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The Tempus Fugit project: time flies with no return

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January 2023

The Tempus Fugit project: time flies with no return

As everyone knows, but tries not to think about, our time will one day run out. That is written into our DNA. It was handed down to us from our ancestors through a long chain that we pass on to our descendants. The chain of life. A chain that stretches back to time immemorial. Tempus Fugit is a crazy watchmaking project to create a watch that can be handed down over 10,000 years, a time capsule that records our fleeting participation in this long chain, generation after generation.


t’s a beautiful October day in the Joux Valley, the bucolic cradle of the greatest of grand complications. Cows graze peacefully on gentle green slopes; time seems to have stood still. One thinks of Virgil and his Georgics, which celebrates the profound beauty of nature and the tilling of the soil, a poem of epic proportions composed around 30BC, which aspired to peace as civil war was raging. Of these millennia-old verses, we all know at least two iconic words, inscribed on many a sundial: tempus fugit.

Time flies. But to do it justice, the line of verse should be recited in its entirety: “Sed fugit interea, fugit irreparabile tempus, singula dum capti circumvectamur amore”, or: “Meanwhile it flies, time flies with no return, while we err, captives of our love of detail.”

“Captives of our love of detail”?

And it is precisely in the company of a passionate captive of a love of detail that we currently find ourselves: Dominique Renaud, the renowned watchmaker and co-creator of Renaud & Papi, a workshop specialising in the most complex of grand complications that was acquired by Audemars Piguet. He left it a few years back to devote himself to his wildest projects as an independent watchmaker (remember his DR01, a ’spatially pivoting blade resonator’?). He takes us to the workshop of another passionate lover of detail, the ingenious young watchmaker, Julien Tixier.

Julien Tixier, Dr. Benoît Dubuis and Dominique Renaud
Julien Tixier, Dr. Benoît Dubuis and Dominique Renaud

It’s a truly astounding workshop where, once again, time seems to have stood still: less than 50m² in size, literally crammed to bursting with the most traditional and rarest small-scale watchmaking machines, and all the tools and instruments for creating, shaping and decorating a watch from start to finish, including the exterior. In this incredible mini-manufacture he reigns supreme (we will come back in detail to the career of Julien Tixier in a subsequent issue). It is here that the equally incredible adventure of the Tempus Fugit watch was played out.

The DRT Tempus Fugit incorporates a unique complication: a power reserve of... one's own life. The mechanism displaying the life reserve is based on personal factors provided to an external algorithm incorporating the latest scientific knowledge on risk, particularly in terms of the environment, physiology, and genomics.
The DRT Tempus Fugit incorporates a unique complication: a power reserve of... one’s own life. The mechanism displaying the life reserve is based on personal factors provided to an external algorithm incorporating the latest scientific knowledge on risk, particularly in terms of the environment, physiology, and genomics.

Let’s start with the DNA

It all began in the mind of a third man, Dr. Benoît Dubuis, president of the Swiss Academy of Engineering Sciences, director of Campus Biotech in Geneva, former dean of EPFL in Lausanne and president of Fondation Inartis.

A team made up of geneticists, statisticians and businesses in the field of genomics had created an algorithm that calculates personal life expectancy with the help of risk parameters based on environment, lifestyle and genetic makeup. That gave him the idea of designing a watch with a personalised “countdown” function based on the results of this algorithm of probable life expectancy. He approached Dominique Renaud.

The latter found the idea slightly shocking, but agreed to think it over. Who would want a watch that calmly counted down the remaining days of their life? Pure torture! But, he thought, if this countdown were not in the form of a cut-off point towards which we are irrevocably moving, but on the contrary one of life expectancy – in watchmaking terms a “life reserve” – linked to a perpetual calendar, programmable up to 2100, the proposition became rather more acceptable. Even better, by linking this life reserve to an even rarer, millennia-long perpetual calendar programmed to function for ten thousand years, we could transform our own mortality into a link in a long chain of lives with the aid of a “telltale” watch, a philosophical timepiece to hand down from generation to generation. More than just a watch, it would be a time capsule combining the mechanical arts and existential questions. “That’s what makes this watch totally disruptive!” exclaims Dominique Renaud.

This exceptional watchmaking challenge and the concept of highlighting the timeless march of successive finite periods won over Benoît Dubuis, who agreed to fund it with Fondation Inartis.

Designed entirely with transmission in mind

Dominique Renaud got to work and designed the first models of this unprecedented movement. Armed with these prototypes, he set off to see Julien Tixier, in his eyes the most promising young watchmaker of his generation. These two generations collaborated step by step on the Tempus Fugit, adding numerous innovations as they went along.

“Everything, absolutely everything in the development, architecture and execution of this watch is about transmission,” Julien Tixier explains. “In thousands of years the watch should always be simple to repair. It has to be possible to maintain it regularly. So it’s designed to be as simple as possible, despite the complexity of its function. And at the same time as the watch is handed down, it has to be possible to transmit the “timeless” know-how that allowed it to be made.”

“Everything, absolutely everything was made here, except one part: a micro-disc for the life gauge.”

The movement of the Tempus Fugit is remarkably compact: it measures just 31.5mm in diameter and 7.6mm thick. These small dimensions were made possible thanks first and foremost to a totally innovative, patented design: the Secular Perpetual Calendar. Instead of the traditional feeler-spindles, which make for much more cumbersome movements, the system was reversed and is designed as a highly compact, modular calculator, all the components of which are stacked around a single axis (to transform it into a “standard” perpetual calendar, programmed “only” up to 2100, you just remove one of the layers): a suspended train just 8.3mm in diameter and 1.85mm thick, with no fewer than 51 parts.

The most compact century perpetual calendar produced to date
The most compact century perpetual calendar produced to date

The “life gauge” indicating to wearers the progress of their life expectancy (or life expectancy reserve) is read around the edge of the movement by the progression of a coloured ring, programmed for 100 years, which moves forward one notch just once a year. “But there is no precise date of death; that’s suggested by a zone of fading colour over a few years,” says Dominique Renaud. This gauge is calibrated according to the data supplied by the owner and analysed by the starting algorithm. Symbolically, an electronic chip with the owner’s genome is incorporated into the movement (when ownership changes, it can be replaced by a new chip and the gauge reprogrammed).

There’s another surprise: a secret message chosen by the owner is engraved on a hidden plate and will suddenly appear at the outer edge of the movement on a given date a few years, decades or centuries hence. It’s both philosophical and romantic.

The movement is literally locked up in a monobloc case sealed by a lock “identical to that of a safe”, which can only be opened by an accredited watchmaker. With no visible crown or correctors, the watch is adjusted through the rear crystal by means of a small key hidden inside the pin of the removable bracelet.

The time just flew by

While the concept of temporal transmission from one generation to the next is at the heart of the Tempus Fugit project, it was also an active part of its execution. Between the seasoned, 60-something Dominique Renaud, and the extraordinarily gifted but not yet thirty Julien Tixier, transmission was continuous. The elder is full of praise for the younger man. “He gives me more than I give him”, he insists. From Dominique’s models, Julien created 3D models (between an ancient rose-turning machine and a lathe, not far from an enamelling kiln, stands a computer), drew up the plans and dimensions and got to work.

“Everything, absolutely everything was made here, except one part: a micro-disc for the life gauge and its highly complex internal teeth, which would have taken far too long,” says Julien, while from the outset everything was designed to be as simple as possible, whether in terms of function or production. While the watch itself can hope to live for thousands of years (the date of its own death is not indicated, we just know that it will stop on 31 December 9999), it was made to be highly wearable: compact, discreet and devoid of all frills. Timeless.

But when Julien says he sought to simplify production, Dominique corrects him: “He insisted on working with his own detent escapement, which requires a whole lot of adjusting, counted the balance spring himself, choosing it from a batch of beautiful old hairsprings; he made the dial, did the electroplating, made the case; he’s proficient in every kind of decoration, he tempers the steel, handles the kiln, polishes his pivots, cuts teeth himself, programmes a small CNC machine standing in a corner…” 

Both worked on every component, discussing continually in what was visibly a very fruitful collaboration. For these “captives of a love of detail”, time just flew by.

Ah yes – one final detail: the price. This was calculated according to the “characteristic impedance of a vacuum”, or the physical constant Z0, which results from the different amplitudes of electrical and magnetic fields that are propagated in a vacuum. Which, after calculation of the equation (the details of which we will spare you) comes to 376,730Ω. Or, in more understandable terms, 376,730 Swiss francs. (But this is not guaranteed for 10,000 years).

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