  One of the oldest science problems - possibility of the perpetuum mobile is
discussed. The interest to this problem was provoke a result, published in J.
Low Temp.Phys. 112, 227 (1998); cond-mat/9811148, which contradicts to the
second law of thermodynamics. According to this result, the thermal
fluctuations can induce a voltage with direct component in a inhomogeneous
superconducting ring at an unaltered temperature corresponded to the resistive
transition of the ring segment with the lowest critical temperature. This
result arises from obvious statements: 1) the switching of a ring segment
$l_{b}$ into and out of the normal state, while the rest of the ring (segment
$l_{a}$) remains superconducting, can induced a voltage with dc component (It
is shown that, in spite of the wide spread opinion, this statement is correct
because the superconductivity is a macroscopic quantum phenomena); 2) the
thermal fluctuations switch the mesoscopic ring segment $l_{b}$ with lowest
critical temperature $T_{sb}$ into and out of the normal state at $T \simeq
T_{sb}$, while the rest of the ring remains superconducting if $T_{sa} > T
\simeq T_{sb}$. In order to resolve the contradiction between these obvious
statements and the second law of thermodynamics a possibility of the second
order perpetuum mobile is considered theoretically. It is shown that from two
type of the perpetuum mobile, only type "b" and only in quantum systems is
possible. According to the presented interpretation, the total entropy, as the
measure of the chaos, may be systematically reduced in some quantum system
because a "switching" between the classical and quantum mechanics is possible.
Instruction for the making of the perpetuum mobile is enclosed.
