Before Thermodynamics

Episodes:

• Before the Classical Greeks

• Empedocles and Aristotle

• Thermometers and Barometers

• The Ideal Gas Law

• Phlogiston and Caloric Theory

• Steam Engines and Calorimeters

• Atomic and Kinetic Theory

• Cryophysics today

Introduction

The history of thermodynamics is marked by two famous suicides. Around 434 BC, Empedocles threw himself into a volcano. In 1906 AD, Ludwig Boltzmann hung himself while on vacation with his family.

Both believed that matter was made of atoms.

Empedocles only had the force of his philosophy and reason, while Ludwig Boltzmann had solid mathematical proof that the only explanation for thermodynamic phenomena was the atomic model.

In 1909, Jean Baptiste Perrin was finally able to convince the physics world that matter was indeed atomic, drawing on theories from Einstein concerning Brownian Motion, as well as the work of Boltzmann and others. In 1910, thanks to the results of the Millikan Oil Drop experiment, he was able to count the number of atoms in a mole, earning him the Nobel Prize in 1926.

It was a long, long road through history, with many false turns and contradictions, but we had finally achieved a level of understanding of the universe that would stand to this day. Thermodynamics and statistical mechanics are two cornerstones of physics that directly relate temperature, pressure, volume, and the motion of molecules, atoms, and even subatomic particles. Today we think nothing of it, but we have a lot to learn from our ancestors.

In this video series, I am going to explore some of the most important events in history to try and accurately retell an ancient story, the story of thermodynamics.

At the heart of thermodynamics is the fundamental questions that examine the heart of what the universe actually is.

• What is matter?

• What is a vacuum?

• What is hot and cold?

• How does heat and temperature relate to other forms of energy?

• What can we do with heat?

The story of thermodynamics began with philosophers questioning the wisdom of the myths of creation and the nature of the gods. They asked what the universe was made of, what the structure of everything was. Some of the earliest, yet false, notions gave rise to alchemy, which attempted to uncover the true nature of life and death, as well as attempting to unlock the secrets to transmute substances. Alchemy gave way to chemistry as these false notions were abandoned, but then new questions arose that could only be answered by talking about heat and temperature.

Eventually, steam power came to be relied upon not just for gimmicks but to feed people’s families in the mines in England. People wanted to know how big the machines could be, how much coal was necessary and whether they could use less. And so considerable investigation went into the question of how to build better engines, and soon, we unlocked the secrets of matter itself, how it is organized, why it behaves the way it does.

The final question we answered was on the nature of reality, whether reality was composed on discrete bits of matter, indivisible and primary, or whether things were composed of infinitely divisible bits. It would take Jean Baptiste Perrin to convince the Physics world it was so (the chemists had believed it since Dalton’s experiments long before). With that acknowledgement came not just knowledge, but the ability to probe the structure of atoms themselves, uncovering radioactive phenomena, the true nature of Quantum Mechanics, and ultimately the Standard Model of Particles that we know lie at the absolute bottom of reality itself.

On Thermometers

The first great discovery, I believe, was the thermometer.

It is not know when people first began measuring temperature with a device. Certainly, we can tell whether something is hot or cold simply by touch.

There is some evidence that people like Hero of Alexandria at least understood the concepts behind the thermoscope. Whether they built any or used them is a mystery, but the concept is simple.

Build a bulb of glass, with a tube. Fill the tube with water, and invert it into a dish of water. As the temperature rises, the air in the bulb expands, lowering the water level. As it cools, the air contracts, raising the water.

We can trace the ideas behind the thermoscope all the way back to Empedocles in his 460 BC book On Nature. Yes, that Empedocles! Even the ancient Greeks understood that there was a relationship between the volume of a gas and its temperature.

Although we don’t have evidence of when these devices were first created, in the time of Galileo Galilei, such devices could be bought and sold in markets. Galileo is credited with inventing the device, and understood the principles behind it as early as 1593. He mentioned to his friend Cesara Marsili in 1606 that he had invented the thermoscope. There is some debate, however, whether Galileo simply understood the device and described how to build it, or built one himself.

In 1654, 8 years after Pascal’s experiments with the barometer, Ferdinando Il de’ Medici created the first completely sealed thermometer.

On Barometers and Vacuums

In the late summer of 1630, Giovanni Battista Baliani wrote the famous Galileo

Calorimeters

Part 2: The Ancient Greek Philosophers

We have decent records of the ancient Greek Philosophers. At the time their writings were first made, writing was a new thing for them. Although we don’t necessarily have complete texts, we do have quotes and fragments, enough to reconstruct what they likely thought and said.

These fragments have been passed down meticulously through the ages. We have our ancestors to thank for that. Countless men and women sacrificed everything to preserve and protect these words and ideas.

The end of the Middle Ages is marked by the Renaissance, a renewal through the rediscovery of sorts of these ancient texts and ideas, along with the courage to question it and challenge these ideas. People at the forefront of this revolution had read and understood the ancient Greeks in their native tongue, and were ready to challenge them.

The ancient Greeks, in addition to many other things, had thoughts about thermodynamics. Among these thoughts, several stand out as entirely relevant. They are:

1. Atomism vs. monism

2. The Void

3. The Four Elements

4. Measuring Temperature

The ideas that these philosophers shared were well-known by any scholar of the early scientific period, and were at the forefront of their investigations.

Thales

Regarded as the first of the pre-Socratic ancient Greek philosophers, Thales taught that all substance was derived from water. In addition to many amazing accomplishments in the field of Geometry, Thales is known for supposing that all matter was really water in different forms. Notably, it wasn’t so much what something was made of but how it was put together, and what shape it took, that changed what it was and how it behaved.

Pythagoras

I shouldn’t need to introduce Pythagoras, except to state that he believed numbers were at the heart of everything. I don’t know how to interpret this in a modern physics sense, except to say that yes, it does seem that numbers appear everywhere.

It’s too bad he had a hard time accepting irrational numbers.

Parmenides

Parmenides is contemporary with Thales and is credited with some very powerful ideas, ideas that lasted into the 20th Century.

In Parmenides’ only surviving work On Nature, of which we only have fragments, Parmenides argues that reality is really one great whole. We are all connected, everything together, and there is no change, as existence is eternal. Parmenides argues that what we think we see as we see things change is really due to our limited sensory faculties, and our frenzied minds trying to make sense of it. Change, in other words, is merely illusion. “Whatever is, is; and what is not cannot be.”

One of Parmenides’ key arguments was that nothing could not exist, or rather, there was only existence, as non-existence was a contradiction of itself. I am sure he had lots of problems with the number “0”.

Although Parmenides ideas sound foolish today, back then, and well through the scientific revolution, he was taken very seriously.

Heraclitus

In contrast and contemporary with Permenides was the philosopher Heraclitus. He is famous for saying, “No man ever steps in the same river twice.” He noted that everything was in constant change. Seemingly contradictory, he also supposed that all things were made of opposites, even though “the path up and down are one and the same.”

Heraclitus also taught the concept of Logos, the word, which all reality conforms with. Perhaps we can interpret this as the laws of nature, as they really are. However, humans, even hearing Logos, cannot seem to grasp a full understanding, each of us living according to our interpretation of that Logos which is shared freely among us.

Heraclitus believed that fire was the most basic element, and all other elements derived from it.

Empedocles and The Four Elements

Empedocles is credited as coming up with the four classical elements: earth, air, water and fire.

The most ancient texts survived Babylonian times, and seems to have described four gods that personify the cosmic elements: sea, earth, sky, wind. These texts are from the 18th-16th Century BC. Other Babylonian texts seem to describe these as independent of the deities, but they did seem to think that the entire universe was made of them.

Prior to Empedocles, Greek philosophers were consumed with understanding the essence of nature, the core element that caused everything to exist. Heraclitus proposed fire as the source element from which all other elements were derived. Thales, water as the source element. Anaximenes proposed air as the source element. Anaximander argued that there was an element beyond the basic four that could be transformed into any of the four, and that the four could be tranformed into each other.

This system and systems like it are found in pretty much every major culture of the earth.

The idea of four elements lasted well into the scientific revolution. When theories of phlogiston and caloric were being introduced, people gradually realized that there were more than four elements, or rather, some of the elements were not like the other.

Empedocles (494-434 BC) is credited with the four-element theory, where everything is derived from earth, water, air, and fire particles. Empedocles called these “roots” and asserted that they could not be created or destroyed. It was the mingling of these elements that make up everything we can observe. If their proportions were brought together, life could exist, and when they were out of balance, death would result. Specific ratios would create different kinds of creatures.

Empedocles theorized that there was a universal attractive force called love, and universal repellant force called strife. Love would bring the elements together to mingle harmoniously, while strife would cause them to separate into their pure form. These two forces, when combined, would cause all motion and all being. If either force dominated, then the universe would be in a static state, either separated into its constituent 4 elements, or joined together in perfect harmony.

Empedocles and the Conservation of Mass and Energy

“Nothing new comes or can come into being; the only change that can occur is a change in the arrangement of the elements.” It would take until the 1770s for someone to put that in writing in the books of physics.

Empedocles also believed he was an immortal god. He tested his theory by throwing himself into the volcano Mt. Etna c. 434 BC.

Socrates

Can too much be said about Socrates? In this case, yes. Aside from giving us the Socratic method, and nailing logic down pat, there isn’t much to say.

Plato

Socrates’ disciple and the founder of the Academy at Athens, Plato had some fairly strange ideas about reality. He talked about the theory of forms, that reality itself is a shadow or a dim reflection of some greater reality. He talked about how things exist as a reflection of some purer mathematical existence. IE, a human is a reflection of some perfect form of a human that can only exist beyond the material universe.

Plato proposed that the four elements were really the same thing in different platonic solid shapes.

Aristotle and Aether

Plato’s disciple Aristotle is credited as being the father of science. One of the most well-respected philosophers of the ancient world, it wouldn’t be until the Renaissance that European philosophers and scientists began to question his conclusions.

Aristotle is widely credited as the focal point which really drove philosophy towards modern science. I would say of all the thing Aristotle has said, his ideas of naming and categorizing all things, not just animals but phenomena, is the most powerful. If we simply look at things and try to find similarities and differences, we will begin to understand the patterns behind them. With patterns comes understanding and eventually, theories that can be tested with experimentation. (Though Aristotle embraced observation and reason, he did not say anything about experimentation.)

Aristotle didn’t believe as Empedocles, thinking that the four elements were really of the same substance taking different shapes. Aristotle also addded Aether, what we called “quintessence” – the fifth essence, or element – throughout the Middle Ages.

I suppose that this was proposed because not all phenomena could be explained by simply combining the four elements in different forms. Perhaps Aristotle envisioned a universal force or energy that motivated the particles to behave the way they do. Thus, Aristotle saw a difference between matter and energy, and concluded that matter simply reacted to energy. This sort of thinking isn’t too different from how we see the world today.

Aristotle’s Sensible Qualities

In the work On Generation and Corruption, Aristotle proposed “sensible qualities”, attributes of the elements that were shared between them. Fire was both hot and dry. Air is hot and wet. Water is cold and wet. And earth is cold and dry.

This thinking began to separate out qualities of matter from the matter itself. “Hot” and “Cold”, “Wet” and “Dry” were not things, but aspects of matter, which could change shape from “Wet” to “Dry” or “Cold” to “Hot.

Galen and the Four Humors

Galen, the most famous physician of the ancient world, and the ancestor to the medical science, proposed the four humors, bodily fluids that made up a living being. Each person has a natural balance of those fluids which was seen in their personality. If these humors came out of balance, then they would become sick, and could only be cured by bring the humors back into balance.

Galen: Four Humors: yellow bile (fire), black bile (earth), blood (air) (extroversion), phlegm (water).

Galen was clearly playing with the theories that Empedocles had proposed, that living matter was made up of the four elements acting in harmony, and that death would occur when they fell out of balance.

In order to bring the sick person back into health, Galen proposed the practice of extracting the humor for which the person had too much of at the time. This practice continued almost into modern times.

When we see how Galen applied the concept of the four elements to medicine, and how Empedocles believed that simply recombining the four elements in their proper proportions would give rise to all forms of matter, is it any wonder that the pursuit of alchemy and the ability to transmute substances to gold would seem reasonable? Alchemy played a big role in founding chemistry, obviously, but also introducing precision and accuracy into their processes, two critical things necessary to begin to understand thermodynamics.

Atomism vs. Monism

There was considerable debate in ancient times about atomic theory. “Atom” means “no cut”, and was the idea that there were tiny, discrete things, not unlike marbles or beads, that made up all of matter and perhaps even the forces of nature. We now know that indeed, atoms, or rather, the fundamental particles, give us the foundation of all matter (atoms being composed of electrons and protons and neutrons, and protons and neutrons being composed of quarks.) All the forces of nature (except gravity) has been positively identified as having a carrier particle, an indivisible “atom” of force, energy, and momentum. We also know due to Quantum Mechanics that systems were discrete jumps exist naturally all around us, due to the wave nature of reality.

The idea of atomism was inextricably linked to the idea of the void. If there were atoms, then there had to be a void between them. If there were not atoms, then there was no need for a void to separate things.

Democritus surmised that only atoms and the void existed, and nothing else. He suggested that there were infinitely many atoms of infinite kind, in a variety of shapes.

Parminedes, on the other hand, denied the existence of motion, change, and void. All existence was one great whole. Change and motion were mere illusion. Parminedes rejected trusting one’s senses to underatnd the universe, and instead relied solely on abstract reasoning.

Democritus didn’t reject everything Parminedes had said. Instead, he proposed that there was a void dividing Parminedean matter, else change could not be explained at all.

Plato argued against mechanistic materialism. Reality had things like beauty that could not be explained by atoms randomly arranging themselves. To Plato, reality itself was a mere reflection or shadow of a greater reality that held meaning and purpose. Plato argued that the most basic elements were merely different forms of the same substances, the forms being the platonic solids. Fire was a tetrahedron; air was an octahedron; water an icosahedron, and earth, a cube.

Aristotle rejected the idea of atoms, but instead, thought of matter as clay. Clay, in the hands of a potter, can be shaped into any number of shapes; fired and hardened; then crushed and reformed into clay again, a theory called Hylomorphism.

Aristotle did argue that there was some minimum amount of material that retained the properties of the material. Any further subdivision would cause it to lose its essence, an idea called Minima Naturalia. This was related to Hylopmorphism – what is a mug without a handle, or a bottom? If you were to cut matter beyond this limit, you would find elemental water, or earth, or air or fire.

Many other ancient philosophers had ideas about atomism and monism, too many to present here. What is important, however, is that it would take until the early 1900s to correctly understand the nature of the atoms and their behavior. We’ll talk about the order of events and the tragedy of Boltzmann when we get to that.

The other theory, monism, no less servicable, provided for infinitely divisible substances that composed matter and forces and energies. Although we know that we can break down everything into atoms, we do consider things as substances composed of infinitely tiny parts in Thermodynamics, and we are able to arrive at correct predictions by doing so. So the theory of monism is also very useful in modern physics. We’re going to see how we use statistical mechanics to link monistic and atomic thinking together, showing how they are really the same thing.

Thermoscopes

By the time of Galileo, a device known as a thermoscope was being sold commercially. No one can point to where this device was first invented, but there is evidence that it may have been used extensively in the ancient world.

This device was simply an inverted glass bulb in a tub of water. The air would expand or contract according to the temperature, and the pressure would cause the water to rise or fall in the neck, making it possible to see whether the temperature was rising or falling.

However, in terms of accuracy, this could hardly be considered a proper thermometer. For one, it measured pressure and temperature together, without separating the two. And for another reason, it was highly inaccurate and incapable of measuring the kinds of temperatures we would like to measure – freezing and boiling water.

Part 3: The Middle Ages and Rennaissance

The modern theories of thermodynamics arose by very intelligent people trying to organize their understanding of the world around them, and then testing those ideas against reality.

The ideas of Aristotle to name and categorize and thus deduce were in full swing. The earliest scientists spent their time understanding ideas, naming phenomena they observed, and trying to get more and more careful measurements to test the prevailing theories.

This was the first step to truly understanding thermodynamics: classifying the things you observe around you, and trying to find similarities and differences by using exact terminology, even inventing words if you need to. And then trying to quantify things to find the relationship between them.

The Four Elements in Medieval Times

The concept of the four elements, plus quintessence, survived and thrived throughout the Middle Ages and well through the Renaissance. It wasn’t until alchemy began its transformation into chemistry that people began to identify actual elements and isolate them, culminating in the Periodic Table of the Elements. I won’t discuss that process at all, instead focusing on the thermodynamic properties of the four elements.

Fire was seen as the catalyst for change, even going so far as to suppose that there were fires that burned not in the material but in the celestial realm. The sun was associated with fire.

Water was seen as the cause of tumult, misfortune, and chaos. The moon was associated with water, suggesting that they understood well how the tides were affected by the moon. It would have to wait until Isaac Newton that connected tides and the moon through gravity.

Earth was seen in dirt and rocks. It was also the fibers that made up clothing, ash, and everything substantial, such as metals and more.

Air was seen as the communicator and carrier.

The idea that all matter was made up of four elements is why so much attention was paid to alchemy. Of course you can transmute anything substantial into gold – it was just a matter of figuring out how to extract or add the right amounts of fire, water, and air. Of course, gold being valuable, fortunes were wasted trying to understand the ratios of the four elements, and countless experiments performed, until the first steps in chemistry were started. And chemistry and thermodynamics are inxtricably linked together.

Part 4: Early Scientific Period

As the Renaissance came to a close, and sometimes earlier, intelligent people began subjected the ideas of the ancients to serious tests with carefully measured experiments. Fairly quickly, it became apparent that the ancients were wrong about most things. However, we needed new ideas to replace the old. Let’s discuss some of the new ideas.

Theories of Heat and Cold

Everyone knows what heat is. It comes from fire. It comes from rubbing your hands together. But what is it? What is it made of? Where does it come from, and where does it go?

Democritus argued that hot and cold, like sweet and bitter, were mere sensory experiences, an illusion caused by the interaction of matter with the person experiencing it. But Aristotle proposed that they were characteristics of matter, entirely real and measurable.

Fire as an Element

If you were an early alchemist, perhaps you would like to isolate fire the same way air, earth, and water can be isolated and purified. However, isolating fire is an impossible task. At best, you can create things that burn, or things that don’t burn.

Isn’t it natural to imagine fire as something stored inside of an object, ready to be released under the right conditions? Thus, fire cannot exist independently of the things it inhabits, and cannot be an element the same way air, water, and earth are.

Phlogiston

https://en.wikipedia.org/wiki/Phlogiston_theory

Becher and Stahl introduced the theory of Phlogiston in the 1600s.

Phlogiston was an idea of the alchemists from the 17th Century. It was replaced by Caloric Theory in the 18th Century, as alchemy began to transition into modern chemistry.

Phlogiston was thought to be the substance that left burning and rusting matter, which was known to release heat. Thus, objects, before they were burned, had plenty of phlogiston, but after burning, lacked it. Phlogiston was neither destroyed nor created, but transferred from one body to another.

Of course, we now know that what the alchemists were describing was the process of oxidation.

A careful measurement of the mass of objects that have been burned in one sort of fire or another would show that certain metals, such as magnesium, would burn and gain mass. We know that it is because it gains oxygen atoms. This contradicted the idea that phlogiston left the burning object, unless you imagine that phlogiston has negative mass.

It took Lavoisier in the 1770s to show that Phlogiston was really oxygen reacting with things.

Regardless, the idea of Phlogiston was shown to be almost useless. As time marched on, the theories of Caloric began to gain favor.

Caloric

(Also: frigoric)

Caloric, similar to Phlogiston, was the idea that there was some substance of heat, and it flowed from hotter bodies to colder ones.

Caloric Theory was proposed in 1787 by Lavoisier. (https://web.archive.org/web/20060826144815/http://che.konyang.ac.kr/COURSE/thermo/history/1700.html)

1. Caloric is an elastic fluid, made of particles which repel each other. (Thus, it cannot be isolated.)

2. Particles of Caloric were attracted by matter.

3. Caloric is indestructible and uncreatible.

4. Caloric can either be sensible (increasing temperature of a body) or latent (combined with matter to form different states of matter.)

5. Caloric has weight.

Caloric seemed to explain why it was that hot things cooled and cold things warmed up. Caloric repelled itself, so it would spread out and fill the cold object until and equilibrium was reached.

If you wanted to measure caloric, you needed a calorimeter,

Note that Sadi Carnot developed his Carnot Cycle solely based on the idea of Caloric.

Rumford’s 1798 work showed that you could create heat through friction, which involves no transfer of substance at all. He noticed that as the bore of a cannon was carved out, the temperature of the cannon would greatly increase. The idea that you can expend work to create heat proved that heat was not a substance at all, but that it was related to kinetic energy.

Further work by Joule in 1842 produced reproducible results that nailed the phenomena down. However, even as late as 1850, Thomson was still trying to explain changes in temperature in terms of caloric.

Joule, Black, and Lavoisier, by using careful, accurate, reproducible measurements were able to prove to the world that heat was another form of energy, and that adding kinetic energy to a substance could heat it up. They were able to match changes in temperature to precise amounts of work performed. Indeed, Clausius showed that if you were careful, and treated caloric as a form of energy, and energy itself, not caloric, were conserved, then you would make correct predictions.

Thus, the element of fire was eliminated.

Note that Caloric Theory is still useful to explain some phenomena in Thermodynamics. You can think of thermal energy as spreading out the same way substances dilute in water.

Voids and Vacuums

Parmenides in the 5th Century BC, in his poem On Nature, postulated that a void, what we would call a vacuum, could not exist. “If the void is, the it is not nothing. Therefore, it is not the void.” (This is similar logic that would keep the number 0 from being recognized for many, many years.) Furthermore, if there was void, then it would be the only thing that could separate matter, and since all things were connected, there was no void in between them. All of existence exists as it is, as it will ever be, as it has ever been. What we experience is mere illusion, a tiny facet of the grand universe.

Democritus said the universe was only atoms and the void. Although he accepted much of what Parmenides was selling, he wanted an explanation for what the illusion of change actually was, and argued the the universe is made up of infinitely many Parmenidean entities separated by a vacuum.

Aristotle deined the void and finite entities.

Theories that where nothing was, Aether still existed. Even Maxwell surmised that EM waves were wiggling through the Aether. Wasn’t until Michelson-Morley experiment that we determined void was real.

Medieval scholars and early scientists attemped, unsuccessfully, to create a vacuum. What they didn’t know is that in mines, they couldn’t pump water more than thirty feet – because they were creating vacuums.

It was Galileo who urged his student Torricelli to investigate the well-known phenomena that water could not be pumped more than 30 feet out of a mine. In a simple experiment, a glass tube is filled with mercury, open only on one end. When the glass tube is inverted, only about 30 inches of mercury rose in the tube, the rest composed of nothing at all. Torricelli correctly reasoned that it was because the mercury was being pushed up by the pressure of the atmosphere, not being sucked up by a vacuum.

Thus, we not only knew vacuums existed, but we could create them easily, and at the same time, measure pressures exactly.

Temperature

Drebbel, Fludd, Galileo and Santorio in the 16th and 17th centuries were able to measure temperature using a rudimentary thermometer (thermoscope). This device was likely invented by Philo of Byzantium and Hero of Alexandria, and relies on the fact that the mercury rises or falls depending on how hot or cold it is.

Thus, we have long known that there were ways to quantify “hotness” and “coldness”, and if we had spent more time trying to accurately quantify it with greater precision and reliability, perhaps we would’ve discovered some principles of thermodynamics even earlier.

As we began to isolate pressure from temperature, modern themometers become a common object. Carefully calibrated so that precise measurements could be made, this made it possible to accurate quantify temperatures in repeated experiments.

Relationship Between Pressure and Volume

Boyle in 1656, working with Hooke, built an air pump. They noticed that PV = constant. At the time, they thought of air monistically, as static material that did not move much, not as a system of moving particles. By 1660, Boyle was theorizing about “air springs”.

It wasn’t until thermometers became more accurate and thus temperature quantifiable that the relationship between pressure, volume, and temperature begain to be understood. Gay-Lussac was able to give an early version of the Ideal Gas Law. Before this, however, Papin was able to build a “bone digester” in 1679, a device that could produce steam in a closed vessel. This showed that even if it wasn’t quantified, it was understood that temperature was also related.

Papin theorized about building a steam engine as he observed the pressure release valve releasing rhythmically. Savery in 1697 was able to build the first engine based on his designs. This attracted a lot of attention, and soon Carnot, “the father of thermodynamics” published Reflections on the Motive Power of Fire in 1824. This was the beginning of modern thermodynamics.

With Carnot’s work, we understood, finally, how kinetic energy, thermal energy, pressure, volume, and temperature were all related. We had abandoned any hope of finding any sort of substance that was pure heat – Phlogiston or Caloric. We knew that heat was merely another form of energy.

Part 5: The Rest is History

Since Carnot’s work in 1824, thermodynamics developed rapidly. Joule found the equivalence between heat and work in 1843, developing the theory of conservation of energy and explaining why heat could do work.

In 1850, Clausius coined the term “entropy” to denote the energy that would be lost in a thermodynamic system.

In 1854, Thomson coined the term Thermo-dynamics.

In 1871, Maxwell formulated the first theories of Statistical Mechanics with Clausius.

In 1875, Boltzmann was able to connect entropy to molecular motion.

In 1876, Gibbs published a paper formulating the grand equality and the Gibbs free energy equation. He also originated the concept of “enthalpy”, but we would have to wit until Onnes coined that term many years later.

Footnotes

A Side Note

There is a lot of people who wrinkle their noses at the idea that God or the gods have anything to do with modern science. I am of the firm belief that it was ancient and modern humans, who confronted with a belief in supernatural forces, strove to understand it. We’re going to see a story of humanity unfold in the following episode, and we’re going to trace people who thought everything happened according to the will of the gods or God and there was nothing one can do to change it transform into people who thought they could question the gods or God and determine their own fate.

I don’t want this video to turn into yet another battle line in the Atheists vs. Christian war that started back in the 1800s by misguided people who didn’t know as much as they should’ve. Instead, I want to show both Christian and Atheist alike how they have a common heritage of ideas, and how we agree far more than we disagree especially when it comes to things like hard science.

So set aside your pre-conceived and likely false notions, and pay attention to what I have learned studying physics and dabbling a little in philosophy.

On Eurocentrism

This is a journey that occured through the lens of European people living mostly in Europe or coming from Europe in the time period leading up to the early 20th Century. I am not ignoring the other cultures besides the ancient Greeks and Europeans. I am well aware that other cultures developed fantastic ideas, often correct ideas.

What happened in Europe, the two revolutions, the key to unlocking modern science, was that the ancient Greeks began to reason about the gods and the early scientists began to experiment. These two things were almost unique to these two cultures. No other culture that I know of went to such an extreme with these ideas.

Old Introduction

In order to truly appreciate thermodynamics, I think a brief jaunt through the history of this field before it developed is warranted. The earliest pioneers of our modern theory were familiar with at least some of these ideas, and in their investigation, were at least able to debunk them, and at best propose something better.

I think it’s important to understand how we went from ignorance to knowledge. Or rather, how we went from knowledge of things that were not so to knowledge of things as they really are. It also helps to disprove modern concepts or ideas that have crept in that simply aren’t true, sometimes even in scientific circles.

The key figures who put together the ideas that make up thermodynamics were in Europe, and based their ideas off of their predecessors all the way up to Ancient Greece. I’m going to focus on the ideas they were familiar with and their revolutionary proposals.

The rest, is as you say, history!