This law, derived from the principle of
conservation of energy, is expressed as E = Q - W, where E is the
inside change in energy, Q is the
heat the
environment transfers
into the system, and W is the
work the system does. In another words, it means that:
The
inside energy in a system
isolated from another systems remains constant
The
change in the
inside energy of a system that is not
isolated is
equal to the
energy that crosses its boundariesinto or out of another systemsIt can be further extrapolated to
mean that despite all the processesgoing on in the universe, the
total energy contained in the universeremains constant.