If we want to know how a point moves in a plane, we can often write a simple equation. For example, y = ax+b defines a straight line, y = ax² + bx + c a parabola, an equation with x³ in it a curve with a maximum and a minimum, and so on. More complex equations define more complex curves. We can go three-dimensional and use x, y, and z to generate surfaces of various shapes.

If we want to know how different physical factors interact, we can often obtain empirically, by experiment, a relationship which becomes a physical law. We know that the pressure of a gas is proportional to the absolute temperature if the volume is kept constant. We know that a massive body released in a vacuum will fall to the earth with a constant acceleration. We know how the density of water varies with the temperature; this is more complex, with a maximum at 4 degrees C. We also know how the viscosity, surface tension, heat conductivity, electric conductivity and a host of other properties, of water and other liquids, vary with the temperature, pressure, and the presence of dissolved substances. We know when water converts to steam and when to ice; these are sudden phase changes, not continuous as the preceding examples. We know this for many different substances. We even know how mixtures and solutions (bi- and multi-component systems) act; that the components lower each other’s melting point and raise each other’s boiling point, i.e. have an effect on the phase changes.

However, note that some of these things we know only WHEN OTHER THINGS ARE KEPT CONSTANT, as in the gas example. Simplifying assumptions are made, as in releasing massive objects IN A VACUUM, or assuming that the water is 100% pure. Such limiting conditions are artificial; they never occur in nature. In nature we encounter mixtures, not pure substances. We encounter multiple variables, none of which remain constant; we encounter synergistic or inhibitory effects, whereby the independent variables interact among themselves as well as affecting the dependent variable. The whole can often be either larger or smaller than the sum of the parts, depending on the nature of these interactions.

Laboratory experiments are artificial little bits of reality, in which we try to isolate a single cause and relate it to a simple outcome. It can be a bit more complicated in multi-variate experiments, but not much, or we would lose our way in the welter. Experiments give us the truth and nothing but the truth, but not the whole truth. The WHOLE truth is a SYSTEM, which is probably too complex for us ever to understand in all its rich detail.

Nature gives us, for example, the weather; with many factors, such as local air pressure and air temperature differences, humidity, wind speeds in many directions, input of sunlight which depends on cloud cover which depends on all the above, mixing in to produce ever-changing momentary outcomes, which never reach equilibrium in the sense of settling down to constant values without further change, or even to predictable periodicities. We no longer have linear causes and effects, but branchings and cycles, where the effect may in turn become the cause of further events, or provide feedback (positive or negative) within its own cycle. We are now far away from drawing simple geometric curves or inducing simple physical laws that can be written down as a single concise equation.

Before the invention of computers, it took meteorologists so long to figure out, by complex calculations, what tomorrow’s weather will be, that before they finished, tomorrow’s weather was here. They can keep ahead of the game now, with faster calculations by machine. But how are the data actually manipulated in nature that tomorrow’s weather comes on time, with unmistakable single-valued outcomes of all the variables?

In the computer, calculations like this are performed by a process called “simulation”: we specify as many simple binary relationships between variables as we can, in the form of equations (linear or otherwise), put them all in, enter the initial values of the variables, and let the machine run through all the branchings and cycles of causes and effects that we specify. In the machine, it is done by very fast switchings (on and off) by tiny electrical circuits. HOW IS IT DONE OUT THERE IN NATURE? The variables interact DIRECTLY, you might say, without being “simulated” as electric currents; but what does “directly” mean? Is it not really a vast super-simulation, with even more variables than we can manage to feed into the computer? What is the difference between reality and simulation? More variables and more complexity, sure; but at least as a thought experiment, we can imagine our simulations increasing in complexity, until they approach that level. THEN will there be a difference?

Sometimes students play simulations of international relations. Most such “games” on the market are relatively simple, with few variables; yet they can be fairly “realistic”. Again, we can imagine increasing the complexity by adding more variables and more subtleties, until we approach “reality”.

In the film “The War Game”, the young student unknowingly tapped into the U.S. armed forces computer and asked it to play a game called “thermonuclear war”. When the student found out that this was “real”, he asked the computer to stop. “Why?” asked the machine. “Because this is reality, not a game”, said the human. “What is the difference?” said the machine, in genuine chilling ignorance. But the human KNEW that the difference is VAST in its consequences. Is this only because the only game the computer knew was incomplete? But what IS complete reality? In the war-game “reality”, it includes all the suffering and destruction. In the game, the victor and loser would walk away and play again some day; in reality, they would not. Is it only that in the game there were missing variables, that all outcomes were not taken into considerations? Or is the difference something more? I would now say, 5 years later, that the main difference between virtual reality and “real” reality is that in virtual reality you cannot be killed, but in “real” reality you can.

The universe is by definition vaster than any other system we know. Its process is an interplay of uncountable variables (not truly infinite, but uncountable by humans). It is ever changing, like the weather, though more slowly in most respects. It may or may not eventually come to equilibrium – a dead stop – when all the interactions are played out. In the meantime, it runs on in complex webs of causes and outcomes, according to pre-existing natural laws. The ability theoretically to predict its future, if only we knew the position and velocity of all particles at a given time (Laplace), is meaningless; no computer could keep up with the calculations in real time. (Also, by Heisenberg’s uncertainty principle, we CANNOT know the position and velocity of even ONE particle at the same time.) The universe would evolve faster than the computer program, just as the weather appeared before meteorologists could predict it.

As I walked alone one day thinking about this, it hit me. The universe could not be anything other than a vast simulation. Its creator set the physical laws and the initial conditions, like a super-programmer, and now is letting it run, to see what will happen. A vast experiment by an unimaginably superior (but perhaps not truly infinite) mind. Perhaps God runs several universe-simulations at the same time (whatever “time” may mean in this context), each set with different physical laws (programs) and initial conditions (starting data). Perhaps God runs billions of them.

But is our Universe “real” if it is a simulation? What else could be “more real”? Theologians say that we are thoughts in the mind of God. We are more real than OUR thoughts, because God’s mind is orders of magnitude more real than our minds. There must be degrees of reality. Hindu theology considers the world to be “maya” (appearance, illusion), or “lila” (a game). How close to the idea of a simulation! We have merely put it in a modern idiom.

The visible world is like quickly changing computer graphics in three dimensions – a hologram in all its shimmering beauty – a playful dance of Shiva.

But what could be more real? The mystics have an answer – God is the ultimate reality, the ground of all Being, “begotten, not created”. Not a simulation at all, but a rock-hard “diamond being” (Jung). All else is Lila.