Which temperature scale is known as the absolute Celsius scale?

The Kelvin scale is known as the absolute Celsius scale because it is directly related to the Celsius temperature scale and represents absolute temperature. The Kelvin scale starts at absolute zero, which is 0 Kelvin, equivalent to -273.15 degrees Celsius. This relationship allows temperature measurements in Kelvin to be directly converted to Celsius by adding or subtracting 273.15.

In scientific terms, the Kelvin scale is essential in calculations involving thermodynamics and physical chemistry, where absolute temperature is needed for formulas and laws, such as the ideal gas law. Because of its absolute nature, the Kelvin scale is universally used in scientific research and applications.

In contrast, the other temperature scales do not have this direct relationship with absolute temperature. For example, the Fahrenheit scale is more commonly used in everyday scenarios, particularly in the United States, and does not align with the principles of absolute temperature. The Rankine scale is similar to the Kelvin scale but uses Fahrenheit degrees, while the Reaumur scale also has its own unique zero point that does not correspond to absolute zero. Thus, the Kelvin scale stands out as the absolute temperature scale in scientific contexts.