There is no way the history of physics can be discussed without mentioning the history of thermodynamics. This is because thermodynamics itself is exceptionally fundamental and integral to physics. As a result of this, thermodynamics feature prominently in the advancement of magnetism, classical mechanics, chemical kinetics, and quantum mechanics. The steam engine’s introduction and advances, electricity generation, cryogenics, and the internal combustion engine were made possible only because of thermodynamics.
Thermodynamics in Ancient Times
Energy has always been something that fascinated human beings, even from ancient times. In 3000 BC, ancient Egypt’s people regarded heat as a holy thing and had it linked to their religions and mythologies. In ancient India, the Vedic concepts include heat (or fire) as one of the five basic elements that formed everything’s existence.
As for the Western philosophers, there were discussions of earth, water, air, and fire as the essential elements of the Universe itself. By 500 BC, a philosopher from Greece named Heraclitus popularized his ‘flux and fire’ concept, and he insisted that the three main elements in nature were water, earth, and fire.
Thermodynamics in the 15th – 19th Centuries
By the early modern period, many thinkers viewed heat as a type of invisible fluid that could be measured, and they called it the caloric. For bodies that could store this invisible fluid, scientists took note, which was brought about the idea of heat capacity. It would not be until the 1750s that Joseph Black, a chemist from Scotland, gave it a name and started researching it.
By the 18th and 19th centuries, scientists had made remarkable progress and forgot about the invisible fluid’s concept of a physical caloric. They decided to redefine heat as nothing but an expression of the internal energy of a system.
Hence, the definition of heat today is that it is the transfer of uncoordinated thermal energy. Reference is always made to atomism when relating thermodynamics with statistical mechanics. Ancient philosophers like Democritus and Leucippus laid the foundation for this, and it would later evolve into the atomic theory. The atomic theory itself would not be vindicated until there was proof of atoms in the 20th century.
Further advances were made in the field in the 16th and 17th centuries, with scientists like Robert Fludd, Cornelius Drebbel, Santorio Santorio, Galileo Galilei, and others contributing in no small measure. They were even able to come up with an early type of thermometer called a thermoscope. This was used to measure the relative heat in the air.
Thermodynamics Evolves into Proper Science
In 1656, Robert Boyle, a physicist, and chemist from Ireland, dramatically impacted the evolution of thermodynamics as a standard science on its own. While working with Robert Hooke, a scientist from England, Boyle noticed the correlation between pressure and volume. A French chemist and physicist named Joseph Louis Gay-Lussac drew inspiration from this and, in 1802, came up with his famous Gay-Lussac’s law.
Advances would continue nonstop. By 1824, things had gone so far that Sadi Carnot, a French physicist, and mechanical engineer, also called the father of thermodynamics, was already investigating the link between power, heat, and engine efficiency. That is generally regarded as the commencement of thermodynamics as modern science.
This leap in understanding led to engines’ development, like the Savery Engine and eventually steamed engines like the Newcomen engine and the Watt steam engine. It was engines such as these that would trigger the Industrial Revolution in Britain and across the globe. With time, scientists like Rudolf Clausius, James Joule, James Clerk Maxwell, Willard Gibbs, and Ludwig Boltzmann continued their immense contributions to thermodynamics.
Thermodynamics: 20th Century and Beyond
There has been a relentless march of progress in this field but specific advancement is worth mentioning. In 1900, Max Planck suggested that light can be in the form of discrete frequency emissions, which led him to postulate his black-body radiation law.
By 1905, Albert Einstein would prove to do even more groundbreaking work in this field with his explanations on the Brownian motion’s photoelectric effect and mathematical analysis. By 1906, the formulation of the third law of thermodynamics was done, and in 1926, Enrico Fermi and Paul Dirac came up with their revolutionary Fermi-Dirac statistics. Progress continued steadily, so much so that by 1974, Stephen Hawking predicted black holes’ nature. Today, work continues relentlessly in the field of thermodynamics. If there is any aspect of physics that will shed more light on the nature and workings of the Universe, then this is it.