All human attempts at creating a perpetual motion machine have failed. They fall prey to imperfect energy recycling - that is with every revolution/ cycle of a process they gradually lose energy to the surrounding environment as either friction and heat, sound or light etc.
This is due to entropy and the laws of thermodynamics. However, I often wonder based on the conservation law: that energy cannot be created nor destroyed ...is the universe itself a perpetual motion machine?

Some believe entropy leads eventually to heat death- where all molecules in the universe lose their kinetic energy and the fabric of space reaches 0 thermal energy or “absolute zero”.

What I don’t understand is that if this is the case where has the energy gone? It must still be there right?
My simplistic and most probably highly reductive conclusion is that 0 = -1 + 1. 0 being pure potential( does not require time as it is a non-acting/un manifested state) and -1 to 1 being “rate”: a sort of relativity between time and energy/motion.
Pure potential in this case (all time periods, all energy levels, all rates combined which fundamentally cancel each other out) can be split into “un-cancelled” states: integers other than zero which can then interact. This interaction is entropy as entropy leads back to the 0 state (rate slowing down from minimal time maximum energy - Big Bang to minimum energy maximal time -“heat death”. Both would be born of zero point potential and both would die as zero point potential with the beginning of time and the end of time respectively