What is the definition of absolute zero?

Absolute zero is defined as the coldest temperature theoretically possible, which corresponds to a point where the entropy of a perfect crystal is zero according to the third law of thermodynamics. This temperature is equivalent to 0 Kelvin, -273.15 degrees Celsius, or -459.67 degrees Fahrenheit. At absolute zero, it is theorized that particles occupy their lowest energy state, resulting in the cessation of thermal motion.

While it's true that at absolute zero, molecular motion theoretically stops, this description highlights a consequence of reaching such a temperature rather than providing a comprehensive definition. The temperature of space varies considerably depending on various factors and is not a fixed measure of absolute coldness, distinguishing it from absolute zero. The lowest temperature recorded on Earth is an empirical measurement and does not reflect the theoretical bounds of temperature as defined by absolute zero. Thus, understanding absolute zero within the context of thermodynamic principles underscores its significance as the foundational limit of the temperature scale.