The second law of thermodynamics entails that all energetically isolated systems tend toward absolute equilibrium. Conversely, life, order and the capacity to do useful work are possible only in case of energetic inequality between parts of the system. This raises the question: how could life have evolved if the alleged tendency of the Universe is to increase entropy until universal death (Schrödinger’s paradox). The common retort, that life as a local phenomenon is consistent with the second law, does not extend to existence of a world in which life is possible.

Evolution of life necessarily involves a decrease in entropy (or an increase in local order) and intensification of energetic disequilibrium between some parts of the system. A local decrease in entropy does not violate the second law only if, at the same time, the overall entropy of the world increases by at least as much. This would be possible if the universe ‘begun’ with a positive balance of disequilibrium, or order, which could then be broken down to release useful energy (Lehninger, Albert. Principles of Biochemistry, 1993) but the idea of a ‘beginning’ has highly problematic implications. Genesis, creation or appearance of a world out-of-nothing, with a positive amount of disequilibrium or useful energy, would be a violation of the first law of thermodynamics. Another way, if the second law is non-trivially true then the first law had to be violated for the universe to come into being.

The premise that a positive amount of energy is required for the universe to exist is disputed by proponents of the zero-energy universe hypothesis, which postulates that the total positive energy associated with matter is cancelled exactly by gravitational energy, which is deemed ‘negative’. Existence of negative energy is inferred from the alleged fact that gravity causes a free-floating body to gain kinetic energy at the same time as gravitational energy, defined as the energy available to bring two free-floating masses together by means of gravitational attraction alone, also increases. Since the first law dictates that the net energy of the system must remain constant, gravitational energy is given the negative sign to cancel out the positive change in kinetic energy. I contend that the increase in gravitational attraction during free-fall does not entail a positive change in gravitational energy. The potential energy available to bring two masses together by means of gravity alone is the total area under the curve of gravitational force v. the distance between masses. As the distance decreases, a definite amount of the potential energy is converted into kinetic energy, thereby reducing the available potential energy. The first law is not violated because energy is only converted from one form into another. The mechanics of gravity is akin to a mass being pulled-in by a nonlinear spring, or better, an arrow being accelerated by a compound bow. At full draw only a thin tail of the available potential energy (area under the curve) is converted into kinetic energy but, as the arrow advances, more energy is converted per distance. Similarly, gravity does not require explanation in terms of ‘negative energy’, what counts against the zero-energy universe hypothesis (although there may be other reasons to accept this hypothesis as plausible).

If the world contains a non-zero amount of energy, then its creation would entail that the law of energy conservation is false, and that energy can in fact be created out of nothing. This is a highly undesirable implication, unsupported by evidence and begging the question: how could anything be created out of nothing? Assuming that the zero-energy universe hypothesis is false, the paradox of creation can be avoided only if energy had always existed, before the Big Bang, and only if entropy can increase without limit (otherwise an infinite past would not be possible).

The Big Bang is usually understood to signify an adiabatically closed system (energy cannot be added or removed from the system) which was highly homogenous and in a state of perfect equilibrium (maximum entropy for its size and content). This system has then allegedly exploded to form the universe, but how could the explosion occur if the system was in equilibrium and energetically closed? Explosion entails a release of useful energy, and equilibrium entails no useful energy, therefore a contradiction, or so it seems. Something is evidently missing from this picture. The explosion hypothesis does not of itself violate the second law because as the volume of the system increases so does the maximum entropy that the system may possess: an increase in space results in a lower overall density of energetic particles per volume, a lower average frequency of their interactions and therefore a longer time required for the system to reach equilibrium. The main difficulty lies in explaining the initial trigger of explosion, the energetic discontinuity which had caused the temporary equilibrium just prior to the Big Bang to be disrupted and for the explosion to follow. According to Edward Tryon (in Is the Universe a Vacuum Fluctuation? Nature, 1973. p396-397) “there is no apparent reason for such an event to occur.”

Any disturbance from the state of equilibrium would have to involve either creation ex nihilo, contradicting the first law of thermodynamics, or an external interference with the system, contradicting the premise that the system is closed and thus simply kicking the proverbial can further down the road. Both possibilities are unattractive, as they raise as many questions as they purport to answer. I favour the idea that no creation or beginning of the universe could ever take place. This proposition can be accommodated by speculating that the Big Bang (or something like it) is not an event at some particular time but a permanent property of every possible world, with no beginning or end. This would require an ‘infinite’ history being contained within what retrospectively appears to be a finite past, or, what amounts to the same effect, that the dimension of time expands with the universe, proportionally to the increasing maximum entropy. The first millisecond of the Big Bang would then contain an infinite history while appearing to be of finite duration (a millisecond) to some future observer.

With respect to the second law, this resembles the schema of Achilles and the tortoise. Taking Achilles to represent the actual entropy of the world and the tortoise the maximum possible entropy (entropy at the absolute equilibrium-state), the tortoise will ‘always’ stay ahead of Achilles if spacetime itself stretches in proportion to the locally apparent distance between the two competitors. Another way to visualise the problem is in terms of perspective: distant sections of the road on which an observer is travelling appear narrower than the section of the road directly beneath the observer, and the speed of movement of distant vehicles appears to be slower that to observers inside those vehicles. Beyond certain distance, to infinity, all moving objects converge to a static point.

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