It has recently been stated to the effect that any human can never accurately describe the world that he/she is in. Since any observer is part of the reality he/she is observing, there is no way to give a completely accurate description of it. No observer is completely objective, because no observer is completely outside the world. Any statement about the world is a statement about the observer, also, which introduces bias.

Granted, this is quite true. Being a part of a system means one is not completely objective. The case can be made that what we experience is not true at all, but merely an illusion. The following example will illustrate this fact; the observer cannot prove that the state of the world is how he/she experiences it.

Everything that one learns or experiences is communicated to the brain through various senses of the body. You walk to the store because your brain tells your legs to move, but you know that you are actually doing it because of your various senses. Let's go through them: You see yourself getting up by light bouncing off various objects and entering your eye, which sends the message along the nervous system to the brain. You feel yourself moving through space because your moving puts forces on fluids in the inner ear, which are translated into balancing signals that are sent along the nervous system to the brain. You feel yourself walking because your weight puts pressure on your feet, which has touch sensors that send messages along the nervous system to the brain. You hear your footsteps because particles of air hit sensors in your ear that transform the frequency of the air movement into signals that travel along the nervous system to the brain. You smell the pollution because particles in the air touch sensors in the nose that send the signals, and you know the rest. The important point here is that it is impossible for you to know what you are doing or what your surroundings are without bodily sensors sending messages, along the nervous system, to the brain.

One important ramification of this fact is that one could create any experience simply by sending the correct signals along your nervous system. If someone sent the correct signals along your nervous system, you would hear birds chirping. If someone sent the correct signals along your nervous system, you would feel yourself moving, feel the ground underneath your feet, and small a pie baking in the oven. Indeed, many of these things can be made to happen already, simply by people poking around in your head. Many experiments have been performed that, by applying pressure to the brain during surgery, resulted in the person experiencing different phenomena. Of course, it was not controlled; however, controlled situations are theoretically possible.

It is therefore possible to eventually create entire experiences, such as a rollercoaster ride, simply by attaching equipment to your nervous system that would send the correct signals. Simply by sitting in a chair, attached to some machine, you would think you were falling over a cliff, flying, swimming, eating, etc. If the right signals were sent, it would be impossible for you to tell the difference between what you thought you were experiencing and what was really happening. In fact, your whole day could happen simply by the machine looking at the signals your brain was sending out (for the feet to move, the mouth to speak, the eyes to focus, etc.) and send the correct responses back along the nervous system. You would experience a complete day's worth of activities, and it would be equivalent to those events actually happening. You would not know the difference.

This could be done for an hour, a minute, a day, or a hundred years, providing your brain was kept alive. It would also be very safe; you could even stab yourself and the machine would determine whether you actually died or not (remember, you're only experiencing what the machine tells you to). In other words, a brain could be taken, and a whole life could be experienced by that brain, and, as far as that brain (person?) knew, his/her life was being lived normally, and all experiences were actually happening. (Copyright © 1995 Garret Wilson. I've suddenly realized that this would be a great idea for a book).

The implication of this, however, is a bit scary. There is no way to tell for certain, then, if your actions are actually taking place, and if your experiences are true. The date could actually be 3500 at the moment, and you are hooked up to a machine creating a world in the late 20th century. There would be no way for you to tell. Look at the calendar. What you think you see could be signals sent through your nervous system mimicking those formed when the patterns of light from the calendar hit your sensors (which do not actually need to exist; the machine could be bypassing the sensors and sending the information straight to the nervous system). Ask a person walking by for the date. The machine sends signals that make you think the person tells you March 29, 1995. Remember that, once physical phenomena interact with your sensors, the sense is translated into electrical pulses, so if some equipment is actually creating exactly the same pulses, there is no way for one to tell the difference.

It is therefore impossible to know what the world is like. You, reading my paper, could actually be one brain hooked up to one machine. Nothing else has to exist. The machine is, at this moment, telling you that you have a person named Garret Wilson in your class who is writing a ridiculous paper. In reality, the machine would probably not want to give itself away, so you would probably never meet someone with such a theory, but it is possible, nonetheless. It could also be the reverse: my brain and a machine is all that needs to exist; I could be imagining that I'm writing this paper, that I have you for a teacher, or that it's getting dark already and this paper was due yesterday.

Indeed, how can you prove that the world you see really exists? There could actually be ten people, with ten machines hooked up to their brains, and each person imagines worlds with completely different properties! All your experiments are, after all, gathered through your senses, and everything you read by your fellow scientists are sensed through the eyes. Everything you've ever heard from your colleagues has been heard with your ears. Bodily sensors tell you everything—or that big machine...

Here's where it gets tricky, and a bit speculative (no seriously, everything up to now was not speculative as far as concerning what is possible). As it has been stated, your physical arm need not exist; you could simply think you see it, feel, it, etc. Your eyes need not exist, a machine could simply send signals to your brain that tells you what to see. Following this reasoning, how do you know what your brain is like? Sure, you've seen pictures in books, but that's just being fed to you, from the machine. If you've had the (lucky?) experience of operating on another person and seeing there brain, remember that what you are referring to as a human doesn't necessarily exist; the entire world could simply be an "unreality" created by a machine. There is no way to know what your own self is like. Therefore, there is no way to know if you actually have a brain at all!

Since all your physical surroundings you think you know about are merely signals your brain is receiving, your very physical brain could very well not exist. How would you know? Go ahead, cut open your head. The machine could decide that, once you actually reach this point, instead of making you think you see a brain, you might see a flower, or a socket set. But, even if you did see a brain, it could possibly be just like everything else; an illusion.

If your brain does not then need to exist, what is the machine feeding signals to? The whole idea of a brain (or even matter, for that matter), can very well be something very specific to the "something" hooked up to the machine, sending signals, creating feedback. Everything you think of as physical only needs to be simulated by the machine. So, if nothing physical needs to exist, what is there to think? Consciousness? What is consciousness, anyway; is it tied to any physical structure (the brain)? But didn't we just decide that there's no way for us to tell if the brain even exists?

Consciousness is a strange thing; at the moment, scientific mechanists would say (I assume) that everything one does is simply a product of the pattern of neurons and the series of their firings and interactions in the brain. Assuming the brain does exist, for a second, it would make sense that if my brain was transferred from my body and peripheral nervous system and put in the body of someone else, I would then see through their eyes, walk with their legs, and feel with their hands. Now, what if my brain was duplicated exactly, down to the last neuron, and placed in that body. There would be no difference between the two brains, mine and the duplicate. Would I then see out of my eyes and out of the other person's? Or is my self-awareness merely an illusion, and each brain will have self-awareness thoughts?

Still, this consciousness thing is so clearly defined (in humans, at least). If I split my brain and put half of it in another person, would I see from their eyes and mine? The whole question here is, why does each person see out of there own eyes and not out of another persons? What is consciousness?

As we have seen, since the observer is part of the world that he is observing, there are some things that cannot be proven conclusively, simply because the observer is examining himself. No observer is objective in the sense that he/she is outside and completely separate from the world he/she is observing. But what are the consequences of this? I seriously don't believe that I'm just a consciousness hooked up to a machine (unless maybe the brain is the machine controlling my consciousness), and I really believe that a physical world exists as we experience it, more or less. (I guess if a machine is controlling what we think, it could also control what we believe, so...) For all practical purposes, then, we can take the world for the way we picture it with our senses. If the world is really just a trick by some equipment, there would be nothing we could do about it. (Indeed, even if we "kill ourselves," how would we know that we would do something called "dying," if there is such a thing?)

In science, such unprovable (and non-disprovable) concepts are simply ignored, because they are useless. It was once believed that, if light was a wave, it was "waving" through some mysterious substance called aether, which could neither be seen, felt, heard, smelled, or tasted. In other words, it could not be detected. Since Einstein showed that the aether was unnecessary to explain the properties of light, scientists have not since stated that the aether does not exist; its existence instead became irrelevant. If it wasn't detectable and or necessary to explain any phenomena, it wasn't to be messed with. This reasoning is referred to as Occam's razor: we should always take the simplest path and ignore more clumsy alternatives, especially if the alternatives can never be measured (Kaku, 263). Therefore, the problems of the observer being part of the observable universe can for the most part be ignored. It is safe and wise to assume that what we experience is true, and that our scientific experiments are to be considered rationally and trusted.

Epilogue

Alas, I've since learned that the ideas presented here are by no means new; they have been the subject of numerous books and Star Trek episodes, with doubtlessly more to come.

Garret Wilson, December 1997

January 3, 1998

Forget Star Trek episodes; I was in the middle of Trudy Govier's Socrates' Children a couple of weeks ago and realized that what I presented in this essay are just a rehash of the ideas of Descartes, who lived in the 1600's. Sure, I had heard of, "I think, therefore I am," but had no insight into what it actually meant. Although I didn't quite make it to that stage in so many words in this essay, Descartes would have said, "I can know at least that I exist in some manner, because I'm thinking about whether I exist or not, and there has I have be some sort of thinking being that exists." As for my reasoning, it is quite intriguing that I followed closely the same line of reasoning that Descartes did, albeit with more modern examples. Perhaps it isn't so strange, though, since my ideas are based on centuries of scientific thought, which are in turn based upon the ideas of philosophers such as Descartes.

January 30, 2000

A movie that came out a few months ago, "The Matrix," relied on concepts similar to ones in this essay. Now Raymond Kurzweil, Ph.D., writing in Psychology Today Online, recreates almost exactly some of the arguments advanced here. Read the article, "Live Forever: Uploading the Human Brain," at http://www.psychologytoday.com/features3.html

Works Cited

• Kaku, Michio. Hyperspace. New York, N.Y.: Oxford University Press, 1994