The Forgotten History of Sleeping in Two Shifts

Zaria Gorvett. The forgotten medieval habit of ‘two sleeps’. BBC, January 2022

For much of human history, people didn’t sleep through the night in one long stretch. Instead, they slept in two parts: an early “first sleep,” followed by a quiet period of wakefulness around midnight, and then a second sleep until morning. This pattern was so common that people once referred to it casually in court records, letters, and literature.

Historian Roger Ekirch uncovered this forgotten habit while studying life before the Industrial Revolution. He found that the time between sleeps, often called “the watch,” was used for prayer, conversation, chores, or simply reflection. People didn’t see this midnight waking as a problem; it was a normal part of nightly life.

The two-sleep pattern likely existed because nights were long and dark before artificial lighting. People went to bed earlier and woke naturally in the middle of the night. Modern experiments show that when people live without electric light, their sleep often returns to this older rhythm on its own.

Biphasic sleep began to disappear in the 19th century as gas lamps, electric lights, and factory schedules pushed bedtimes later while mornings stayed the same. Sleep became compressed into a single block, and the old pattern faded from memory. Understanding this history may help explain why waking up at night doesn’t always mean something is wrong. For most of human history, it was simply how people slept.

How Our Neighborhoods Shape Our Health

Noaeen, M., Rostami, A., Ghanem, I. et al. Mapping neighbourhood-level drivers of type 2 diabetes for precision public health using predictive and causal machine learning. Sci Rep, January 2026.

Type 2 diabetes is often discussed as a disease of individual lifestyle (diet, exercise, and genetics). But a new study from the University of Toronto reveals a deeper truth: where you live may be just as important as how you live.

Using artificial intelligence and advanced causal modeling, researchers analyzed data from over 1,100 neighborhoods across the Greater Toronto Area. Instead of focusing on individuals, they examined neighborhood-level features such as obesity rates, physical activity, income, age structure, mental health, and work stress. Their goal was not only to predict where diabetes is most common, but also to understand which factors actually drive that risk.

The results were striking. The AI models were able to identify high-diabetes neighborhoods with more than 95% accuracy. The strongest predictors were familiar – high obesity, physical inactivity, and older populations, but the causal analysis uncovered something more surprising: mental health was one of the most powerful protective factors. Neighborhoods with better average mental well-being had substantially lower diabetes rates, even after accounting for income, age, and lifestyle.

Work stress and smoking, on the other hand, were found to raise diabetes risk, highlighting the biological toll of chronic psychological strain. Interestingly, neighborhoods with higher proportions of recent immigrants and visible minorities tended to have lower diabetes prevalence, reflecting the well-known “healthy immigrant effect” and the protective role of social cohesion and cultural practices.

The study suggests a new vision for public health: instead of treating diabetes only in clinics, we should also treat it in communities, through mental-health support, stress reduction, walkable streets, and social infrastructure. In the age of data science, healing may begin not just with the patient, but with the neighborhood.

The Hidden Effects of Living in Space

Wijdan Al-Ahmadi et al., Spaceflight alters molecular networks linked to diverse human diseases in a single cellular model. Sci Adv, January 2026.

When astronauts return from space, many report strange changes. Their hearts beat differently. Their sleep is disturbed. Their vision becomes blurry. Their muscles weaken. For years, scientists have known about these effects, but not fully understood why they happen. A new study gives us a powerful clue by showing what happens inside human cells when they are exposed to space.

In this study, researchers sent human immune cells to the International Space Station and compared them with the same cells grown on Earth. They then examined how thousands of genes behaved in each environment. Nearly one third of all active genes changed their activity in space. This shows that spaceflight does not just cause small damage. It reshapes the way cells function.

Some of the biggest changes were seen in genes linked to the heart and muscles. These genes help control the electrical signals that keep the heart beating normally. In space, they became much more active. On Earth, the same genes are linked to irregular heartbeats, which may help explain why astronauts sometimes develop heart problems during long missions.

The study also found changes in genes that control sleep and the body clock, including those linked to melatonin. This matches the sleep problems many astronauts experience. Genes involved in vision and other senses were also affected, especially those connected to vitamin A and eyesight, helping explain vision changes in space. At the same time, genes that repair damaged DNA were reduced, likely because of cosmic radiation, making cells more vulnerable to long term damage.

These findings suggest that space activates the same biological pathways that cause heart disease, nerve problems, and aging on Earth, but in a much shorter time. By studying life in orbit, scientists may learn not only how to protect astronauts, but also how to better understand illness here on Earth.

In earlier times, our houses, roads, and neighborhoods were all neat, nice and warm. Our pleasures and enjoyments, our understanding of aesthetics, our perception of the arts were each a reflection of our spirit and of the profundity of our world of thought. Our homes were a place of rest and relief in the soft and smooth bosom of nature. Our neighborhoods were each a display and a stage where our world of thought and philosophy of life were exhibited and staged. Our roads that were crowded with mosques, Sufi lodges, schools, and other educational institutions and that made us think, feel, and emotionally inspired as if they were corridors opened to the metaphysical realms were the quintessence of liveliness and exquisiteness, getting us to a journey to a world of fancy evoking more charms and delights than that which is real-a journey imbuing our hearts with the most romantic feelings. Such was our places that we have gotten to know and possessed the experience through those still in existence; and we have seized up those that ceased to exist through the lens of the remains of those yet left.

Once we could constantly feel the mother nature extremely close to us physically and emotionally as if we were held and fondled lovingly in our mother’s bosom; we would never had the feeling of being away from the beauties but would make ourselves acquainted with the manifestations of the Most Beautiful of the Beautiful at different wavelengths at every single day. We would open our windows and doors whenever we wished and let those bountiful Divine beauties becoming manifest all over the place flow even into our bedrooms. We would turn our cottages, houses, villas, and mansions into a nice, charming spot in the universe in proportion to their caliber and could live the joyest of pleasures and the highest of excitements in such a miniature place of bliss. Again whenever we wished we would turn from our dwellings towards our surroundings, fill our ears with multifarious tunes and melodies resonating in the bosom of the entire existence and entertain our hearts with the most pleasing of the musical sounds.

Those days, we would imbibe-as if drinking in sips or taking breaths-all the beauties of our gardens and orchards that were more beautiful than the ornate tails of peacocks and more flamboyant than the wings of butterflies; we would live unquenchable joys and pleasures while taking a glance at the vicinities evoking in our minds the spectacular views of heavenly panoramas.

Just like our homes, our streets, neighborhoods and even towns and cities-with all parts and in all aspects, were like a special spot in the heart, a perspective of our sentiments, and an image of our thoughts reflected in various shapes. We would scent out and find in them the inclinations of our souls, their connectedness with our aspirations and all the immensity and profundity of the features making up our identity. No matter whether worn-out or well-kept, colorful or faded, our homes and streets were like living beings whispering constantly the lyrics of an immense message of the past.

All those buildings and residential areas with their cultivated, delicate, elegant, and oriental characteristics-exactly similar to the polite and courteous people dwelling in those houses, walking through those streets, and residing in those neighborhoods, were somewhat romantic, and more than that they looked like the corridors of heavenly pavilions and the shades of heavenly sceneries.

Some houses from among them were so exuberant and dynamic just like an establishment dedicated to worshipping or educating people. Looking from this perspective, they looked as if one could see the pure companions of Paradise in them. As every soul and sound in them spur mysterious inspirations-like a bud putting out new shoots, we would be filled with amazement and feel ourselves face-to-face with the most invisible and the most unknown of the lights, patterns, shades and hues.

Some of those houses would plant themselves in front of us as if they were petrified records of history and relate many, many stories to us through the fading and rusts here and there, through their calcified façades and their ages old artistic styles, and through the signs of wear and tear formed on their walls as a result of the happenings in the course of time.

As soon as some of those houses came into our view with a stance and style of their own-resembling our virtuous mothers with their loose outer garments evoking chastity and respect in us, they would make a way into us with seriousness, dignity and awe, and would blow self-control and possession into our spirits.

Still some other houses would look like a sign and symbol indicative of the beauty, profundity, grace, elegance, and mellowness of their indwellers through their pleasant colors of rosy pink, orange red, deep chestnut, violet, and lavender blue.

The expanse of our faith, the utmost end of our hopes, and the expectations of the furthest kind would come just before our eyes whenever we saw those houses reflecting the meaning, essence, tint, and style of a shared belief, a shared culture and a shared civilization with the heavenly profundity. The elegance, artistic style and beauty of those houses were so profound and so harmonious with the book of nature that the blueness of the azure sky and the gorgeous patterns of the earth were in close association with most of those houses, and as such one would think of each and every one of these houses as a cradle swaying between the lights, colors, and patterns of the earth and the skies. While one looks around or contemplates right before them, they would feel themselves up in the skies according to the immensity of their imagination and would be mesmerized as if they were the children of incredible bounties.

It was this good taste and pleasure in our landscaping, architecture, and city planning evoking in mind and spirit the feeling of connectedness between the earth and the skies-the feeling that aroused in such people as Pierre Loti (1850–1923) to have their last sleep in the shade of our sycamore maples that are as peaceful as the gardens of Paradise.

Those who lived in our houses and neighborhoods would feel the melodies in all tones, see the flowers blooming in all shades of color in our gardens and woods almost all the time, and experience the joyest of pleasures at the face of the dazzling harmony of the entire existence. Through their openings-one to the skies and the other to the earth, these houses and mansions would make one able to behold such an immense size greater than a hundredfold of their vastness of size and would become a door to the infinitude beyond their spatial largeness.

It was like a fairyland enchanting everyone with those houses in our towns marked with congruence and harmony with one another and those in our villages with their beauties at different wavelengths-with all these houses that provided relief and gave pleasure to the senses; with our roads long drawn out in loops; with our spacious mansions and palaces holding their heads high, honest and blameless as if they personified in concrete form the independence of an efficacious heart in the highest degree. It was such an enchanting land with our houses of prayer as the very heart of this entire harmony; with the minarets at one corner of these places of worship-just like an emphatic interjection in a discourse-proclaiming the greatest truth several times a day; with little domes that are gathered around the essence hidden in the spirit and meaning both the minaret and the mosque communicate; and with a compact group of religious schools, healthcare facilities, hostels and soup kitchens that are like a group of hatches taking refuge in and walking around a sitter. It was such a captivating land with the gardens, woods, swinging cypresses, breezes blowing with fragrant smells, free-standing fountains, drinking fountains, and bowers all over the place that were designed with a unique taste, some of whom were in peace and watchful and some in loud clamor-all of them were in a race to convey a message to us.

People in those days would rush from cities to the country for a change of air and seek for the pleasure of cheerfulness and joy, peace and serenity, and privacy and seclusion, or they move from villages to cities which were not too noisy at the time, experience the elevation, solemnity and seriousness of urban life, and would become accustomed to more systematic and broadminded urban ways. With the belief that they attained more profundity in both thoughts and feelings in cities, they would keep moving there and back.

Alongside the general outlook of the urban and rural life with a shared intellectual and cultural attitude, one could notice the diversity within society that is worthy of mentioning. Every single village, town, or city was kind of reflecting the same matter in a distinct way and expressing, so to speak, a metaphor in a poetic manner in different ways of versification. To a certain degree, each and every single one of them revealed a different style in attitude, composition, and evocative qualities. Each one of them was a miniature of the entire world reminiscent of a feast and festivity in a state of exhilaration, warmth and fervent ecstasy-a miniature formed and built up through hard work and physical and intellectual efforts lasting for ages, attaining a profound aesthetic beauty, and dazzling with their animate and inanimate accessories improving them.

Metropolises were, so to speak, a concord of fineness and beauty in every way through the strenuous efforts of the grand architects and the landscapers with thriving aesthetic tastes. The beauties of our orchards and gardens impressing our hearts like a poem; the stretching of our plains and meadows in joy; the monumental stance of our hills and mountains; the gentle murmuring of our drinking fountains and rivulets into the hearts; the graceful tulips everywhere dimpling up to us as if smiling; the rubicund cheeked roses with diffusing fragrance that we know fairly well for ages; our sweet scented carnations and pinks that are sharp and biting to the taste as if saying, “there is no rose without thorns”; the pleasant daisies that are so common in our lands and thus suffer our aloofness and disregard; the small violets that are so beautiful and yet so low at the soil level as if they are the symbol of unpretentiousness and meekness; the lilies that are so choosy and unwilling to become familiar; the tender, delicate magnolias which are as sensitive as our hearts; the hyacinths as our next door neighbor and relative; and the camellias and orchids that we become familiar later on-all these beauties with a smell reminiscent of elegiac tunes and the colors bringing to mind the eternal beauties would inflame the hearts that were amorous with eternity and would constantly remind us of the realm to be sought. When the chirping of the birds, the humming of insects, the bleating of the sheep, and the breathings of those who love each other for the sake of God were added upon all these beauties, everywhere would become thoroughly imbued with the heavenly shades and hues. Everywhere was vivacious, warm, and joyous like the Garden of Eden and menagerie at such a blessed period of time when nature was preserved and forests were protected.

In such a world time used to pass so much differently that a few hours spent there would turn out to be so copious and fruitful; it would become perpetual, never passing out of our mind.

I do not know if we could unearth and breathe life into these memories we have witnessed and experienced or those we have been told and have still kept in remembrance; however, I will always miss the “Paradise Lost” with its gardens, orchards, gardeners, and everything within it.