  In his seminal paper, Chua presented a fundamental physical claim by
introducing the memristor, "The missing circuit element". The memristor
equations were originally supposed to represent a passive circuit element
because, with active circuitry, arbitrary elements can be realized without
limitations. Therefore, if the memristor equations do not guarantee that the
circuit element can be realized by a passive system, the fundamental physics
claim about the memristor as "missing circuit element" loses all its weight.
The question of passivity/activity belongs to physics thus we incorporate
thermodynamics into the study of this problem. We show that the memristor
equations are physically incomplete regarding the problem of
passivity/activity. As a consequence, the claim that the present memristor
functions describe a passive device lead to unphysical results, such as
violating the Second Law of thermodynamics, in infinitely large number of
cases. The seminal memristor equations cannot introduce a new physical circuit
element without making the model more physical such as providing the
Fluctuation Dissipation Theory of memristors.
