Laws of Thermodynamics

In 41 years of teaching high school physics, I learned that the hard part of teaching is getting kids to work on understanding concepts. The concepts are easy if the students can see some application to their daily lives. But if they did not understand the relevance of the subject, they were not going to work on understanding. To that end, I titled the unit on thermodynamics “Break the Thermo law and You Don’t Survive!” The three laws of thermodynamics are fundamental truths that apply to all of science, and theories that break those laws do not survive.

The laws of thermodynamics have a great deal to do with cosmology and questions about creation. We want to state these laws and try to point out their application to issues related to life, death, and how we live our lives.

THE FIRST LAW OF THERMODYNAMICS: The Total Increase in Thermal Energy of a System is the Sum of the Work Done on It and the Heat Added to It.

I used to tell my classes that this law says, “You don’t get something for nothing.” What does it take to run your car? One student said, “\$2.00 a gallon.” They had learned how to calculate how much energy a gallon of gasoline produces, so I would show them how to calculate how far you ought to be able to drive your car on a gallon of gas. The answer usually came out to be something close to 1,000 miles. “He can’t get that crate of his out of the parking lot on a gallon of gas,” another student volunteered.

“What’s the inconsistency?” I would ask. Then I answered my own question by screaming, “The First Law of Thermodynamics!” The point is that the total thermal energy added to the car (the burning gasoline) will never be equal to the work done by the engine. There will always be energy lost to heating the engine, to friction, to incomplete combustion, and a variety of other energy-consuming problems.

This principle is simply a thermal statement of the Law of Conservation of Energy, and it applies to everything in life. We will never have cars, motors, or heating systems that are 100 percent efficient. Perpetual motion will never happen. There is always a price to pay for any energy that you use. Planet Earth, the solar system, the galaxy, and in fact, the cosmos all operate in conformance to the First Law.

If the cosmos started with a massive singularity of energy, then that total energy is equal to the work that has been done in the cosmos and the energy that still exists within it. Proposing that something can “pop into existence out of nothing” is not a possibility. Energy systems can change, but the First Law will still apply. Quantum mechanics may show us new ways in which energy systems change, but the total energy of the cosmos has not changed even in quantum reactions. The fact that there are newly understood mechanisms of change does not invalidate the First Law. They change how the laws of thermodynamics are applied, sometimes in remarkable ways, but you still do not get something from nothing.

In the beginning, an incredible concentration of energy was created at the point when time and space were created. We know from Einstein’s famous equation E = mc2 that this energy can appear as mass. Those of us who believe in God believe that “God is light” applies to this situation. God just took some of his own essence and produced the singularity that led to the cosmos. Those who reject God’s existence have to believe that some extra-dimensional entity did the same thing, but without wisdom, intelligence, or design.

While we can argue about what that entity is. We cannot argue about the laws of thermodynamics that describe how that initial singularity became the physical world in which we live–and became us as well. The first law of thermodynamics profoundly describes that, and it gives our world order, function, and predictability.

Tomorrow we will look at the Second Law of Thermodynamics.

— John N. Clayton © 2020

Note: Laws are quoted from Physics, Principles and Problems, Glencoe Publications of Macmillan/McGraw Hill, PO Box 508, Columbus, Ohio 43216, pages 256-259.