"It is indeed an opinion strangely prevailing amongst men, that houses, mountains, rivers, and in a word all sensible objects, have an existence, natural or real, distinct from their being perceived by the understanding. But, with how great an assurance and acquiescence soever this principle may be entertained in the world, yet whoever shall find in his heart to call it in question may, if I mistake not, perceive it to involve a manifest contradiction. For, what are the forementioned objects but the things we perceive by sense? and what do we perceive besides our own ideas or sensations? and is it not plainly repugnant that any one of these, or any combination of them, should exist unperceived?"
George Berkeley, "A Treatise Concerning the Principles of Human Knowledge"
The distance between your elbow and your hand varies from the time you are a child to the time you are an adult. Apparently the human mind is able to adapt to such a change in relationship between parts of the body. Thus your mind should be able to adapt to another 30 centimeters or so of increased length between your elbow and your hand. To accomplish this you may attach an extended mechanical arm with a mechanical hand to your arm. It must be some kind of construction which is securely fastened on your forearm, while your real hand is still able to move freely inside a spere in the extended arm. Detectors in a glove you are wearing determine the movements of your real hand and fingers and a computer controls the mechanical hand and fingers to make exactly the same movements. Furthermore, detectors all over the skin of the mechanical hand continuously measure at every spot the pressure, temperature, etc. The glove instantaneously recreates these signals at the corresponding spots on your real hand.
Since you have feeling in the mechanical hand and control it directly, after some time of adaptation you will actually feel your hand to be at the position of the mechanical hand. In order to reobtain hand coordination your brain is be forced to adapt to the mechanical hand as part or your body while awareness of your real hand disappears. And you will probably feel that part of your forearm is located at the position of your real hand.
I will describe a little experiment: I once took a picture of the view from my window and attached the picture to the window. In front of the window I set up a cylinder aimed at the photograph and then closed the curtain between the cylinder and the picture. I then invited a friend in and asked him to look through the cylinder. I opened the curtain and asked him what he saw. He described the view from my window. When I showed him what was attached to the window he was quite surprised to find he had been looking at a photograph instead of the "real" view. Subjects of this experiment told me they had perceived depth in the image. A street lamp seemed close by and a building appeared far in the distance.
Consider the following experiment: You are in a large room which you know well. There are several pieces of furniture, paintings and some other objects in the room. With a friend you agree on the names A,B,C and D for each of the corners of the room. Each of the corners is easily distinguishable from the others because of the characteristic arrangement of the objects in the room. When you walk around the room and then occasionally stop in a corner you are able to recognize immediately which corner you are in. While walking you are constantly oriented as to your location.
Now you ask your friend to blindfold you and to guide you as you walk. He does so and after a journey of a few minutes he tells you to stop. After announcing you are in one of the corners of the room, he asks you whether you are at A,B,C or D, but you have no idea where you are. Since you do not have an answer, your friend tells you to take off your blindfold. You do so and suddenly you can see the room. You recognize your viewpoint immediately and say to your friend whom you notice standing in front of you: "I am in corner C."
Suppose we build a room of which the walls, ceiling and floor consist of video or projection screens. You stand in the middle of the room on a all-directional conveyor belt. You are able to walk in all directions while you stay in the middle of the room. This is achieved by having sensors detect movements of your body. A computer controls the belt so that it constantly moves with the same speed and in an opposite direction to the one in which you walk.
A mile away on a street of the nearby town stands an installation on wheels with several TV cameras. The cameras together record the view from two eye points in all directions. That picture is simultaneously displayed on the videoscreens around you in the room. The screens display the left-eye and right-eye images with a different direction of polarization, while the polaroid glasses you are wearing separate the picture for each eye. This gives you depth perception. The cameras must have a long depth of focus. There is a two-way radio communication link between the installation and the room. Detectors measuring the position of your head are linked to computer-controlled servos to modify the position of the television cameras analogous to the movements of your head. Now, when you look around you see the image from the viewpoint of the robot a mile away. The robot also moves automatically in the same direction and with the same speed as you walk.
The robot has two microphones separated from each other by a distance corresponding to that between your ears. The left and right microphone make the same movements as your right and left ear. You hear the sound through your headphones. Moreover, a microphone in front of your mouth transmits your speech to the robot and can thus be heard by townspeople passing by through a loudspeaker between the two microphones of the robot.
Now we have created a system which allows you to walk through a town without your body actually being there. If the quality of the simulation is good enough there is nothing which ties you to the room you are in. You can only see the town. You have now escaped from the room which you no longer see. You really feel you are in the town. This phenomenon is called telepresence.
If you think that a spirit has a location like a physical object then you may conclude that your spirit has moved a mile away from your body. Your spirit resides in the robot. But you feel not only as if your spirit is in the town but also your body. You not only perceive the town but feel your body is in the town. Your body is visible to you because it is illuminated by the light coming off the TV or projection screens around you.
A friend of yours passes by. He asks you where you are. You say, "I am here right in front of you in this town." He laughs and says that all he sees is a strange installation with cameras and other things moving around. Now you remember. You turn around and in the distance you see the building where your body is located.
If you are standing still and very suddenly start to run you will feel you need little effort to do so. Your body does not seem to be inert. That is, of course, because in the room your body stays in the center and is not accelerated. The laws of Newton have been changed.
Now, if we are technically sophisticated we can also move your other senses to the town. We can create in the room the same temperature and dampness as in the village. We can make you feel the same wind which you would feel at the position of the robot. We could emulate the same smell. It will be difficult to enable you to climb stairs and mountains and give your feet the feeling that is evoked by walking through mud, but in theory it's all possible. We might give your robot body arms and fingers and build a system which permits you actually to feel objects and manipulate them. In theory we can make the system so sophisticated it is impossible for you to find out whether you are "really" in the town or not. If we want, we can also make your secondary body look like a human being.
If you want to experience the effect of such a good quality simulator, do the following: Go outside, walk around and at the same time imagine you are at your home in a room where a simulator has been set up.
One application of such system is, of course, transportation. No longer is it necessary to drive a car or sit in an airplane to go someplace. You can travel to any place in the world instantaneously. Whether you move your body to a different environment or the environment to your body is only a relative difference. If we feel sorry for a convicted murderer in jail we can give him the opportunity to walk around freely without danger to society.
Instead of projecting your view on the walls of the room you may wear a head-mounted monitor which projects the correct image into your eyes. Now, since you cannot see your body anymore you will find out what it feels like to be partly invisible (except for your robot body). Or, if your robot has arms then your arms may look like metal mechanical arms, even though they still feel normal.
We can perform more tricks if the imaging system is in a head- mounted monitor. We can put your robot body next to you in the same room. Now you can walk around your physical body and look at it. We program the belt on which your body stands to keep turning your body so that it faces the same direction. Otherwise as you walk around your body it would turn with you and you could not view it from all sides.
Or, you can hold in one hand a TV camera which records your vision and also the microphones which record your sound. Now you can discover what the world looks like from the viewpoint of your hand. Will you adapt and function well with such a translation of eyes and ears? Is it possible that you will start thinking your mind is in your hand instead of in your head?
We can accomplish much with the system, such as filtering out things we do not like in the environment. For instance, if you are a journalist you can safely go to a war zone to make a report. If you get shot it is only your robot that gets damaged. Of course the adventuresome person will still program his computer to shoot a bullet right next to his heart so that he just survives and has a great story to tell his friends. And how about arranging the system so that you can vary your hight from a centimeter to ten meters as you choose?
If you fear heights or death you can go hanggliding in the Alps without fear of a crash. But it might be more fun to create a system to permit you to fly through the air without any apparatus. We can program the computer to let you rise from the earth by moving your arms up and down like a bird. The robot which records your view could be attached to a helicopter, whereby the helicopter is controlled by the movements you make with your wings.
And how about having sex with your lover while your bed makes a journey from the middle of a busy marketplace to the sky above the Grand Canyon? Speaking of sex, I figure the ultimate test for the sophistication of our technology is to permit two people to make love to one another with their bodies a thousand miles apart.
How about sharing the same body with someone else? This can be achieved by having you use the same robot as your friend, together with the constraint that you can only make exactly the same movements as your friend. If your friend raises his arm with a certain force, your arm will be pulled up with the same force by some mechanism, and vice versa. Thus if you and your friend want to move a certain limb in opposite direction, whoever uses more force has his or her way. It will probably take you both a while before you can walk again, but it might be an amusing game and a good way to get to know each other well. You can communicate through speech, but faster communication may be possible in other ways, such as through subtle body movements. If you have the system display visually both of your EEG's (brain wave patterns), you may learn to communicate through brain waves.
Not only can we transport ourselves to other parts of this world but we can also move to worlds which we ourselves may design. Now we do not need the robot but a powerful computer. Furthermore we must develop complicated software. The computer constantly calculates the image from our viewpoint and feeds that image of the world to the videoscreens around us in the room. It also generates the sounds for us to hear and the signals for our other senses. Of course, the software is interactive with movements of our body and other things we do. An arcade game can realistically come to life like in the movie Tron . Today flight simulators are already quite successful in creating an artificial flight environment.
Controversial scientist Edward Fredkin has a theory that the universe is a computer. (See the article "Did the Universe Just Happen?" by Robert Wright in the April 1988 issue of The Atlantic Monthly .) Fredkin says that a universe (specifically the one we live in) must be discrete. The reason for this is that continuity supposedly cannot exist in nature because this would imply a finite volume in space would contain an infinite amount of information. Space cannot be truly continuous but must be quanticized, since if space were continuous then a particle could be at an infinite number of locations in a finite volume of space. And that is hard to imagine, since an infinite number of bits are required to hold the value of a variable with an infinite number of possible values.
Fredkin also believes that time is discrete, analogous with the clock of a computer. It is not clear whether this assumption corresponds with current theory. The notion that a space can only be in a finite number of states is partly in accordance with modern quantum theory. But the notion of discrete time does not correspond to the part of quantum theory that says the transition from one state to the other is controlled by continuous-time probability functions. Anyway, because the current computers work with one fixed clock frequency, a man-made universe at this point will indeed have discrete time as well as discrete other quantities.
An advantage of a world created by computer is that the law of conservation of energy (including mass) no longer holds. We can produce as many objects as we want without running out of energy or material. Now, if we create our own world with computers it need not necessarily be a world similar to the one we normally live in. We can change the laws of nature as we choose. What about a world in which you can walk through a brick wall or through another person's body?
We can create a world with only two dimensions of space. We can simply put our body between two adjacent walls and call that our two dimensional world, but that is trivial. The art is to design a world where all our body movements still have a function. We can, for example, use the ability of movement of our two arms in three dimensional space to design three or four corresponding arms for our two-dimensional counter body.
Creating a world with four dimensions of space is easier because we do not have to redesign our body. A three dimensional body can exist in a four dimensional space but not in a two dimensional space. Mathematically and with the computer it is perfectly possible to work with four dimensional position vectors, and we can formulate laws of nature in four space dimensions analogous to our three dimensional world. We have to design a logical interface between the four dimensional world and our senses. If we consider that with a two dimensional image in one eye we can perceive three dimensional space fairly well, then with two eyes and maybe some of our other senses we can perceive four dimensions of space. For our eyes it would probably be best to offer them three dimensions of space at a time, as we are used to. That three dimensional space could be, for instance, a mathematical projection of the four dimensional space, whereby we can somehow vary the direction of projection. An interesting question is how well our mind is able to adapt to a world with two or four dimensions of space. Is the human mind capable of acquiring a good four dimensional spatial insight?
The hardware needed for creating the signals for some of our senses (such as touch) is very complicated. We can, however, eliminate the hardware problem and change it to a software problem. We could simulate a world at the location where human perception actually is created: the brain. First we must analyze precisely how the sensory input is coded as input signals for the brain, and we must analyze how the brain output signals that control the body functions are coded. Now suppose we take a volunteer, open his skull and take out his brain. We destroy his body, he won't be needing it anymore. Now if we keep perfusing blood through the brain and are able to keep it alive then we connect electrodes to all the input and output locations of the brain, and we connect those electrodes to a powerful computer with the right kind of software. If our software can analyze exactly the brain output and give the brain the right kind of feedback signals, then the subject will feel just as normal as any other person and think his body is still complete. Our software simulates a world for the subject and he is able to walk around and do everything just the same as usual. It may be interesting to give a male subject a female body instead of the male one he was used to, or vice versa.
Now suppose we design a world in analogy with this one for new people to grow up in. Leaving ethical considerations aside for the sake of argument, suppose we breed or buy a bunch of babies. (According to a Newsweek report they sell for about $4,500 a piece in South Korea, $1,000 in Sri Lanka.) We put their brains in bottles and simulate a world for them as explained above. We let them all live in the same world so they can interact with each other normally. We also put some adults in the world to raise the babies. The adults can be connected to that world either with their bodies intact in a simulation room as explained before or alternately with their brains in a bottle.
Now the babies will grow up and have sex and get pregnant as normal people. The computer can simulate the baby that a woman delivers just as it simulates all the other things in their world. But to simulate a thinking human being is a very difficult software problem. We might circumvent that problem by giving the new child a real brain. We just take another baby from our world and put it's brain in a bottle and connect it to the other world.
We can, if we choose, give people perceptions which are unexplainable by their laws of physics, like sudden angel appearances or plane crashes under mysterious circumstances. Maybe we can induce telepathy by making certain connections between the brains in the bottles. In that case it will be impossible for the people to detect how the information is transported between their brains, since that transportation occurs in a different world outside of their reach.
Aside from car accidents and the like we can make the people die from natural causes like heart attacks and cancer just as in our world. But in that case we don't have to throw away the brain yet. We might create yet another world for the person that died and call that heaven or hell.
Now, like in any culture, the people in the world we created might wonder what their brains look like and how they work. So if a person in that world dies, then the others might open his skull and examine the contents. What they find depends only on the computer program we wrote to simulate their world. We might make them find a massive gold sphere, an Apple Macintosh or a structure of brain cells.
Email: henry@sturman.net