Time is a slippery thing. A minute in a dentist’s chair feels like an eternity, while an hour with friends vanishes in a blink. We live by the clock, yet our brains warp time in ways that defy its steady ticking. Why does time seem to slow in moments of fear, race when we’re engaged, and stretch endlessly in boredom?
The Brain’s Timekeepers
Unlike sight or hearing, time perception doesn’t have a single sensory organ. Instead, the brain pieces it together using multiple systems. The cerebellum and basal ganglia track fine motor actions and milliseconds. The suprachiasmatic nucleus in the hypothalamus syncs daily rhythms to light and dark. But for conscious experiences of time—whether something feels like it takes forever or flies by—the prefrontal cortex and hippocampus take charge.
Memory plays a key role. When we experience something new or exciting, the hippocampus works harder, encoding richer details. Later, when we look back, those dense memories make the event feel longer. Conversely, routine activities leave fewer imprints, so in hindsight, time seems to shrink. This is why childhood summers feel endless—our young brains are constantly absorbing new information—while adulthood is a blur of routines.
Time and Emotion: Why Fear Slows Everything Down
Ever noticed how accidents or moments of extreme fear seem to unfold in slow motion? This isn’t because the brain speeds up like a high-speed camera. Instead, the amygdala—our fear-processing center—goes into overdrive, dumping stress hormones into the system. The brain encodes more details, making it feel like more time has passed.
This “time dilation” effect has been tested. In one experiment, participants free-fell backward into a net while wearing a watch that flashed numbers too quickly to normally read. When asked afterward, they reported experiencing their fall in slow motion, but they couldn’t actually read the fast-flashing numbers. Their perception of time changed, but their ability to process real-time events didn’t.
Why Time Speeds Up as We Age
Ask any adult, and they’ll tell you—time moves faster with every passing year. One theory, the proportionality theory, suggests that as we age, each year becomes a smaller fraction of our life. For a 5-year-old, a year is 20% of their existence. For a 50-year-old, it’s just 2%. The brain, comparing time intervals unconsciously, registers time as moving faster.
Another factor is novelty. The first time we experience something, our brain devotes significant effort to encoding the details. Repeated experiences demand less attention. As childhood is filled with firsts, time feels expansive. But as life settles into predictable routines, fewer new memories are formed, compressing our sense of time in hindsight.
Flies, Birds, and the Fast Lane of Time Perception
Time perception isn’t universal. Each species experiences the passage of time according to how quickly their nervous system processes information. Humans take in roughly 60 frames per second—meaning our brain registers about 60 separate visual images each second. A housefly, however, processes closer to 250 frames per second. To the fly, your hand, which moves smoothly at normal speed for you, appears to inch forward in slow motion. With plenty of time to react, it dodges your futile attempt to swat it.
This phenomenon extends beyond flies. Many small animals, particularly those with high metabolic rates, perceive time in finer detail than larger creatures. Birds, for example, can process visual stimuli much faster than humans, which helps them react with split-second precision when navigating dense forests or escaping predators. Squirrels, always alert to their surroundings, experience a world where events unfold in a slightly heightened reality compared to ours.
What allows these creatures to process time differently? Part of the answer lies in their entire nervous system. Flies have rhabdomeric photoreceptors arranged in a compound eye, made up of thousands of tiny lenses, allowing them to detect rapid changes in motion. But vision alone isn’t enough. Their nervous system processes visual information far more rapidly than ours, enabling them to react in fractions of a second. Birds, too, don’t just have fast eyes; their neural circuits are optimized for rapid decision-making, allowing them to track and snatch moving prey mid-air with pinpoint accuracy. A fast visual system without an equally quick nervous response would be useless—speed matters at every level.
Environmental factors can also play a role. Temperature, for instance, influences metabolic rates, which in turn affects time perception. In warmer conditions, a fly’s neural processing speeds up, making time appear even slower from its perspective. In contrast, in colder temperatures, it reacts more sluggishly, as though time has accelerated beyond its normal grasp.
Time, it seems, is relative not just in the cosmic sense, but in the biological one as well. To a tortoise, we might appear as hyperactive blurs; to a fly, we are lumbering giants stuck in slow motion. Every creature lives in its own version of time, shaped by evolution, biology, and the unique needs of survival.
Can We Hack Time Perception?
If time seems to be slipping through your fingers, the good news is—you can slow it down. The key is novelty. Learning new skills, traveling to unfamiliar places, or even breaking daily habits can create more “mental timestamps,” expanding subjective time. Mindfulness and meditation, which focus attention on the present moment, have also been shown to stretch time perception.
On the other hand, if boredom makes time crawl, engaging in flow states—deep immersion in an activity—can speed things up. This is why athletes, musicians, and gamers often describe losing themselves in their work, unaware of time passing.
Could we ever speed up our perception of time artificially? Theoretically, if we could enhance neural processing—either through drugs, genetic modifications, or brain-computer interfaces—we might extend the boundaries of human perception. Soldiers, athletes, and pilots would gain an incredible edge, reacting to events faster than normal humans ever could. But there’s a downside. Faster perception means more sensory input, which could overwhelm the brain. A fly doesn’t have this problem because its brain is wired for speed, not deep thought. Interestingly, this high-speed processing comes at a cost—flies have short lifespans, often only living a few weeks. Their accelerated perception and metabolism lead to rapid aging and cellular wear. If humans processed the world at 250 frames per second, would we burn out? Would reality feel exhausting? Would it shorten our lifespan?
Living at Different Speeds
Time is relative, but not in the Einstein way we usually think about it. To a dog, whose perception runs a little faster than ours, we must seem sluggish and lazy. To a fly, we’re giants in slow motion. And to a tortoise? We’re probably a blur.
