MADE FOR PIONEERS

A watch that tells the time of leaf-out There is a particular kind of anticipation that lingers in the forest of Sologne in France come early April. Each step upon the damp humus seems to awaken something beneath the bark. This is budburst season, when oaks begin to unfurl their leaves, and the entire forest hums with quiet urgency. I walk alone through the oak stands (Quercus petraea), a spectator of this unfolding concert, where every green tip and birdsong feels precisely cued, like a symphony’s first rising note. I was alone until I crossed paths with Émile R., a forest ranger who has walked these woods for twenty-seven years. A man with slow words and rooted presence, like the very trees he watches over. I asked him, almost playfully, “Can one predict the exact moment of oak budburst?” He smiled, and pointing to a just-unfurling leaf, replied: “You just need to know when the green oak leafroller hatches… That caterpillar is like a living timepiece. Never early, never late. She’s born exactly when the buds open. It’s nearly mathematical.” And so I learned of Tortrix viridana, a small moth whose caterpillar emerges only to feed on the tender young oak leaves. The eggs, laid in June, fall into winter diapause, a stillness suspended in time. It waits, untouched by fleeting thaws, until a precise accumulation of warmth, a sum of degree-days, signals the time to hatch. Photoperiod ,  the length of daylight ,  also plays its part, marking the true end of winter. Diapause prevents premature emergence during deceptive midwinter mildness. Thus, it is the interplay of environmental cues ,  winter’s cold followed by sufficient spring warmth ,  and the insect’s internal clock that enables such exact synchronization. The caterpillar breaks through its shell at the very moment when the young leaf appears: tender, unarmoured by tannins, perfectly timed for its arrival. “If she hatches too early,” Émile told me, “she starves, the bud scales are still hard, she can’t chew through. Too late, and the leaves are already tough and rich in tannins. She can’t digest them. Either way, she dies.” The margin of survival? Just a few days. And that, I realized, is where the forest hides its clockwork. The oak is the dial, the caterpillar its hand. Together they form a timepiece finer than any made by man. What’s more, Émile added, not all caterpillars are alike. “Some populations down south hatch later, in sync with holm oaks or cork oaks. Others here, with early-bursting pedunculate oaks. They’ve evolved to match their host. It’s a sort of loyalty.” Different genetic strains of T. viridana have thus adapted to local oaks, fine-tuning their internal clocks across generations. Natural selection at its most elegant: those that hatch with the budburst survive, and perpetuate the rhythm. Suddenly, I imagined a different kind of watch, one not driven by quartz or atoms, but by thermal pulses in wood. A “watch of the oaks,” that ticks only once a year, when the leaf tips appear, when the caterpillar stirs, when the forest exhales its first breath of spring. And above, in the canopy, great tits (Parus major) time their own nesting. They lay eggs to ensure their chicks hatch just as the caterpillars are at their peak. Meanwhile, the oak is far from defenseless.   “As soon as the caterpillar takes its first bite,” said Émile, “the tree responds. Chemically. Rapidly.”   Tannins accumulate, rendering the leaves unpalatable and toxic. But more than that, the oak warns its neighbors. I looked at him, surprised. “Yes,” he said, “they release volatile compounds. Signals in the air. Nearby trees pick them up. They start building defenses even before being attacked.” A forest that listens and responds. A caterpillar that races against chemistry. An ecosystem where every heartbeat, every opening leaf, is a signal. I thought of all this as we stood beneath a young oak. One bud had split, revealing a tiny green ripple, the caterpillar already feeding. Somewhere in the canopy, a bird called out. Another timekeeper, no doubt. As I left the forest that day, I dreamed of a different kind of chronometer, a timepiece not measuring seconds, but seasons. A watch guided by degree-days, by scent, by the trembling of a caterpillar’s egg. A diapause watch that does not count time, but waits for it. And in place of a ticking hand, a tiny green larva, telling me the hour of the oak. Our world is filled with wonders. I hope this story inspires you. Until the next one… A. Fost Consultant, Field Reporter, Observer of Time. Welcome to MADE FOR PIONEERS, where I explore the signs, clues, and effects of time on our natural world, the cosmos, and everything in between. Driven by an insatiable curiosity, I occasionally venture into unexpected topics that spark my interest. Through my notes, I aim to inspire creativity at Maison Augé, a creator of timekeepers and measuring tools rooted in natural mechanisms.  

The History of Sundials: Humanity’s Ancient Clock I recently learned that there is a sundial on the surface of Mars. Yet long before it landed there, in the deserts of Egypt, sundials had already shaped how we understand time. Before the ticking of mechanical clocks or the glow of digital screens, our ancestors relied on shifting shadows to structure their days. Their ingenuity, passed through generations, created devices that were not only functional but reflections of the way civilizations saw themselves in the vast order of the cosmos. Ancient Sundials: Time in the Shadows I remember standing in the Valley of the Kings, feeling the heat of the sun radiate from the limestone. "This," said Dr. Elias Karam, an Egyptologist specializing in early timekeeping, "is where the oldest known sundials were found. A simple L-shaped device, placed in the sand, dividing the day into twelve sections." The Egyptians, around 1500 BCE, had already begun measuring time with stone and shadow, structuring their days with the sun’s arc. Farther east, the Babylonians and Chinese were tracking time with gnomons—upright pillars that cast shadows in predictable patterns. By 800 BCE, the Chinese had refined the technique, using calibrated shadow lengths to estimate the hour. The Greeks took these ideas and applied geometry, creating the first sundials with hemispherical bowls, an innovation Anaximander introduced to Greece around 560 BCE. "What the Greeks did," explained Dr. Livia Petrova, a historian of ancient mathematics, "was transform sundials from mere tools into instruments of precise astronomical observation." In Rome, sundials arrived as trophies of conquest. General Marcus Valerius Messalla took one from Sicily in 263 BCE and set it up in the Forum. It told inaccurate time for nearly a century, calibrated for the wrong latitude. "Imagine the daily frustration," laughed Marco Bellini, a Roman historian. "A city running on an imported sundial, always slightly off!" But Rome adapted, mass-producing sundials for public squares, villas, even portable versions for travelers. Archaeologists have found bronze pocket sundials engraved with latitudes of different provinces, allowing an officer stationed in Gaul or Syria to know the hour back home. Medieval and Islamic Innovations: Time and Faith Sundials didn’t disappear after Rome fell; they simply found new purpose. In medieval monasteries, monks carved "mass dials" into church walls, using them to time prayers. Some of these, like the one at St. Gregory’s Minster in Yorkshire, carried cryptic Old English inscriptions. I ran my fingers over the grooves of that very dial once, tracing the same markings a Saxon monk had centuries before. Meanwhile, in the Islamic world, timekeeping reached new levels of precision. Ibn al-Shatir, a 14th-century scholar in Damascus, built a sundial for the Umayyad Grand Mosque that corrected seasonal variations. "He aligned the gnomon with the Earth’s axis," said Dr. Yusuf al-Hakim, an expert on medieval Islamic science, "a breakthrough that led directly to the concept of equal-length hours." His portable sundials even included a built-in compass, ensuring travelers could find both the time and the direction of Mecca in one glance. The Renaissance: A Golden Age for Sundials By the Renaissance, sundials had evolved into statements of scientific achievement. The era’s astronomers, including Johannes Kepler, refined our understanding of Earth’s orbit and the sun’s movement, explaining why sundials sometimes ran ahead or behind clocks. "Kepler gave us the Equation of Time," noted Dr. Sabine Laurent, a scholar of Renaissance astronomy. "His insights allowed sundials to become more accurate than ever before." It wasn’t just science; sundials became exquisite objects. In Poland, Johannes Hevelius crafted a grand sundial for Wilanów Palace, turning timekeeping into a work of art. Town squares featured monumental sundials, their Latin inscriptions urging passersby to reflect on life’s passage. "Horas non numero nisi serenas," read one in Florence. "I count only the sunny hours." A poetic sentiment, but an impractical philosophy for a working clockmaker. The Industrial Age and Beyond: From Obsolescence to Art By the 18th century, pendulum clocks replaced sundials as the primary means of timekeeping. "The turning point was the railway," said Thomas Abernathy, a historian of industrial technology. "Trains needed precise schedules. Sundials, bound to the movement of the sun, couldn’t compete with standardized time zones." And yet, sundials never vanished. Victorian scholars preserved historic dials, and towns still used them to reset mechanical clocks. Even in the modern world, sundials remain part of human landscapes. Maharajah Jai Singh II, dissatisfied with the inaccuracies of existing astronomical tables, constructed the Samrat Yantra in Jaipur—a 27-meter-high sundial so precise that its shadow moves visibly from minute to minute. In California, the Sundial Bridge casts a functional shadow across a dial plaza, while in Taipei, the world’s once-tallest skyscraper serves as a gnomon for an urban sundial park. I remember the moment I saw the Mars Rover’s sundial. A small, unassuming calibration device, yet inscribed with the words: "Two Worlds, One Sun." The realization struck me—this journey, from a carved stone in the Egyptian sand to an interplanetary mission, is not just about measuring time. It is about our need to mark our place within it. Sundials do not simply tell us when we are. They remind us who we are, standing under the same sun as those before us, watching the shadows move in silent testament to our passage through history.  

We all have a broad idea that Earth's magnetic field shifts over time. In fact, the magnetic poles move due to the continuous flow of molten iron and nickel in the outer core. This process, known as the geodynamo effect, generates the planet's magnetic field. Because this flow is turbulent and ever-changing, the poles are not fixed. Instead, they drift sometimes slowly, sometimes rapidlyas seen with the North Magnetic Pole, which has accelerated its movement from Canada toward Siberia in recent decades. What strikes me as particularly fascinating is that this movement can be measured not only with scientific instruments but also by observing life itself. The Loggerhead Sea Turtle In 1996, a loggerhead sea turtle named Adelita made history. Marine biologist Wallace J. Nichols fitted her with a satellite transmitter in Baja California, Mexico, and set her free into the vast Pacific. What followed was an extraordinary journey14,500 kilometers (9,000 miles) over 368 days before she reached the coastal waters of Japan, the place she was likely born. Adelita’s voyage provided the first-ever real-time tracking of a sea turtle across an entire ocean, confirming what scientists had long suspected: turtles can navigate the seas with astonishing precision, guided by nature’s invisible map. How Did She Achieve Such a Feat? Turtles are not the only creatures capable of covering vast distances with unerring accuracy; migratory birds share this ability. From my research, I found that scientists have two leading theories on how this remarkable navigation works. It all comes down to two biological mechanisms: Magnetite Crystals – Tiny iron-based minerals in the brains or beaks of some animals (like birds) act as internal compasses, aligning with Earth's magnetic field to provide directional cues. Cryptochrome Proteins – Found in the eyes of birds, turtles, and other creatures, these light-sensitive proteins undergo a reaction when exposed to light, allowing animals to “see” magnetic directions through a process influenced by quantum mechanics. When Sea Turtles Land on the Wrong Beach As precise as this system seems, I have heard from former colleagues studying sea turtle navigation that it isn’t always flawless. Some turtles return to nest only to find themselves just 200 meters away from their original hatching beach so close, yet not quite right! But in reality, the turtles are not wrong. Their navigation is perfect; it is Earth’s magnetic field that has shifted! The turtles are precisely where they were meant to be relative to the magnetic markers they imprinted at birth. It is the planet’s magnetic landscape that has moved beneath them. Take a moment to appreciate the poetry of this: we can track the movement of Earth’s magnetic field using only these beautiful marine creatures, whose journey across the seas is guided by an invisible force that is itself in motion. Our world is filled with wonders. I hope this story inspires you. Until the next one… A. Fost Consultant, Field Reporter, Observer of Time. Welcome to MADE FOR PIONEERS, where I explore the signs, clues, and effects of time on our natural world, the cosmos, and everything in between. Driven by an insatiable curiosity, I occasionally venture into unexpected topics that spark my interest. Through my notes, I aim to inspire creativity at Maison Augé, a creator of timekeepers and measuring tools rooted in natural mechanisms.