Temperature > 07 - Third Law of Thermodynamics

Third Law of Thermodynamics or just a rule?

Two great names in Physics, Walther Nernst (11864-1941) and Max Planck (1858-1947) distinctly established two principles that attempt to establish the third law of Thermodynamics, idealizing systems whose entropy tends to a minimum value, or even zero.

Nernst proposed a principle: that the entropy of a system in thermodynamic equilibrium tends to a finite constant S0 when the temperature tends to absolute zero,  SS0 when T0

The constant S0 is the same for any state of a system at zero temperature. In other words, S0 is independent of thermodynamic quantities.

Planck's Principle results in: S0 = 0

Therefore, according to Planck, the constant S0 = 0 is universal, that is, it is the same for any system.

This law was re-discussed in 1930, when Franz Simon questioned it by raising questions about glass, to which the principles did not apply. According to the principle, entropy would be zero for systems in thermodynamic equilibrium. A possible justification for this is that glass would not be a system in thermodynamic equilibrium. Simon also disputed, in 1937, that the third law would only apply to pure crystals.

To this day, there is no absolute certainty as to whether it is a law or a rule. Some scholars in the field claim that there is an exception, hence the doubt. The original form stated says that it is impossible for a system to reach absolute zero, because for this to happen there would have to be a perfect order of the molecules that make up the portion of matter in question.

Recent research conducted by John Cumings shows that there is no correlation between the statement of the third law of thermodynamics and the experimental results obtained with water. Ice tends to organize itself, like all other substances, so much so that the oxygen atoms establish a well-ordered crystal lattice, which does not occur with the hydrogen atoms. According to Dr. Cumings,

"The hydrogen atoms stop moving, but they simply stop where they are, in different configurations throughout the crystal, with no correlation between them, and not even one of them lowers its energy enough to reduce its entropy to zero."

In other words, ice constitutes an exception to the third law of thermodynamics, which states that absolute zero is a temperature at which the thermodynamic system would find its state of perfect molecular order, so that the entropy of the system would fall to zero.