on an itinerant fisherman’s wrist horrified them.
As time technology grew nimbler, so did temporal thinking. It could be on a galactic scale; Albert Einstein theorized that billion-year-old collisions between black holes would be detected in waves of energy that continue to ripple across the universe, a prediction finally confirmed in 2016. Einstein also claimed correctly that time slows if you move fast enough (accelerating clocks grow heavier). Put an atomic clock, which keeps time by means of caesium electrons, losing one second in thirty million years, on a GPS satellite, which orbits earth at 18,000 mph, and sure enough, it loses 38 microseconds a day, requiring special electronics to recalculate its positioning. Thanks to such awesome precision, we can build targeted missiles and little gadgets capable of traversing chasms of space, landing on speeding comets and burying their noses in faraway planets’ secrets.
Computers and digital faces replaced the soothing flow of revolving arms with numbers, giving time a staccato beat – an apt prelude to the disruptions ahead, when smartphones would become our favourite means of telling time. Yet to some amazement, the watch is not dead. Luxury sales soar. The Rolex, Hublot or diving watch, equally true on the seabed or atop Everest, sits like a jewel on its owner’s wrist – perhaps, if he is a man, his only jewel. It is there less to indicate that its wearer is manacled to a schedule (even if this is how he is able to afford it) than to imply enduring success – the same message issued by Elizabeth I’s rhinoceros clock in Whitehall. Canny manufacturers market these beauties as heirlooms-in-waiting: a signal of your grip on time. This is in marked contrast to today’s other horological success story, Apple’s smartwatch, which does not passively purvey temporal information. No, it is a nagging device, buzzing like a wasp to alert its owner to an appointment or to that dire emergency, the arrival of another email – rupturing the user’s attention while ostensibly micromanaging her time.
We have travelled far from event time, which patterned our forefathers’ days according to the occasions that mattered, to a strange new, non-event time, which continually interrupts our flow. The smartwatch reminds me of that disquieting truth: whoever controls time also controls people.
Does this version of time work for you? Or does it make you its slave?
2. Our fictional units of time
In 1914, as the world geared up for the Great War, an inquisitive seven-year-old began dissecting her new favourite toy, an alarm clock. She wanted to see this peculiar thing, time. Seven alarm clocks died grisly deaths before her mother cottoned on to what was happening and gave her one device on which to experiment.
Grace Brewster Murray Hopper never found what she was looking for. Instead she became a mathematician, joining the US Navy in the next world war to help devise a computer. When hostilities ended in 1945, the Navy said that at thirty-eight she was too old to join the regular force, so off she went to devise the first programming language using solely English words, flooring sceptics who imagined computers could only do arithmetic. The Navy soon took her back.
Rear Admiral Hopper was reluctantly demobbed at seventy-nine, two decades after the regular date. By then she was known as Amazing Grace, having popularized the term ‘debugging’ after fishing a dead moth from a computer’s innards. But she is best remembered for her post-retirement lectures. One day, fed up with being asked why satellite signals were so slow, she chopped a telephone cable into 11.8-inch lengths. This, she explained, doling them out to her audience, is the distance light travels in a nanosecond (a billionth of a second). Yes, even lightning speed takes time.
Hopper stretched the limits of her era, ignoring rules and feminine expectations in order to prolong her career, as well as to turn computers into fatally word-friendly devices. Yet even one as resourceful as she could not locate time either within or outside an alarm clock, for the reason that time does not exist. Our units for measuring it – millennia, centuries, years, months, weeks, days, hours, minutes – are also fictional. A nanosecond seems solid enough when you flop it about in a length of copper cable, but is no less arbitrary a way to measure our progress through the fourth dimension of existence than the gold stars on the badge of a McDonald’s trainee, marking his rise from novice to expert burger flipper. The crucial feature of seconds and years is their regular arrival (unlike McDonald’s stars).
All units of measurement are belief systems created to organize facts. Universality bestows a veneer of objectivity, yet these units are no less subjective than the yard, which was introduced by Henry I, ruthless fourth son of William the Conqueror, who outmanoeuvred his brothers, standardized measures and restored England’s coinage. His yardstick? The distance from his thumb to his nose. Similarly, calendars are the legacies of quarrels between astronomers, theologians and monarchs. Although most of us follow the solar year (identified by sixteenth-century Polish astronomer Nicolaus Copernicus as approximately 365 days, 5 hours, 48 minutes and 45 seconds), the Christian, Islamic and Chinese religious festivals stick with lunar months, just like our oldest calendar in the Lascaux cave.
In AD 398 St Augustine of Hippo queried the validity of such celestial yardsticks:
I heard from a learned man that the motions of the sun, moon, and stars constituted time, and I assented not. Why should not rather the motions of all bodies be time? What if the lights of heaven should cease, and a potter’s wheel run round, would there be no time by which we might measure those revolutions?
And it turns out that not even the sky is reliable. As life accelerates, the planet’s solar orbit is slowing by fractions of a second each year. Blame gales in our mountains, which cause the earth to jiggle on its axis, and the friction of tides, which drag the earth’s rotation by 2.3 metres per second, per day, every hundred years (an effect partially masked by a glacial rebound, since the last Ice Age, of land once trapped beneath continental ice sheets, which speeds earth’s rotation by 0.6 metres per second per day). This slowdown maddens the engineers who nurse the atomic clocks on which our communications and defence systems depend. After all, if these fall out of synch with the planet, a missile or satellite will veer off course.
One nanosecond. One foot. If a misdirected drone were whizzing at you, you would care a lot about missing nanoseconds. But in general, such measures mean little to you and me, since our senses cannot compute such minuscule intervals. Time only gains purpose as a tool that we can use.
What is the point of femtoseconds (a quadrillionth, or millionth of a billionth, of a second)? It sounds a nonsense word, perhaps a satirical comment upon the emasculation of time, slivered into such absurdities. But although Concorde could not have travelled an atom’s breadth in such a minute interval, scientists, aided by femtoseconds, can track, instant by instant, what transpires at the atomic level during phase transition, that mystifying moment when a liquid becomes solid and free-range particles suddenly lock into a lattice, like dancers at a military dance. Our tiniest temporal unit yet is Planck time (the time it takes light to travel 4 × 10-35 metres) – mind-boggling, yet necessary, since it permits quantum physicists to comprehend the force that keeps life turning: gravity.
3. The comforts of time – or, why we love linear
You too are a clock. The beat of your life is the tempo of events – occasions whose rhythm dictates how relaxed or stressed you feel. A life borne on a steady routine can be titanically productive, as the philosopher Immanuel Kant demonstrated, his schedule so unwavering that amused citizens of Königsberg are said to have set their clocks by his afternoon stroll.
We invented time from a need for predictability. In his 1781 Critique of Pure Reason, Kant observed that time is ‘at the foundation of all our intuitions’. Without it, how could we make sense of the world, distil lessons from experience, decide what to do when, or guess how long it will take? Time’s numbers and dates impose a reassuring form on vast existential uncertainties such as duration, decay and amorphous feelings like our sense of inevitability, empowering us to co-operate and compete as no other animal can.
Anything that gives time definition and direction is a blessing if you are an upright ape whose life’s work is, essentially, to survive an unpredictable environment and convince yourself that fleeting existence has a purpose. Recalling yesterday, dreaming about tomorrow: these mental co-ordinates extend a miraculous thread on which