12-1-zeroth-law-of-thermodynamics-thermal-equilibrium_summary

The Zeroth Law of Thermodynamics states that if two systems, A and B, are in thermal equilibrium with each other, and B is in thermal equilibrium with a third system, C, then A is also in thermal equilibrium with C. This law is fundamental to understanding the behavior of thermal systems, as it defines thermal equilibrium as the state when two bodies are in thermal contact, and no heat transfer (or energy transfer) occurs between them. It is sometimes called the zeroth law because it was formulated after the first and second laws of thermodynamics, but it is essential to the principles of thermodynamics. Examples of heat transfer that demonstrate the zeroth law of thermodynamics include an ice cube melting in a glass of soda or a hot glass of water cooling in a room. In these cases, heat from the hotter object (ice, water, or room) flows towards the colder one until thermal equilibrium is reached, at which point both objects have the same temperature. Thermodynamics engineers apply the principles of thermodynamics to mechanical systems to create or test products that rely mainly on the interactions between heat, work, pressure, temperature, and volume, with opportunities arising in industries such as aerospace, chemical manufacturing, power plants, engine manufacturing, and electronics. In the context of Zeroth Law, a thermodynamics engineer might, for example, design equipment to optimize energy production from renewable sources in the aeronautics industry. Thermodynamics engineers need a college degree in related engineering fields, such as chemical, mechanical, or aerospace engineering, with specific coursework in physics and physical chemistry focusing on thermodynamics.