Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Posting-Version: version B 2.10.1exp 10/6/83; site hlexa.UUCP Path: utzoo!linus!decvax!harpo!eagle!mhuxi!houxm!ihnp4!hlexa!hsf From: hsf@hlexa.UUCP Newsgroups: net.books,net.philosophy,net.sf-lovers Subject: Time and Immortality (part 4) Message-ID: <374@hlexa.UUCP> Date: Mon, 24-Oct-83 17:52:34 EDT Article-I.D.: hlexa.374 Posted: Mon Oct 24 17:52:34 1983 Date-Received: Tue, 25-Oct-83 04:57:04 EDT Organization: AT&T Bell Laboratories, Short Hills, NJ Lines: 110 (c) Copyright 1983 by Henry Friedman (Copying for personal use by users of net is authorized.) The Arrow of Time As stated in Part 2, we are, as it were, three-dimensional creatures living in a four-dimensional world. We see the world changing, things moving, time flowing from present into future. Yet the new reality of spacetime suggests that such appearances are an illusion, that everything is "already there," statically arrayed in spacetime. Let's return to the motion picture analogy to help clarify these two opposing views of reality. Imagine that we have unrolled the reels of film from a long movie onto the floor of a gymnasium, laying the film in a spiral around the floor. Then, imagine that we have climbed onto a raised platform in the center of the gym, with a very powerful pair of binoculars, from where we can see all of the frames spread out before us. The movie frames can be compared to a portion of our universe, spread out in time. Since we can choose any single frame of our movie and call it "now," past and future on the film are merely relative directions, not specific sections of film. All frames in one direction from the frame we selected as "now" represent the past, and all the frames in the opposite direction along the strip represent the future. If we became disoriented and forgot which direction was which along the spiraling strip, we could easily verify it. We could use our binocu- lars to search for any type of event in the movie that would be nonreversible in everyday life. For example, if we saw in one frame that a character in the movie was in a swimming pool and, as we followed along the strip, he or she rose from the water and eventually landed on a diving board, we would know that we had been moving along the strip in a direction toward the past. If we picked a frame, examined it and then looked at another frame, far enough from the first, we would notice that peo- ple or things had *moved* or *changed*. However, if we then cut out several of such frames in which change was notice- able, placed them in front of us and looked at them all at once, nothing would really seem to be *moving* or *chang- ing*, in the everyday sense of time: everything would just be "already there," all at once. But if we were then to run a strip of the film through a movie projector and view it, the everyday sense of time would immediately return. People and things in our movie would again seem to be moving and changing and becoming in time. And time would *flow* again, as the point of time called the present continually became the past, and the future revealed itself as the present. And that is our everyday view of time: not a four- dimensional continuum, but merely a measure of the continual processes of change (relative to processes that appear *uni- form*, such as the rotation of the earth on its axis or around the sun, or the vibrations of atoms in a crystal). Gary Zukav ("The Dancing Wu Li Masters") compares our lim- ited, everyday view of time to viewing spacetime through a narrow slit in a piece of cardboard. It is if the cardboard were moving to reveal only the single moment of time that lay behind the slit. This is like our motion picture pass- ing in front of the projector aperture, one frame at a time. But why is this so? Why *are* we limited to seeing time as a flow of changes? Musn't the "arrow of time" be, after all, embedded in the fundamental reality of our universe? The philosopher of the "manifold" would agree that there is an arrow, as far as the aspect of *direction* is concerned, but not that the arrow *moves*. We know that time is not the same in all directions, as evidenced by the law of entropy (the diffusion of energy always increases) and by nonreversible causal processes. The probability is very low that a dynamited building will reconstruct itself or that all the molecules of perfume will ever return to the bottle. But the fact that time has direction does not require that it *flow*. In everyday reality, however, things move and change in time. So doesn't there have to be something unique about that ever-moving point of time that we call "now," the only point of time that we ever seem to experience? Adolf Gruenbaum addresses the above questions in his book "Philosophical Problems of Space and Time." Drawing upon the work of the philosopher H. Bergmann, he writes that the commonsense, everyday experience of time as a flow of events -- as distinct from the reality of a spacetime continuum -- is entirely a product of the consciousness of sentient organisms. He adds that the idea of "now" has no basis in reality apart from the significance imparted by such conscious experiences. In other words, it is not *time* that flows; rather, *conscious awareness* flows, as it were, through time, giving time the appearance of motion. Our conscious awareness serves as the motion picture projec- tor, if you will, that makes the film strips of time come to life -- that limits us to a three-dimensional view of reality. Our consciousness acts like the crest of a "vir- tual wave" of awareness moving through time. Of course, no mystical connotation is intended regarding mind or cons- ciousness: all of the various brain states and sensory information which underlie our consciousness must, also, be "already there," arrayed in spacetime. Our subjective experience is as if our conscious awareness rippled through these brain states in a serial order. (This chapter to be continued in part 5.)