The difference between 0°C (zero degrees Celsius) and absolute zero is significant and relates to the temperature scales used to measure temperature.
0°C is the freezing point of water under normal atmospheric pressure. It is a reference point on the Celsius scale, which divides the temperature range between the freezing and boiling points of water into 100 equal intervals. It is a commonly used temperature scale in everyday life and in many scientific contexts.
Absolute zero, on the other hand, is the lowest possible temperature that can be theoretically achieved. It is denoted as 0 Kelvin (0 K) on the Kelvin scale or -273.15°C on the Celsius scale. Absolute zero represents the complete absence of thermal energy in a system, where molecules and atoms have minimal or no kinetic energy.
The Kelvin scale is an absolute temperature scale that starts from absolute zero as its reference point. Unlike the Celsius scale, which sets the freezing point of water at 0°C, the Kelvin scale sets absolute zero at 0 K. The Kelvin scale has the same size intervals as the Celsius scale, so a difference of 1 K is equivalent to a difference of 1°C.
In summary, 0°C represents the freezing point of water, a commonly used reference point in everyday temperature measurements. Absolute zero, at 0 K or -273.15°C, is the lowest possible temperature, representing the absence of thermal energy. The Celsius scale is based on the freezing and boiling points of water, while the Kelvin scale uses absolute zero as its starting point.