High Touch High Tech

How Sleep Cycles Have Changed as Society Has Changed

A Scientific Look at Human Sleep Through Time

Sleep is a biological necessity, yet how humans sleep has shifted dramatically as society has evolved. While modern life often frames sleep as an eight-hour nightly obligation, scientific and historical evidence shows that human sleep patterns have been shaped and reshaped by technology, culture, and social structure.

Understanding how sleep has changed offers insight into why modern sleep problems are so common and why they are not simply a matter of personal failure or poor habits.

The Biology of Sleep: A Constant Beneath the Change

At the core of human sleep is the circadian rhythm, an internal biological clock that operates on an approximately 24-hour cycle. This system regulates sleep and wakefulness, hormone secretion (including melatonin), body temperature, and metabolism.

Light is the strongest external signal influencing circadian rhythms. Exposure to light, especially blue-wavelength light, suppresses melatonin and promotes alertness, while darkness allows melatonin levels to rise, signaling the body that it is time to sleep. This biological mechanism has remained consistent throughout human evolution, even as environments and lifestyles have changed.

Sleep Before Industrialization: Aligned With Nature

Light-Driven Sleep Timing

Before widespread artificial lighting, human sleep was closely synchronized with the natural day–night cycle. Sunset marked the beginning of reduced activity, while sunrise prompted waking. Seasonal variations also influenced sleep length, with longer sleep durations commonly reported during winter months.

Segmented Sleep Patterns

Historical documents from Europe and other regions describe a phenomenon known as segmented sleep, in which people slept in two blocks separated by a period of wakefulness around midnight. During this time, individuals might pray, read, reflect, or engage in quiet household tasks.

While this pattern appears frequently in historical records, modern anthropological research suggests sleep patterns varied widely across cultures and environments. Some pre-industrial societies practiced consolidated sleep, while others exhibited seasonal or flexible patterns depending on climate and lifestyle.

Sleep Duration in Traditional Societies

Contrary to popular belief, pre-industrial populations did not necessarily sleep longer than modern humans. Studies using wearable sleep monitors in hunter-gatherer and horticulturalist societies without electricity show average sleep durations ranging from approximately 5.7 to 7.1 hours per night, comparable to many industrialized populations.

The Industrial Revolution: A Major Turning Point

The Industrial Revolution introduced two powerful forces that permanently altered sleep:

Artificial Light

The widespread use of gas and electric lighting extended waking hours well beyond sunset. Evening light exposure delays melatonin release, shifting sleep onset later into the night and altering circadian timing.

Clock-Based Schedules

Factory work, standardized timekeeping, and compulsory schooling imposed fixed wake times, regardless of individual biological preference. Over time, societies transitioned toward monophasic sleep, a single consolidated sleep period, which became the cultural norm in industrialized nations.

This shift represented one of the first large-scale mismatches between biological rhythms and social expectations.

Modern Society: Technology and Circadian Conflict

Screens and Blue Light

Modern LED lighting and digital screens emit blue-rich light that strongly suppresses melatonin. Evening exposure delays sleep onset and reduce sleep pressure, making it harder to fall asleep at socially required bedtimes.

Social Jet Lag

The term social jet lag describes the discrepancy between biological sleep timing and externally imposed schedules. Many individuals sleep later on free days than on workdays, creating a pattern similar to repeated time-zone travel. This misalignment has been associated with increased daytime sleepiness, mood disturbances, and metabolic fluctuations.

Sleep Quantity vs. Sleep Timing

Large international studies show that people in industrialized societies may not sleep less than those in non-industrial settings. However, modern sleep is often more fragmented, more irregular, and more biologically misaligned, largely due to artificial light and social constraints rather than reduced opportunity to sleep.

Recent Social Experiments: What Happens When Schedules Change?

During the COVID-19 pandemic, widespread remote work and flexible schedules provided a natural experiment in sleep behavior. Many people reported sleeping longer and closer to their natural circadian preferences, highlighting how social structure often restricts sleep timing.

This period demonstrated that sleep patterns can shift rapidly when societal constraints are relaxed.

What Science Tells Us Overall

Several key conclusions emerge from sleep research across history and cultures:

• Human sleep biology has remained stable, but sleep expression is highly flexible
• The eight-hour, uninterrupted sleep model is not a universal historical norm
• Artificial light and rigid schedules are primary drivers of modern sleep disruption
• Many sleep problems stem from circadian misalignment, not personal failure

Understanding sleep as a biological process shaped by social forces allows for a more compassionate and evidence-based view of modern sleep challenges.

Conclusion: Learning From Our Sleep History

Sleep has never been a static behavior. From segmented nights by candlelight to late evenings illuminated by screens, human sleep reflects the world we build around ourselves. Modern science suggests that improving sleep may require not just individual behavior changes, but broader awareness of how light, work, and social expectations interact with our biology.

By recognizing how society has shaped sleep, we can better understand how to protect it.

At High Touch High Tech, we believe that science is most powerful when it is experienced, questioned, and explored firsthand. From understanding the biology of sleep to uncovering how our daily lives shape human behavior, we love helping students connect scientific concepts to the world around them. Through our on-site, in-school field trips, we transform classrooms into living laboratories, bringing hands-on experiments, curiosity, and discovery directly to students. By making science engaging and accessible, we aim to inspire the next generation of thinkers, innovators, and lifelong learners.

Come back next week and check out our next blog exploring the “sleep cycles” of plants!

Citations

1. Roenneberg, T., et al. (2012). Social jetlag and obesity. Current Biology, 22(10), 939–943.
2. Yetish, G., et al. (2015). Natural sleep and its seasonal variations in three pre-industrial societies. Current Biology, 25(21), 2862–2868.
3. Ekirch, A. R. (2001). Sleep we have lost: Pre-industrial slumber in the British Isles. American Historical Review, 106(2), 343–386.
4. Wright, K. P., et al. (2013). Entrainment of the human circadian clock to the natural light–dark cycle. Current Biology, 23(16), 1554–1558.
5. Cho, Y., et al. (2015). Effects of artificial light at night on human health. Chronobiology International, 32(9), 1294–1310.
6. Blume, C., Garbazza, C., & Spitschan, M. (2019). Effects of light on human circadian rhythms, sleep and mood. Somnologie, 23, 147–156.
7. Robbins, R., et al. (2021). Sleep duration and timing during the COVID-19 pandemic. Sleep Health, 7(2), 248–251.
8. Street lights in Singapore (8233226620).jpg Flickr images reviewed by File Upload Bot (Magnus Manske) Media needing category review as of 15 April 2016 Photographs by Edwin Soo Singapore photographs taken on 2012-11-30
9. Flaming June, by Frederic Lord Leighton (1830-1896).jpg

The Winter Solstice: The Science Behind the Shortest Day

Each year in late December, we experience a turning point in Earth’s journey around the Sun: the winter solstice. Often described as the “shortest day of the year,” the winter solstice marks a precise astronomical moment.

What Is the Winter Solstice?

The winter solstice occurs when Earth’s Northern Hemisphere is tilted as far away from the Sun as possible. At this moment, the Sun follows its lowest and shortest path across the sky, resulting in the fewest daylight hours of the entire year.

This isn’t caused by Earth being farther from the Sun, Earth is actually closest to the Sun in early January. Instead, the solstice happens because Earth is tilted about 23.5 degrees on its axis. That tilt controls how much sunlight each hemisphere receives throughout the year.

Why Is It the Shortest Day?

On the winter solstice:

• The Sun rises at its southernmost point on the horizon
• Solar noon is lower in the sky
• Sunlight strikes the Northern Hemisphere at a more indirect angle

All of this reduces both the duration and intensity of sunlight we receive. In much of the continental United States, daylight lasts only about 9–10 hours on the solstice.

When Do We Start Gaining Daylight?

Here’s the hopeful part: the return of the light begins immediately after the winter solstice.

• In the days following the solstice, daylight increases by about 1–2 minutes per day
• By late January, the daily increase can approach 2–3 minutes per day
• The rate continues to increase until around the spring equinox

Interestingly, the latest sunrise doesn’t occur exactly on the solstice, it happens a few days later. This is due to the way Earth’s elliptical orbit and axial tilt interact, a phenomenon known as the equation of time.

How Long Until the Summer Solstice?

From the winter solstice in late December, there are approximately 182 days until the summer solstice, which occurs around June 20–21.

That long arc from shortest day to longest day represents Earth slowly tipping the Northern Hemisphere back toward the Sun—bringing longer days, higher sun angles, and eventually summer warmth.

A Brief History of Solstice Celebrations

Long before modern astronomy, people noticed the solstice’s significance.

• Ancient stone structures like Stonehenge align with solstice sunrises and sunsets
• Roman celebrations such as Saturnalia honored the return of longer days
• Norse cultures observed Yule, a festival centered on light, renewal, and survival

While the traditions varied, the shared theme was universal: the Sun’s return meant hope, food, and life.

High Touch High Tech offers programs demonstrating the Earth’s tilt, solar eclipses, and lunar eclipses through hand-on experiments. We will bring the laboratory to your school! Go to sciencemadefun.io to check for a location near you!

Citations

• National Aeronautics and Space Administration (NASA). Earth’s seasons and axial tilt.
• National Weather Service. Winter solstice and daylight changes.
• Time and Date AS. Daylight length and solstice timing.
• Smithsonian National Museum of Asian Art. Historical solstice observances.
• Royal Museums Greenwich. Solstices and equinoxes explained.

On September 11, 2025 I attended a faculty introduction to the Biology Department at the University of North Carolina Asheville. Six Doctors of Biology introduced themselves and spoke briefly about their work. After each summary of the classes they teach and the research they are currently focused on, they each sat at a table of three to five students to answer questions and discuss their research further. They had conversations with each table of students.

Dr. Melinda Grosser was the director of the event as well as offering an overview of her own roles as professor and the research she is currently working on. She is doing extensive research on Staphylococcus Aureus because of its resistance to antibiotics. Her lab is using a control and comparing that to any mutations that may occur in their samples. She hopes to be able to design a knockdown strain. They are hoping to silence the antibiotic-resistant genes.

Dr Courtney Clark-Hachtel spoke about her study of Tardigrades and their remarkable resilience. She focuses on a particular species, Hypsibius exemplaris. Tardigrades are resilient in many ways, the most common is ability to desiccate or dry themselves out in times of drought stress. However, Dr. Clark-Hachtel is specifically focused on their ability to repair DNA after radiation exposure. Her lab is experimenting with observing how the DNA providing this ability reacts in other systems.

Dr Ted Meigs worked for the department of cancer research and pharmacology from 1996-2003. He has been a professor at UNCA for 23 years. He is currently researching how cells function and how molecules interact with cells. He has continued his research on cancer at UNCA. His lab is currently focused on the proteins involved in switched DNA that contribute to cell mutation on or off.

Dr Jonathan Horton has been a biology professor at UNCA for over 20 years. His focus is on forest mycology and ecology. His lab recently evaluated the vast amount of fallen trees due to hurricane Helene last September and their relation to possible changes in mycorrhiza. He has created a fungarium, a collection of dried fungus specimens. His collection exceeds 450 and he is working on getting a DNA bar code for each.

Dr. Camila Filgueiras teaches entomology along with other courses at UNCA. Her research focuses on how insects interact with their environment. She aims to understand the relationship of insects, plants, and microbes. One of her specific studies are on the American Chestnut and chestnut blight, Cryphonectria parasitica. Her lab also examines all pathogens affecting the majestic trees.

Dr Rebecca Hale is the director of undergraduate research. Her current research focuses on animal behavior where ecology and evolution overlap. Specifically, she is studying the parental behavior of salamanders. Not all species of salamanders have the same parental behavior. These behaviors include maternal care, paternal care and no care. One of the main species she studies is the Marble Salamander, Ambystoma opacum. The parental behavior of the Marble Salamander is that some mothers stay with her eggs and curve their body around the eggs to hold any moisture in contact with the eggs. This begins the hatching process. They do not stay for the hatching of the eggs.

Every professor had a chance to have a short chat with each student. They were all excited about their research and very engaging. They answered questions from the students and asked many questions of their own. When a student exhibited a focused interest on a particular branch of biology each professor offered to extend a conversation on the subject beyond the seminar. Many of the professors share their research with each other, for biological systems overlap.

We often view art and science as distinct disciplines; however, they are deeply intertwined. Integrating art with science has numerous benefits. First and foremost, art can make science concepts more interesting and engaging. At its core, science was born out of curiosity and an innate human drive to understand the world around us. Art enhances our creativity, communication skills, and problem-solving. Those benefits are drivers of curiosity, which perpetuate the drive for scientific exploration. These disciplines are really two sides of the same coin.

The powers of STEAM (Science, Technology, Engineering, Art, and Math) education start with our youngest learners. It can not only set foundations for lifelong learning, but also a love for learning. We never stop learning. Even our oldest learners personally benefit from pursuing STEAM education. Fostering creativity improves their quality of life, amongst many other benefits. Here at High Touch High Tech, we have programs that are specifically designed to integrate art and science for preschoolers, elementary students, and seniors alike.

So, why is creativity so indispensable to science? Science is inherently contestable. Therefore, scientific knowledge will always be ad interim. That is how we continue to grow in our knowledge. It may seem counterintuitive that good scientists try to prove themselves wrong rather than right. That can be uncomfortable for us. We desire clarity and reassurance in our understanding of the world, but it is this uncertainty that makes creativity so important. Scientists must look critically at their data. We use creativity to develop alternative explanations, and this is central to innovation.

We face challenges, both known and unknown. How we discover new possibilities and find solutions to our challenges can come about through upheavals in our historic ways of thinking. By integrating art with science, we reinforce the integral role of creativity with learning and better equip the students of today to become tomorrow’s innovators.

High Touch High Tech exists to help you bring art and science to your students; we are Science Made Fun! All of our programs deliver fun and engaging STEAM activities to students. Find a franchise location near you!

World Economic Forum – https://www.weforum.org/stories/2023/07/creativity-science-matters-ways-to-achieve-it/

High Touch High Tech would like to celebrate the importance of trees! Trees have many functions. One major one is that they provide habitat for 80 % of terrestrial biodiversity! Champion trees are determined by factors such as height and diameter and the champion titles are awarded to many species of tree. To learn all about this you could check out the website: https://www.americanforests.org/champion-trees/champion-trees-registry/?gclid=CjwKCAjwvfmoBhAwEiwAG2tqzCeucx870G8EmSA-OXPJOLXOSoRzVrLmS1n3rXgp5edKTnyUEIQMkRoCCfQQAvD_BwE. 

Today’s Champion tree is in Monroe County Florida. It is the Wild Banyantree or Ficus citrifolia. The trunk circumference on this Wild Banyontree is 244 inches and it reaches a height of 42 feet! The crown spread is 83 feet! 

Have you ever discovered a bag of cornmeal or a box of cereal that was shoved to the back of the pantry for long enough to forget, looked inside, and found it crawling with some sort of worm or beetle?  Chances are this is the mealworm or darkling beetle. They are commonly found around any grain storage areas due to the larvae’s insatiable desire for vegetative remains and delicious grains. Good news though: if food is what you were after when you discovered them, they can be eaten too!

Let’s start from the beginning. The oldest known record of mealworms was found in archeological digs exploring bronze age Turkey.  This means mealworms have been munching on our cereal for thousands of years!  Though they originated in the Mediterranean region, due to colonization and trade, they can now be found just about anywhere on earth.

The lifecycle of this insect begins as an egg that is about 0.05 mm and oval shaped. After about 4-19 days, depending on temperature consistency, the eggs hatch.  They prefer a temperature from 77-81 degrees. The female beetle lays about 70-100 eggs at a time. The newly emerged larvae are light orange or whitish and are about 3mm long; tiny! The baby larvae feed on vegetation and dead insects. They eat almost constantly and molt between each stage or instar. They go through about 9-20 instars through the duration of about 90-114 days. After the final molt when the larvae have reached the grand size of one inch it enters a pupate stage. The larvae will undergo a drastic change of physical features and attributes. The pupa is whitish and color and grow for about 3-30 days, once again depending upon temperature, they emerge as an adult darkling beetle!

The habitat of a darkling beetle in nature is dead grasses, leaf litter, decomposed organic matter, under old logs, and any other form of decomposing vegetation. Most often though they can be found near animal enclosures and food storage site including your pantry at times.

Uses for mealworm larvae include food for poultry, livestock, pigs, fish, reptile, pet birds, fish bait, and humans! They are packed with nutrients with every 100 grams of larvae raw having 206 calories and 14-25 grams of protein as well as potassium, copper, sodium, selenium, iron, and zinc. Compared to beef, mealworms are much more sustainable and occupy a much smaller amount of space. In May of 2017 Switzerland approved mealworms as a food and in 2021 they were approved by the European Union. Here in the U. S., there isn’t a specific regulation, and they can sometimes be found in novelty shops, or perhaps on sustainable homesteads if you search.

                For commercial or mass production, the space and energy required to raise mealworms is very little compared to livestock farms. You can raise them on oats, wheat, sliced potatoes, carrots, apples and just about any organic vegetative material.

Mealworms can also be used to recycle polystyrene! They can consume polystyrene at a rate of 34-39 mg per day. Specifically, the microorganism inside their gut is responsible for this action. They of course don’t prefer polystyrene and overall, it isn’t good for their long-term health, however it is possible and could be a source of recycling in the future

The possibilities of mealworm use may bring us closer to sustainability as we change towards mindsets and habits conducive to the preservation of the earth. You could easily set up your own mealworm operation to aid in supplementing your backyard chickens or ducks. All you need is a few plastic bins and a few mealworms and some grain to start the process. Even their “waste,” known as frass, can be used as a fertilizer. As we examine possibilities for a more sustainable the future, one thing is for sure:  mealworms can teach us so much about ecological cycles. Incorporating these models in our lives as we approach sustainability is key.

For more on mealworms and decomposers check out our podcast! https://spotifyanchor-web.app.link/e/LXdEenw2pub

For more on mealworms visit : https://study.com/academy/lesson/mealworms-lesson-for-kids-facts-life-cycle.html

Shan M Ritch

Why do we want cookies or cake after a Meal? Is there something physiological that makes that happen? Max Planke, from the Florida Institute for Neuroscience, decided to find out. It was already known that there is a group of nerve cells, called the POMC neurons, that make us feel full after a meal. But what Planke discovered was that these same nerve cells are responsible for sugar cravings. After eating the sugar treat there is a release of opiate endorphins giving a satisfying feeling. When studying this process in mice it was discovered that the endorphin release happens just by anticipating the sugary treat! Scientists think understanding this process could help with obesity.

So, this explains what and why for dessert cravings but is there science in the dessert itself? Of course, there is because cooking is chemistry! Let’s bite into this by analyzing chocolate cake. To create the perfect moist soft chocolate cake the protein gluten in flour must be processed perfectly. When mixed with water the gluten is activating creating a web like structure that traps air bubbles. If you look at cake with a magnifying glass, you can see the results of those bubbles. When sugar and chocolate are added the sugar caramelizes adding flavor and texture. Then when butter or oil is added it inhibits the gluten formation. Once again, the amount of each ingredient is crucial to get the desired flavor and texture.

Between the ages of 2-4 children ask why repetitively. This is because the world around them has come into focus and they want to understand All Of It! That curiosity can be nourished by presence and wonder all through our lives. So, when you have a craving for that perfect chocolate cake after a wonderful meal, we know it’s because of the neurons in our stomachs and if you are curious why a chocolate cake from your grandma tastes best it is because she has repeated a recipe that is tried and true!

https://www.sciencedaily.com/releases/2025/02/250213143309.htm

https://maxplanckneuroscience.org/institute/mpfi-neuroscience/

https://cwcpediatrics.com/2025/07/21/why-is-my-child-asking-so-many-questions-understanding-the-why-phase/

 Indigenous Americans have contributed in the field of science in numerous ways. Here are just a few of the many indigenous scientists to highlight.

Dr. Susan La Flesche Picotte (June 1865-Sep.1915) was one of the first indigenous people and first indigenous woman to earn a medical degree! She worked diligently on public health reforms such as school hygiene, food sanitation, and combat tuberculosis.

Dr. K. Tsianina Lomamawaima was born in 1955. She researched indigenous studies, anthropology, history, and political science. She is currently a professor at Arizona State University! She wrote the book They Called it Prairie Light: The Story of Chilocco Indian School in 1994.

Dr, Leroy Little Bear went to the University of Utah in 1975. He up until 1977 was a researcher at the University of Lethbridge where he is the founding member of the Native American Studies Department. He has received awards such as the Officer Order of Canada and the Alberta Order of Excellence.

John Herrington, born 1958, served in the U. S, Navy and also was a mission specialist at NASA on the Endeavor space shuttle! He also did work in the Aquarius underwater laboratory simulating survival during extreme conditions.

Mary Golda Ross Aug 1908-April 2008) was an Aerospace Engineer who helped design planes and spacecraft. She was from the Cherokee Nation. She was a founding member of the Society of Women Engineers.

Feel free to follow any of the links below to learn more!

https://www.sciencebuddies.org/blog/native-american-scientists-engineers

https://en.wikipedia.org/wiki/K._Tsianina_Lomawaima

https://en.wikipedia.org/wiki/John_Herrington

https://en.wikipedia.org/wiki/Leroy_Little_Bear