The Order of Time

Carlo Rovelli
2017
In translation by Simon Carnell and Erica Segre 2018

When but a lowly student of mathematics, struggling (not entirely successfully) with eigenvectors, binomial coefficients, imaginary numbers and other such exotic spresms, I was told something remarkable about time.

The study of Dynamical Systems deals with how objects behave under the influence of forces: movement, in a word. The equations developed to describe the change in speed and position of objects use a value t, which stands for time. For each value of t for time, an equation gives a result: this is the condition of the object at that time.

The ‘sorry what was that?’ moment came on being told that the equations don’t give a damn if you run the numbers through them one way or the other. As far as mathematics is concerned, we can go back in time. As far as we’re concerned, time appears more straight forward. But not, of course, straightforward. It’s an elusive concept, and that despite time perhaps being what we’re made of.

Comprehensive anticipatory design scientist and awesome synth freak-out, Buckminster Fuller, was inspired by Einstein’s theories of the relativity of time and space to say: ‘I am not a thing – a noun. I seem to be a verb’. Similarly Einstein inspired, and similarly brilliant, the mathematician and philosopher Alfred North Whitehead proposed that the world is made up of – rather than tiny atoms of stuff – tiny durations of time. The new science of relativity implied that the most basic element of existence is an event.

So, if for the maths it doesn’t matter, why do our events only seem to happen in one direction? The guilty party is the Second Law of Thermodynamics, which tells us that ‘heat passes only from hot bodies to cold, never the other way round.’ Rovelli goes on to explain it like this:

‘Thermal agitation is like a continual shuffling of a pack of cards: if the cards are in order, the shuffling disorders them. In this way, heat passes from hot to cold, and not vice versa: by shuffling, by the natural disordering of everything.’

The natural increase of disorder is called entropy. It is the only formula of physics that agrees with our experience of time.

 

Against the Clock

We all love a rags-to-riches story. So much so that when Christopher Booker claimed to have distilled all stories into seven basic forms, rags-to-riches was one of them. When Einstein’s story is told, it usually includes the detail that he was a lowly patent office clerk when he developed many of his most famous theories. Often it’s suggested that the undemanding nature of the job, to such an outstanding if as yet unrecognised intellect, left him with plenty of time to think great thoughts.

No doubt there’s some truth to that. But Einstein worked in a patent office at just the time when it was beginning to matter what time it was somewhere else. For most of human history it was immaterial whether people living far away marked exactly the same time. Noon is when the sun is highest, and if noon for one village is half an hour before or after that of another, what difference does it make if it takes a full day to travel between them?

With the advent of railways and the telegraph, pressure grew for time to be standardised. In the mid-nineteenth century, Great Western Railway imposed ‘railway time’ on its stations, so that staff didn’t have to continually adjust to local time as trains chuffed along their lines – time on a train differing from time in the station it arrived at could easily lead to accident.  A later proposal to make noon everywhere in the world the same time as noon in London – we British have always thought the world revolves around us – was rejected by everywhere else in the world, and instead the time zones we still use today were agreed on.

Invention was required to synchronise clocks between railway stations and time zones, and many patents relating to that purpose were submitted. Einstein, Technical Expert (Third Class), was tasked with reviewing these, and it would be surprising if his professional concern with the problem of synchronising time had no bearing on his discovery that time is ultimately relative. No doubt he would have approved of Buckminster Fuller, who wore three watches: one for the time zone he was in, one for the zone he had come from, and one for the zone he was going to.

Time, as Rovelli explains and Bucky Fuller knew, is different from place to place. And from time to time. Before clocks, time was told by the position of the sun as it moved from sunrise to sunset. Each day was divided into twelve hours, but as the days lengthen and shorten through the seasons, so also did the hours. An hour in winter was much shorter than an hour in summer.

Not only do there seem to be many ways of telling the time, Rovelli shows that there is no absolute now that can be shared between us all. Jorge Luis Borges outlined the problem in his essay A New Refutation of Time:

‘At the beginning of August 1824, Captain Isidoro Suarez, at the head of a squadron of Peruvian hussars, assured the victory of Junin; at the beginning of August 1824, De Quincey issued a diatribe against Wilhelm Meisters Lehrjahre; these deeds were not contemporaneous (they are now), inasmuch as the two men died – the one in the city of Montevideo, the other in Edinburgh – knowing nothing of each other…’

Rovelli explains the incompatibility of nows by imagining communication with someone on the planet Proxima b. The message you receive now represents what was now for the other person four years ago. So is that person’s current now whatever they are doing four years after they sent the message? Well, if during that time they travelled back to Earth, their time would have passed more slowly than yours, due to time dilation, so that their ‘now’ of four years after the message might be ten years in your future. Your ‘nows’ don’t fit.

To ask which moment on the other planet is now is ‘like asking which football team has won a basketball championship, how much money a swallow has earned, or how much a musical note weighs.’ ‘Now’ refers only to what is happening nearby. Borges says that ‘Every instance is autonomous’, and Rovelli agrees: ‘Times are legion: a different one for every point in space.’

 

Marking Time

Rovelli, not averse to a poetic flourish, says that ‘song, as Augustine observed, is the awareness of time. It is time.’ Augustine was speaking of psalms, a word meaning words to be sung, but Borges, in his translation of the relevant passage, speaks of the poem, which will suit my purpose:

‘Before beginning, the poem exists in my expectation; when I have just finished, in my memory; but as I am reciting it, it is extended in my memory, on account of what I have already said; and in my expectation, on account of what I have yet to say. What takes place with the entirety of the poem takes place also in each verse and each syllable.’

Proust describes much the same thing in In Search of Lost Time when Swann first hears the famous ‘little phrase’, a snatch of music that captures his imagination:

‘Doubtless the notes which we hear at such moments tend, according to their pitch and volume, to spread out before our eyes over surfaces of varying dimensions, to trace arabesques, to give us the sensation of breadth or tenuity, stability or caprice. But the notes themselves have vanished before these sensations have developed sufficiently to escape submersion under those which the succeeding or even simultaneous notes have already begun to awaken in us. And this impression would continue to envelop in its liquidity, its ceaseless overlapping, the motifs which from time to time emerge … did not our memory … by fashioning for us facsimiles of those fugitive phrases, enable us to compare and contrast them with those that follow.’

Song, or music, each note of which gains its character from relations to those that preceded it and those that are anticipated, intensifies our experience of time. Is it time itself?

Don Paterson, in his thorough study The Poem: Lyric, Sign, Metre (blog post pending), goes back to basics when considering the rhythm of poetic diction:

‘Two occurrences of identical or sufficiently similar things are all we need to raise our suspicions of the existence of a pulse: the brain goes ‘I just heard/felt/saw one of those!’ However, we need three occurrences to confirm it, since this creates two successive instances of an even length gap.’

The theory is much like Augustine’s: to recognise a pulse, we must remember a related previous event and anticipate, then have confirmed, a future one.

Rovelli notes the influence of Aristotle, who thought of time as the measurement of change, and Paterson agrees that time, as it appears to us, derives from the experience of what he calls ‘pulse’ – which does seem basic to music, or song, too. But Paterson goes on to comment on an argument also examined by Rovelli: whether time is only the perception of regular change¹, or is a dimension of its own, as Newton had it, through which we ‘travel’ (time is very frequently spoken of using spatial metaphors).

 

A Matter of Perspective

Here I’m going to digress, dragging out an old hunch of mine with the excuse that it will provide a useful analogy for one of the more remarkable ideas that Rovelli has about time. That hunch is, counter-intuitively, that the more literal and clearly defined a word is, the less accurate it is. We know that the map is not the territory: that the word we use to describe a thing is not the thing. Words are abstractions and so always leave something of reality out. And the more closely we define a word, the more of reality it leaves out.

And thank god it does: the purpose of words, of language, of thought, is to break down the enormous movement of the world through us into smaller, tamer bits that we might have some hope of managing. For most of our purposes, it’s very useful to be able to pick out and focus on particular aspects of the world. The more we inhabit the abstract world of words, though, the greater the danger that we mistake the map for the territory and miss the glorious excess of the real world.

Paterson has it that: ‘the very fact that we write poetry is a sign that we doubt the adequacy of our everyday language to reality; the poetic function in language is the principle means by which we try to make it fit for the purpose.’

Poetry works with words in a way that exceeds their denotative (dictionary definition) meaning, and embraces their connotative meaning. The word ‘beer’ denotes ‘alcoholic drink made from yeast-fermented malt flavoured with hops‘. It could connote, among many things, conviviality, the homeliness of a pub, parties – or vomit, violence and vandalism. Connotative meaning is broader and its limits are less clearly defined. It seems more vague.

One method of connotation is the symbol, in which a concrete detail stands for an abstract quality. As, for instance, in these lines from Crow Alights by Ted Hughes:

‘He saw this shoe, with no sole, rain-sodden,
Lying on a moor.
And there was this garbage can, bottom rusted away,
A playing place for the wind, in a waste of puddles.’

The concrete details of shoe, garbage can, puddles and the empty moor they lie in, stand in for the abstract quality of something like ‘bleakness’. The piling up of the details reinforces the reading of each one as bleak, and the context of the whole poem does so still more. Poems work like that. You might think, ‘hmm, that shoe lying on a moor seems bleak,’ and wonder if the poem is about bleakness. The next lines seem to confirm it. Perhaps you re-read earlier lines to see if you can find something meaning bleakness there that you’d missed first time round.

In this way a poem’s details point us to some meaning beyond the literal, and we then read that meaning back in as the motivation for those details appearing in the poem. Paterson puts it like this: poetic detail ‘both predicts and is predicted by the [poem’s meaning], and is both anterior and posterior to it.’

Because a poem’s meaning is connotative and is generated by the context of the whole poem, it can’t be given a denotative definition such as ‘bleakness’. It’s obvious that the lines from Hughes given above are much richer in meaning than a phrase like ‘life is bleak’. Paterson imagines each poem as a symbol of some new abstract meaning that cannot be said in other words: it’s no use to try to work out what a poem ‘really’ means, as the poem is the only way of saying what it means.

Leaving behind the literal, specific sense of the individual words, we approach the specific sense of just these words in this order. The connotative, poetic meaning that seemed more vague may in fact allow us to capture a greater swathe of whatever’s out there, pointing to previously un-articulated aspects of reality, and with such nuance and precision that any other way of saying won’t do.

The precision with which our words filter our experience blurs that experience and blinds us to its full range. What we say can then only be accurate according to our limited point of view. The disruption that poetry brings lets us expand our view and see that our truths are only partial.

 

There’s No Time

But if our words filter the incessant barrage of sensory information we receive into more manageable chunks, so do our senses, our bodies, filter the still greater deluge of forces flowing through us into sights, sounds, smells, and so on, that we experience. The discoveries of science have shown us that the universe is astronomically larger than we guessed, that it is everywhere fizzing with energies invisible to us. Paterson, on this subject, quotes Philippe Jaccottet: ‘This world is just the tip / of an infinite conflagration’. We know it only through our human body and mind, in almost all circumstances interpreting it according to our human need.

If the full range of our experience is blurred by the words we use to describe it, so also is all of our experience blurred by the sensory capacities of our bodies and our point of view of the universe. Rovelli tells us that this blurred perspective is time.

As has been mentioned, Rovelli describes entropy as the shuffling of a pack of cards. The universe, like the shuffled cards, moves from order to disorder. But what do we mean by order? If we have a pack of cards arranged so that ‘the first twenty-six … are all red and the next twenty-six are all black’ and then shuffle it, we notice the particular and remarkable configuration that the pack started out with, and that this pattern is broken up.

The order of the pack is a result of our having focused on a particular aspect of the cards: their colour. What if we notice that ‘the first twenty-six cards consist of only hearts and spades[?] Or if they are all odd numbers, or the twenty-six most creased cards in the pack, or exactly the same twenty-six as three days ago…’

In all possible arrangements of the pack there will be some aspect of the cards that appears ordered. If we notice one of these before the pack is shuffled, then it will look like the pack becomes disordered. We see a change from order to disorder because we have chosen to focus on one particular aspect.

In the same way, the entropic increase of disorder, and hence the phenomenon of time, is a result of our human perspective. We can’t see, or sense in any other way, the teeming, microscopic interactions of quantum stuff that constitute the universe. Our sensory apparatus doesn’t have such fine resolution and so the universe we sense is a blurred version of the real thing. Like language in general, entropy describes the universe at the inexact, ‘blurry’ level of human perception. At our level of resolution, we notice the phenomenon of entropy.

At a more precise, quantum level of resolution, entropy no longer stands out as a remarkable feature of molecular behaviour. A full description of the universe abandons time. A full vision of the universe sees it altogether, at once.²

If we accept Rovelli’s account,³ it follows that any projected heat death of the universe would mark a ‘death’ only of the human ability to observe order in the universe. It would be the point beyond which the behaviour of the universe is no longer visible to us. The progress of entropy – what we call time – is simply a degeneration of vision, in which the universe remains as it always is, but we become gradually blind to it.

 

 

¹ The measurement of change implies regularity. Utterly irregular change, in which nothing resembled what came before, would give us nothing to hold on to, no things that could be measured against each other. We must be able to compare and contrast, as Proust says. Both change and regularity, difference and similarity, are necessary for time, as we can see in the phenomena that ground our sense of it: the turning and orbit of the earth, the orbit of the moon, the beating of the heart, the breath in and out.

² I got quite excited when I first read Rovelli’s idea of time, imagining all sorts of things the universe might be beyond our blurred perception of it. But his position, though containing much of interest, is not quite so original, and boils down to the well-known block universe theory. In this theory, a modern version of eternalism, all of space and time exists in an unchanging four-dimensional block and it is only our perception of small parts of it, one after the other, that give the illusion of movement through time. A very rough analogy is the illusion of movement generated by the projection of light through the frames of a film reel.

³ And, of course, many people would quibble. For an overview of various alternative philosophies and physics of time I refer you, not for the first time, to the excellent Stanford Encyclopaedia of Philosophy for articles on Time and more specifically the Thermodynamic Asymmetry of Time.