Karma has been likened to the laws of physics, particularly to Newton’s 3rd law of motion: for every action there is an equal and opposite reaction. I prefer the comparison with the law of energy conservation, where Karma is a conservation of spiritual energy.

But even if we already know this to be true, it probably still deserves more thinking. Or application. After all - looking at the material world - there is a big difference between knowing the rule, and applying it to solve physics textbook problems. And there is another fairly big difference between solving physics problems and solving the engineering problems that ultimately impact people’s lives. Each requires the former, but it also requires taking into consideration other rules and some specific constraints.

Let’s consider the typical flow when applying this law for a physics problem. The first (and probably the most difficult) step is figuring out the bounds of the system. Without the bounds, we cannot write the equation. It’s of no use that the energy is conserved in the whole universe because it’s too general. We need to be particular to the little system we’re interested in, but not too particular that we’re overlooking a significant energy leakage to the exterior. If the leakage is too high, we need to extend the bounds of the system and consider additional variables before we apply the law. For example, we might ignore the friction with the air when computing the velocities of 2 heavy balls after colliding - the system includes the 2 balls and excludes everything else. But we would not ignore the heat transfer between an electrical resistor and the surrounding air when computing its temperature during current flow.

The question now arises. What are the bounds of our karmic system? As a space bound, we could consider the indivdual as the system, or we could consider their family. Their country, or the whole human species. What about other species? It does not seem implausible that humanity benefits at the loss of other beings and vice-versa. Then there is the time bound. Do things cancel out within a generation’s time, a species’ time or longer than that?

There is also the question of what exactly is this thing we’re conserving and measuring. When we say good karma and bad karma, can we reduce it to a measure of happiness or are there more subtle, perhaps orthogonal measures? Even in physics, energy is kind of an abstract thing and can take many forms (kinetic, thermal, magnetic, nuclear, etc.). We know the famous E = mc^2 which basically equates it to mass, but then what is mass? Isn’t it a thing resisting movement? Yet movement is energy? Strange.

An interesting system to consider is the lifetime of an indivdual and their cummulated happiness.
It is widely believed that karma cannot be compensated within a lifetime. This is probably an immediate consequence to the feeling of unfairness in the world, yet the feeling could be deceiving. The problem is, dead people can’t talk. So we cannot know the bliss felt by an abused and ill slave or the misery felt by a glorious king during the last seconds of their lives. It could amount so much as to compensate for the years before, especially taking into account the time warping effects of the chemicals released by the brain during death. In this could lie the mystery of reincarnation, heaven and hell.