Reverse Engineering Puzzle $M + F \rightarrow C \,$ Male M and female F react yielding the product of a 15-year old child C The spontaneity criterion can be used to determines if a reaction if feasible The central function of the EoHT is the collection of knowledge concerning how human chemical reactions are understood according to the spontaneity criterion.
In science, reverse engineering is the analysis of a completed system in order to isolate and identify its individual components or building blocks. [1]

Overview
In human thermodynamics, the reverse engineering puzzle refers to analysis or the completed system of the science of thermodynamics in order to isolate and identify the individual components and building blocks need for the explication of any and all aspects of human activity and phenomenon, which one wishes to solve, using the the laws of thermodynamics, laws which have been confirmed to govern the operation of the entire universe, and thus by reduction human activity.

In chemistry, physical chemists, such as Jacobus Van't Hoff and Walther Nernst, use a type of reverse engineering in order to figure out chemical operations and mechanisms. The rule is that the theory developed to model any and all chemical operations and processes must obey the laws of thermodynamics.

 In 2010, scientists found that the Rubik's cube can always be solved in twenty steps, given any starting configuration. [2]
Rubik's cube
Reverse engineering, in the hmol sciences, is similar to solving a Rubik’s Cube in a particular number of steps: “there are many different algorithms, varying in complexity and number of moves required, but those that can be memorized by a mortal typically require more than forty moves.” In 2010, an international team of researchers using computer time lent to them by Google, found that starting from any given configuration the Rubik’s Cube can always be solved in 20 moves or less. It took people about 15-years, following the introduction of the cube in 1974 by Hungarian architect Erno Rubik, to find the first position that requires 20 moves to solve. It has taken 36-years, using modern computer technology, to prove that twenty moves suffice for all positions. [2]

This idea that an starting positional logic can be solved in a particular number of steps is the essential rule followed in the human molecular sciences, in that given any configuration of a question, e.g. does a human have a soul (Nahum), is there free will (Darwin), what is morality (Goethe), what is good versus evil (Teilard), what is life? (Schrodinger), what is death? (Thomson), what is love? (Hwang), is there a struggle for existence? (Thims), what is our purpose? (Schneider), etc., each query can be solved in a particular number of steps.

Reverse engineering: spontaneity puzzle
The central reverse engineering puzzle in the mind of American chemical engineer Libb Thims' work is captured the puzzle as to how the chemical reaction spontaneity criterion (ΔG < 0) applies to human relationships. Historically, in circa 1995, while an undergraduate chemical student at the University of Michigan, Thims began to wonder how the Gibbs free energy model of reaction spontaneity, particularly as discerned through Beckhap's law, applies to the male-female reaction, the central process of society, in which a man meets a women, they fall in love (20 percent of people fall in love at first sight and marry that person), produce a child; an entity which then begins to detach from the family household at about the fifteen-year mark; a reaction process that 85 percent of people will go through.

This so-called "spontaneity criterion puzzle" is a sort of reverse engineering problem-puzzle as to how to apply the well-established chemical reaction spontaneity criterion to the modeling of the spontaneities of human-human reactions, particularly in regard to mate selection, so as to be able to 'predict', in a theoretical (or actual) sense, spontaneous reactions in human relationships.

The central issue, with this thick riddle, is the understanding of how enthalpy change ΔH and entropy change ΔS are to be understood in human chemical reaction terms, over the course of multiple decades, so as to yield a quantitative measure of Gibbs free energy change, between two points in time, differing by multiple years. It takes a minimum of at least 5-7 years, even for a well-schooled chemical thermodynamicist, to arrive at even a partial idea, interpretive visualization, or intuitive understanding as to how to go about gaining insight into this puzzle. A precipitate of this effort is the EoHT wiki, launched in 2007.

In sum, Thims' central research, since circa 1995, has been to elucidate, quantitatively, how the basic, multi-year human reproduction reaction (relationship, sex, and offspring), which 85% of people go through, can be energetically predicted, via free energy determinations:

G = H – TS

as quantified using the spontaneity criterion (ΔG < 0), which states that spontaneous chemical reactions must show a decrease in Gibbs free energy over the extent of the reaction, i.e. the summation of the enthalpic (ΔH) and entropic (–TΔS) factors involved in the system interaction must show a decrease in value over time, if the reaction or process is to be universally favored. This dissection of human interactions can also be expressed via the relation between the chemical affinity A or the force of reaction existent between reacting species to Gibbs free energy change ΔG:

A = – ΔG

as proved in 1882 by German physicist Hermann Helmholtz in his "The Thermodynamics of Chemical Processes", and applied to the modeling of human relationships by German polymath Johann Goethe in his 1809 Elective Affinities. In sum, in order to understand love in the context of relationships and how one correctly chooses who to love, one has to be able to measure enthalpy ΔH and entropy ΔS changes involved in human activity? The specific human chemical equation, which Thims originally began to mediate on is the following pair of human mating reactions:

M + FA → BA
M + FB → BB

where M is one male, FA is a hypothetical female, FB is a second hypothetical female, BA is a child product of the first pairing, and BB is a child product of the second pairing. To rule to determine which reaction should be chosen, is that the reaction most energetically favored (exergonic) will be the one that shows the most decrease in Gibbs free energy G over time in the extent of the reaction.

The use of chemical equations to model human reactions, to note, is a very deep subject. The fact that only eight people, in history (see human chemical reaction history), are known to used chemical equations, such as above, to model human processes, such as colloquial love the chemical reaction motto, exemplifies this.
The dimension of time, in this example, being the difference between the initial "state" of the reaction, or day in which the pair first begin to react, and the final state of the reaction, signified as the day, some 15 or more years later, at which point the offspring product begins to detach from the parental structure, going of on its own.

The spontaneity rule itself is relatively simple, quantified by the following simple equation: ΔG < 0. It is the understanding of quantities that compose free energy:

▬▬▬$G = U + p V - T S\,$

namely internal energy U, pressure P, volume V, temperature T, and entropy S, among other facts (such as chemical potential μ, external forces, gravity, free energy coupling, etc.), however, which, invariably, require a new field of research and conceptual understanding, where people are defined technically as boundaried "systems of human molecules", a subject never rigorously done before, in spite of the fact that over 300-people have published views on the theoretical application of thermodynamics to human activity.

An example of the difficulties encountered, in synthesizing this application, is the understanding of the "end state" (15 or so years after first sex), of the ordering of the system of humans, involved in the process of a human reproduction reaction (sex), such as above, which, in mechanism, is defined more exactly as a double displacement reaction (double elective affinity) of the form:

M + F → M≡F + Child

It is at this point, that the subject of chemical / physics nature of the human bond "M≡F" becomes a central subject of study, one that has never been done before. Nearly two-thirds of the 2007 textbook Human Chemistry, written by Thims, was devoted to the elucidation of the nature of human chemical bonds considered purely as a chemical bond. [1]

In any event, pairing feasibility can be understood via chemical thermodynamics, namely by the fundamental equation characterizing the relation between affinity A and free energy G change:

A = – ΔG

in conjunction with the spontaneity criterion rule defining spontaneous reactions:

ΔG < 0

In short, whichever mating reaction actuates a greater negative change in the Gibbs free energy, where G is a function of enthalpy and entropy:

ΔG = ΔH – TΔS

will be more energetically-favored and less prone to divorce (debonding). Beyond this, there are complicating issues associated with the quantification of external forces, chemical potential factors, gravity, equilibrium effects, system boundary issues, free energy coupling, enthalpy-entropy compensation, etc., factors that each effect human chemical reactions. Thims is currently interested in trying to understand how the Gibbs fundamental equation, in which the change in energy U of a system can be written as the product of an intensive and an extensive parameter:

$\Delta U = \sum_{i} X_{i} \Delta Y_{i} \,\!$
where Xi is an intensive quantity, such as pressure or temperature, and Yi is an extensive quantity, such as volume, can be applied to a human social system.

References
1. Licker, Mark. (2003). Dictionary of Engineering (reverse engineering, pg. 461). McGraw-Hill.
2. Anon. (2010). “Study Uncovers Every Possible Rubik’s Cube Solution”, AFP, Aug 12.