Rise of the vacuum airship

Sorry folks, I had to take the full story down - it violates New Scientist's rights agreement, which was entirely my oversight. The published version of the article is available to NS subscribers here.

The City is the City

My brief from the wonderfully named Dream Adoption Society of the Zbigniew Raszewski Theatre Institute in Warsaw – for their 2019 exhibition The City is the City (the allusion to China Miéville is intended) – was to express a dream of the utopian city of the future. I’m not sure I did that, but here is what I gave them.

________________________________________________________________________

When trying to imagine the future, I tend to look back to the past. What we can find there are not answers but reasons to be humble.

It’s one thing to laugh at how wide of the truth the forecasts of a century or so ago were about the warp and weft of life today: all those moonbases, jet packs, flying cars. But it is more useful to think about why they were wrong.

The finest example, in many respects, of a vision of the future city in the late nineteenth century was supplied by the French author and illustrator Albert Robida in his books The Twentieth Century (1882) and its sequel The Electric Life (1892). Set in the 1950s, the first book shows the life of a Parisian woman called Hélène Colobry as she goes about her life as a recent law graduate; in the second we meet engineer Philoxène Lorris and his son Georges. In a series of glorious illustrations, Robida shows us a world of electric light, interactive televisions (“telephonoscopes”), airborne rocket-shaped cars and dirigibles, all in a style that is the very epitome of steampunk – and not a bit like the way things turned out.



The Parisians who populate Robida’s world could have stepped straight out of the fin de siècle, all elegant hats and parasols. And while the skies swarm with vehicles, the city below is architecturally recognizable as the Paris of Robida’s time. Our first inclination might be to read this as anachronistic – but wait, isn’t Paris indeed still that way now, with its art nouveau Metro stations and its Haussmann boulevards? So Robida is both “wrong” and “right”: he didn’t anticipate what was coming, but he reminds us that cities, and the entire texture of life, are palimpsests where traces of the past going back decades, centuries, even millennia, coexist with the most up-to-the-minute modernity.

More than that: the devices of modernity have built into them a visual and conceptual continuity with the past, for how else could we at first have navigated them? The joke has it that a young person, seeing for the first time a real floppy disk, exclaims “Hey, you’ve 3D-printed the Save icon!” I’ve no idea if this was ever actually said, but it is inadvertently eloquent as well as funny.

Thus forewarned, let us stroll into the utopian city – and discover that, as ever, it reflects our own image, our fantasies and fears, our current, compromised, patchwork technologies. This place is after all where we live here and now, but allowed to have grown and morphed in proportion to our old obsessions and habits, disguised with a veneer of synthetic futures. We have walked a circle and re-entered the present from another direction.

*

Utopia is an invention of the Renaissance, and ever since the quasi-theocracies imagined by Thomas More and Francis Bacon it has been bound up with the city and the city-state. In Tommaso Campanella’s The City of the Sun (1623), the philosophical and political foundations of his utopia are inseparable from the fabric of his city with its seven concentric walls: a design that, like the Gothic cathedrals of the Middle Ages, represented the construction of the entire (now Copernican) cosmos. The very walls have a pedagogical function, covered with pictures and diagram that illustrate aspects of astronomy, mathematics, natural history and other sciences.


Palmanova in northern Italy has a radial design echoed in Tommaso Campanella’s utopian City of the Sun, reflecting the political ideals of social order and harmony.

For producing this vision, Campanella suffered 27 years of imprisonment and torture – reminding us that, when they began, utopian cities of the future were not forecasts of what technology might deliver but statements of political intent.

And, I can hear urban theorists sigh, when was a city ever not a statement of political intent? Cities speak about the societies that build them. The rich man in his high castle, the poor man at his gate – traditionally, real cities have symbolized not the heavens but the hierarchies here on earth. As the brutalist concrete modernism of housing complexes near my home in south London is slowly demolished, I see a failed experiment not just in architecture but also in social philosophy – just, indeed, as was the case when those rectilinear grey hulks of the 1950s and 60s replaced the Victorian slums that stood there before. And no one doubts that the disappearance of the hutongs of Beijing before the march of high-rise, daringly asymmetrical steel and glass makes a statement about what China is determined to leave behind and what it aspires to become.

So while my instinct, as an avid follower of trends in self-organization, complexity and new materials, is to bring science and technology to bear on the question of utopian urbanism (and I’ll get to that), I am reluctant to say a word on such matters before admitting that this question is primarily bound up with politics and demographics.

Not that I want first to make predictions about that; at this particular moment in history I would hesitate to forecast the politics of next week. Rather, I want to acknowledge that whatever fantasies (that is all they will be) I spin, they have to build on some kind of social philosophy before we think about the fabric.

But this is more complicated than it used to be, and the reason why is partly technological. One of the interesting aspects of Robida’s drawings is that his skies above the cityscape are sometimes a dense web of telephone wires. He evidently felt that whatever the twentieth century city would look like, communication and information networks would be important for them.

Now those wires are disappearing. Why? First, because they began to run underground, in optical fibres able to pack a far greater density of information into a narrow channel, encoded in pulses of light. But ever more now it is because the wires have become virtual: the networks are wireless.

“Wifi” is like that Save icon: a ghost of past technology condensed into an avatar of modernity. You need to be rather old to see it as anything more than a “dead metaphor”, meaning that it now stands only for itself and its etymological roots have themselves become irrelevant and invisible. Older readers, as the phrase goes, will hear the echo of “hifi”, which the term was coined to imitate: high fidelity, referring to the high-quality reproduction of sound in home audio systems, or more generally, to the superior conveyance of (audio) information. The “wi”, of course, is “wireless”, which harks back to the miracle that was radio. By means that many people considered semi-magical in the 1920s and 30s, sound and information could be broadcast through the air as radio waves rather than along transmission wires.

This seemed like an occult process, and indeed was initially thought by some to be allied to spiritualism and mediumship: the “ether” that was seen as the material medium of radio waves was suspected of also being a bridge between the living and the dead. When television arrived – so that you could not only hear but even see a person hundreds of miles away – the mystical aura of “wireless” technology only increased.

What has this to do with the city of the future? It illustrates that new technologies, especially of communication, have psychic implications as well as infrastructural ones. Even with a web of wires as dense as Robida’s, no one would have imagined a future in which you can sit in a coffee shop and, with a slab of glass and silicon held in your hand, tap instantly into more or less the sum total of existing human knowledge: to read in facsimile Isaac Newton’s original Principia, or watch in real time images of a spaceship landing on an asteroid. No one imagined that, thanks to technological innovation, we would in 2018 be producing as much data every two days as we produced throughout all of human existence until 2003.

And the truly astonishing thing is that this seems normal. More, it is regarded now almost as a human right, so that we are irritated to find ourselves in an unban space where every cubic centimetre of empty space is not animated by this invisible and ever expanding information flow.

Why in heaven’s name should we be expected to make sense of this situation as well as simply to exploit it? From a perceptual point of view, wifi wrecks spacetime. These ten square centimetres of reality are no longer where I am sitting in (say) Starbucks on Euston Road, but are the living room of my sister in Canberra, with whom I am chatting on Skype. Do you think it is just coincidence that the ways we interact with information technology are often indistinguishable from the symptoms of psychosis (and I’m not just talking about the associated addictions and other dysfunctional behaviours)?

Add to this now the possibility that even what might seem like the concrete existence of your own immediate environment can be tinkered with, overlain with the metadata of augmented reality. How then are we supposed to police the borders of virtual and real? Is it even clear what the distinction means? But if it is not, then who decides? And who decides where in that space of possibilities “normality” lies?

So look: a utopian city of the future must recognize that there will be more technologies like this, and also that people will adapt to them without ever quite processing them psychically. One thing Robida’s future citizens are never doing is sitting in their public-transport dirigibles staring at little black tablets in their palm, and frowning at them, laughing or weeping at them, talking to them. To Robida’s readers that would have made no sense at all.

It’s an easy matter to see how technologies and networks of information have changed our lives and built environments. Ever more people can work from home, for one thing – and the proper way to say this is that the boundaries of work and domesticity have become porous or almost invisible. What is perhaps more striking is how these technologies have been assimilated by, and altered, life in places far removed from the centres of modern development: rural sub-Saharan Africa, the plains of Mongolia. A weather app is handy if you want to know whether to take your umbrella with you in Paris; it is rather more than that if you are a farmer in Kenya.

It is precisely this importance of information that makes it a currency of political and economic power. Increasingly indices of development include the question of wifi access and screens per capita. Censorship of information technologies has become a significant means not just of social control but of employment in some countries; democracy is struggling (and failing) to keep pace with the tools that exist for manipulating opinion and distorting facts. As professor of communication John Culkin famously said, “We shape our tools, and thereafter our tools shape us.”

*

The struggle between, say, the Chinese authorities to censor the web and users’ efforts to evade them are, in an Orwellian sort of way, a metaphor for the tensions that exist in any complex adaptive system that unfolds in a social context. They are a dance between attempts at centralized control and design and the tendency of such systems to grow of their own accord. Both the internet and cities are often presented as exemplars of human constructs that no one designed, although of course the truth is that design and planning simply have limited impact. Christopher Wren’s orderly, utopian vision of London after the Great Fire of 1666 was never realized because of the city’s irrepressible urge to reform itself – with all the attendant chaos – while the embers were scarcely cool.

Perhaps the central revelation of the scientific study of complex adaptive systems is that this spontaneous growth is not merely chaotic and random, but follows particular law-like regularities – albeit ones quite unlike the geometric designs of Campanella and Wren, and which more closely resemble, and often exactly reproduce, the growth laws of living organisms.


The growth and form of cities like London resemble those of natural processes, like fluid flow through porous rock or the spread of a bacterial colony.

These regularities exist not because the agents responsible for growth – the people who build new roads and houses, say – are so intelligent, but precisely because their intelligence is, in this context at least, so limited. It’s not very clear what kinds of structures intelligent agents create when they are exerting their full cognitive capacities – the question is less studied theoretically – but there is some chance that they might be either too complex for any laws to be apparent at all, or totally random (the two could of course be indistinguishable). But when agents have very constrained cognition – when they act according to rather simple laws – then complex but nonetheless rather predictable and law-like group behaviour emerges. Cities, for example, show so-called scaling laws in which everything ranging from their crime rate to their innovative capacity, and even the speed of walking, varies with size according to a rather simple mathematical relation. They grow in a manner similar to tumours and snowflakes: they look like natural phenomena. Ants, wasps and termites are by no means cognitively sophisticated, but their social structures and even their architecture – their nests and mounds – certainly can be.


The complex architecture of tunnels in a termite mound, revealed here by taking a plaster cast. Photo: Rupert Soar, Loughborough University.

This doesn’t mean that humans are cognitively simple too (although who knows where that scale starts and ends?). Rather, our social systems inherently reduce the amount of cognition needed, and perhaps have evolved precisely in order to do so. It’s why we have traditions, conventions, norms and taboos. It’s why we have traffic lanes, speed limits, highways codes. (Traffic is a particularly clear example of complex behaviour, such as waves of stop-start jamming, emerging from agents interacting through simple rules.)

There is a strong case, then, why a well-designed city of the future would be quite unlike the precisely planned and geometrically ordered city-utopias of the past. Self-organized systems commonly show desirable traits, such as efficiency and economy in use of space and energy, robustness against unpredictable outside disturbances, and the ability to adapt to changing circumstances. The trick is to find the “rules of engagement” between agents that create such outcomes and do not risk getting trapped in “bad solutions”.

Another way of saying this, perhaps, is that there is no point in trying to specify what an urban utopia would look like; rather, the important questions are what qualities we would like it to have (and to avoid), and what kinds of constraints and underlying rules would guide it to towards those outcomes. There is no reason to think that either of these things have universal answers for all cultures and all places.

What surely is clear is that the social ethos and the physical fabric will be intimately connected, as they always have been. What a city looks like both reflects and determines the values of the society it accommodates.

One piece of futurology that I am tentatively prepared to offer is that the utopian city will be protean. It will be able to change its physical state in ways that bricks and mortar, tarmac and steel never could. These capabilities are already being incorporated into materials at the level of individual buildings and civil-engineering structures. In fact to a limited extent they always have been: historical lime mortars are self-healing in their capacity to reconstitute themselves chemically and cement together cracks. Today, self-repair is being built into construction materials ranging from plastics to asphalt to steel, for example by incorporating cavities that release air-setting glues when broken open.

It’s a small step towards what have become dubbed “animate materials”, which have some of the qualities of living systems: an ability to grow in response to environmental cues, to heal damage, to alter their composition to suit the circumstances, to sense and alter their surroundings. Trees and bones reshape themselves in response to stress, removing material where it is not needed and reinforcing it where the danger of failure lurks. And they are of course fully biodegradable and renewable.

For such reasons, natural ecosystems are a flux not just of materials and energy but of information. They even contain information networks: trees, say, communicating via airborne hormones and subterranean root systems. There is no clear distinction between structural fabric, sensors, and communication and information systems: the smartness of the material is built-in, invisible to the eye. This is the direction in which our artificial and built environments are heading, so that they are ever less a tangle of wires and increasingly a seamless interface as bland and cryptic as an iPod. The mechanisms are unseen, often inseparable from the materials from which they are made.

And this is one reason why we don’t have robot butlers. What a great deal of redundant design would be needed to create such a humanoid avatar; how much effort would have to be expended simply to ensure that it does not trip on the carpet. In a sufficiently smart, adaptive, wireless environment, a mere static cylinder will do instead; shall we call her Alexa? The future’s technology needn’t pay much heed to surface and texture – faux-mahogany Bakelite, smooth, glossy plastic, gleaming steel – because the interface will be on and within us: responding to vision, voice, posture, perhaps sheer thought.

Which leads to the real question: who will we be?

Here there is another lesson to be learnt from Robida’s wonderful books. He has very evidently taken the citizens of late nineteenth-century Paris and deposited them in what was then a futuristic-looking world. We might laugh at how transparent a ruse that is now, but we’ve a tendency to do the same. All those images of utopian cities (often in outer space) from the 1950s might have granted to the futuristic citizens a bit of nifty, brightly coloured and stylishly minimalist clothing, but there were the same rosy-cheeked, smiling nuclear families, the dad waving goodbye to the blond-haired kids on his way to work. We even do this with our vision of alien and artificial intelligence, attributing to them all the same motives as ours (for better or worse) but just with fancier tech.

Yet not only social mores and norms but also the very nature of identity is mutable over time. Arguably this is more true now than ever, so there is no reason to suppose the transformation of identity will be any less rapid in the future.

Already modernity demands that we adopt multiple identities that surface in different situations, often overlapping and increasingly blurred but defining our views and choices in distinct ways. Traditional social categories that defined identity, such as age, class, and nationality, are becoming less significant, as are distinctions between public and private identity. Old definitions based on class, ethnicity and political affiliation are ceding to new divisions, for example marked by distinctions of urban/rural, well/poorly educated, young/old, connected/off grid. In our fictional dystopias, such divisions are sometimes genetic, perhaps artificially induced and maintained.

What’s more, identities are being increasingly shaped by active construction, documentation, affiliation and augmentation. The kind of manufactured and curated public profile once reserved for celebrities is now available to billions, at least in principle. We arrange and edit our friendships and our memories, attune our information flows to flatter our preconceptions, and assemble our thoughts, experiences and images into packages that we present as selves.

We still have no idea what kind of societies will grow from these opportunities for self-definition. If traditional attributes of individual identities become more fragmented, communities might be expected to become less cohesive, and there could be greater marginalization, segregation and extremism. Yet hyperconnectivity can also produce or strengthen group identities in positive ways, offering new opportunities for community-building – which need pay not heed to geography and spatial coordinates.

The city is a living embodiment of its citizens. They have selected the contours, the technologies, the interfaces that they believe best represent them. That’s why utopian dreams are just another way of looking at ourselves. So be careful what you wish for.

Just how conceptually economical is the Many Worlds Interpretation?

An exchange of messages with Sabine Hossenfelder about the Many Worlds Interpretation (MWI) of quantum mechanics has helped me sharpen my view of the arguments around it. (Sabine and I are both sceptics of the MWI.)

The case for Many Worlds is well rehearsed: it relates to the “measurement problem” and the idea that if you take the “traditional Copenhagen” view of quantum mechanics then you need to add to the Schrödinger equation some kind of “collapse postulate” whereby the wavefunction switches discontinuously from allowing multiple possible outcomes (a superposition) to having just one: that which we observe. In the Many Worlds view postulated by Hugh Everett, there is no need for this “add on” of wavefunction collapse, because all outcomes are realized, in worlds that get disentangled from one another as the measurement proceeds via decoherence. All we need is the Schrödinger equation. The attraction of this idea is thus that it demands no unproven additions to quantum theory as conventionally stated, and it preserves unitarity because of the smooth evolution of the wavefunction at all times. This case is argued again in Sean Carroll’s new book Something Deeply Hidden.

One key problem for the MWI, however, is that we observe quantum phenomena to be probabilistic. In the MW view, all outcomes occur with probability 1 – they all occur in one world or another – and we know even before the measurement that this will be so. So where do those probabilities come from?

The standard view now among Everettians is that the probabilities are an illusion caused by the fact that “we” are only ever present on one branch of the quantum multiverse. There are various arguments [here and here, for example] that purport to show that any rational observer would, under these circumstances, need to assign probabilities to outcomes in just the manner quantum mechanics prescribes (that is, according to the Born rule) – even though a committed Everettian knows that these are not real probabilities.

The most obvious problem with this argument is that it destroys the elegance and economy that Everett’s postulate allegedly possesses in the first place. It demands an additional line of reasoning, using postulates about observers and choices, that is not itself derivable (even in principle!) from the Schrödinger equation itself. Plainly speaking, it is an add-on. Moreover, it is one that doesn’t convince everyone: there is no proof that it is correct. It is not even clear that it’s something amenable to proof, imputing as it does various decisions to various “rational observers”.

What’s more, arguments like this force Everettians to confront what many of them seem strongly disinclined to confront, namely the problem of constructing a rational discourse about multiple selves. There is a philosophical literature around this issue that is never really acknowledged in Everettian arguments. The fact is that it becomes more or less impossible to speak coherently about an individual/observer/self in the Many Worlds, as I discuss in my book Beyond Weird. Sure, one can take a naïve view based on a sort of science-fictional “imagine if the Star Trek transporter malfunctioned” scenario, or witter on (as Everett did) about dividing amoebae. But these scenarios do not stand up to scrutiny and are simply not science. The failure to address issues like this in observer-based rationales for apparent quantum probabilities shows that while many Everettians are happy to think hard about the issues at the quantum level, they are terribly cavalier about the issues at the macroscopic and experiential level (“oh, but that’s not physics, it’s psychology” is the common, slightly silly response).

So we’re no better off with the MWI than with “wavefunction collapse” in the Copenhagen view? Actually, even to say this would be disingenuous. While some Everettians are still happy to speak about “wavefunction collapse” (because it sounds like a complicated and mysterious thing), many others working on quantum fundamentals don’t any longer use that term at all. That’s because there is now a convincing and indeed tested (or testable) story about most of what is involved in a measurement, which incorporates our understanding of decoherence (sometimes wrongly portrayed as the process that makes MWI itself uniquely tenable). For example, see here. It’s certainly not the case that all the gaps are filled, but really the only thing that remains substantially unexplained about what used to be called “collapse” is that the outcome of a measurement is unique – that is, a postulate of macroscopic uniqueness. Some (such as Roland Omnès) would be content to see this added to the quantum formalism as a further postulate. It doesn’t, after all, seem a very big deal.

I don’t quite accept that we should too casually assume it. But one can certainly argue that, if anything at all can be said to be empirically established in science, the uniqueness of outcomes of a measurement qualifies. It has never, ever been shown to be wrong! And here is the ultimate irony about Many Worlds: this one thing we might imagine we can say for sure, from all our experience, about our physical world is that it is unique (and that is not, incidentally, thrown into doubt by any of the cosmological/inflationary multiverse ideas). We are not therefore obliged to accept it, but it doesn’t seem unreasonable to do so.

And yet this is exactly what the MWI denies! It says no, uniqueness is an illusion, and you are required to accept that this is so on the basis of an argument that is itself not accessible to testing! And yet we are also asked to believe that the MWI is “the most falsifiable theory ever invented.” What a deeply peculiar aberration it is. (And yet – this is of course no coincidence – what a great sales hook it has!)

Sabine’s objection is slightly different, although we basically agree. She says:

“Many Worlds in and by itself doesn't say anything about whether the parallel worlds "exist" because no theory ever does that. We infer that something exists - in the scientific sense - from observation. It's a trivial consequence of this that the other worlds do not exist in the scientific sense. You can postulate them into existence, but that's an *additional* assumption. As I have pointed out before, saying that they don't exist is likewise an additional assumption that scientists shouldn't make. The bottom line is, you can believe in these worlds the same way that you can believe in God.”

I have some sympathy with this, but I think I can imagine the Everettian response, which is to say that in science we infer all kinds of things that we can’t observe directly, because of their indirect effects that we can observe. The idea then is that the Many Worlds are inescapably implicit in the Schrödinger equation, and so we are compelled to accept them if we observe that the Schrödinger equation works. The only way we’d not be obliged to accept them is if we had some theory that erases them from the equation. There are various arguments to be had about that line of reasoning, but I think perhaps the most compelling is that there are no other worlds explicitly in any wavefunction ever written. They are simply an interpretation laid on top. Another, equally tenable, interpretation is that the wavefunction enumerates possible outcomes of measurement, and is silent about ontology. In this regard, I totally agree with Sabine: nothing compels us to believe in Many Worlds, and it is not clear how anything could ever compel us.

In fact, Chad Orzel suggests that the right way to look at the MWI might be as a mathematical formalism that makes no claims about reality consisting of multiple worlds – a kind of quantum book-keeping exercise, a bit like the path integrals of QED. I’m not quite sure what then is gained by looking at it this way relative to the standard quantum formalism – or indeed how it then differs at all – but I could probably accept that view. Certainly, there are situations where one interpretational model can be more useful than others. However, we have to recognize that many advocates of Many Worlds will have none of that sort of thing; they insist on multiple separate universes, multiple copies of “you” and all the rest of it – because their arguments positively require all that.

Here, then, is the key point: you are not obliged to accept the “other worlds” of the MWI, but I believe you are obliged to reject its claims to economy of postulates. Anything can look simple and elegant if you sweep all the complications under the rug.

Physics and Imagination

This essay appears in Entangle: Physics and the Artistic Imagination, a book edited by Ariane Koek and produced for an exhibition of the same name in Umea, Sweden.

______________________________________________________________________

It would seem perverse, almost rude, not to begin a discussion of imagination in physics with Einstein’s famous quote on the topic, voiced during a newspaper interview with the writer George Viereck in 1929:
“I'm enough of an artist to draw freely on my imagination, which I think is more important than knowledge. Knowledge is limited. Imagination encircles the world.”

For a fridge-magnet inspirational quote to celebrate the value of imagination, you need look no further. But context, as so often with Einstein, is everything. He said this after talking about the 1919 expedition led by the British physicist Arthur Eddington to observe the sky during a total solar eclipse off the coast of Africa. Those observations verified the prediction of Einstein’s theory of general relativity that starlight would be bent by the gravitational field of a massive body like the sun. Einstein told Viereck that “I would have been surprised if I had been wrong.” Viereck – a fascinating figure in his own right, who had previously interviewed (and showed some sympathy for) Adolf Hitler and wrote a psychological and gay-inflected Wildean vampire novel in 1907 – responded to that supremely confident statement by asking: “Then you trust more to your imagination than to your knowledge?”

You could say that Einstein’s reply was a qualified affirmative. And this seems very peculiar, doesn’t it, for a “man of science”?

The story dovetails with Einstein’s other well-known response to the eclipse experiment. Asked by an assistant (some say a journalist) how he should have felt if the observations had failed to confirm his theory, he is said to have responded “Then I would feel sorry for the dear Lord. The theory is correct.”

Compare that with the statement of another celebrated aphoristic physicist, the American Richard Feynman:
“It doesn't matter how beautiful your theory is, it doesn't matter how smart you are. If it doesn't agree with experiment, it's wrong.”

Who is right? Einstein trusting to imagination, intuition and artistry, or Feynman to the brutal judgement of empiricism? If we’re talking about scientific methodology, Feynman is right in spirit but nonetheless displaying the limitations of the physicist’s common “naïve realist” position about science, which assumes that nature delivers uncomplicated, transparent answers when we put to it questions about our physical theories. Yet Einstein’s general relativity was a theory so profoundly motivated and so conceptually satisfying, despite the mind-boggling shift it demanded in conceptions of space and time, that it could not be lightly tossed on the scrapheap of beautiful ideas destroyed by ugly facts.

So the sensible way to have handled a discrepancy with observed “facts” like those collected by Eddington in his observations of the positions of stars during an eclipse would have been to wonder if the observations were reliable. Indeed, Eddington was later accused of cherry-picking those facts to confirm the theory, perhaps motivated by his Quaker’s desire to bring about international reconciliation after First World War had triggered the ostracising of Germany. (It seems those charges were unfounded.) Nature doesn’t lie, but experimentalists can blunder.

*

There’s a deeper reason to valorize Einstein’s claim about imagination in physics. What I feel he is really saying is that imagination precedes knowledge, and indeed establishes the precondition for it. You might say that when the shape of imagination sufficiently fits the world, knowledge results.

We have never needed more reminding of this. In his unfinished magnum opus Novum Organum the seventeenth-century English philosopher Francis Bacon presented knowledge as the product obtained when raw facts – observations about the world – are fed into a kind of science machine (what we might now call an algorithm) and ground into their essence. It was an almost mechanical process: you first collect all the facts you can, and then refine and distil them into general laws and principles about the way the world works. Bacon never completed his account of how this knowledge-extraction process was meant to work, but at any rate no one in science has ever successfully used such a thing, or even knows what it could comprise.

Yet Bacon’s vision threatens to return in an age of Big Data – especially in the life sciences, where the availability of information about, say, genome sequences or correlations between genes and traits has outstripped our ability to create theoretical frameworks to make sense of it. There’s a feeling afoot not only that data is intrinsically good but that knowledge has no option but to fall out of it, once the mass of information about the world is large enough.

Physicists have received advance warning of the limitations of that belief. They have their own knowledge machines: sophisticated telescopes and particle detectors, say, and most prominently the Large Hadron Collider and other particle colliders capable of generating eye-watering quantities of data about the interactions between the fundamental constituents of the world. But they already know how little all this data will help without new ideas: without imagination.

For example? There are some good reasons to believe that if physics is going to penetrate still further into the deep laws of nature, it needs a theoretical idea called supersymmetry. So far, all we know about the particles and forces of nature is described by a framework called the Standard Model, which contains all the ingredients seemingly needed to explain everything seen in experiments in particle physics to date. But we know that there’s more to the universe than this, for many reasons. For one thing, the current theory of gravity – Einstein’s general relativity – is incompatible with the theory of quantum mechanics used to describe atoms and their fundamental particles. Supersymmetry – a putative connection between two currently distinct classes of particle – looks like a promising next step to a deeper physics. Yet so far, the LHC’s high-energy collisions have offered no sign that it’s true.

What’s more, there’s nothing in the Standard Model that seems to account for the “dark matter” that astrophysicists need to invoke to explain what they see in the cosmos. This mysterious substance is believed to pervade the universe, invisibly, being felt by ordinary matter only through its gravitational influence. Without something like dark matter, it is hard to make sense of the observed forms and motions of galaxies: how they rotate without shedding stars like a water sprinkler. The reasons to believe in dark matter – and moreover to believe it exceeds the mass of ordinary visible matter by a factor of about five – are very strong. Yet countless efforts to spot what it consists of have failed to offer any clues. Huge quantities of data constrain the choices, but no evidence supports any of the theories proposed to explain dark matter.

These are – there is no avoiding the issue – failures of imagination. Supersymmetry and dark matter are wholly imagined theories or entities, but the collective imagination of physicists has not yet made them vivid enough to be revealed or disproved. It is possible that this is because they are imaginary in the more literary sense: they exist only in our minds. And they are not alone; dark energy (which causes the universe to expand at an increasing rate) and string theory (one candidate for a theory that would unite gravity and quantum mechanics) are other components of the physicist’s imaginarium waiting to be verified and explained or to be dismissed as unicorns, as the ether, as the philosopher’s stone.

A single observation – one experiment revealing a discrepancy with a definite theoretical prediction, or one sighting of a new kind of particle – could change the situation. Maybe it will. But it is equally possible that we will need ultimately to concede defeat, and to extent the imagination of physics into new territory: for example to accept, as some are already arguing, that what we call “dark matter” is a symptom of another physical principle (a modification to the theory of gravity, say) and not a true substance.

There’s nothing embarrassing or damning in all this. It’s not that physics itself is failing. The situation is just business as usual in science: to have mysteries awaiting explanation, even ones of this magnitude, is a sign of health, nor sickness. For individual physicists whose reputations hang (or seem to) on the validity of a particular idea, that’s scant comfort. But for the rest of us it’s nothing short of exhilarating to see such deep and broad questions remaining open.

*

The real point is that imagination in physics is what the paths to the future, to new knowledge, are built from. Actual knowledge – things we can accept as “true”, in the sense that they offer tried and tested ways of predicting how the world behaves – has been assembled into an edifice as wonderful and as robust as the Gothic cathedrals of stone, the medieval representations of the physical and spiritual universe. But at the point where knowledge runs out, only imagination can take us further. I think this is what Einstein was driving at.

The invitation is often to suppose that this imagination operates only at the borders of physical theory: at, you might say, the cliff-face of physics that tends to dominate its public image, where we find exotica like string theory, black holes, cosmology and the Higgs boson. But physics, perhaps more than any other science, has a subtle, fractal-like texture in which gaps in knowledge appear everywhere, at all scales. Imagination was needed to start to understand that strange state of matter made of grains: powders and sand, part fluid and part solid. It is currently blossoming in a field known as topological materials, in which the electrical and magnetic properties are controlled by the abstract mathematical shapes that describe the way electrons are distributed, with twists akin to those in the famous one-sided Möbius strip. It was imagination that prompted physicists and engineers to make structures capable of acting as ‘invisibility shields’ that manipulate and guide light in hitherto inconceivable ways. In all these cases, as in science more broadly, the role if the imagination is not so much to guide us towards answers as to formulate interesting and fruitful new questions.

What does this imagination consist of? We’d do well to give that question more attention. I would suggest that it is, among other things, a way of seeing possibilities: a rehearsal of potential worlds. That’s what justifies Einstein’s comparison to the work of the artist: imagination, as Shakespeare put it, “bodies forth the forms of things unknown.” The scientist’s theories, as much as the poet’s pen, “turns them to shapes and gives to airy nothing a local habitation and a name.” That name could be “general relativity” – why not?

What’s the source, though? Many ideas in fundamental physics grow from what might seem the rather arid soil of mathematics. Supersymmetry and string theory are predicated in particular on the conviction that the deepest principles of the physical world are governed by symmetry. What this word means at the level of fundamental theory might seem less apparent to the outsider than what it implies in, say, the shape of a Grecian urn or the pattern of wallpaper, but at root it is not so very difference: symmetry is about an equivalence of parts and their ability to be transformed one into another, as a left hand becomes a right through the mirror reflection of the looking glass.

Well, it might seem arid, this mathematics. But imagination is as vital here as it is in art. What mathematicians value most in their colleagues is not an ability to churn out airtight proofs of abstract theorems but a kind of creativity that perceives links between disparate ideas, an almost metaphorical way of making connections in which intuition is the architect and proof can come later. Both mathematicians and theoretical physicists commonly speak of having a sense that they are right about an idea long before they can prove it; that proof is “just the engineering” needed to persuade others that the idea will hold up.

Let’s be cautious, though, about making “engineering” the prosaic, plodding part of science though. The common perception is that theorists do the dreaming and experimentalists just build the apparatus for putting dreams to the test. That’s just wrong. For one thing, it’s typically experiment that drives theory, not the other was around: it’s only when we have new instruments for examining the world that we discover gaps in our understanding, demanding explanation. What’s more, experiment too is fuelled by imagination. No one tries to see something unprecedented – farther out into space (which means, because light’s speed is finite, farther back in time), or into the world of single atoms, or into the spectrum of radiation outside the band of light our eyes can register – unless they have conjured up images of what might be there. Sure, you need some existing theory to guide your experimental goals, to show potentially fruitful directions for your gaze; but no one sails into uncharted territory if they think all they’ll find is more of the same, or nothing at all. “If you can’t imagine something marvellous, you are not going to find it”, says physics Nobel laureate Duncan Haldane. “The barrier to discovering what can be done is actually imagination.” And the power and artistry of the experimenter’s imagination comes not just from dreaming of what there is to be found in terra incognita, but also from devising a means to travel there.

When I speak of dreams, I don’t just mean it metaphorically, nor just in the sense of waking reverie. To judge from the testimony of scientists themselves, dreams can function as sources of inspiration. True, we should be a little wary of that; the notion of receiving insight in a dream became a romantic trope in the nineteenth century, and careful historical analysis often reveals some hard and very deliberate graft, as well as a very gradual process of understanding, behind scientific advances that were recast retrospectively as dream-revelations. But it happens. Several contemporary physicists have attested to insights that came to them in dreams, as the conscious mind that has been long pondering a problem loosens its bonds on the margins of sleep and admits a little more of the illogic on which imagination thrives.

All the same, we shouldn’t think that the physicist’s imagination always works in the abstract, in the realm of pure thought. Very often, it takes visual form: finding the right symbolic representation of a problem, such as Feynman’s famous “diagrams” for studying questions in the field of quantum electrodynamics (in essence, the theory of how light and matter interact), can unlock the mind in ways that more abstract algebraic mathematics or calculus can’t. Pen and paper can be the fuel of the imagination. As Cambridge physicist Michael Cates (incumbent of the chair previously held by Stephen Hawking and Isaac Newton) has said, “I need a piece of paper in front of me and I’m pushing symbols around on the page… so there’s this interaction between processing in your head and moving symbols around.” Never underestimate the traditional blackboard as a tactile, erasable aid to the imagination. The productivity of such aids is no surprise. Ask a child to think of a story, and it’s ne easy matter. Give them a doll’s house full of figurines, and they’re away.

*

Yet whether it is theoretical or experimental, this imagination in science (as in art) is not idle fantasy. It is a condensation of experience: it takes what you know and plays with it. I do mean “plays”: imagination is nothing if not ludic. But it is also the very stuff of thought. One interpretation of cognition, in the context of artificial intelligence, is that it is largely about figuring out the possible consequences of actions we might make in the world: an “inner rehearsal” of imaginary future scenarios. Imagination in science extends that process beyond the self to the world: given that we know this, mightn’t things also be arranged like that?

It’s much more than a guess, then, and as Shakespeare hints, has almost the power of an invocation. Truly, the scientific imagination can invoke into being something that was not there before. Isaac Newton was cautious about his “force of gravity”, knowing that he risked (and indeed incurred from his arch-rival Gottfried Leibniz) accusations of occultism. Yet all the same this “force” became – and remains – a ‘thing’ in physics, even if we can regard it as a figure of speech, a convenient conceptual tool that general relativity invites us to regard otherwise as curvature of spacetime. It’s a process entirely analogous to the way Shakespeare goes on to speak, in A Midsummer Night’s Dream, of how correlation leads us to imagine causation:
Such tricks hath strong imagination,
That if it would but apprehend some joy,
It comprehends some bringer of that joy.

In this way we’re reminded that imagination shares the same etymological root as “magic” – which, in the age just before the time of Isaac Newton, did not necessarily mean superstitious agency but the “hidden forces” by which natural magicians comprehended and claimed to manipulate nature. In that regard Newton wasn’t, as John Maynard Keynes claimed, the “last of the magicians”, in the sense of his having a belief in occult forces (such as gravity, acting invisibly across space). No, if that was Newton’s “magic” then today’s physicists share a conviction in it, for any model in physics awards imagination this role of employing imagined causative agencies – things we might not perceive directly but which manifest through their effects, such as dark matter, dark energy, or the Higgs field – to explain what we see.

Now, though, physics places demands on the imagination as never before. I’m struck by how dark matter and dark energy, say, commandeer known concepts (mass, energy) that may or may not turn out to be appropriate. Even more challenging are efforts to provide some physical picture of quantum mechanics, the kind of physics generally used to describe atoms and fundamental particles. These objects don’t seem to conform to our intuitions derived from the everyday world of rocks and stones, tennis balls and space rockets. They can, for example, sometimes display behaviour we associate not with particles but with waves. They appear to be able to influence one another instantaneously over long distances; they are said to exist “in several states or places at once.”

Yet these descriptions are attempts – often clumsy, sometimes misleading – to make quantum mechanics fit into the forms of our conventional “classical” imagination. Arguments and misperceptions follow, or a disheartening decision to draw a veil over quantum improprieties by calling them “weird”. We can and should do better, but this will require a reshaping, an expansion, of our imaginative faculties. We have to develop a kind of intuition that is not constrained by our daily experience – because if there’s one thing we can be sure about in quantum mechanics, it’s that it demands the possibility of phenomena that lie outside this experience.

To venture into unknown territory, where imagination is at a premium, is a risk. To put it bluntly, your imagination is more likely to lead you astray than toward the truth. It is no magical guarantor of insight. Will you take that risk? Mathematical physicist Jon Keating has put the problem succinctly: “[How can we] encourage people to make them feel more comfortable with the failure that comes with most creative and imaginative ideas?” Unless we get better at that, educationally or institutionally, science will suffer.

And it’s very possible that physicists won’t alone accomplish the feats of imagination needed to crack their hardest problems. They may need to find inspiration from philosophy, art, literature, aesthetics. Imagination doesn’t recognize categories and boundaries – it is a power that aims to encircle the world.

Still trying to kill the cat

Some discussion stemming from Erwin Schrödinger’s birthday prompts me to set out briefly why his cat is widely misunderstood and is actually of rather limited value in truly getting to grips with the conundrums of quantum mechanics.

Schrödinger formulated the thought experiment during correspondence with Einstein in which they articulated what they found objectionable in the view of QM formulated by Niels Bohr and his circle (the “Copenhagen interpretation”, which should probably always be given scare quotes since it never corresponded to a unique, clearly adduced position). In that view, one couldn’t speak about the properties of quantum objects until they were measured. Einstein and Schrödinger considered this absurd, and in 1935 Schrödinger enlisted his cat to explain why. Famously, he imagined a situation in which the property of some quantum object, placed in a superposition of states, determines the fate of a cat in a closed box, hidden from the observer until it is opened. In his original exposition he spoke of how, according to Bohr’s view, the wavefunction of the system would, before being observed, “express this by having in it the living and the dead cat (pardon the expression) mixed or smeared out in equal parts.”

This is (even back then) more careful wording than the thought experiment is usually afforded today, talking specifically about the wavefunction and not about the cat. Even so, a key problem with Schrödinger’s cat if taken literally as a thought experiment is that it refers to no well defined property. In principle, Schrödinger could have talked instead about a macroscopic instrument with a pointer that could indicate one of two states. But he wanted an example that was not simply hard to intuit – a pointer in a superposition of two states, say – but was semantically absurd. “Live” and “dead” are not simply two different states of being, but are mutually exclusive. Then the absurdity is all the more apparent.

But in doing so, Schrödinger undermined his scenario as an actual experiment. There is not even a single classical measurement, let alone a quantum state one can write down, that defines “live” or “dead”. Of course, it is not hard to find out if a cat is alive or dead – but it is very hard to identify a single variable whose measurement will allow you to fix a well defined instant where the cat goes from live to dead. Certainly, no one has the slightest idea how to write down a wavefunction for a live or dead cat, and it seems unlikely that we could even imagine what they might look like or what would distinguish them.

This is then not, at any rate, an experiment devised (as is often said) to probe the issue of the quantum-classical boundary. Schrödinger gives no indication that he was thinking about that, except for the fact that he wanted a macroscopic example in order to make the absurdity apparent. It’s now clear how hard it would be to think of a way of keeping a cat sufficiently isolated from the environment to avoid (near-instantaneous) decoherence – the process by which “quantumness” generally becomes “classical” – while being able to sustain it in principle in a living state.

Ignoring all this, popular accounts typically take the thought experiment as a literal one rather than as a metaphor. As a rule, they then go on to (1) misunderstand the nature of superpositions as being “in two states at once”, and (2) misrepresent the Copenhagen interpretation as making ontological statements about a quantum system before measurement, and thereby tell us merrily that, if Bohr and colleagues are right, “the cat is both alive and dead at the same time!”

My suspicion is that, precisely because it is so evocative, Schrödinger’s thought experiment does not merely suffer from these misunderstandings but invites them. And that is why I would be very happy to see it retired.

Of course, there is more discussion of all these things in my book Beyond Weird.

A Place That Exists Only In Moonlight: a Q&A with Katie Paterson

I have a Q&A with Katie Paterson in the 25 April issue of Nature. There was a lot in Katie’s comments that I didn’t have room for there, so here is the extended interview. The exhibition is wonderful, though sadly it only runs for a couple more weeks. This is science-inspired art at its finest.



___________________________________________________________________________

Scottish artist Katie Paterson is one of the most scientifically engaged of contemporary artists. Her work has been described as “combining a Romantic sensibility with a research-based approach, conceptual rigour and coolly minimalist presentation.” It makes use of meteorites, astronomical observations, fossils and experiments in sound and light to foster a human engagement with scales in time and space that far exceed our everyday experience.

Many of her works have astronomical themes. All the Dead Stars depicts, on a sheet of black etched steel, the location of around 27,000 stars that are no longer visible. For the Dying Star Letters (2011-) she wrote letters of condolence for every star newly recorded has having “died” – a task that got ever more challenging with advances in observing technologies. And History of Darkness (2010-) is an ongoing archive of slides of totally dark areas of the universe at different epochs and locations.

For Future Library (2014-2114), 100 writers including Margaret Atwood and David Mitchell will write stories (one is commissioned each year since 2014) that will be kept in sealed storage until 2114, when they will be printed on paper made from 1,000 trees being planted in a forest in Norway. Paterson has said of the project that “it questions the present tendency to think in short bursts of time, making decisions only for us living now.”

Some of your works speak to concerns about degradation of the environment and the onset of the Anthropocene – Future Library, for example, and the Vatnajökull project (2007-8) that relays the live sound of meltwater flowing within an Icelandic glacier to listeners who dial in on mobile phones. Do you think that what can seem like an overwhelming problem of environmental change on scales that are hard to contemplate can be made tangible and intelligible through art?

Future Library has a circular ecology built into it: words become enmeshed in growing trees, which, fed by water and light, a century later will become books. It’s a gathering, and the trees spell out time. The artwork is made with simple materials, people, nature and words, and its connected to feelings and senses. The phone call I set up to the glacier was an intimate one-to-one experience; listening to a graveyard of ice. The crisis of global warming does not feel intimate when it’s screeching at us through screens and graphs – yet of course it is. Our planet is disappearing. Humans understand suffering, the cycle of birth and dying. We need a contemporary approach to what Stephen Hawking called ‘Cathedral thinking’: far-reaching vision that is humanly relatable.

David Mitchell sees an optimistic message in Future Library (as well as an exercise in trust): it is, he says, “a vote of confidence in the future. Its fruition is predicated upon the ongoing existence of Northern Europe, of libraries, of Norwegian spruces, of books and of readers.” How confident are you that the books will be made?

We have put many methods in place to ensure that the books will be made. Each tree is marked on a computerized system, and the foresters take great care. We are investigating the likely methods of making ink in 100 years’ time. The city of Oslo has taken this artwork to their heart, and even the king and queen of Norway are involved. We have a Trust whose mandate is to “compassionately sustain the artwork for its 100 year duration.” Yes, Future Library is an exercise in trust. This year’s author Han Kang described the project as having an undercurrent of love flowing through it. It concerns me, and certainly says something about our moment in time, that we even question whether it will be possible to make books in just 100 years. We have clearly reached a crisis.

You have said “Time runs through everything I make.” Your work deals with the scales of distance and time that astronomers and geologists have to consider routinely, but which far exceed human intuition. How can we cope with that?

I find professions that routinely deal with long timescales fascinating. For the foresters in Future Library, 100 years is normal. Geologists work across time periods where major extinctions become plots on a map. Astronomers work with spans of time that go beyond everything that has ever lived. However, this routineness may blur the immensity of the concepts at hand. All the same, we can unearth materials fallen from space and comprehend that they go back far beyond humanity’s time on earth. Our technologies are advanced enough to look to a time beyond the Earth’s existence, approaching the Big Bang. Humans have devised and created these images, yet they exceed our capacity to understand them.
For me the route to a different kind of understanding of time is through the imagination. That’s the space that provides the most freedom and openness. My art attempts to deal directly with concepts that I can’t get to otherwise. Perhaps mathematical languages enable something similar. My journey in astronomy has been a search for connection: understanding that we are not separate from the universe, but are intrinsically linked.

Your work Light Bulb to Simulate Moonlight (2008) does exactly what it says on the tin. The bulb was created in collaboration with engineers at OSRAM. Can you explain how it was made?

I approached Dieter Lang, innovation manager and lighting engineer at OSRAM, and asked him to adapt the methods they use to make ‘daylight bulbs’ to recreate moonlight. I wanted to create a whole lifetime of moonlight – a bulb that lasts the length of an average human life. Dieter took light measurements under a full moon in the countryside outside Munich. I’d always imagined the futility of trying to recreate something as ineffable as moonlight, yet I was happy with the result – the light bulbs burn very brightly, a yellowy-blue tinged light, which changes according to your distance to it, just like the moon.



Do you see projects like the “dead stars” works or History of Darkness as attempts to connect us to the vastness of deep space and time? Or might they in fact suggest the futility of trying to keep track of all that has happened in the observable cosmos?

It oscillates somewhere in between. History of Darkness has futility written into it, capturing infinite darkness from across space and time. Each slide could contain millions of worlds, and learning that these images refer to places beyond human life and even the Earth may expand our relationship to these phenomena, and enhance the sense of our fallibility. All the Dead Stars was made in 2009. I’d like to update it in years to come – it might become an expanse of white dots, as telescopes become even more powerful and abundant.
I’m always drawn to the idea of the universe as deep wilderness. No matter how extensive our research and advanced technologies become, we can never ever truly access the great beyond. I read that our ‘cosmic horizon’ is around 42 billion light years away. What lies beyond, whether finite or infinite, will forever remain outside our understanding. Creating artwork is as much my own way of grappling with the “divine incommensurability” of our position in the universe, as much as an attempt to communicate it with others.

In Earth-Moon-Earth (Moonlight Sonata Reflected from the Surface of the Moon) (2007), you encoded Beethoven’s sonata in Morse code, broadcast it to the surface of the moon in radio waves, and reconstructed the partial score from the reflections. That evidently required some powerful technology. And in 2014 an ESA mission to the Space Shuttle enabled your project of returning a fragment of meteorite to earth orbit. How do these collaborations with scientific institutions come about?

Earth-Moon-Earth was created with “moon bouncer” radio enthusiasts: underground groups of people sending messages to each other via the moon. I simply wrote them letters. While studying at the Slade [art school in London] I wandered into the Rock & Ice Physics Laboratory next door [in University College London]. They allowed me to play my glacial ice records in their walk-in freezers. That was when I found out quite how easy it was to approach others in different fields. With the moonlight bulb I simply called round a number of lighting companies till I came across the right person. The map of the dead stars involved hundreds of researchers. Some scientists are far more involved than others, from sharing data (NASA gave me the recipe for the scent of Saturn’s moon) to developing the artworks very closely with myself and my studio. [Astronomers] Richard Ellis and Steve Fossey have played an enormous role. I tend to approach people who are experts in niche fields, such as type 2a supernova, and I ask to draw on their specialization. It’s their passion, so they are generally receptive. This can be a chance to share their knowledge in a way that they haven’t been asked to before, that will become manifest in an artwork engaging with totally different audiences. Of course there can be bafflement, but so far it’s been overwhelmingly positive.
Recently, for the first time researchers from came to me. I received a message from a group of scientists working on a mission proposal to NASA, inviting me to join their team as a ‘space-artist/co-investigator’ inquiring into cosmic dust. I’m extremely happy about this, not only for the creative potential but because the scientists have shown genuine concern that an artist might have something of value to contribute to their research. The group understands that art can be a way to share their knowledge through a different, more experiential, channel.

Your concepts clearly draw on – and indeed derive from – new scientific discoveries and techniques. For example, The Cosmic Spectrum (2019) is a large rotating colour wheel on which segments show the “average colour” of the Universe (as perceived by the human eye) from the Big Bang until the present, partly using data from the 2dF Galaxy Redshift Survey. How do you stay abreast of the latest scientific developments, and what do you tend to look for in them?

I discovered [astronomer] Ivan Baldry’s work on the cosmic spectrum several years ago. Many of my ideas sit on the back burner for years and manifest themselves at later stages. I don’t feel on top of scientific developments, but sometimes just one experience has enough potency to carry projects through years later.
I’m drawn to current investigations into the sunsets on Mars caught by NASA’s Mars Curiosity rover – but equally by botanical records from bygone eras, or the ray of light in a Florentine cathedral that marks the solstice built centuries ago. Sometimes just looking at titles on the shelves of science libraries can be enough to evoke compelling images. My inspirations have been wide and varied: from looking through telescopes to extremely distant galaxies, to tending a moss garden in a Zen monastery (a universe in itself). I’ve always drawn inspiration from artists, writers, musicians and thinkers whose work has a cosmic dimension: for example, raku ceramicists molding ‘the cosmos in a tea bowl’.

Some of your works exist only as the ongoing collection of ideas in the book A Place That Exists Only in Moonlight (2019). Occasionally they find a striking resonance with concepts that, for a cosmologist or physicist say, might almost seem like a thought experiment or research proposal: “A reset button for the universe pressed only once”, say, or “The speed of light slowed to absolute stillness”. Do you ever find that the scientists you collaborate with or encounter are inspired by your ideas into asking new questions or conducting new investigations themselves?

A Place that Exists Only in Moonlight arose out of a period of heavy production. I wanted to find a ‘lighter’ approach, which is the creative core of everything for me; just the ideas themselves. The book contains artworks to exist in the mind, many of which refer to suns, stars, moons, planets, earthly and cosmic matter. The cover is printed with cosmic dust: a mixture of moondust, dust from Mars, shooting stars, ancient meteorites and asteroids. I wanted the reader to be able to hold and touch the material the words describe, while taking them in. The Ideas are like thought experiments, Zen koans, Gedankenexperiment. In a way that’s true of all my artworks. What time is it on Venus? What texts will be read by unborn people? Is it possible to plant a forest using saplings from the oldest tree on earth, can we make ink to be read only under moonlight? I’m always curious. I will post copies of the book to everyone I have worked with, and I would be very happy indeed if they chose to conduct new investigations themselves.

A Place That Exists Only in Moonlight, an exhibition that pairs Paterson’s works with studies of light, sky and landscapes by J. M. W. Turner, is at the Turner Gallery in Margate, UK, until 6 May.

Out of the ashes of Notre Dame

There is no positive spin to put on the fire that has gutted Notre Dame Cathedral, and it could sound idiotic to think otherwise. This was one of the masterpieces of the Gothic era, a place where – as Napoleon allegedly said of Chartres – an atheist would feel uneasy (although this atheist instead felt moved and inspired). I don’t yet know the extent of the damage, but it is hard to imagine that the thirteenth-century northern rose window will have survived the inferno, or that the west front of the building, which has been called “one of the supreme architectural achievements of all time”, will emerge intact. Even if the building is eventually restored – and I am sure it will be – one might wonder what will be the point of a twenty-first-century facsimile, bereft of the spirit and philosophy that motivated the original construction.

And yet… The Gothic cathedrals already undermine notions of “authenticity”. In past ages, they weren’t seen as buildings that had to be maintained in some “pristine” state at all costs. Ever since they were erected, they were modified and redesigned, sometimes with very little care for their integrity. This happened at Notre Dame in the seventeenth century, when the flame of Gothic had long gone out. There was a fashion for plonking grotesque, kitsch marble sculptures in place of medieval statuary, which was indeed the fate of Notre Dame’s high altar. The vandalism went on through the eighteenth century – and that was even before the Revolutionaries did their worst, melting down metal bells, grilles and reliquaries and then using the cathedral as a kind of warehouse. The Gothic revival of Viollet-le-Duc in the nineteenth century had better intentions but not always better taste.

This was ever the way, even in the Middle Ages: bishops would decide that their cathedral had become old-fashioned, and would commission some new extension or renovation that as often as not ended up as a jarring clash of styles. The notion of conservation and a “respect for the old” simply didn’t exist.

And that’s even before we consider the ravages of unintentional damage. Many of the wonders of Gothic architecture only came about as a result of fire in the first place. That is how we got Chartres: thanks to a fire in 1194 that destroyed the building commissioned in the 1020s (after the cathedral before that was burnt down). The conflagration was devastating to the morale of the local people: according to a document written in 1210, they “considered as the totality of their misfortune the fact that they, unhappy wretches, in justice for their own sins, had lost the palace of the Blessed Virgin, the special glory of the city, the showpiece of the entire region, the incomparable house of prayer”. Yet look what they got in its place.

And they had no hesitation in putting a positive spin on it. Another early thirteenth-century account asserted that this was God’s will – or the Virgin’s – all along: “She therefore permitted the old and inadequate church to become the victim of the flames, thus making room for the present basilica, which has no equal throughout the entire world.”

And so it went on throughout the Middle Ages and beyond: the astonishing edifices of the Gothic masters fell or burnt down, got neglected or half-dismembered, were subjected to undignified “improvement”, were ransacked or, later, bombed. Chartres has had catastrophic fires too: no one seems now too bothered that the original roof and allegedly wonderful timberwork beneath it were consumed by flames in 1836, or that the replacement we see today was originally intended only to be temporary.

What happened today at Notre Dame is truly a tragedy. But we shouldn’t forget that these magnificent buildings have always been works in progress, always in flux. Perhaps, in mourning what was lost, we can see it as an opportunity to marvel again at the worldview that produced it: at the ambition, the imagination, the profound union of technical skill and philosophical and spiritual conviction. And we can consider it a worthy challenge to see if we can find some way of matching and honouring that vision.