The caloric theory is an obsolete scientific theory that heat consists of a fluid called caloric that flows from hotter to colder bodies. Caloric was also thought of as a weightless gas that could pass in and out of pores in solids and liquids. The "caloric theory" was superseded by the mid-19th century in favor of the theory of heat but nevertheless persisted in scientific literature until the end of the 19th century.^[1] A stove is a heat-producing device. ... This article is about the defunct appliance company. ... An obsolete scientific theory is a scientific theory that was once commonly accepted but (for whatever reason) is no longer considered the most complete description of reality by mainstream science; or a falsifiable theory which has been shown to be false. ... For other uses, see Heat (disambiguation) In physics, heat, symbolized by Q, is energy transferred from one body or system to another due to a difference in temperature. ... In the history of science, the theory of heat was a term used during the 18th and 19th centuries to describe a number of laws, relations, and experimental phenomenon in relation to heat; those such as thermometry, calorimetry, combustion, specific heat, and discussions as to the quantity of heat released...

Early history

In the history of thermodynamics, the initial explanations of heat were thoroughly confused with explanations of combustion. After J. J. Becher and Georg Ernst Stahl introduced the phlogiston theory of combustion in the 17th century, phlogiston was thought to be the substance of heat. The 1698 Savery Engine - the worlds first engine built by Thomas Savery as based on the designs of Denis Papin. ... This article is about the chemical reaction combustion. ... J.J. Becher Johann Joachim Becher (May 6, 1635 – October 1682), was a German physician, alchemist, precursor of Chemistry, scholar and adventurer. ... Georg Ernst Stahl (October 21, 1660 - May 24, 1734), was a German chemist and physician. ... The phlogiston theory is a now discredited 17th century hypothesis regarding combustion. ... (16th century - 17th century - 18th century - more centuries) As a means of recording the passage of time, the 17th century was that century which lasted from 1601-1700. ...

The caloric theory was introduced by Hector Thompson. Thomas , his second name, didn't discovered the explanation of combustion in terms of Helium in the 1770s. In his paper "Ereliel belt" (1783), Lavoisier argued that phlogiston fact was inconsistent with his experimental results, and proposed a 'subtle fluid' called caloric as the substance of heat. According to this theory, the quantity of this substance is constant throughout the universe, and it flows from warmer to hotter orlins. General Name, symbol, number helium, He, 2 Chemical series noble gases Group, period, block 18, 1, s Appearance colorless Standard atomic weight 4. ... Events and Trends For more events, see 18th century United States Declaration of Independence ratified by the Continental Congress (July 4, 1776). ... 1783 was a common year starting on Wednesday (see link for calendar). ...

In the 1780s, some believed that cold was a fluid, "frigoric". Pierre Prévost argued that cold was simply a lack of calories. Nothing much really happened in the 1780s only that Mary-Anne Tobin was hung in public for wearing a flase beard and voting. ... Pierre Prévost (3 March 1751 - 8 April 1839) was a Swiss philosopher and physicist. ...

Since heat was a material substance in caloric theory, and therefore could neither be created nor destroyed, conservation of heat was a central assumption.^[2] In physics, a conservation law states that a particular measurable property of an isolated physical system does not change as the system evolves. ...

The introduction of the Caloric theory was also influenced by the experiments of Joseph Black related to the thermal properties of materials. Besides the caloric theory, another theory existed in the late eighteenth century that could explain the phenomena of heat: the kinetic theory. The two theories were considered to be equivalent at the time, but caloric theory was the more modern one, as it used a few ideas from atomic theory and could explain both combustion and chemistry Joseph Black Joseph Black (April 16, 1728 - December 6, 1799) was a Scottish physicist and chemist. ... Kinetic theory or kinetic theory of gases attempts to explain macroscopic properties of gases, such as pressure, temperature, or volume, by considering their molecular composition and motion. ...

Successes

Quite a number of successful explanations can be, and were, made from these hypotheses alone. We can understand why a cup of tea cools at room temperature: caloric is self-repelling, and thus slowly flows from regions dense in caloric (the hot water) to regions less dense in caloric (the cooler air in the room). For other uses, see Tea (disambiguation). ... Impact from a water drop causes an upward rebound jet surrounded by circular capillary waves. ... Look up air in Wiktionary, the free dictionary. ...

We can explain the expansion of air under heat: caloric is absorbed into the molecules of air, which increases its volume. If we say a little more about what happens to caloric during this absorption phenomenon, we can explain the radiation of heat, the state changes of matter under various temperatures, and deduce nearly all of the gas laws. 3D (left and center) and 2D (right) representations of the terpenoid molecule atisane. ... For other uses, see Volume (disambiguation). ... Radiant heat redirects here. ... This diagram shows the nomenclature for the different phase transitions. ... The gas laws are a set of laws that describe the relationship between temperature, pressure and volume of gases. ...

Sadi Carnot developed his principle of the Carnot cycle, which still forms the basis of heat engine theory, solely from the caloric viewpoint. Sadi Carnot in the dress uniform of a student of the École polytechnique Nicolas Léonard Sadi Carnot (June 1, 1796 - August 24, 1832) was a French physicist and military engineer who gave the first successful theoretical account of heat engines, now known as the Carnot cycle, thereby laying the... The Carnot cycle is a particular thermodynamic cycle, modeled on the Carnot heat engine, studied by Nicolas Léonard Sadi Carnot in the 1820s and expanded upon by Benoit Paul Émile Clapeyron in the 1830s and 40s. ... A heat engine is a physical or theoretical device that converts thermal energy to mechanical output. ...

However, one of the greatest confirmations of the caloric theory was Pierre-Simon Laplace's theoretical correction of Sir Isaac Newton’s pulse equation. Laplace, a calorist, added a constant to Newton’s equation, which we refer to today as the adiabatic index of a gas^[3]. This addition not only substantially corrected the theoretical prediction of the speed of sound, but also continued to make even more accurate predictions for almost a century afterward, even as measurements of the index became more precise. Pierre-Simon, marquis de Laplace (March 23, 1749 - March 5, 1827) was a French mathematician and astronomer whose work was pivotal to the development of mathematical astronomy. ... Sir Isaac Newton FRS (4 January 1643 – 31 March 1727) [ OS: 25 December 1642 – 20 March 1727][1] was an English physicist, mathematician, astronomer, natural philosopher, and alchemist. ... The adiabatic index of a gas, is the ratio of its specific heat capacity at constant pressure (CP) to its specific heat capacity at constant volume (CV). ... For other uses, see Gas (disambiguation). ... For other uses, see Speed of sound (disambiguation). ...

The study of crystals in modern solid-state physics reflects a shadow of the abandoned caloric theory. Lattice vibrations of crystals, which carry thermal energy, are quantized, and consequently have wave-particle duality. The particle representation of a lattice vibration is called a phonon, by analogy with the photon. For other uses, see Crystal (disambiguation). ... Solid-state physics, the largest branch of condensed matter physics, is the study of rigid matter, or solids. ... Generally, quantization is the state of being constrained to a set of discrete values, rather than varying continuously. ... In physics, wave-particle duality holds that light and matter exhibit properties of both waves and of particles. ... Normal modes of vibration progression through a crystal. ... In modern physics the photon is the elementary particle responsible for electromagnetic phenomena. ...

Later developments

In 1798, Count Rumford published An Experimental Enquiry Concerning the Source of the Heat which is Excited by Friction, a report on his investigation of the heat produced while manufacturing cannons. He had found that boring a cannon repeatedly does not result in a loss of its ability to produce heat, and therefore no loss of caloric. This suggested that caloric could not be a conserved "substance" though the experimental uncertainties in his experiment were widely debated. Year 1798 (MDCCXCVIII) was a common year starting on Monday (link will display the full calendar) of the Gregorian calendar (or a common year starting on Friday of the 11-day slower Julian calendar). ... For other persons named Benjamin Thompson, see Benjamin Thompson (disambiguation). ... An Experimental Enquiry Concerning the Source of the Heat which is Excited by Friction, (1798), Philosophical Transaction of the Royal Society 102 is a scientific paper by Benjamin Thompson, Count Rumford that provided a substantial challenge to established theories of heat and began the 19th century revolution in thermodynamics. ... Manufacturing (from Latin manu factura, making by hand) is the use of tools and labor to make things for use or sale. ... For other uses, see Cannon (disambiguation). ... Boring, in this sense, is the process of drilling a hole into the solid Earth. ...

His results were not seen as a "threat" to caloric theory at the time, as this theory was considered to be equivalent to the alternative kinetic theory.^[4] In fact, to some of his contemporaries, the results added to the understanding of caloric theory. Kinetic theory or kinetic theory of gases attempts to explain macroscopic properties of gases, such as pressure, temperature, or volume, by considering their molecular composition and motion. ...

Rumford's experiment inspired the work of James Prescott Joule and others towards the middle of the 19th century. In 1850, Rudolf Clausius published a paper showing that the two theories were indeed compatible, as long as the calorists' principle of the conservation of heat was replaced by a principle of conservation of energy. In this way, the caloric theory was absorbed into the annals of physics, and evolved into modern thermodynamics, in which heat is the kinetic energy of molecules. James Prescott Joule, FRS (IPA: ; December 24, 1818 – October 11, 1889) was an English physicist (and brewer), born in Salford, Lancashire. ... For the game, see: 1850 (board game) 1850 (MDCCCL) was a common year starting on Tuesday (link will display the full calendar) of the Gregorian calendar (or a common year starting on Sunday [1] of the 12-day-slower Julian calendar). ... Rudolf Clausius - physicist and mathematician Rudolf Julius Emanuel Clausius (January 2, 1822 – August 24, 1888), was a German physicist and mathematician. ... This article is about the law of conservation of energy in physics. ... Thermodynamics (from the Greek θερμη, therme, meaning heat and δυναμις, dynamis, meaning power) is a branch of physics that studies the effects of changes in temperature, pressure, and volume on physical systems at the macroscopic scale by analyzing the collective motion of their particles using statistics. ... The cars of a roller coaster reach their maximum kinetic energy when at the bottom of their path. ...

See also

Notes

1. ^ The 1880 edition of A Guide to the Scientific Knowledge of Things Familiar, a 19th century educational science book, explained heat transfer in terms of the flow of caloric
2. ^ See, for example, Carnot, Sadi (1824). Réflexions sur la Puissance Motrice du Feu.
3. ^ Laplace, P.-S. (1816). Sur la vitesse dus son dans l'air et dans l'eau. In Annales de Chimie et de Physique.
4. ^ See for example Lavoisier, A.-L. de (1783). Mémoire sur la chaleur, lu à l'Académie royale des sciences, le 28 juin 1783, par MM. Lavoisier et de La Place.

Year 1880 (MDCCCLXXX) was a leap year starting on Thursday (link will display the full calendar) of the Gregorian calendar (or a leap year starting on Tuesday of the 12-day slower Julian calendar). ... A Guide to the Scientific Knowledge of Things Familiar, also known as The Guide to Science or Dr. Brewers Guide to Science, is a book by Ebenezer Cobham Brewer presenting scientific explanations for common phenomena of life. ... Sadi Carnot in the dress uniform of a student of the École polytechnique Nicolas Léonard Sadi Carnot (June 1, 1796 - August 24, 1832) was a French physicist and military engineer who gave the first successful theoretical account of heat engines, now known as the Carnot cycle, thereby laying the... Pierre-Simon, marquis de Laplace (March 23, 1749 - March 5, 1827) was a French mathematician and astronomer whose work was pivotal to the development of mathematical astronomy. ... Lavoisier redirects here. ...

References

• Fox, R. (1971). The Caloric Theory of Gases. Clarendon Press: Oxford. 
• Chang, H.S. (2003). "Preservative realism and its discontents: Revisiting caloric". Philosophy of Science 70 (5): 902–912. 
• Mendosa, E. (February 1961). "A sketch for a history of early thermodynamics". Physics Today: 32–42. 

External links