IMO this shows that the universe is a volume of matter and energy undergoing a reversible adiabatic process. Time does not go backwards, rather, there is a function that allows the potential energy of the system to be restored either cyclically or continuously. I believe this function is carried out by black holes. A quasar is like a candle burning in a closed container, with lots of fuel and oxygen. As the temperature increases the flame remains small. But when the container reaches the ignition temperature all the fuel in the container spontaneously ignites. This event is called "Flashover", and in cosmological terms this is when a black hole grows at an asymptotic rate, consuming all. A star creates heavier elements from lighter ones, but a black hole does the opposite: creating lighter elements from heavier ones, resetting the universe, or a portion of it, to a primordial state with a high potential energy and low entropy.

So I think it's possible the universe might actually be a perpetual motion machine, but only on an extragalactic or even cosmological scale and only when periodically undergoing gravitational collapse. We have been taught that this is impossible because the evidence we've collected for thermodynamic laws are based upon a brief snapshot of the universe.

I'm still pondering the ultimate question: Why is there something rather than nothing. Obviously, we can ask this question only because there is something rather than nothing. But there is no reason to believe that will always be so. Somewhere or somewhen there may be nothing. Maybe reality flickers in and out of existence on vast timescales like an instantiation of an otherwise transcendental object with no limit to temporal extrapolation. A sine wave can be imagined as infinite in both directions, but it is truncated within the edges of a page, and in fact instantiated on a page. Maybe the universe came into existence when enough matter flickered into existence to create an event horizon, which trapped it forever in a state of material existence. Imagine universes flickering in and out of existence in some infinite nothingness.

Deep questions need deep answers.