Context: As the universe evolves in time, more and more of its energy becomes trapped in irreversible states (i.e., as heat or other kinds of increases in disorder). This has been referred to as the inevitable thermodynamic heat death of the universe. In this heat death the energy of the universe does not change, but the fraction of energy which is available to do work through a heat engine, or be transformed to other usable forms of energy (through the use of generators attached to heat engines), grows less and less.

Question: As the universe evolves in time, more and more of its energy becomes trapped in what?
Answer: irreversible states

Question: What is it referred to when more and more of energy becomes trapped in irreversible states?
Answer: inevitable thermodynamic heat death of the universe

Question: In this heat death of energy, what does not change?
Answer: energy of the universe

Question: As the universe evolves in time, less and less of its energy becomes trapped in what?
Answer: Unanswerable

Question: What is it referred to when more and more of energy becomes freed from irreversible states?
Answer: Unanswerable

Question: In this heat death of energy, what changes?
Answer: Unanswerable

Question: how much energy is not available to do work through a heat engine?
Answer: Unanswerable

Question: what is not attached to heat engines?
Answer: Unanswerable