Look in a mirror and remember your younger self. By middle age, the face of the youth hangs there, recognizable still, but camouflaged by blotches, creases and sags. The most expensive cosmetic procedures cannot conceal the truth from more than a fleeting glance. We get older without daily awareness of our passage. John Milton conveyed this with customary elegance in an early sonnet in which he cast time as ‘the subtle thief of youth’. That subtlety is everything. Time is missed so easily, clocked when our attention is on it, then flying onwards when life shakes us from its contemplation. Even when we are watchful, however, we are aware of just a sliver of it.

One second can be divided into 1,000 milliseconds or 1 million microseconds. Microseconds might as well be flying by in fairyland, but we are attentive to movements that occur in a few milliseconds. From the Hawaiian shore, we marvel at the sight of a humpback whale breaching the water, and follow the steep curve of continuous motion and blunderous re-entry into the ocean. A video recording allows us to enjoy the titanic leap remotely on a mobile phone or television screen. Digital images captured at the standard cinematic speed of 24 frames per second are separated by 42 milliseconds (thousandths of one second). Watching the video, we perceive the movement of the whale throughout its breach, and we are unaware that individual images flash before us, like the pages of a flip-book, or cards upturned from a deck. The motion of the animal seems as smooth in the video as watching it live.

Some experiments suggest that the brain operates like a video camera, assembling movements as a series of discrete images to provide us with the illusion of continuous action. This feature of the underlying mechanism of vision is apparent from evidence showing that we can perceive the order in which distinct images are displayed when they are separated by as little as 3 milliseconds. Hummingbirds beat their wings fifty times per second, which means that a full up-and-down sweep is completed in 20 milliseconds. This puts the motion of their wings at the edge of our awareness; the body of the hovering bird is sharp, while its wings fill blurred triangles. Looking at something faster, we notice the disappearance of a cat flea from one position and its seemingly instantaneous reappearance a pillow’s-breadth away across a white bed sheet. In fact, a circus of hundreds of fleas could jump in quick succession, one after the other, in the time that elapses during the blink of an eye.

Human sensitivity to sound and to touch resides in roughly the same time frame as vision, with 2-millisecond audio bursts or needle-pricks making an impression on our consciousness and shorter stimuli escaping notice. The overlap between these senses is not surprising, because the mechanisms that underlie all forms of awareness run on the same nervous hardware. Faster events can certainly kill us, but natural selection has not seen fit to engineer a sensation that would allow us to out-manoeuvre an oncoming bolt of lightning, cobra strike or stingray barb. Evolution spends its time working on the avoidance of more common causes of youthful death. This leaves us riveted to seconds and detached from an awful lot of life.

In the seconds that it takes to leave home in the morning, Eden – my garden in Ohio – is exploding with invisible movements, with a fusillade of spores bursting into the air from tiny fungi that have sprouted on rabbit pellets since sunrise, leafhoppers jumping from the car roof using gear wheels that spin faster than the pistons in the Porsche, and pond hydras firing barbs into their prey using pressurized harpoons. Does any of this matter to us? No more than the daily revolution of Earth, in the sense that we do not need to know that this Lilliputian circus is in full swing to get on with the day. Sunrise and sunset happened long before we understood that the Earth was spinning on its soft axle, rather than staying put and allowing the Sun to fling itself about us every day. Indeed, a survey conducted a few years ago revealed that as many as a quarter of Americans adhere to a classical view of the heavens.

The uneducated may feel contented with the simplicity of their world view, or are unaware that there is more to know, but there is an awakening that comes from understanding that Earth is in motion and that life is lived on timescales that lie outside common comprehension. Mention of the cosmos is significant in this biology book, because a glimpse of the richness of nature lived in a single second is every bit as powerful as the sense of awe most of us feel when we look at the Milky Way on a clear night. As William Blake put it, ‘If the doors of perception were cleansed every thing would appear to man as it is, infinite.’ The thrill of watching a high-speed video recording of a dragonfly rowing through the air on its stained-glass wings can be as stirring as seeing a solar eclipse.

These views of nature fast can be appreciated for their own beauty, without any need for us to ponder questions of wider importance. But there is also a practical side to studying the brilliance of fast movements, because nature fast is the foundation for nature slow. We cannot understand one without the other. Every second of the life of a body is populated with chemical reactions, sparking nerves and sliding muscle fibres. Scrutiny of these fast events is a vital part of figuring out how we work and how we might repair the damage resulting from accident or illness. Nature fast holds comparable significance for ecologists who study the biology of forest canopies or hydrothermal vents on the sea floor. Every organism is constrained by the speed of the chemical and physical reactions inside its cells. Working in the other direction, from slow to fast, the examination of slow nature helps us to understand why fast mechanisms work the way they do. Every exchange and transformation of molecules that keeps a cell running has to pass muster from generation to generation. Natural selection imposes itself as an inescapable filter that permits effective combinations of fast chemical reactions to flow through time and rejects anything that impairs survival. From microbe to whale, everybody lives on processes that play out over a range of timescales.

Bottom up and top down, we explore the entire timetable of the universe in this book, from slivers of a second to billions of years. After considering the fastest movements in nature, we turn to whole seconds. We mark time in seconds whenever we pay attention to the present, closing our eyes in moments of bliss to keep the feeling going a little longer, or, more often, waiting for seconds to pass, standing in line at the supermarket or sitting in a dentist’s chair as the drill spins thousands of times per second, willing ourselves into the future. Minutes are more elusive, noted as soon as they have gone rather than as they pass. That is the way our perception of the environment is wired, and it comes from the biological need to make decisions from one second to the next. Nature seems to be attuned to this metre, although the precise length of a second is our invention, defined now by the frequency of an atomic clock. Our hearts beat every second – five times faster than the pulse of a hibernating marmot, and much slower than the twenty-beats-per-second flutter in the chest of a hummingbird. Elsewhere in the body, fluids ebb and flow every few seconds in the lymphatic and nervous systems, and bowel movements and orgasms obey similar pulse rates. Waves of much faster biochemical reactions control these and other second-by-second bodily fluxes, which illustrates the way in which we are swept into the future by the totality of natural processes that traverse several timescales.

Many of the behavioural programmes followed by animals are sustained for minutes and hours, and we have adopted hours as the main time intervals in our schedules. Daily or circadian rhythms are layered over the hours, and lengthier processes that depend on the accumulated effects of these activities orchestrate the life cycles of many animals, plants and microbes. The growth of plants and other photosynthetic organisms illustrates the link between the days and weeks of life. When sunlight bathes a forest of giant kelp, the flattened blades of these magnificent algae elongate by 0.5 m (1½ ft) per day, and on land, bamboo canes extend twice as fast, emitting an audible crackle. With the passage of months, seasonal changes in plant growth are evident in a cycle of greening that washes over the northern and southern hemispheres. Algal blooms cause widespread changes in ocean colour, too, particularly in coastal areas, where the seawater is enriched with nutrients that pour from the land. We mark months as they come and go, but sleep through one-third of the time and stay focused on the experiences of our conscious minutes and hours.