Thinking that raking up leaves would be good exercise, I raised the big front door of the garage and went in. I dropped the rake with a clatter into the garden cart and backed out of the garage. As I was turning to go over to the south side of the front lawn – whump! – something walloped me on the back of my head.
I heard my neighbor, Jack, shout, “Good shot!”
I yelled, “All right! Who did that?” Behind me, when my eyes got reorganized, I spotted a white volleyball under shrubs along our driveway.
Jack and a sandy-haired man were eyeing me from the neighboring driveway beyond our fence. They looked a little concerned, but I could see that inside they were laughing about what had just happened.
Jack’s companion held up his hand and admitted apologetically, “It was me.”
“Sorry, John,” called Jack. “We didn’t mean to.” He grinned. “Michael isn’t that good a shot.”
From a hook at the side entrance of Jack’s house, a rope was stretched overhead across his driveway to the maple tree at our fence. Obviously Jack and his friend had been playing a sort of volleyball for two. Just as I appeared at the corner of our garage, Jack’s friend had spiked a wild one over the fence and it had smacked me on the head.
I came over to the fence.
Jack leaned his head toward his friend. “This is Michael Coventree. As you know, he’s an astrophysicist at the university. Michael, your victim is John Ross. He’s a writer.”
“Ah yes,” Michael nodded. “You’re the chap who’s writing about the mysteries of time. Marie told me about you. Said we should get together someday.” Then he chuckled. “I didn’t expect to make a hit with you right away though!”
“Well, you’ve already made me see stars,” I countered.
Jack moved toward some lawn chairs and waved. “Come on over, John. We need to cool down for a while.”
As I came around onto our neighbor’s lawn, Marie was bringing out lemonade, glasses and some big vanilla cookies. She looked at Michael and me and said, “I’m glad you two have finally met.”
“Thanks to his skill at volleyball,” I muttered, raising an audible smile all around.
When we were settled into the chairs and sipping, Michael spoke reflectively. “I understand you’d be interested in what I think about time. Well, if it weren’t for time, my colleagues and I would be out of business. Time is essential to both the speed of light and its frequency. We astronomers specify how far apart things are in space in terms of the time it would take for light to travel the distance between them – light-years. The frequencies which we detect in the spectrum of light from a star tell us a good deal about that star’s chemical makeup. Everything in physics involves time in one way or another. There’s a ‘t for time’ symbol in every dynamic equation. But none of us really knows what it means, other than numbers we can read off a clock. We probably should think more deeply about something so fundamental as time.”
Then he chuckled, “Sorry about that foul ball though. Obviously I’m not very good at estimating distances and directions for the balls I wallop here on Earth.”
“… or timing!” I muttered.
Jack offered an engineer’s explanation of what had happened. “Michael simply smacked the ball with a certain force at a certain angle which took it over the fence. But you stuck your head into its trajectory and so you got hit. Poor timing on your part, I’d say!”
“Surely you don’t think that the accident was my fault!” I exclaimed.
Michael chimed in. “Not entirely. You were hit by a rubber ball. But if somebody had not made that ball out of rubber and inflated it with air, it couldn’t have bumped you. If farmers had never grown food for me to eat, I wouldn’t have had energy to drive the ball over the fence. If that fence had been constructed two meters higher, the ball would not have cleared it. If Jack and I had been playing chess here, you wouldn’t have been hit by a volleyball. If it hadn’t been Saturday afternoon, Jack and I would have been at work instead of playing volleyball on his driveway. If…”
“Okay! Okay!” I interrupted. “So you volleyballers are practically innocent!” I protested. “You claim I got whumped because everything in the whole universe just happened to be the way it was at that particular moment and not some other way. Maybe next you’ll be saying that I got hit because that was the way the conditions at the beginning of the universe worked themselves out. So, no fault of yours, I was hit by history. Belatedly bashed by the Big Bang! That reasoning means that I can’t pin the blame on anybody or anything. Looking for the cause is useless. There ain’t no justice!”
Jack stabbed the air with his forefinger. “Just a minute, now, both of you. Nothing physical ever happens without a cause. If you apply a certain force to drive a certain mass in a certain direction, everything else keeping out of it, you can predict exactly what will happen. Cause-and-effect thinking really works. Balls don’t ever take off by themselves and fly through the air. They have to be projected by something or someone. Without a cause nothing would ever start moving, and if no moving ever took place there wouldn’t be any such thing as time.”
Jack continued: “Time, you must have noticed, always moves along in the same direction as cause-and-effect. Time is just a matter of succession – this thing happens first and then that thing happens next, and so on. Well, the connection between what takes place earlier and what follows later is just simply cause-and-effect. Is there any other way to explain the order in which things come about? Time is just the order of the happenings. What else is there about time that isn’t in ‘before and after’? Time is only cause-and-effect under a different name. Just accept that fact and you won’t be troubled any longer by what you are calling – so I hear – the ‘mysteries of time.’”
Michael was shaking his head. He was ready when Jack finished. “Jack,” he said, “you probably think of cause-and-effect in much the same way as you think of falling dominos. When a long row of them is standing upright not far behind one another and the first one in line is pushed over, it topples the next one. In falling, that one knocks over the next one and that one the next in succession until every domino in the line has fallen. So, in your way of thinking, what happens in one state of the world decides what happens in the next state of the world, and that determines the next, on and on. Right?”
Jack nodded. “Yup. And that’s the way it goes too with a train of gears.”
Michael continued with his argument. “When the first domino falls it starts a ‘causal chain’ that runs all the way through to the end of the whole line of dominos. Because the dominos are standing at some distance from each other, the motion that runs through the whole lot does take time. However at the precise moment when one falling domino makes actual contact with the next, no more distance has to be moved through. Two dominos which are touching each other obviously must be coexisting at the same instant, so when they first come into immediate contact, no ‘before and after’ relation is occurring between the two. As the first domino continues to fall, however, it will be sliding down the length of the one which is falling behind it, making new momentary contacts. But it is gravity that keeps the dominos falling, not the contacts. Time enters the causal chain mostly while domino after domino is falling through the distance that separates it from the next one and approaching its final prone position.”
I interrupted. “If the essential thing about causal interaction – the actual contact – involves no time at all, that’s like when I touch my thumb and finger, I feel the contact simultaneously in both of them.”
Michael ignored that and continued. “The toppling action between dominos can proceed only when the dominos have been placed close enough to each other so that if one should fall another will get hit. Time is clearly involved in the creative process of setting up dominos in such a way that each will contact a successor when it falls a certain distance. To keep the causal sequence moving along, each domino has to be within reach of the one which is falling toward it. In other words, each domino has to be in the right place at the right time. A falling domino won’t have any effect at all on dominos that aren’t there in the line because they haven’t been put there yet. A falling domino won’t knock over one that is still in the box or lost or hasn’t even been manufactured yet. Time is elapsing during the fall of each domino, but the falling period is much more than the contact between pairs.”
Jack was frowning quizzically, but Michael was on a roll. “Lots of movements take place which were not started by any actual impact. If John had seen that volleyball coming, he would have ducked before the ball could make contact with his head. Even if it is never actually delivered, a punch aimed at your belly can make you flinch.
“Earth keeps rotating every twenty-four hours and orbiting the sun every year, even though nothing is pushing it from behind. The standard units of time for our clocks and calendars – days and years – are set by those movements which don’t depend at all on a succession of causal impacts.
“As you know, for sound to be transmitted, vibrations must push and pull molecules of air or some other substance, bumping one thing into another on and on. But light and other forms of electromagnetic radiation can travel quite easily through a vacuum where there’s nothing whatever to bump into which will then bump into anything else.
“And, as you also know, events that come after other events are not necessarily caused by the previous events. Each day follows a night, but nobody ever says that the night is what causes the next day or that any one of Earth’s daily rotations is what causes the next one.”
Jack quickly spoke up. “Nobody knows for sure what or who caused the earth to start spinning and orbiting, but I’m dead sure that it will keep right on spinning and orbiting until friction causes it to slow down or some massive impact causes it to swerve.”
Michael couldn’t argue with that. He nodded, but went on: “In science we seem to pay attention mostly to what it takes to start something moving or to change its speed or direction, and don’t ask why things keep on going after we’ve sent them off. We don’t really know what causes a thing in motion to resist being slowed or stopped or changed in direction. To avoid facing up to our utter ignorance about such phenomena we look wise and invent labels like ‘mass’ and ‘inertia.’ We don’t consider it strange that when we apply a force to push something, simultaneously, automatically and mysteriously an opposing force will crop up and push back. If we pull on something, a counter-force which we neither intended nor created will arise immediately and pull back against us. If we try to change the direction in which a body is moving, or to change its speed, for some unknown reason it will resist our efforts. Apparently we have given up trying to find out what causes these remarkable reactions to emerge.”
I was fascinated by what Michael was saying. Jack too was all ears, especially when Michael said next: “We scientists talk glibly about the unchanging ‘laws of nature.’ Yet nobody knows what caused these ‘laws,’ what keeps them from changing or what is enforcing them. A law is actually only a description of the way things always go. By itself a law does absolutely nothing.
“A ‘natural law’ simply states that whenever you come upon a certain kind of interaction, you will find a certain set of interrelationships. Notice that time is taken for granted in the ‘whenever’ and also in the future tense, ‘will find.’ Natural laws are omnitemporal – they assume that similar things everywhere will behave similarly under similar conditions at all times.”
I was astonished when he went on to say, “Quite possibly it is the universal agency of time which enforces the laws which govern all physical changing. In whatever happens, time is involved. If we’re looking for causes, why won’t we ever say, ‘Time did it’?”
Pouring himself a refill of lemonade, Jack protested, “You’ve got to be pulling my leg! Everybody knows that time by itself never does anything whatsoever. Time is always the same – uniform, featureless and completely neutral. An hour of time today is the same as any hour years from now. You physicists believe that an experiment which you perform today will produce the same results if someone else should perform the same experiment under the same conditions ten years from now. The date of the experimenting doesn’t matter a hoot. Time by itself doesn’t start anything. It doesn’t end anything. Time causes nothing.”
Michael had a ready reply. “Will the rubber in your volleyball, Jack, be as bouncy ten years from now as it is today? Rubber ages. It will have become brittle and crumbly. We three used to be young, but you know as well as I do that aging is reducing our strength; it’s slowing our faculties and changing our features. The fabric in these chairs is aging. And you engineers know that after some time under constant strain even metal gets fatigued. Time by itself really does things. Right now it is cooling down our coffee. Eventually it will cool down everything that’s hot. Left alone, with time, radioactive atoms radiate and decay unpredictably for no known reason or cause. So, Jack, I’m not as sure as you are that time is only a nonparticipating bystander while material causes are energetically pushing, pulling and changing the world.”
I was sitting there open-mouthed. Here was a highly respected scientist suggesting that time itself is an active agent in the ongoing transformation of the world. That sounded a little like my childhood notion that Time is a powerful personal presence capable of threatening the destiny of everybody and everything.
Just then, I remembered a smart saying which I once saw on a poster: “Time keeps everything that can happen from happening all at once.” Michael had just mentioned time’s destructive activity, so I added, “But time doesn’t just drag things down. At least it does something that’s positive. It keeps everything that can happen from happening all at once! Time strings events out in an orderly way so they don’t tumble around us in senseless confusion.”
Jack passed the cookies. I took advantage of the lull to contribute another thought. “There’s something that neither of you has mentioned: the lastingness of material things. In Egypt those ancient pyramids are still standing. Last night, Jack, you put your truck in the garage there. If you went over and opened the door you’d be surprised if it wasn’t in there still. You’d be plenty upset if signatures on contracts didn’t last. Lasting is a matter of time. What doesn’t continue to exist for a discernible length of time isn’t counted as a real thing. But why do material things persist? What causal contact makes that fence retain its original form for so long?”
Jack explained, “The fence remains the same because there is nothing to stop its molecules doing what they’re doing. There is nothing to stop their atoms from running through the same patterns of orbits and vibrations again and again. That’s like the reason Earth keeps revolving around the sun in much the same pattern year after year: empty space.”
What seemed a brilliant thought occurred to me. “If things like your fence, Jack, are shielded from the elements, termites, rot, fire and such, they will persist in being what they are and staying where they are because nothing but time is acting in or on them. Maybe time itself is what is sustaining them, keeping them in existence much as they are. Hey! That may be an exciting approach to a longtime physical mystery.”
Michael heard me, but his mind was still dealing with what Jack had said about cause-and-effect being all there is to time. He was eager to break in. “I’ve just thought of something else. If I were standing here holding a very heavy stone, motionwise nothing much would appear to be happening. But all the while my muscles would be straining to keep from dropping that rock. My arms and back would certainly be feeling my effort to maintain the deadlock between me and gravity. When forces are balanced and nothing is moving, nobody looks for what maintains the standoff. When things are in equilibrium, no causes are visibly operating, yet time keeps operating just the same.
“When a loaded vehicle stops on a bridge, in spite of the stresses and strains the structure won’t sag very far. Nothing much about the bridge will appear to be changing, yet time will still keep going on.
“During a whole night the wound-up spring of my old alarm clock will remain utterly motionless, all tensed up in its coil. No causal transaction takes place until the alarm-set catch releases the spring and activates the bell-ringer. All through my clock’s motionless but tension-filled hours of night, time was going on as usual. ‘Balance of forces’ situations like these tell me that causation is definitely not the same thing as time.”
Jack shook his head. “Michael,” he said, “you’re a hard guy to argue with. Anyway, I know for sure that before I can do certain things, certain other things have to happen. I can’t truck logs off a mountain before a road has been built. I can’t start the truck unless a good battery has been put under the hood. I can’t build anything until I have the building materials on site. You know right well what I’m saying: causes come before effects.”
I had a sudden thought. “Jack, you just said that if something is absent at the time you need it, you’re helpless. Is the absence of something also a cause? I gather from what you just said that a lack of contact between supplies and the building site can delay the progress of a project as much as an accidental causal contact – say, a truck backing into scaffolding and collapsing it. Having workers sick or hanging around doing nothing can set back your project. But that’s not the kind of thing you would ordinarily call a ‘cause.’ Time keeps going on, even if the materials haven’t arrived. While productive work is not getting done, the mere passing of time is eating up your bank balance.”
“You’ve got that right,” Jack admitted. “When I take on a construction project, everything has to happen at the right time and in the right order. I study the blueprints and arrange a workable schedule for the delivery of materials and the trades. Weather permitting, if everything goes according to plan, I know I can put up a proposed structure in a predictable length of time. That goes into the contract.”
I picked up the thread of what Jack had just said. “The planning process takes up a lot of your available time. If you didn’t have enough time, you probably wouldn’t come up with the creative ideas you need. Your ideas turn into blueprints, the delivery schedules and the directing of operations. Without your ideas the structure wouldn’t get built your way. Tell me: how is it that, without physical contact occurring, your flimsy, immaterial ideas can exert such effective causal power over massive materials – concrete, steel, glass and workers? It would seem that time has something causal to do with both the originating of your ideas and the progress of your building.”
“I don’t know about that,” Jack replied, “but I do know that time is mighty important to me. As I said, building materials have to be delivered at the right time, so that the various trades can do their thing. If tradespeople have to stand around waiting to start their task, or keep getting in each other’s way, the delays put the project’s completion time in jeopardy. If the framing isn’t finished, if the plumbing, wiring, and heating ducts have not been installed in the right order, work may have to be undone and redone. Whether ideas are causes or not, I know that a project is in trouble if the work doesn’t follow the plans I draw up.”
He paused for a moment. “Discussing causes and time may be fun for you two, but for me time is money, and money provides me with my living. You guys can speculate all you want about what part time plays in the world, but I know for sure that it’s my use of time that makes me my living.”
“Ah yes – ‘living’.” said Michael, brightening. “That reminds me of something I should have mentioned earlier. Living beings are composed of interacting systems. Each of those systems depends on others. As my heart beats, it circulates blood that brings nutrients from my digestion and oxygen from my lungs to supply all parts of my body, including the muscles of my heart itself. My arm puts food in my mouth, starting it on its way through my digestive system. From that system come the nutrients which in turn sustain not only the muscles that work my heart and lungs but also those that move my arm. My life depends on the completing of all these circuits: from my arm back to my arm and from my heart back to my heart.
“Now which component of any of these circular systems would you say causes my life to keep going: heart? arteries? muscles? throat? stomach? bowels? liver? lungs? veins? No one particular organ in any of the circuits can properly be called the single cause that keeps me alive and functioning. All of my vital organs and systems are participating.
“Systems behave like an old social stunt that we used to pull off once in a while. People are asked to stand around in a circle, each one standing closely behind the person ahead. When the circle is complete, everyone is told to sit down on signal. Each person should then be sitting on the lap of the person behind. Should be fun. They sit down relying on there being a trustworthy lap behind for support. But if someone cheats and steps out of the circle, the person ahead will land on the floor. Everyone up ahead all around the circle will also fall – not knocked down by contacts, like falling dominos, but due to the absence of the support on which they were counting.”
Just then Marie appeared and called Jack to the phone.
He left quickly and I grinned a little smugly. “I wonder if Jack’s causal theory could explain how the tiny bit of energy transmitted to him by his wife’s voice from the direction of the house was able to move his body so quickly in the opposite direction, from here over to the house. Do you know of any physical principle that explains the causal power of human desires, love or authority…?” I hesitated, then added with a smile, “… or the causal power of time?”
Michael smiled back and added, “Or the attractive power of beauty, truth and goodness.” Both of us were silent for a while – reflecting on the conversation. Then I said sincerely, “Michael, I’m really glad to have met you. Not only are you, I think, a kindred spirit, but you’ve started me thinking in new ways about time.”