effect of collisions on monochromatic radiative equilibrium, Monthly Notices of the Royal Astronomical Society, 88: 493–502.
- Gyarmati, I. (1970). Non-equilibrium Thermodynamics. Field Theory and Variational Principles, translated by E. Gyarmati and W.F. Heinz, Springer, Berlin, pp. 63–66
- Glansdorff, P., Prigogine, I., (1971). Thermodynamic Theory of Structure, Stability and Fluctuations, Wiley, London, ISBN 0-471-30280-5, pp. 14–16.
- Bailyn, M. (1994). A Survey of Thermodynamics, American Institute of Physics Press, New York, ISBN 0-88318-797-3, pp. 133–135.
- Callen, H.B. (1960/1985), Thermodynamics and an Introduction to Thermostatistics, (first edition 1960), second edition 1985, John Wiley & Sons, New York, ISBN 0–471–86256–8, pp. 309–310.
- Bryan, G.H. (1907). Thermodynamics. An Introductory Treatise dealing mainly with First Principles and their Direct Applications, B.G. Teubner, Leipzig, page 3.
- Mach, E. (1900). Die Principien der Wärmelehre. Historisch-kritisch entwickelt, Johann Ambrosius Barth, Leipzig, section 22, pages 56-57.
- Serrin, J. (1986). Chapter 1, 'An Outline of Thermodynamical Structure', pages 3-32, especially page 6, in New Perspectives in Thermodynamics, edited by J. Serrin, Springer, Berlin, ISBN 3-540-15931-2.
- Maxwell, J.C. (1872). Theory of Heat, third edition, Longmans, Green, London, page 32.
- Tait, P.G. (1884). Heat, Macmillan, London, Chapter VII, pages 39-40.
- Planck, M. (1897/1903). Treatise on Thermodynamics, translated by A. Ogg, Longmans, Green, London, pages 1-2.
- Planck, M. (1914), The Theory of Heat Radiation, second edition, translated into English by M. Masius, Blakiston's Son & Co., Philadelphia, reprinted by Kessinger.
- J. S. Dugdale (1996, 1998). Entropy and its Physical Interpretation. Taylor & Francis. p. 13. ISBN 978-0-7484-0569-5.
- F. Reif (1965). Fundamentals of Statistical and Thermal Physics. McGraw-Hill. p. 102.
- M. J. Moran, H. N. Shapiro (2006). "1.6.1". Fundamentals of Engineering Thermodynamics (5 ed.). John Wiley & Sons, Ltd. p. 14. ISBN 978-0-470-03037-0.
- T.W. Leland, Jr. "Basic Principles of Classical and Statistical Thermodynamics". p. 14. "Consequently we identify temperature as a driving force which causes something called heat to be transferred."
- Tait, P.G. (1884). Heat, Macmillan, London, Chapter VII, pages 42, 103-117.
- Beattie, J.A., Oppenheim, I. (1979). Principles of Thermodynamics, Elsevier Scientific Publishing Company, Amsterdam, 0–444–41806–7, page 29.
- Landsberg, P.T. (1961). Thermodynamics with Quantum Statistical Illustrations, Interscience Publishers, New York, page 17.
- Thomsen, J.S. (1962). "A restatement of the zeroth law of thermodynamics". Am. J. Phys. 30: 294–296.Bibcode:1962AmJPh..30..294T. doi:10.1119/1.1941991.
- Maxwell, J.C. (1872). Theory of Heat, third edition, Longman's, Green & Co, London, page 45.
- Pitteri, M. (1984). On the axiomatic foundations of temperature, Appendix G6 on pages 522-544 of Rational Thermodynamics, C. Truesdell, second edition, Springer, New York, ISBN 0-387-90874-9.
- Truesdell, C., Bharatha, S. (1977). The Concepts and Logic of Classical Thermodynamics as a Theory of Heat Engines, Rigorously Constructed upon the Foundation Laid by S. Carnot and F. Reech, Springer, New York, ISBN 0-387-07971-8, page 20.
- Serrin, J. (1978). The concepts of thermodynamics, inContemporary Developments in Continuum Mechanics and Partial Differential Equations. Proceedings of the International Symposium on Continuum Mechanics and Partial Differential Equations, Rio de Janeiro, August 1977, edited by G.M. de La Penha, L.A.J. Medeiros, North-Holland, Amsterdam, ISBN 0-444-85166-6, pages 411-451.
- Maxwell, J.C. (1872). Theory of Heat, third edition, Longmans, Green, London, pages 155-158.
- Tait, P.G. (1884). Heat, Macmillan, London, Chapter VII, Section 95, pages 68-69.
- Buchdahl, H.A. (1966), p. 73.
- Kondepudi, D. (2008). Introduction to Modern Thermodynamics, Wiley, Chichester, ISBN 978-0-470-01598-8, Section 32., pages 106-108.
- The kelvin in the SI Brochure
- "Absolute Zero". Calphad.com. Retrieved 2010-09-16.
- C. Caratheodory (1909). "Untersuchungen über die Grundlagen der Thermodynamik". Mathematische Annalen 67(3): 355–386. doi:10.1007/BF01450409.
- Swendsen, Robert (March 2006). "Statistical mechanics of colloids and Boltzmann's definition of entropy". American Journal of Physucs 74 (3): 187–190.doi:10.1119/1.2174962.
- Balescu, R. (1975). Equilibrium and Nonequilibrium Statistical Mechanics, Wiley, New York, ISBN 0-471-04600-0, pages 148-154.
- Kittel, Charles; Kroemer, Herbert (1980). Thermal Physics (2nd ed.). W. H. Freeman Company. pp. 391–397.ISBN 0-7167-1088-9.
- Kondepudi, D.K. (1987). "Microscopic aspects implied by the second law". Foundations of Physics 17: 713–722.Bibcode:1987FoPh...17..713K. doi:10.1007/BF01889544.
- Feynman, R.P., Leighton, R.B., Sands, M. (1963). The Feynman Lectures on Physics, Addison–Wesley, Reading MA, volume 1, pages 39–6 to 39–12.
- Tolman, R.C. (1938). The Principles of Statistical Mechanics, Oxford University Press, London, pp. 93, 655.
- Peter Atkins, Julio de Paula (2006). Physical Chemistry (8 ed.). Oxford University Press. p. 9.
- Prati, E. (2010). "The finite quantum grand canonical ensemble and temperature from single-electron statistics for a mesoscopic device". J. Stat. Mech. 1: P01003.arXiv:1001.2342. Bibcode:2010JSMTE..01..003P.doi:10.1088/1742-5468/2010/01/P01003. arxiv.org
- Prati, E., et al. (2010). "Measuring the temperature of a mesoscopic electron system by means of single electron statistics". Applied Physics Letters 96 (11): 113109.arXiv:1002.0037. Bibcode:2010ApPhL..96k3109P.doi:10.1063/1.3365204. arxiv.org
- Kittel, Charles; Kroemer, Herbert (1980). Thermal Physics(2nd ed.). W. H. Freeman Company. pp. Appendix E.ISBN 0-7167-1088-9.
- The cited emission wavelengths are for black bodies in equilibrium. CODATA 2006 recommended value of2.8977685(51)×10−3 m K used for Wien displacement law constant b.
- "World record in low temperatures". Retrieved 2009-05-05.
- A temperature of 450 ±80 pK in a Bose–Einstein condensate (BEC) of sodium atoms was achieved in 2003 by researchers at MIT. Citation: Cooling Bose–Einstein Condensates Below 500 Picokelvin, A. E. Leanhardt et al., Science 301, 12 Sept. 2003, p. 1515. It's noteworthy that this record's peak emittance black-body wavelength of 6,400 kilometers is roughly the radius of Earth.
- The peak emittance wavelength of 2.89777 m is a frequency of 103.456 MHz
- Measurement was made in 2002 and has an uncertainty of ±3 kelvin. A 1989 measurement produced a value of 5,777.0±2.5 K. Citation: Overview of the Sun (Chapter 1 lecture notes on Solar Physics by Division of Theoretical Physics, Dept. of Physical Sciences, University of Helsinki).
- The 350 MK value is the maximum peak fusion fuel temperature in a thermonuclear weapon of the Teller–Ulam configuration (commonly known as a hydrogen bomb). Peak temperatures in Gadget-style fission bomb cores (commonly known as an atomic bomb) are in the range of 50 to 100 MK. Citation: Nuclear Weapons Frequently Asked Questions, 3.2.5 Matter At High Temperatures. Link to relevant Web page. All referenced data was compiled from publicly available sources.
- Peak temperature for a bulk quantity of matter was achieved by a pulsed-power machine used in fusion physics experiments. The term bulk quantity draws a distinction from collisions in particle accelerators wherein high temperatureapplies only to the debris from two subatomic particles or nuclei at any given instant. The >2 GK temperature was achieved over a period of about ten nanoseconds during shot Z1137. In fact, the iron and manganese ions in the plasma averaged 3.58±0.41 GK (309±35 keV) for 3 ns (ns 112 through 115). Ion Viscous Heating in a Magnetohydrodynamically Unstable Z Pinch at Over2×109 Kelvin, M. G. Haines et al., Physical Review Letters 96 (2006) 075003. Link to Sandia's news release.
- Core temperature of a high–mass (>8–11 solar masses) star after it leaves the main sequence on the Hertzsprung–Russell diagram and begins the alpha process (which lasts one day) of fusing silicon–28 into heavier elements in the following steps: sulfur–32 → argon–36 → calcium–40 → titanium–44 → chromium–48 → iron–52 → nickel–56. Within minutes of finishing the sequence, the star explodes as a Type II supernova. Citation: Stellar Evolution: The Life and Death of Our Luminous Neighbors (by Arthur Holland and Mark Williams of the University of Michigan). Link to Web site. More informative links can be found here , and here , and a concise treatise on stars by NASA is here.[dead link]
- Based on a computer model that predicted a peak internal temperature of 30 MeV (350 GK) during the merger of a binary neutron star system (which produces a gamma–ray burst). The neutron stars in the model were 1.2 and 1.6 solar masses respectively, were roughly 20 km in diameter, and were orbiting around their barycenter (common center of mass) at about 390 Hz during the last several milliseconds before they completely merged. The 350 GK portion was a small volume located at the pair's developing common core and varied from roughly 1 to 7 km across over a time span of around 5 ms. Imagine two city-sized objects of unimaginable density orbiting each other at the same frequency as the G4 musical note (the 28th white key on a piano). It's also noteworthy that at 350 GK, the average neutron has a vibrational speed of 30% the speed of light and a relativistic mass (m) 5% greater than its rest mass (m0). Torus Formation in Neutron Star Mergers and Well-Localized Short Gamma-Ray Bursts, R. Oechslin et al. of Max Planck Institute for Astrophysics., arXiv:astro-ph/0507099 v2, 22 Feb. 2006. An html summary.
- Results of research by Stefan Bathe using the PHENIXdetector on the Relativistic Heavy Ion Collider atBrookhaven National Laboratory in Upton, New York, U.S.A. Bathe has studied gold-gold, deuteron-gold, and proton-proton collisions to test the theory of quantum chromodynamics, the theory of the strong force that holds atomic nuclei together. Link to news release.
- How do physicists study particles? by CERN.
- The Planck frequency equals 1.85487(14)×1043 Hz (which is the reciprocal of one Planck time). Photons at the Planck frequency have a wavelength of one Planck length. The Planck temperature of 1.41679(11)×1032 K equates to a calculated b /T = λmax wavelength of2.04531(16)×10−26 nm. However, the actual peak emittance wavelength quantizes to the Planck length of1.61624(12)×10−26 nm.
Bibliography of cited references
- Adkins, C.J. (1968/1983). Equilibrium Thermodynamics, (1st edition 1968), third edition 1983, Cambridge University Press, Cambridge UK, ISBN 0-521-25445-0.
- Buchdahl, H.A. (1966). The Concepts of Classical Thermodynamics, Cambridge University Press, Cambridge UK.
- Middleton, W.E.K. (1966). A History of the Thermometer and its Use in Metrology, Johns Hopkins Press, Baltimore MD.
- Miller, J. (2013). Cooling molecules the optoelectric way, Physics Today, 66(1): 12–14.
- Partington, J.R. (1949). An Advanced Treatise on Physical Chemistry, volume 1, Fundamental Principles. The Properties of Gases, Longmans, Green & Co., London, pp. 175–177.
- Quinn, T.J. (1983). Temperature, Academic Press, London, ISBN 0-12-569680-9.
- Schooley, J.F. (1986). Thermometry, CRC Press, Boca Raton, ISBN 0-8493-5833-7.
- Roberts, J.K., Miller, A.R. (1928/1960). Heat and Thermodynamics, (first edition 1928), fifth edition, Blackie & Son Limited, Glasgow.
- Thomson, W. (Lord Kelvin) (1848). On an absolute thermometric scale founded on Carnot's theory of the motive power of heat, and calculated from Regnault's observations, Proc. Cambridge Phil. Soc. (1843/1863) 1, No. 5: 66–71.
- Thomson, W. (Lord Kelvin) (March 1851). "On the Dynamical Theory of Heat, with numerical results deduced from Mr Joule’s equivalent of a Thermal Unit, and M. Regnault’s Observations on Steam". Transactions of the Royal Society of Edinburgh XX(part II): 261–268; 289–298.
- Truesdell, C.A. (1980). The Tragicomical History of Thermodynamics, 1822-1854, Springer, New York, ISBN 0-387-90403-4.
- Tschoegl, N.W. (2000). Fundamentals of Equilibrium and Steady-State Thermodynamics, Elsevier, Amsterdam, ISBN 0-444-50426-5.
- Zeppenfeld, M., Englert, B.G.U., Glöckner, R., Prehn, A., Mielenz, M., Sommer, C., van Buuren, L.D., Motsch, M., Rempe, G. (2012). Sysiphus cooling of electrically trapped polyatomic molecules, Nature, 491: 570–573.
- Chang, Hasok (2004). Inventing Temperature: Measurement and Scientific Progress. Oxford: Oxford University Press. ISBN 978-0-19-517127-3.
- Zemansky, Mark Waldo (1964). Temperatures Very Low and Very High. Princeton, N.J.: Van Nostrand.
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- An elementary introduction to temperature aimed at a middle school audience
- from Oklahoma State University
- Average yearly temperature by country A tabular list of countries and Thermal Map displaying the average yearly temperature by country
GISS Surface Temperature Analysis
The Elusive Absolute Surface Air Temperature (SAT)
The GISTEMP analysis concerns only temperature anomalies, not absolute temperature. Temperature anomalies are computed relative to the base period 1951-1980. The reason to work with anomalies, rather than absolute temperature is that absolute temperature varies markedly in short distances, while monthly or annual temperature anomalies are representative of a much larger region. Indeed, we have shown (Hansen and Lebedeff, 1987) that temperature anomalies are strongly correlated out to distances of the order of 1000 km.
Q. What exactly do we mean by SAT
A. I doubt that there is a general agreement how to answer this question. Even at the same location, the temperature near the ground may be very different from the temperature 5 ft above the ground and different again from 10 ft or 50 ft above the ground. Particularly in the presence of vegetation (say in a rain forest), the temperature above the vegetation may be very different from the temperature below the top of the vegetation. A reasonable suggestion might be to use the average temperature of the first 50 ft of air either above ground or above the top of the vegetation. To measure SAT we have to agree on what it is and, as far as I know, no such standard has been suggested or generally adopted. Even if the 50 ft standard were adopted, I cannot imagine that a weather station would build a 50 ft stack of thermometers to be able to find the true SAT at its location.
Q. What do we mean by daily mean
A. Again, there is no universally accepted correct answer. Should we note the temperature every 6 hours and report the mean, should we do it every 2 hours, hourly, have a machine record it every second, or simply take the average of the highest and lowest temperature of the day ? On some days the various methods may lead to drastically different results.
Q. What SAT do the local media
A. The media report the reading of 1 particular thermometer of a nearby weather station. This temperature may be very different from the true SAT even at that location and has certainly nothing to do with the true regional SAT. To measure the true regional SAT, we would have to use many 50 ft stacks of thermometers distributed evenly over the whole region, an obvious practical impossibility.
Q. If the reported SATs are not
the true SATs, why are they still useful ?
A. The reported temperature is truly meaningful only to a person who happens to visit the weather station at the precise moment when the reported temperature is measured, in other words, to nobody. However, in addition to the SAT the reports usually also mention whether the current temperature is unusually high or unusually low, how much it differs from the normal temperature, and that information (the anomaly) is meaningful for the whole region. Also, if we hear a temperature (say 70°F), we instinctively translate it into hot or cold, but our translation key depends on the season and region, the same temperature may be 'hot' in winter and 'cold' in July, since by 'hot' we always mean 'hotter than normal', i.e. we all translate absolute temperatures automatically into anomalies whether we are aware of it or not.
Q. If SATs cannot be measured, how
are SAT maps created ?
A. This can only be done with the help of computer models, the same models that are used to create the daily weather forecasts. We may start out the model with the few observed data that are available and fill in the rest with guesses (also called extrapolations) and then let the model run long enough so that the initial guesses no longer matter, but not too long in order to avoid that the inaccuracies of the model become relevant. This may be done starting from conditions from many years, so that the average (called a 'climatology') hopefully represents a typical map for the particular month or day of the year.
Q. What do I do if I need absolute
SATs, not anomalies ?
A. In 99.9% of the cases you'll find that anomalies are exactly what you need, not absolute temperatures. In the remaining cases, you have to pick one of the available climatologies and add the anomalies (with respect to the proper base period) to it. For the global mean, the most trusted models produce a value of roughly 14°C, i.e. 57.2°F, but it may easily be anywhere between 56 and 58°F and regionally, let alone locally, the situation is even worse.
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NOTE: IN AL GORE'S BOOK ' AN IN CONVENIENT TRUTH ON PAGE 24, WE FIND THESE DETAILS:
In a pre-indutrial world, just the right amount of the sun's energy was soaked up by greenhouse gasses in the atmosphere. It was a wonderfully balanced system and accounts for why Earth is sometimes called the Goldilock's planet - neither too hot like Venus with its thick poisonous atmosphere nor too cold like Mars -, which has practically no atmosphere at all.
LETS NOTE HERE THAT IN HISTORICAL TIMES, THERE WAS NO PLANET VENUS, AND MARS HAD A WONDERFUL ATMOSPHERE ON IT AND PEOPLE LIVED THERE AND THERE WAS OCEAN'S RIVERS, TREES, BUSHES, GRASS, ETC. AT SOME POINT A COMET CAME PAST MARS, TORE MOST OF ITS ATMOSPHERE OFF AND BECAME VENUS THE PLANET. TODAY, THE ATMOSPHERE OF MARS IS SIMILAR TO EARTH AT 17,000 FT, AND THERE ARE PEOPLE LIVING THERE, INCLUDING MILITARY UNDERGROUND. SOME PEOPLE LIVE ABOVE GROUND IN LITTLE HUTS, AND ITS A DANGEROUS PLACE BECAUSE THERE ARE ALSO WILD ANIMALS THERE THAT NEED TO EAT.
SEE INFORMATION ABOUT A MAN NAMED BASAGLIA WHO WAS THERE AS A CHILD AND SAYS THAT THE CHILD BARACK OBAMA WAS ALSO THERE WITH HIM.www.projectpegasus.net
AL GORE GOES ON TO SAY: But when too much of the atmosphere is made up of greenhouse gasses, it leads to global warming. The sun's energy enters the Earth's atmosphere. Some of that energy warms up the earth and its atmosphere and then is re-radiated back into space in the form of infrared radiation. But greenhouse gasses soak up some of the infrared.
The problem we now face is that the atmosphere is being filled by human-caused carbon dioxide and other greenhouse gasses. This traps a lot of the infrared radiation that would otherwise escape. As a result, the temperature of the Earth's atmosphere and oceans is getting dangerously warmer.
THIS IS WHAT THE CLIMATE IS ALL ABOUT:
German scientists probing global warming said Friday they had detected a major temperature rise this year in the Arctic Ocean and linked this to a progressive ...
www.greatdreams.com/warming3.htm - Similarto GLOBAL WARMING - 2004 - 2009
GLOBAL WARMING DOES NOT COME FROM FOSSIL FUELS! ... 4-25-04 - DREAM : I had a global warming dream this morning, you will find interesting:
www.greatdreams.com/solar/changing_sun.htm - Similarto THE CHANGING SUN - CAUSING GLOBAL WARMING
France, who counted no fewer than seven eruptions. GLOBAL WARMING IS CAUSED BY THE SUN. CYCLE 24 MAY BE LATE ACCORDING TO SCIENTISTS -
Nov 16, 2012 ... This means that the 'plateau' or 'pause' in global warming has now lasted for about the same time as the previous period when temperatures ...
www.greatdreams.com/iceage_and_tree.htm - Similarto A LITTLE ICE AGE - THE BROKEN TREE OF LIFE
THE CAUSE OF THE CURRENT GLOBAL WARMING. FROM: http://users.erols. com/dhoyt1/annex10.htm. Causes of Global Warming of about 0.5 C, 1880-1997
www.greatdreams.com/iceage.htm - Similarto ICE AGE - INTERVIEW WITH A GEOLOGIST
Jan 26, 1998 ... These common sense questions are not usually taken up in the discussions of alleged global warming-climate change, by the little ...
In a reply to an ERN subscriber who had sent me an article from a notorious global warming sceptic, I wrote the following with all the climate change deniers in ...
www.greatdreams.com/hydrogen.htm - Similarto HYDROGEN - Dreams of the Great Earth Changes
HYDROGEN. THE ANSWER TO GLOBAL WARMING? THE DREAM AND THE REALITY. by Dee Finney. 2-13-02 - The radio was on with Art Bell and the topic ...
Feb 10, 2004 ... The information is supported by the things I have discovered while doing separate research on global warming and the catastrophic eruption of ...
www.greatdreams.com/chems.htm - Similarto NATIONWIDE CHEMTRAILS - VIRULENT BIO-TOXIN SOUP
If global warming only took 40 years, how would we prepare for that? What if we had several years in a row when rainfall was less than normal? We would have ...
www.greatdreams.com/climate/gore_u_n.htm - Similarto AL GORE GOES TO THE UN - Dreams of the Great Earth Changes
Jul 17, 2008 ... Stern stipulates that the action needed to curb the effects of global warming would have to be conducted on a global scale. Every country would ...
Well it already is happening all over the planet in the form of pollution, global warming, earthquakes, volcanic eruptions and much more. Prediction tries to place ...
www.greatdreams.com/climate/carbon-trading-conspiracy.htm - Similarto MAURICE STRONG - RIGHT HAND MAN
The tawdry tale of the top two global warming gurus in the business world goes all the way back to Earth Day, April 17, 1995 when the future author of “An ...
www.greatdreams.com/climate/apotheosis.htm - Similarto WHAT IS APOTHEOSIS - Dreams of the Great Earth Changes
None were quite as alarming as what Lord Christopher Monckton had to say in Minnesota recently about global warming as pre-text to the installation of a world ...
www.greatdreams.com/blog-2012-3/dee-blog355.html - Similarto Dee Finney's blog October 28, 2012 page 355 REMOTE VIEWING ...
Oct 28, 2012 ... However, unrecognized warming from the ground, unrecognized by any of the ' global warming' scientists is occurring, exactly as described by ...
www.greatdreams.com/australia_database.htm - Similarto AUSTRALIA DATABASE - Dreams of the Great Earth Changes
AUSTRALIA TOLD TO EXPECT REFUGEES FROM GLOBAL WARMING AFP ... The conservationists currently visiting Australia say climate change is raising ...
www.greatdreams.com/drought_database.htm - Similarto DROUGHT - Dreams of the Great Earth Changes
Global Warming. DREAMS OF GLOBAL WARMING. Tsunami. TSUNAMI IN OUR FUTURE ... Nature of Tsunami. The waves created by a sudden disturbance in .
Feb 19, 2008 ... He said despite warnings that global warming would melt glaciers and raise the sea level, Venetians had historically faced exceptionally high ...
Feb 8, 2012 ... First, they attended numerous meetings on the Al Gore-spawned global warming hoax, exposing it as a racist, genocidal attack on the ...
www.greatdreams.com/eeyore/birds-and-bees.htm - Similarto THE YEAR OF THE BIRDS AND THE BEES
They're also leaving at the wrong time, because global warming is giving them false signals. It's become important for scientists to understand how birds ...
Apr 5, 2012 ... Trenberth also elaborates on the link between tornadoes and climate change in a recently published paper, which notes that "Global warming ...
www.greatdreams.com/eeyore/polar_bears.htm - Similarto POLAR BEARS - ARE THEY GOING EXTINCT?
May 4, 2007 ... They reported in February that global warming "very likely" is caused by human use of fossil fuels such as oil, gas and coal. Environmental ...
www.greatdreams.com/weather.htm - Similarto EXTREME WEATHER - SUMMER 2000 - A New Prophecy by Edgar ...
Mar 26, 2000 ... El Niños have become more frequent and progressively warmer over the past century, and new data and analysis suggest that global warming ...
www.greatdreams.com/nibiru.htm - Similarto THE TRUTH ABOUT NIBIRU - by Alex
Aug 12, 2003 ... changes, one being the global warming with its natural consequence – the melting of the glaciers. The effect of glaciers melting, because of ...
www.greatdreams.com/contents.htm - Similarto dreams of the great earth changes - table of contents
A LITTLE ICE AGE FOLLOWS GLOBAL WARMING · APACHE NATIVES DATABASE · Is The Ark of the Covenant in Ethiopia? 12-24-09 - WHAT IS APOTHEOSIS ...
of how we might have been should fate and time and geography have made ... Global warming, deforestation, mass species extinction, and depletion of the .
Slash-and-burn agriculture, sloppy conservation, overtaxed water supplies and soaring populations are mostly to blame. But global warming is taking its toll, too.
Nov 28, 2012 ... This localized warming is caused by anthropogenic global warming, according to some scientists through strengthening of the Antarctic annular ...
Aug 4, 2008 ... While global warming is being officially ignored by the political arm of the Bush administration, and Al Gore's recent conference on the topic ...
global warming / housing / health / industry / intercultural. exchange / interfaith action / intergenerational projects /. international law / internet / land use ...
www.greatdreams.com/kemp.htm - Similarto JACK KEMP
May 2, 2009 ... Environmentalists opposed to the treaty say that those who do believe inglobal warming continue to hope that proof is just around the corner.
www.greatdreams.com/Montauk_Superman_Programming.htm - Similarto Andy Pero, Montauk 'Superman' Programming Victim (June 13, 2000)
Jun 13, 2000 ... Guiding Principles | Global Warming | Gang Stalking | Monoatomic Gold · Hope | Healing Thought Forms | Vanquish Fear | Hydrogen Peroxide ...
www.greatdreams.com/china/china-attacking-america.htm - Similarto CHINA AT WAR WITH AMERICA - Dreams of the Great Earth Changes
That might even mean plugging your noses and agreeing to work with the nuclear loving, tree-hugging fake CO2 global warming crowd. If we isolate the truly ...
Nov 2, 2010 ... Weather is going crazy around the world and all the mainstream media talks about is "climate change" "global warming"...etc. But they won't ...
Jul 15, 2012 ... A LITTLE ICE AGE FOLLOWS GLOBAL WARMING · APACHE NATIVES DATABASE · Is The Ark of the Covenant in Ethiopia? 12-24-09 - WHAT ...
Apr 20, 2008 ... "This is a collision of breakthrough technology, a demand for bamboo products and global warming. I didn't have the brilliant foresight to see it, ...
Apr 1, 2014 ... www.greatdreams.com/warming.htm - Similarto THE MYSTERY OFGLOBAL WARMING. Though these new measurements of ocean surface ...
www.greatdreams.com/haarp-sun.htm - Similarto HAARP VS THE SUN - Dreams of the Great Earth Changes
One example of how earthquakes (and climate shift including so-called global warming) can be triggered is HAARP, a U.S. military electromagnetic EM ...
Jan 25, 2013 ... Retrieved 02/25/2009. adam knows best about global warming. edit ... that are far warmer than any relevant for the global warming debate" ...
Jan 24, 2005 ... Today, even as the Bush Administration belittles global warming, the prospects of a worldwide warm-up may make nuclear power seem sweet ...
Sep 20, 2011 ... GLOBAL WARMING. http://search.yahoo.com/search;_ylt= A0oGdV9ZlnhOISwAiYZXNyoA ...
www.greatdreams.com/haarp_database.htm - Similarto HAARP DATABASE - Dreams of the Great Earth Changes
One example of how earthquakes (and climate shift including so-called global warming) can be triggered is HAARP, a US military electromagnetic EM .
May 20, 2006 ... But because of man-made global warming, most hurricane scientists say now we will probably be getting Category 4 and 5 hurricanes more ...
Perilous Times and Global Warming 14 killed by fierce tornadoes in central Florida* By Barbara Liston ORLANDO, Florida (Reuters) - Fourteen people were ...
www.greatdreams.com/air_you_breathe.htm - Similarto THE AIR YOU BREATHE IS MAKING YOU SICK
Aug 13, 1998 ... Dangers are carbon dioxide and methane gases, greenhouse gases leading to global warming, photo-chemical production of ground-level ...
Nov 18, 2011 ... They can probably expect some global warming in about 100000 years, after the ice melts that's going to cover Canada. This is the meaning of ...
Dec 17, 2011 ... It has a high global warming potential: 72 times that of carbon dioxide over 20 years, and 25 times over 100 years, and the levels are rising.
www.greatdreams.com/magellan/magellan.htm - Similarto magellan - the world traveler - Dreams of the Great Earth ...
Predictions that global warming will be greatest in the polar regions are now being borne out. Arctic sea ice has been shrinking by 3% each decade since 1970.
Apr 15, 2012 ... www.greatdreams.com/warming3.htm - Similarto GLOBAL WARMING - 2004 - 2009. A record Russian heat wave caused massive wildfires and ...
May 25, 2004 ... THE MYSTERY OF GLOBAL WARMING ... The estimates by the Office for National Statistics do not prove that the extra deaths were caused by ...
www.greatdreams.com/earth_orbit.htm - Similarto Impossible to nudge earth into different orbit!
Jun 27, 2001 ... About 23 million years ago, a huge ice sheet spread over Antarctica, temporarily reversing a general trend of global warming and decreasing ...
www.greatdreams.com/disclosure_project.htm - Similarto DISCLOSURE PROJECT MAY 9, 2001
May 9, 2001 ... Stephen Greer stated that we CAN end global warming and pollution. We can do this gradually, with no loss of jobs to anyone, through ...
Canada Weather · Earthwatch - Weather on Command · Global Warming - Early Warning Signs · DREAMS OF THE GREAT EARTHCHANGES. MAIN INDEX.
www.greatdreams.com/weather/weather_anomalies.htm - Similarto WEATHER ANOMALIES - Dreams of the Great Earth Changes
GLOBAL WARMING - 2003 - 2004 - 2005 compiled by Dee Finney DO NOT . ..... suspect were caused by global warming and the El Nino weather phenomenon, ...
www.greatdreams.com/oil/peak_oil_consequences.htm - Similarto PEAK OIL AND ITS CONSEQUENCES
... Hot Air and the Global Energy Crisis. Portobello Books. ISBN 1-8462-7004-9. Leggett Jeremy. The Carbon War: Global Warming and the End of the Oil Era.
California could lose 30 percent to 70 percent of the snowpack to the ills of greenhouse gases and global warming, Steven Chu, director of the Lawrence ...
Dec 27, 2010 ... Weather is going crazy around the world and all the mainstream media talks about is "climate change" "global warming"...etc. But they won't ...
www.greatdreams.com/asteroid_database.htm - Similarto ASTEROID - Dreams of the Great Earth Changes
Even if the global superstorm doesn't hit us, many people believe that global warming will effect our planet in a very negative way. Killer Asteroids .
www.greatdreams.com/chgnews.htm - Similarto LATEST EARTHCHANGES NEWS -
3-19-2002 - GLOBAL WARMING PAGE YOU CAN TRACK IT HERE! ... 6-8-00 - GLOBAL WARMING ISN'T REALLY HAPPENING DEPENDS ON WHEN YOU ...
Feb 13, 2012 ... Deforestation contributes to the worldwide green house effect of global warming. In the U.S., among the most severe problems are water ...
www.greatdreams.com/australia/australia.htm - Similarto AUSTRALIA - Dreams of the Great Earth Changes
Dec 20, 2005 ... But years of drought, which some blame on global warming, have savagely depleted the huge dams built 60 years ago to hold the snow melt ...
www.greatdreams.com/alignment.htm - Similarto FUTURE PLANETARY ALIGNMENT
But a number of highly respected scientists, who were not in on the "coverup," rejected totally the theory of "global warming." Rather, they [rightly] pointed out that ...
www.greatdreams.com/2008/thomas_vilsack.htm - Similarto THOMAS VILSACK - Dreams of the Great Earth Changes
Dec 1, 2006 ... "Energy security will revitalize rural America, reestablish our moral leadership on global warming," he said. On Iraq, he said it is time to begin to ...
www.greatdreams.com/wildfires-2009.htm - Similarto WILDFIRES - 2009 - Dreams of the Great Earth Changes
Morse, the executive director of the environmental group Global Preservation Projects, said he's not surprised by so many fires, blaming it on global warming.
www.greatdreams.com/end_time_flood.htm - Similarto THE FLOOD - AN END TIME PROPHECY
Jul 24, 2002 ... SEE GLOBAL WARMING. OTHER PROPHECIES. In the end time of the current dimension of life, the end will come suddenly. Luke 21:34-36 ...
www.greatdreams.com/solar/.../space-weather-september-2009.htm - Similarto SOLAR WEATHER and some interesti - Dreams of the Great Earth ...
Sep 30, 2009 ... GLOBAL WARMING: From 2002 to 2008, decreasing solar irradiance has countered much anthropogenic warming of Earth's surface. That's the ...
Jul 31, 2009 ... ... downs to natural weather and climate variations and distinguish their subtle effects from the larger pattern of human-caused global warming.
www.greatdreams.com/tuning.htm - Similarto THE TUNING AND OUR PART IN IT
Russian scientists further warn that the West's “obsession” with manmade GlobalWarming is a deliberately designed propaganda effort to shield their peoples ...
Apr 25, 2008 ... Aside from ethanol we've seen rising demand as well as crop failures in various parts of the world because of drought and global warming ...
www.greatdreams.com/flood_database.htm - Similarto FLOOD DATABASE - Dreams of the Great Earth Changes
Global sea-level rise to flood parts of Tuvalu this weekend. AUCKLAND, Feb 16, 2000 (AFP) -. Global warming and the associated sea-level rise will threaten .
www.greatdreams.com/environ.htm - Similarto THE ENVIRONMENT - Dreams of the Great Earth Changes
Feb 13, 2001 ... EPA APPD - U.S. EPA Atmospheric Pollution Prevention Division EPA -GLOBAL WARMING - The US Environmental Proteciton Agency
www.greatdreams.com/japan_database.htm - Similarto JAPAN DATABASE - Dreams of the Great Earth Changes
JACK KEMP DREAM VS GLOBAL WARMING · JACK KEMP POLITICAL POLICIES · LAWRENCE OF ARABIA WAS WRONG ... www.greatdreams.com/ contents.
Apr 18, 2008 ... The Anunnaki Remnants are confused by the clearing of the planet by such means as global warming, volcanoes, fires, wars, and etc.
www.greatdreams.com/political/blue-dog-democrat.htm - Similarto WHAT IS A BLUE DOG DEMOCRAT
Nov 24, 2005 ... As officials from nearly 180 nations start to gather Monday in Bonn, Germany, to confront the vexing problem of global warming, the issue is no ...
http://www.greatdreams.com/nobody_wants_peace.htm. THE MYSTERY OF GLOBAL WARMING ... of the world's most distinguished meteorologists, including ...
www.greatdreams.com/interview/henry-deacon-planet-x.htm - Similarto UFOexperiences: AN = INTERVIEW WITH 'HENRY DEACON + ...
Global warming is partly because of the greenhouse effect, and that certainly makes things worse, but most of it is because of increased solar activity.
Feb 9, 2013 ... It has also been suggested that cooking food, directly or indirectly, utilizes Btu's and releases gases associated with global warming.
Oct 10, 2002 ... The government is investigating whether the heat wave has been caused byglobal warming or deforestation. But weather experts say it was ...
"I believe there is global warming, but what we're talking about isn't global warming. We're talking about regional warming," Alden said. John See, a regional ...
www.greatdreams.com/india_database.htm - Similarto INDIA - Dreams of the Great Earth Changes
DREAMS OF GLOBAL WARMING. Tsunami. ... www.greatdreams.com/ drought_and_heat.htm. PUZZLES 108 is the number of names of the Goddess in India, ...
Apr 12, 2013 ... May 5, 2003 – ... all kinds of disasters, weather changes, storms, earthquakes, volcanos, meteors hitting earth, plagues, global warming raising ...
www.greatdreams.com/constellations/birth_of_a_new_age.htm - Similarto THE WOMAN WITH CHILD - THE BIRTH IS IMMINENT
Jun 4, 2008 ... Global Warming is nothing more than a cover-up for climate change, due to Solar changes. Editors note: It is important to know that we are ...
Felix and Dean have also refueled talk of whether global warming might be playing a ... But they differ on the key question of whether global warming is making ...
www.greatdreams.com/weather/massive_floods_in_history.htm - Similarto MASSIVE FLOODS IN HISTORY - Dreams of the Great Earth Changes
Global Warming Melts Winter Joy at Top German Resort <http://www.planetark. com/dailynewsstory.cfm/newsid/29086/story.htm> HURRICANES / TYPHOONS ...
www.greatdreams.com/survival_database.htm - Similarto SURVIVAL - Dreams of the Great Earth Changes
May 15, 1999 ... want to be prepared for the ... www.greatdreams.com/survival.htm ... www. greatdreams.com/fire-2005.htm. GLOBAL WARMING - 2003 - 2004 - ...
Oct 22, 2012 ... (See http://en.wikipedia.org/wiki/South_Atlantic_Anomaly ) Global warming that's been ongoing for 400 years correlates with expansion of the ...
www.greatdreams.com/venus.htm - Similarto Rare Transit of Sun by Venus - Predictions of What is to Come
Jun 8, 2004 ... The planet is apparently condemned to an eternal cycle of global warming, with surface temperatures that hover around 480C. There are ...
www.greatdreams.com/food/food-depopulation.html - Similarto FOOD AND DEPOPULATION - Dreams of the Great Earth Changes
The primary tools that Agenda 21 Sustainable Development uses are global warming lies, water shortages (like the man made drought in California, which also ...
www.greatdreams.com/africa_database.htm - Similarto AFRICA - Dreams of the Great Earth Changes
THE MYSTERY OF GLOBAL WARMING. Most deaths would be in developing nations in Africa, Latin America and Southeast ... Africa: Grain yields are expected ...
Jan 18, 2012 ... 7) The iceburgs breaking from global warming 8) The complete collapse of our universe into the singlerity 9) pre-quakes from a continental ...
www.greatdreams.com/london_bombing.htm - Similarto LONDON BOMB BLASTS - Dreams of the Great Earth Changes
First to the people of London, and now at the G8 summit, where their topic Number 1 --believe it or not-- was global warming, the second was African aid.
Aug 13, 2004 ... Global warming “Depending on the sea temperature and the wind speeds, it is then expected to gather force before hitting the US,” he warns.
Did it suffer from a case of global warming run amok – or something else? When Akatsuki reaches Venus in December, it will begin to solve some of the ...
www.greatdreams.com/encke.htm - Similarto COMET ENCKE AND THE TAURID STREAM
Nov 15, 1999 ... He also believes that climatic changes, including fears of present global warming , may have a cosmic component. There is sufficient evidence, ...
May 5, 2003 ... ... all kinds of disasters, weather changes, storms, earthquakes, volcanos, meteors hitting earth, plagues, global warming raising the sea level.
Mar 7, 2012 ... Starting in spring, 2011, environmental and global warming activist Bill McKibben took the question of the pipeline to NASA scientist James ...
May 2, 2014 ... In this time of global warming it is wise to plant trees wherever possible and to nurture living ones. Trees are cooling. They prevent evaporation ...
Feb 22, 2014 ... ALL OUR PHOTOS. Dee Finneys blog. start date July 20, 2011. today's date February 22,2014. page 646. TOPIC: ILLIMINATI COMPILATION.
www.greatdreams.com/disasters-none.htm - Similarto did the extraterrestrials lie to alfred webre on july 4th, 2008?
Jul 4, 2008 ... 2003, Global Warming? heat related, 2000 just in London alone. .... 2-4-07, Jakarta Flood, 20 floods related to global warming due to rising ...