The Origin of Thermodynamics (Thermo)

Goals

  1. Explain why thermodynamics came into existence.
  2. Describe the rewards of learning thermo.
  3. Define thermo

The Origin Story

In early human history, people learned to control fire for cooking, warmth, and protection.
Heat was immediately tied to survival and success.

As societies grew, people learned to build machines that could do work for them, such as water wheels that ground grain, sawed wood, and powered simple machinery.
Creating machines that do useful work is an essence of engineering.

In the 1700s and 1800s, heat-driven machines, especially steam engines, became central to industry and transportation.
They powered factories, pumps, mills, and locomotives, making the conversion of heat into work economically critical.

A major problem quickly became obvious: inefficiency.
Only a fraction of the fuel’s energy became useful work; much of it was lost as heat. Fuel was expensive, machines were hard to compare, and improving designs by trial and error was slow, risky, and costly.

People needed a reliable way to answer practical questions:

Summary:
Heat and work are profoundly useful. Energy is the source of both.
Thermodynamics was created to provide a reliable way to relate energy, heat, and work so we can design and build systems that do their jobs well.

Examples

  1. To do its job well, a laptop computer must use energy efficiently so its battery lasts a long time.
    It must also reject heat in ways that prevent overheating.
    Thermodynamics is essential for understanding and designing both of these behaviors.

  2. To do its job well, a jet airplane must efficiently convert the energy stored in its fuel into useful work in the form of thrust.
    At the same time, passengers must be kept comfortable through heating, cooling, insulation, and airflow.
    Thermodynamics is essential for both propulsion and thermal management.

Bottom line:
Thermodynamics is essential for success with many real-world design tasks because so many systems involve energy, heat, and work.

Why Learn Thermo (Rewards)

  1. Succeed when you are problem solving in the context of systems that use work, energy, heat, or power. Since most systems involve these concepts, thermo is profoundly useful.

  2. Have a simple causal model of how energy, work, and heat relate to each other.

Thermodynamics

Thermodynamics is the branch of physics that explains how energy moves and changes form, how heat, energy and work relate, and the limits on how efficiently heat can be turned into useful work.

Thermodynamics is relevant when results matter and those results depend on energy, heat, work, or power.

You don’t need thermodynamics to operate most systems—but you do need it to explain, design, improve, or reliably predict their results.

For example, more than 99% of people who use computers do not need thermodynamics. But the small fraction of people who design, improve, test, and troubleshoot computer power and thermal systems absolutely do.

Success Criteria

  1. Define thermo.
  2. Explain why thermo was developed.
  3. List the rewards that people get from learning thermo.
  4. Given a scenario, identify whether thermo is releavnt.

Tasks with Feedback

Task:

What is thermodynamics?

Task:

What rewards does thermodynamics provide to people?

Task:

Is thermodynamics important if you are striving to understand how the human body works in the context of playing tennis?

Task:

Is thermodynamics important if you are striving to design and build a solar power system for a house?

Task:

Is thermodynamics important if you are riding a bicycle? With respect to riding a bicycle, when is thermodynamics important?

Task:

Is thermodynamics important for running a chain saw? With respect to a chain saw, when is thermodynamics important?

Task:

People invented steam engines without using thermodynamics; therefore, thermodynamics is not needed. Critique this argument.

Task:

Propose a simple test to identify when thermodynamics is important in a context.