41. However, real systems may behave nearly as an isolated system for finite ( possibly very long ) times. 42. Is universe a isolated system ? Preceding talk ) 23 : 18, 26 December 2014 ( UTC) 43. Whenever thermal energy diffuses within an isolated system , temperature differences within the system decrease ( and entropy increases ). 44. The change in exergy of an isolated system is equivalent, but opposite the value for irreversibility of that system. 45. However, for given single frames of reference and for isolated systems , the relativistic mass is also a conserved quantity. 46. The opposite of a mechanically isolated system is a mechanically open system, which allows the transfer of mechanical energy. 47. They are not perpetual motion machines because they are consuming energy from an external source and are not isolated systems . 48. The second law of thermodynamics states that the entropy of an isolated system always increases to a maximum equilibrium value. 49. In isolated systems it is consistently observed that as time goes on internal rearrangements diminish and stable conditions are approached. 50. The transfer of energy as work into an adiabatically isolated system can be imagined as being of two idealized extreme kinds.
