Understanding Temperature

Temperature is one of the most universal concepts of the physical world. Often used to define the level of comfort in any given environment, the sensation of temperature is understandably part of our everyday lives. It’s the matter of hot or cold, light or dark, summer or winter. But how can something so simple be measured and defined? To explain the concept of temperature, we must first understand the fundamental principles behind it and appreciate its application in our lives.

What is Temperature?

Simply put, temperature is a measure of the amount of heat energy present in a given system. Specifically, this measure is the average kinetic energy of molecules in the system; the greater their motion, the higher their kinetic energy and the higher their temperature. An important factor to consider here is that temperature does not signify the absence of energy; with a temperature of zero, molecules in a completely isolated system may still retain some energy of motion. However, this value can be considered as the lowest temperature possible as any further decreases would equate to negative energy, something that is overlooked from a thermodynamic perspective.

Temperature Scales

When measuring temperature, the scale being used to define and label the values is just as important as the temperature itself. Historically, a variety of temperature scales were invented, including the Rankine, Réaumur, and Fahrenheit scales. Each of these scales was expressed in different units, restricting the accuracy and reliability of their measurements; luckily, the Celsius or centigrade scale was invented in 1742 and has since become the standard scale of measurement, eliminating the confusion of multiple or contrasting scales.

Therefore, temperature is a measure of heat energy that is expressed through the Celsius scale, and as such, is a familiar metric of the physical world. As we continue to understand temperature and its application, the need for accuracy and refined scales will become even more significant. We have come a long way in improving the accuracy of temperature measures and the research and development of more efficient scales, so understanding temperature is more important than ever.