Essay by Valerie Paulsen

I can remember wondering, as a child, how big the world was. I imagined myself traveling far away, until I reached the end of everything. There I encountered an impenetrable wall that reached in all directions as far as my mind's eye could see. In an instant, I realized there must be something on the other side of the wall. That there would always be something on the other side, no matter how far away the "end of everything" might be.

Years later, while revisiting one of those mental journeys, I was jolted by a staggering realization. For one galvanizing moment, my mind reeled. The inconceivable thought that confronted me would forever change my view of reality.

The vision appears only with great effort. It sweeps through my mind like an electric shock, and is gone. I once had a friend who saw it too, a long time ago.

Unlike my original journey, the vision is three-dimensional. My mind sees a cosmic view of the endlessly receding expanse of the universe, but that in itself is ordinary. The vision is that infinity can never be a boundary - and space cannot exist without one! The paradox is startling, and causes a feeling of vertigo as the thought slips away.

The vision cannot be adequately described with words. To see it, you must think visually. Clear your mind of all verbal dialogue and concentrate outside yourself. Focus visually on the idea that everything goes on forever in all directions, and try to take it to its limit.

If you succeed, you will see that the three-dimensional world in which you live must surely be a deception. If you think you "get it", but are not completely sure, then you don't. The effect is not subtle.

You might try to dismiss this by saying the human mind cannot comprehend infinity. Or perhaps you believe that the universe closes on itself in a fourth dimension, and is therefore not infinite. If so, I ask that you temporarily set aside your skepticism, and read on:

The flip side of the infinitely large is the infinitely small. Early theorists proposed that matter was made of indestructible particles that were too small to see. By the early 20th century, that idea had given way to the modern atom, with its nucleus and orbiting electrons. Although the electron was believed to be a "dimensionless point", the nucleus was known to have a definite size. With the invention of atom smashers, it was soon learned that the nucleus was made of smaller pieces, now known as protons and neutrons. For a while, they were believed to be elementary, but eventually internal components were revealed. Those components, known as quarks and gluons, so far seem to be dimensionless points with no internal structure. And so it goes...

These ideas are far removed from the experience of everyday life, where the material world seems to obey common sense rules. For example, solid objects can't pass through each other, and forces can't be exerted without some kind of physical contact. The exceptions are things like light or magnetic fields that involve "energy" instead of matter. But matter is nothing but various types of energy fields in condensed form, as expressed by Einstein's famous equation:

Energy = (mass) x (speed of light) x (speed of light)

To understand this more graphically, you can do a simple experiment. It works best with a couple of Neodymium-Iron-Boron magnets about a cubic inch in size. Grasp one in each hand and position them on opposite sides of a thick barrier, such as an open wooden door. Keep them far apart until there is something between them to prevent contact. Be careful, the forces produced can cause physical injury if the magnets get too close! The experiment is most impressive when the magnets are positioned to repel each other. Although there is nothing connecting them but a so-called "magnetic field", your body will tell you there is something very physical pushing them apart, a kind of springy, slippery, blob-like thing that feels very real. What you are sensing with your hands and arms is a macroscopic example of the very essence of all condensed matter! Everything - solids, liquids, gases, even plasmas, are made of nothing but microscopic force fields! And fields are not things - they are just abstract vector descriptions.

About a half century ago, a classic experiment was carried out that demonstrated the ability of the human visual system to reprogram itself. Volunteers were fitted with special glasses that inverted everything they saw. At first, they could only stumble about in confusion, but after using the glasses continuously for a few days, their visual system corrected for the inverted scene and everything looked normal!

I won't suggest trying this yourself, but there is a much simpler experiment that you can do. All that is required is a large mirror. Position yourself in front of the mirror so that your reflection appears at least a meter away. Relax and focus your attention on your face. Now gently touch the lower part of your face with your fingertips, while concentrating on your reflected image. Make sure you can't see your hands directly, but only in the mirror. Slide your fingers on your face to create a continuous sensation of touch. You will feel your face on the other side of the mirror! You might have to practice this over a period of a few days, before it works. But once you learn how, you should be able to do it anytime. Unlike the experiment with glasses, this one is subjective. Only you will know when it succeeds. But it demonstrates that the perception of physical reality can be easily reprogrammed.

The human brain can be likened to a massively parallel analog computer. The development of the neural net chip has resulted in a resurgence of electronic analog computing, which was popular before the introduction of the microprocessor. Although the possibility of a conscious digital computer remains controversial, it is at least hypothetically possible for an electronic analog computer to simulate the brain, and by extension, the thought process.

Imagine that such a computer was connected to other computers that were programmed to simulate the behavior of the natural world. In a way, this would be just like a human brain that was asleep and dreaming vividly. Now let's go further and imagine that the computer was actually conscious, and that it could "see" its virtual reality world the same way we see ours. Say that the computer mind was highly intelligent, and that there were no connections between the outside "real" world and the computer. Would it be possible for the artificial intelligence to figure out that the world it lived in was really just information programmed into a machine?

This is a popular science fiction theme that dates back at least fifty years, and has been popularized in television shows like Doctor Who and Star Trek. The general consensus is that there would be no way for the machine intelligence to ever know that its world was not real, let alone the true nature of the computer in which it resided. It would "see" three dimensional space, and would assume that the objects in its universe were actually separated by physical distance. It might even invent the concept of infinity, and ponder its impossibility. How could it ever prove that the "space" it perceived, and even its own self-awareness, was just an illusion produced by computer algorithms?

If you got this far, you probably know what I am getting at. The paradox of unending space. The lack of anything solid at the core of matter. Force fields that feel like objects. The adaptability of the senses. The knowledge limits of a hypothetical artificial consciousness.

I submit that the three dimensional space in which we live does not exist! The distance that we perceive separating objects is an illusion. The evidence suggests that it is a qualia, like the familiar color of green leaves, the sound of a musical note, the feeling of warmth, or the thirst for water. In other words, what we experience as volume extending away from ourselves is just a mental projection.

The objective reality of the universe is probably impossible for the human mind to comprehend. I'm not saying there is not some property of the universe that accounts for the perception of spatial dimensions. I think there is. But it seems to be beyond our ability to perceive it directly, just as we can only visualize time as a series of places.

You might ask, if this is true, are there any practical consequences? I don't know. What do you think?

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