At research stations such as Concordia and Vostok, when the Sun sets in May and does not return until September, the very idea of day and night collapses. Human circadian rhythm begins to fail, because the body is biologically programmed to rely on sunlight to regulate melatonin for sleep and cortisol for alertness. In the absence of solar light, the brain enters a state scientists call free running, where internal timekeeping loses its anchor. As a result, the human biological clock slowly stretches. A single day no longer lasts 24 hours, but can drift into 28 or even 30 hours without the person realizing it.
Within this distorted rhythm, a phenomenon known as stretched sleep begins to emerge. Surrounded by temperatures that can plunge below minus 80 degrees Celsius and an outside world wrapped in absolute darkness, many individuals fall into unusually deep and prolonged sleep cycles. Firefighters, engineers, and technicians stationed there have reported going to bed on what they believed was Monday night, only to wake up convinced it was still the same day, then discovering it was already Wednesday afternoon. Without sunrise or sunset as reference points, the mind loses its ability to measure time accurately. Twelve hours of sleep may feel like a brief nap, while a short rest can feel endlessly long.
As external sensory input diminishes, the brain compensates by turning inward. This is where intensely vivid and prolonged dreams appear. Many people in Antarctica describe dreams that are cinematic, colorful, and structured like long narratives unfolding over what feels like days or weeks. Lucid dreaming becomes more frequent, as the brain generates its own stimulation to replace the silence and darkness outside. Upon waking, confusion often follows. With the same dim artificial lighting and the same blackness beyond the window, the boundary between dream memory and real experience begins to blur. People frequently ask their colleagues whether a conversation, a meal, or a task actually happened, or if it was only dreamed moments ago.
While some individuals sleep excessively, others experience the opposite extreme. A condition informally called The Big Eye occurs when darkness triggers chronic insomnia. These individuals may sit motionless for hours, staring into space in a state resembling involuntary meditation. Time perception becomes completely unreliable. What feels like a few minutes of quiet reflection can, in reality, stretch into several hours without any awareness of its passage. This sensation of frozen time can be unsettling, yet strangely calm.
For those who endure the six month night, the experience often evolves beyond science and enters the realm of philosophy. People learn to release rigid schedules, no longer forcing their bodies to obey clocks that have lost meaning. Instead, they begin listening to hunger, fatigue, and alertness as internal signals rather than external rules. When the Sun finally rises again in September, many describe the moment as a form of psychological rebirth. It feels like awakening from an ancient, endless sleep, carrying fragments of long, surreal dreams that only the Antarctic darkness could produce. The return of light does not merely illuminate the ice, but reawakens the human sense of time, self, and reality itself.