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Thermodynamics.
Transformation of energy

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History Of Thermodynamics

History Of Thermodynamics

Thermodynamics is the branch of classical physics that studies and describes the thermodynamic transformations induced by heat and work in a thermodynamic system, as a result of processes that involve changes in temperature and energy state variables.

The history of thermodynamics is a fundamental stage in the history of physics, chemistry and the history of science in general. Due to the relevance of thermodynamics in many parts of science and technology, the history of thermodynamics has been subtle in nature with the development of classical mechanics, quantum mechanics, magnetism and the science of chemical velocity, and in more remote practical fields such as meteorology, information theory and biology (physiology), and the steam engine, internal combustion machinery. It is also linked to technological advances such as cryogen and electricity generation.

The development of thermodynamics continued and continued with atomic theory. In addition, with an ingenious approach, he mobilized new directions in probability and statistics; See, for example, the timeline of thermodynamics.

Thermodynamics since ancient times

The ancients saw heat as something related to fire. The ancient Egyptians considered that heat was related to mythological origins. In Western philosophical tradition, Empedocles proposed a four-element theory, in which all substances derive from earth, water, air and fire. Around 500 a. C., the Greek philosopher Heraclitus argued that the three main elements in nature were fire, earth and water.

In the modern period, heat was thought to be a measure of an invisible fluid, known as caloric. The bodies were able to contain a certain amount of this fluid, which led to the term heat capacity.

In the eighteenth and nineteenth centuries, scientists abandoned the idea of ​​a physical caloric and, instead, understood heat as a manifestation of the internal energy of a system. Today heat is the transfer of disordered thermal energy.

Atomism is a central part of the current relationship between thermodynamics and statistical mechanics. Ancient thinkers like Leucippus and Democritus, and later the Epicureans, as atomism advanced, laid the foundations for later atomic theory. Until experimental testing of atoms was provided later in the twentieth century, atomic theory was largely driven by philosophical considerations and scientific intuition.

The Greek philosopher Parmenides of the 5th century BC uses verbal reasoning to postulate that a vacuum, essentially what is now known as a vacuum, in nature could not occur. This opinion was supported by Aristotle's arguments, but was criticized by Leucipo and Hero of Alexandria. From ancient times to the Middle Ages, several arguments were presented to prove or disapprove the existence of a vacuum and several attempts were made to build a vacuum, but all were unsuccessful.

European scientists Cornelius Drebbel, Robert Fludd, Galileo Galilei and Santorio Santorio in the 16th and 17th centuries were able to measure the relative "coldness" or "heat" of the air, using a rudimentary air thermometer.

In 1643, Galileo Galilei believed that the abhorrence of nature's emptiness is limited. Pumps operating in mines had already shown that nature would only fill a vacuum with water to a height of ~ 30 feet. Knowing this curious fact, Galileo encouraged his former student Evangelist Torricelli to investigate these alleged limitations.

Atomic theory

Atomic theory is a physical theory that assumes that everything in the world consists of the smallest particles: atoms, linked together by nuclear and electrical forces. In the twentieth century, it was demonstrated in practice that an atom can be divided into even smaller subatomic particles.

Thermodynamics as a science

Irish physicist and chemist Robert Boyle in 1656, in coordination with the English scientist Robert Hooke, built an air pump. When using this pump, Boyle and Hooke noticed the pressure-volume correlation: PV = constant. At that time, the air was supposed to be a system of motionless particles, and it was not interpreted as a system of moving molecules.

The concept of thermal movement emerged two centuries later. Later, after the invention of the thermometer, the property temperature could be quantified. This tool gave Gay-Lussac the opportunity to derive his law, which led shortly after to the ideal gas law. But, already before the establishment of the ideal gas law, a Boyle associate named Denis Papin built a bone digester in 1679, which is a closed container with a tightly fitting lid that confines steam until high pressure is generated.

Steam machine

Later designs implemented a steam release valve to prevent the machine from exploding. Observing how the valve moved rhythmically up and down, Papin conceived the idea of ​​a piston and cylinder engine, an alternative engine.

However, in 1697, based on Papin's designs, engineer Thomas Savery built the first steam engine. Although these first engines were raw and inefficient, they attracted the attention of the leading scientists of the time. One of those scientists was Sadi Carnot, the father of thermodynamics, who in 1824 published Reflections on the driving power of fire, a speech about heat, power and motor efficiency. This marks the beginning of thermodynamics as modern science.

In the following years, more variations of steam engines were built, such as the Newcomen Engine and later the Watt Engine. Over time, these first engines would eventually be used instead of horses. Therefore, each engine began to associate with a certain amount of "horsepower" depending on how many horses it had replaced. The main problem with these first engines was that they were slow and clumsy, converting less than 2% of fossil fuel, usually coal, into useful work. Hence the need for a new science of motor dynamics.

Evolution history of thermodynamics so far

The history of thermodynamics marks its beginnings in 1824. It was Sadi Carnot, in 1824, the first to demonstrate that heat exchange work between two sources can be obtained at different temperatures. Through Carnot's theorem and Carnot's ideal machine (based on the Carnot cycle) he quantified this work and introduced the concept of thermodynamic efficiency.

In 1848, Lord Kelvin, using the Carnot machine, introduced the concept of effective thermodynamictemperature and is responsible for a statement of the second principle of thermodynamics.

In 1850 James Prescott Joule demonstrated the equality of the two forms of energy (then it was believed that the caloric liquid still existed).

Having reached this, the problem arose that, if it were possible to obtain the total heat of work, it would not have been possible to obtain the inverse. This result also landed Clausius who in 1855 presents his inequality to recognize reversible processes of the irreversible and state of the entropy function.

In 1876 Willard Gibbs published the treatise "On the balance of heterogeneous substances" (On the balance of heterogeneous substances) that showed how a thermodynamic process could be represented graphically and how to study energy, entropy, volume, temperature and The pressure could foresee the eventual spontaneity of the process considered.

The case of thermodynamics is emblematic in history and in 'the epistemology of science: it is one of those cases in which the practice has pioneered the theory itself: the first one is designed for the steam engine, then its theoretical functioning was systematized through its basic principles.

Relationship of thermodynamics with solar energy

The history of thermodynamics has a fundamental role in the field of solar energy and specifically in thermal solar energy. The use of solar radiation to obtain heat began to be used in ancient times. Primitive cultures used it without being aware of it.

Later, different civilizations have developed their architecture to take advantage of solar heat in an efficient way, as detailed in the history of solar energy. This is what is now called passive solar energy.

Around 1767, Horace Bénédict De Saussure had invented the solar collector. This new solar collector had a decisive impact on the history of solar energy and the development of low temperature thermal solar energy. The solar collector takes advantage of thermodynamic physics to perform heat transfers and thermodynamic transformations.

In this way, the laws of thermodynamics began to play a fundamental role in the development of renewable energies, specifically solar energy.

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Last review: October 10, 2019