1well i think yes its always increasing....
universe has no surrounding (this is only a theory and obv its not proven)
i hav a doubt abt the adiabatic thingy....coz yeah it can be true that theres no energy exchange between the universe and its so called surroundings....
but also we need to consider that universe is continuously expanding...so today if some area is not a part of the system (universe)..tmrw it may become a part
on the other hand....adiabatic process deals only with SURROUNDINGS and/of the system...
so i am diplomatic on adiabatic thingy....
anyway m not an expert or a scholly and this was just my opinion...i myt be wrong...
11though talking someting hypothetical...but we are not sure of existence of only one universe..there can be other universe..also.....there can be 2..3 ...4 or infinite universe...then these are the surroundings..basically surrounding actually doesn't means of universe...its just every thing that can exist in the surrounding of the system...
as far the theory we consider the thing that is containg in "our" universe....but as u r talking interuniversally...there may be exchange of energy from other universes..
1do u guys believe in parallel universe theory???? wat if there is no parallel universe???