
Principles of Analog Electronics
34
Between the degree Celsius and the Kelvin there is one conceptual difference.
While the rst is derived from the different indications between two specic pas-
sages of the state of water (liquid to solid: 0°C and liquid to gas: 100°C), the sec-
ond is associated with the absolute measure of the total energy of a system. Given
that any system considered cannot have a negative value of energy (nor can a gas
have a volume smaller than zero), it follows that the unit of measurement of Kelvin
cannot assume negative values. The temperature of zero Kelvin is absolute zero
and corresponds to no energy. A system wit