Future Stories

CHAPTER 1

What Is the Future?

Time as a River and Time as a Map

What is the future? The answer ought to be simple. After all, we live in time. So isn’t the future just that part of time that hasn’t happened yet?

The trouble is that once you start thinking hard about these questions, things get tricky very fast. There is not even a consensus about what the future is within modern futures studies. As Jim Dator writes, “‘Time’ and ‘The Future’ would seem to be two of the most central concepts for Futures studies, but in fact, ‘time’ was barely discussed by the founders of Futures studies, and has seldom been problematized subsequently.”²

No wonder! Thinking about the future can make your brain hurt. The philosophy of time leads us into a scholarly jungle full of beautiful ideas, metaphysical thickets, and philosophical creepy-crawlies. I will try not to go too deep. But we have to venture in far enough to see the problems that gather, like lianas, around the ideas of time and the future.

To understand the future we need to understand time, but does time even exist? Or is the word just our name for a sort of conceptual ghost? In the humanities, some scholars prefer vaguer words such as temporalities, which can probably be translated as “experiences of temporal change.”³ Even modern science offers no complete answers. It’s as if no one lives long enough to really get to grips with time. As Hector Berlioz (may have) said, “Time is a great teacher, but unfortunately it kills all its pupils.”⁴ Study time too much and, like the eleventh-century Persian astronomer and poet Omar Khayyám, you’ll start to feel you’re spinning like a Sufi dancer.

In Milton’s Paradise Lost, even Satan’s followers can’t make sense of time.

St. Augustine thought deeply about time as he searched for God’s purpose. In the marvelous book 11 of his Confessions, which remains a fundamental text on time, Augustine asks: “What is time? Who can explain this easily and briefly?” Though he was a deep and subtle thinker, the problem of time always seemed to slip from his grasp. “What then is Time? Provided that no one asks me, I know. If I want to explain it to an inquirer, I do not know.” So frustrated was Augustine that he begged God for help: “My mind is on fire to solve this very intricate enigma. Do not shut the door, Lord my God. Good Father, through Christ, I beg you, do not shut the door on my longing to understand these things which are both familiar and obscure.” As the philosopher Jenann Ismael writes, “There is such a thing as too much deliberation.”⁷

Two Approaches to Time

The problem of time has engaged philosophers, sages, farmers, shamans, theologians, logicians, anthropologists, biologists, mathematicians, physicists, gamblers, prophets, scientists, statisticians, poets, and soothsayers, as well as everyone worried about their own future and the futures of those close to them. Modern philosophers of time distinguish between two main approaches with very different implications for our understanding of the future.⁸ Both are foreshadowed in ancient philosophical traditions. Heraclitus (fl. ca. 535–475 BCE) imagined a world of never-ending change. That meant that the future would be different from the past. His near contemporary, Parmenides, thought change was an illusion, so that past, present, and future should be much the same. Many philosophical and theological traditions have struggled with the relationship between permanence and change. The ancient Indian texts known as the Upanishads insist that there is “an inner core or soul (atman), immutable and identical amidst an outer region of impermanence and change.” In many Buddhist traditions, though, “There is no inner and immutable core in things; everything is in flux.”⁹

The first of our two metaphors follows Heraclitus. It sees time as a sort of flow, like a river, that carries us through never-ending changes. In this view, the future will be different from the past and hard to know. This is how we usually experience time in our everyday lives, so this metaphor feels natural for most of us today. This sort of time is like the turbulent world of ups and downs, joy and grief, birth and death, that some Indian traditions describe as samsara.

On the other side are those who argue that our sense of flow and change is a seductive illusion. “Real time,” as a philosopher of time, the late D. H. Mellor, calls it, does not flow.¹⁰ It is more like a map than a river. This approach is like a god’s view of time, a view from above. From this perspective, change no longer looks like something that happens but more like the difference between two points on a map as experienced by an ant crawling between them. Our sense that the future is different from the past arises, in this view, from our own motion, not from the supposed flow of time. In this view, there is little difference between past and future, and in some sense the future should be knowable because it is already mapped. The idea that permanence lies beneath the superficial changes of everyday life may once have shaped most people’s thinking about time, as I will argue in chapter 5. But in today’s rapidly changing world, it is taken most seriously by philosophers and scientists worried by the logical puzzles thrown up by the idea of time as a flow, puzzles we will look at later in this chapter.

One metaphor implies that we are embedded in time, the other that we can perhaps stand above time. A recent survey of the philosophy of time refers to these two approaches as “dynamic” and “static” time. But philosophers often refer to them, in deference to a famous 1908 article by British philosopher J. Ellis McTaggart, as A-series time and B-series time.¹¹ This is jargon, but the jargon is used so widely by philosophers of time that it is worth getting used to.

In practice, there is much overlap between the two metaphors. Even McTaggart, who saw time as an illusion, agreed that “we never observe time except as forming both these series.”¹² We find a mash-up of these metaphors in one of the most famous definitions of time, that of Sir Isaac Newton. In Principia Mathematica, the most important work of the scientific revolution, Newton writes, “Absolute, true, and mathematical time, for itself, and from its own nature flows equably without regard to anything external, and by another name is called duration.”¹³ Newton’s time “flows” like a river, but it is also “absolute,” and it has extension, or “duration,” like a line on a map.

Time as a River: The Future in A-Series Time

To make the metaphor of time as a river less abstract, let’s join Mark Twain’s young hero Huckleberry Finn and his friend Jim as they raft down the Mississippi:

The flow of A-series time is as majestic as the Mississippi. It carries the flotsam of an entire universe, every star and galaxy, every atom and bug, into the future, just as the Mississippi carries rafts, fishing boats, canoes, yachts, paddle steamers, and driftwood. Our lives are part of that flow.

Huckleberry Finn and Jim live in a dynamic, ever-changing, Heraclitean world as their raft carries them into the future. Though some things seem similar, like the towns they pass each night, the details keep changing. Philosophers use the technical term passage to describe this feeling of never-ending change. The Rubaiyat, in Edward Fitzgerald’s beautiful nineteenth-century translations of Omar Khayyám, captures the sense of passage:

The second thing we learn from the metaphor of time as a river is that the future lies in a particular direction. The raft carries its passengers downstream from their starting point in St. Petersburg, Missouri (Twain was probably thinking of his hometown, Hannibal). The future lies downstream, or ahead of us; or below us if, like many Mandarin speakers, you think of the past as up and the future as down; or behind us if, like many Australian Aboriginal communities and native Hawaiian speakers, you think of the future as behind your back.¹⁶ Wherever it lurks, the future is in a different direction from the past.

The third thing we learn is that the future is hidden. At best we see a sort of fog, without the glittering details, the scents and colors, that give the past and present their iridescence. Huckleberry Finn can remember in the past “borrowing” a mushmelon or “lifting” a chicken that “warn’t roosting comfortable.” The present is fleeting, like the occasional “low chuckle” in the night. But while it’s here, it is more real than anything. Only now can we feel the wind on our cheeks, or the pulse of a great river, or the heft of a “borrowed” watermelon, or the smell of a wood fire. So intense is our experience of the present that some philosophers (“presentists”) argue it is the only reality. I remember hearing an English Buddhist monk, Ariyasilo, reminding us, “The past is gone. The future isn’t here yet. Listen to the birds!”

In A-series time, past and future are very different. Figure 1.1 (on the following page) captures some of the differences. It was prepared by the Bank of England in 2013 to illustrate predictions about inflation. Sections before 2013 describe the past. They are based on detailed information and form a single line. After 2013, details vanish, and data points fan out into a misty cone of possibilities that is soon too wide to tell us anything useful. Just three years into the future, the Bank of England could only make the unhelpful prediction that 90 percent of likely outcomes fell within a range from a 0.5 percent decline in prices to a rise of almost 4.5 percent. Though separated only by the diaphanous veil of the now, past and future are very different in A-series time.

Particularly mysterious is the moment when past and future meet. As we raft downstream, it is as if we are approaching a ghostly supradimensional fleet of possible futures. But as they draw nearer, more and more of those possible futures pop into nothingness until, just as we reach them, the fog disperses and only one is left. The surviving future becomes a dazzling present before slipping into the past.

This is a bit like the strange process known to quantum physicists as the collapse of the wave function. The many possible positions and motions of millions of subatomic particles can be described mathematically by a probabilistic wave function that looks a bit like the Bank of England’s predictions of future inflation rates. But if you measure the system, all the possibilities suddenly collapse into a single, detectable state, like the bank’s descriptions of inflation rates in the past. In A-series time, possible futures seem to collapse in a similar way as they reach us. Where did those other futures go? Did they ever really exist?

We can summarize the main features of A-series time in a type of diagram that we will return to several times in this book: a future cone.¹⁷ To get an idea of the general shape of future cones, go back to Figure 1.1, which showed the Bank of England’s predictions about future interest rates. Tidy the shape up, rotate it ninety degrees counterclockwise, and you have a diagram that includes the past and the future. It looks a bit like a cocktail glass because all our evidence suggests there is only one past, so the past appears as a single line while the future flares out into a cone with many possibilities.

Time as a Map: The Future in B-Series Time

A-series thinking about the future feels right to most people in today’s world. But that was not always true. Philosophers of time, and traditional religions, know of a second type of time, which looks more like a map than a river. This is time as seen by the gods. McTaggart called this B-series time.

B-series time is simpler and more streamlined than A-series time. Past, present, and future are not so different from one another; they are just regions on a map. “Now” is where you happen to be at this moment, and the future is off to one side of your present position. Another observer will define present, past, and future differently, just as an observer in New York will imagine the West differently from an observer in Moscow. Here is a diagram capturing some features of B-series time. The first thing you may notice is that there is no cone! This diagram looks more like a worm than a cocktail glass.

Look at a to-do list or a school timetable and you are looking at the temporal equivalent of a map. Dentist, 9:45. Meeting, 11:30. Dinner with friends, 6:30. The schedule describes a temporal landscape within which future and past are just different places. And of course the metaphor of a map also suggests that the future is knowable: at 6:30 I will be meeting my friends.

B-series time adopts what Huw Price calls the “View from Nowhen,” in which all moments are equal.¹⁸ This is the view from above a map. Imagine flying high above the Mississippi and spotting Huckleberry Finn and Jim on their raft. Unlike them, you won’t feel the chop of the current, but you can see where they have come from and where they are going. For you, different parts of their journey exist in a single space. If we could fly high enough, we might even imagine a map of everything that ever has existed or will exist in the universe. The coordinates of this universal map reach across all of space and time from the deepest past to the remotest future. Eventually, we are seeing a vast, frozen lump of all events and happenings and lives and deaths, the strange four-dimensional entity that the philosopher William James called the “block-universe.” Einstein would call it the “space-time continuum.” The block-universe is full of objects and events. The present moment is not that special because, as William James put it, “every event, irrespective of when it occurs, is fully and equally real, in the same way that events occurring at different spatial locations are fully and equally real.”¹⁹ Though he didn’t have the modern jargon, St. Augustine seems to have believed that God saw a block-universe: “In the eternal, nothing is transient, but the whole is present.” Or, as the philosopher Simon Blackburn puts it, “All events, past, present and future, exist like flies in amber, with greater or lesser distances between them.”²⁰

In the block-universe we shouldn’t grieve for the dead or worry about the future. Albert Einstein captured this feeling in a letter of condolence to the family of his old friend Michele Besso: “He has departed from this strange world a little ahead of me. That means nothing. For us believing physicists, the distinction between past, present and future is only a stubborn illusion.”²¹ The alien Tralfamadorians of Kurt Vonnegut’s Slaughterhouse Five would have sympathized. They live in four dimensions so that, for them, no one dies because “all moments, past, present, and future, always have existed, always will exist.” Similar views of time can be found within many philosophical and religious traditions. The thirteenth-century Japanese Zen monk Dogen writes, “Life is a position of time. Death is a position of time. They are like winter and spring, and in Buddhism we do not consider that winter becomes spring, or that spring becomes summer.”²²

B-series time has other odd features. With no definite “now” to anchor our images of reality, we have to think of everything as extended in time as well as in space, so we have to take more seriously the idea of time as a fourth dimension. That means that as I look down on Huck Finn and Jim, they may appear not as moving dots but as wormlike lines running down the river Mississippi. Kurt Vonnegut’s Tralfamadorians see human beings as huge millipedes, “with babies’ legs at one end and old people’s legs at the other.” The metaphor of a map also threatens our sense that change can occur in only one direction, from past to future. On a map you can move in all directions, so why not move back in time as well as forward?

Many philosophers and scientists are willing to live with the eccentricities of B-series time because A-series time seems to generate even more philosophical and logical conundrums. Take the idea of now, the moment that separates past from future. In B-series time, now is not special. It’s just where/when you happen to be. But in A-series time, now is a special place that really is different from past and future. So shouldn’t we be able to draw a line around now? How long does now last? Augustine argued that “the present occupies no space.”²³ That idea leads to paradoxes that the Greek philosophers knew well. How can something happen if there is no time for it to happen in? The philosopher Zeno (495–425 BCE) invited us to think of an arrow in flight. In an infinitely small moment, it cannot cover any distance. So it must be at rest. Ditto for the next moment and the one before it. Therefore, the arrow cannot be moving. The idea of an infinitely small now doesn’t seem to work philosophically or intuitively.

But what if now is not infinitely small? Perhaps time, like matter and energy, is granular. Does that get us off the hook? Perhaps there is a smallest possible atom of time, a chronon. Perhaps a chronon is the time light takes to cross the smallest possible length in space: about 10^–35 meters long. Of course, our inner experience of now cannot possibly be that small. William James called the psychological now “the specious present.” It probably lasts two or three seconds, as the mind organizes multiple sensations into a single picture of now, because our perceptions depend on neurological processes that edit and link information from many sensors and processors, interpolate where data is missing, and take time to do it all.²⁴ As we experience it, the border between now and the future is a blur of impressions, images, thoughts, and sounds. But if the present is not infinitely small, then some of it must stick into the future and some into the past like a temporal cocktail stick. Doesn’t that make nonsense of the idea that future, present, and past are different? B-series time avoids these paradoxes because it doesn’t treat now as special.

St. Augustine raised another difficulty with A-series time. Where are the past and future when we are in the present, as we always are in A-series time? “Do [they] exist,” he asked, “in the sense that, when the present emerges from the Future, Time comes out of some secret store, and then recedes into some secret place when the past comes out of the present?”²⁵ We never actually experience alternative futures. We only ever meet a single future, and by the time it arrives it has turned into the present. So in what sense do alternative futures exist before we meet just one member of the delegation? Did the delegation ever exist? In B-series time, futures are just places on a map so these problems do not arise.

And here’s another problem that takes us very deep. If time flows, how fast does it flow? Huckleberry Finn timed the Mississippi’s flow past its banks at four miles an hour (6.4 kilometers per hour). Can we time time? Only if we know what it is flowing past. Newton understood the difficulty and tried to solve it by distinguishing absolute time, which he saw as an ultimate framework, like the banks of the Mississippi, from relative time. Newton explained the idea of absolute time by turning to theology, a subject he thought about as deeply as physics. He argued that God’s universal presence provides the ultimate grid for space and time. Though he later retracted the idea, he once described the universe, in a revealing metaphor, as “the Sensorium of a Being incorporeal, living and intelligent.”²⁶

In the secular world of modern science, theological solutions no longer work. Nineteenth-century scientists tried to replace Newton’s idea of God as the ultimate grid of reality with the concept of an “ether,” a gossamer-thin medium through which all energy and matter traveled, and against which you could measure their speed. There were many attempts to detect the ether, but none succeeded. The most famous attempt was the Michelson-Morley experiment, conducted in 1887. This assumed that the speed of light ought to be slower when traveling against or across the ether, so there ought to be a difference in the speed of two light beams that travel at ninety degrees to each other. But no difference could be detected. That left advocates of A-series time with a flow from past to future, but nothing against which the flow could be measured. In chapter 2, we will look at Einstein’s revolutionary solution to this puzzle.

Determinism, Causation, and the Arrow of Time

B-series time avoids the paradoxes of A-series time, but it also raises two profound problems for future thinking. First, the idea of a block-universe can be interpreted to mean that the future is all stitched up, so there are no choices to be made. That seems to be the end of free will, ethics, and morality. Second, in B-series time, change seems to have no clear direction. That is a big problem for future thinking because it deprives us of one of the most powerful ways of forecasting the future: the idea that if A causes B, then when A happens, we can predict B in the near future. Kick a ball now, and I predict it will move in the near future. These questions about determinism and causation threaten fundamental assumptions about how to cope with the future. That’s a high price to pay for the simplicity of B-series time.

Fortunately, there are good answers to these questions that preserve our intuitive sense that (1) we can shape the future because it is not completely predetermined by the past, and (2) causes precede effects because many forms of change occur only in one direction: from past to future.