News
Sunflowers make small moves to maximize their Sun exposure – physicists can model them to predict how they grow
Charles Darwin’s detailed observations of plant movements, such as sunflower circumnutation and self-organization, reveal how randomness helps plants optimize growth and adapt to their environments. Sunflowers!
Last Updated on March 6, 2026 by Daily News Staff
Chantal Nguyen, University of Colorado Boulder
Sunflowers make small moves to maximize their Sun exposure – physicists can model them to predict how they grow
Most of us aren’t spending our days watching our houseplants grow. We see their signs of life only occasionally – a new leaf unfurled, a stem leaning toward the window.
But in the summer of 1863, Charles Darwin lay ill in bed, with nothing to do but watch his plants so closely that he could detect their small movements to and fro. The tendrils from his cucumber plants swept in circles until they encountered a stick, which they proceeded to twine around.
“I am getting very much amused by my tendrils,” he wrote.
This amusement blossomed into a decadeslong fascination with the little-noticed world of plant movements. He compiled his detailed observations and experiments in a 1880 book called “The Power of Movement in Plants.”
In one study, he traced the motion of a carnation leaf every few hours over the course of three days, revealing an irregular looping, jagged path. The swoops of cucumber tendrils and the zags of carnation leaves are examples of inherent, ubiquitous plant movements called circumnutations – from the Latin circum, meaning circle, and nutare, meaning to nod.
Circumnutations vary in size, regularity and timescale across plant species. But their exact function remains unclear.
I’m a physicist interested in understanding collective behavior in living systems. Like Darwin, I’m captivated by circumnutations, since they may underlie more complex phenomena in groups of plants.
Sunflower patterns
A 2017 study revealed a fascinating observation that got my colleagues and me wondering about the role circumnutations could play in plant growth patterns. In this study, researchers found that sunflowers grown in a dense row naturally formed a near-perfect zigzag pattern, with each plant leaning away from the row in alternating directions.
This pattern allowed the plants to avoid shade from their neighbors and maximize their exposure to sunlight. These sunflowers flourished.
Researchers then planted some plants at the same density but constrained them so that they could grow only upright without leaning. These constrained plants produced less oil than the plants that could lean and get the maximum amount of sun.
While farmers can’t grow their sunflowers quite this close together due to the potential for disease spread, in the future they may be able to use these patterns to come up with new planting strategies.
Self-organization and randomness
This spontaneous pattern formation is a neat example of self-organization in nature. Self-organization refers to when initially disordered systems, such as a jungle of plants or a swarm of bees, achieve order without anything controlling them. Order emerges from the interactions between individual members of the system and their interactions with the environment.
Somewhat counterintuitively, noise – also called randomness – facilitates self-organization. Consider a colony of ants.
Ants secrete pheromones behind them as they crawl toward a food source. Other ants find this food source by following the pheromone trails, and they further reinforce the trail they took by secreting their own pheromones in turn. Over time, the ants converge on the best path to the food, and a single trail prevails.
But if a shorter path were to become possible, the ants would not necessarily find this path just by following the existing trail.
If a few ants were to randomly deviate from the trail, though, they might stumble onto the shorter path and create a new trail. So this randomness injects a spontaneous change into the ants’ system that allows them to explore alternative scenarios.
Eventually, more ants would follow the new trail, and soon the shorter path would prevail. This randomness helps the ants adapt to changes in the environment, as a few ants spontaneously seek out more direct ways to their food source.
In biology, self-organized systems can be found at a range of scales, from the patterns of proteins inside cells to the socially complex colonies of honeybees that collectively build nests and forage for nectar.
Randomness in sunflower self-organization
So, could random, irregular circumnutations underpin the sunflowers’ self-organization?
My colleagues and I set out to explore this question by following the growth of young sunflowers we planted in the lab. Using cameras that imaged the plants every five minutes, we tracked the movement of the plants to see their circumnutatory paths.
We saw some loops and spirals, and lots of jagged movements. These ultimately appeared largely random, much like Darwin’s carnation. But when we placed the plants together in rows, they began to move away from one another, forming the same zigzag configurations that we’d seen in the previous study.
We analyzed the plants’ circumnutations and found that at any given time, the direction of the plant’s motion appeared completely independent of how it was moving about half an hour earlier. If you measured a plant’s motion once every 30 minutes, it would appear to be moving in a completely random way.
We also measured how much the plant’s leaves grew over the course of two weeks. By putting all of these results together, we sketched a picture of how a plant moved and grew on its own. This information allowed us to computationally model a sunflower and simulate how it behaves over the course of its growth.
A sunflower model
We modeled each plant simply as a circular crown on a stem, with the crown expanding according to the growth rate we measured experimentally. The simulated plant moved in a completely random way, taking a “step” every half hour.
We created the model sunflowers with circumnutations of lower or higher intensity by tweaking the step sizes. At one end of the spectrum, sunflowers were much more likely to take tiny steps than big ones, leading to slow, minimal movement on average. At the other end were sunflowers that are equally as likely to take large steps as small steps, resulting in highly irregular movement. The real sunflowers we observed in our experiment were somewhere in the middle.
Plants require light to grow and have evolved the ability to detect shade and alter the direction of their growth in response.
We wanted our model sunflowers to do the same thing. So, we made it so that two plants that get too close to each other’s shade begin to lean away in opposite directions.
Finally, we wanted to see whether we could replicate the zigzag pattern we’d observed with the real sunflowers in our model.
First, we set the model sunflowers to make small circumnutations. Their shade avoidance responses pushed them away from each other, but that wasn’t enough to produce the zigzag – the model plants stayed stuck in a line. In physics, we would call this a “frustrated” system.
Then, we set the plants to make large circumnutations. The plants started moving in random patterns that often brought the plants closer together rather than farther apart. Again, no zigzag pattern like we’d seen in the field.
But when we set the model plants to make moderately large movements, similar to our experimental measurements, the plants could self-organize into a zigzag pattern that gave each sunflower optimal exposure to light.
So, we showed that these random, irregular movements helped the plants explore their surroundings to find desirable arrangements that benefited their growth.
Plants are much more dynamic than people give them credit for. By taking the time to follow them, scientists and farmers can unlock their secrets and use plants’ movement to their advantage.
Chantal Nguyen, Postdoctoral Associate at the BioFrontiers Institute, University of Colorado Boulder
This article is republished from The Conversation under a Creative Commons license. Read the original article.
STM Daily News is a vibrant news blog dedicated to sharing the brighter side of human experiences. Emphasizing positive, uplifting stories, the site focuses on delivering inspiring, informative, and well-researched content. With a commitment to accurate, fair, and responsible journalism, STM Daily News aims to foster a community of readers passionate about positive change and engaged in meaningful conversations. Join the movement and explore stories that celebrate the positive impacts shaping our world.
https://stmdailynews.com/category/stories-this-moment
Last Updated on November 13, 2026 by Daily News Staff
STM Daily News | November 12, 2026
Graffiti Cleanup Transforms Oceanwide Plaza
LOS ANGELES — The unfinished skyscrapers known as downtown Los Angeles’ “Graffiti Towers” have reached a visible milestone: most of the exterior tagging has been removed, although completing the long-stalled Oceanwide Plaza development remains a separate challenge.
City officials celebrated the cleanup November 12. According to the mayor’s office, crews cleared graffiti from roughly 250 balconies across the three-tower complex opposite Crypto.com Arena and near the Los Angeles Convention Center. Remaining work has included touch-ups on windows and other exterior areas.
Oceanwide Plaza was envisioned as a mixed-use destination with residences, a luxury hotel, shops and restaurants. Construction stopped in 2019 after Beijing-based developer Oceanwide Holdings could no longer finance the project.
In early 2024, trespassers covered the unfinished towers with graffiti, turning them into an internationally recognized sight. The property also attracted dangerous stunts and heightened concerns about security.
The development entered bankruptcy in February 2024. This July, a bankruptcy court approved a purchase arrangement involving KPC Square, a joint venture between KPC Group and Lendlease. Graffiti removal began while the acquisition was still pending.
What Comes Next for LA’s Graffiti Towers?
The partnership is targeting a January 2027 closing, according to the Los Angeles Business Journal. Financing, a construction contract and required approvals remain important steps before the development can be completed.
For downtown residents and businesses, the cleanup marks tangible progress at a prominent property. However, it does not mean the towers are ready to open, and no firm opening date has been announced.
Sources
- Los Angeles Mayor’s Office, November 12, 2026: https://mayor.lacity.gov/news/mayor-bass-celebrates-graffiti-removal-oceanwide-plaza-clearing-way-full-restoration-and
- Los Angeles Business Journal, November 9, 2026: https://labusinessjournal.com/real-estate/cleaning-up-oceanwide/
- City News Service / MyNewsLA, November 12, 2026: https://mynewsla.com/life/2026/11/12/graffiti-cleanup-milestone-marked-at-oceanwide-plaza-in-downtown-la/
Forgotten Genius Fridays
David Crosthwait: The Engineer Behind Indoor Comfort
David Crosthwait helped solve the challenges of heating large buildings, including Radio City Music Hall. Explore his inventions and lasting engineering legacy.
Forgotten Genius | STM Daily News
When audiences enter New York’s Radio City Music Hall, they notice the stage, the lights, and the sweeping auditorium. The engineering that keeps the building comfortable rarely receives applause.
One of the people behind that comfort was David Nelson Crosthwait Jr., a Black engineer and inventor whose work helped advance heating, ventilation, and temperature control in large buildings.
His career offers a reminder that some of the most useful inventions work quietly around us.
Solving the Problem of Heating Large Buildings
Heating a large building takes more than producing enough heat. Different areas can have different needs: one side may face bitter wind while another receives warming sunlight. Delivering the right amount of heat throughout the building requires careful control.
Crosthwait devoted much of his career to those challenges. A Purdue University engineering graduate, he worked for the C.A. Dunham Company, developing equipment and systems for heating and ventilation.
His inventions included improvements to boilers, thermostat controls, and vacuum pumps. These components helped engineers manage the movement and regulation of heat in larger buildings.
One example appears in U.S. Patent No. 1,727,965, granted in 1929. The patent describes a vacuum steam-heating system designed to serve different sections of a building at different steam pressures. That allowed the system to address varying heating needs while using a shared steam source.
Behind the technical drawing was a practical question: How could one building provide comfortable conditions in spaces that needed different amounts of heat?
His Connection to Radio City Music Hall
Crosthwait’s best-known projects included designing the steam-heating system for Radio City Music Hall at Rockefeller Center.
It was a fitting assignment for an engineer whose expertise centered on the demands of large buildings. While performers entertained audiences, the systems behind the scenes helped make the experience comfortable.
His contributions extended across a substantial body of work. The National Inventors Hall of Fame credits him with 39 U.S. patents and 80 international patents, spanning heating, refrigeration, controls, and other technologies.
Sharing Knowledge and Breaking Barriers
Crosthwait also helped other engineers learn. He wrote technical material, contributed to engineering guides, and later taught steam-heating theory and control systems at Purdue.
In 1971, he became the first Black Fellow of the American Society of Heating, Refrigerating and Air-Conditioning Engineers. Purdue awarded him an honorary doctorate in 1975, and the National Inventors Hall of Fame inducted him in 2014.
His legacy rests in the practical details of engineering: controlling pressure, improving equipment, and making complicated systems work together.
The next time you settle into a comfortable auditorium on a cold evening, consider the ingenuity behind that warmth. David Crosthwait helped make indoor comfort an engineering achievement worth remembering.
Discover more inventors and innovators through the Forgotten Genius series in The Knowledge at STM Daily News.
Related Links
- National Inventors Hall of Fame: David Crosthwait — Biography covering his inventions, patent totals, Radio City Music Hall work, teaching, and professional honors.
- Rockefeller Center: A Rock Center Innovator — Highlights his role in designing Radio City Music Hall’s steam-heating system.
- Original 1929 Patent: U.S. Patent No. 1,727,965 — Technical drawings and Crosthwait’s description of a steam-heating system serving different building sections at different pressures.
- Purdue University Libraries: Historical Timeline — Documents his 1913 graduation and contributions to heating, ventilation, and air conditioning.
Sources: National Inventors Hall of Fame, Rockefeller Center, Purdue University Libraries, and U.S. Patent No. 1,727,965.
Family
The House That Hosts: When Your Home Becomes Your Holiday Entertaining Partner
The House That Hosts: There’s a special pleasure in opening your home for the holidays to share the menu you’ve imagined, welcome guests to the glow of a room ready for company and enjoy the anticipation of familiar faces at the door. This year, make sure the house itself can lend a hand.
The House That Hosts: When Your Home Becomes Your Holiday Entertaining Partner
(Feature Impact) There’s a special pleasure in opening your home for the holidays to share the menu you’ve imagined, welcome guests to the glow of a room ready for company and enjoy the anticipation of familiar faces at the door. Every detail is an opportunity to make the loved ones you’ve invited feel especially welcome.
This year, make sure the house itself can lend a hand.
From the kitchen to the living room to the guest bathroom, residential technology offers new ways to turn a host’s imagination into a memorable experience. The best innovations don’t take over the occasion. They help the person bringing everyone together make it extraordinary.
Nor does a home need an elaborate network of connected gadgets. A few well-chosen technologies can make a difference. Explore these ideas from the bathroom design and technology experts at TOTO to level up the different hosting areas of your home as you prepare to gather with family and friends this holiday season.
The Kitchen: Bringing Something Extraordinary to the Table
The holidays invite a little culinary ambition, and today’s kitchens are borrowing a few tricks from professional chefs.
Imagine presenting a beef tenderloin cooked to a perfect rosy pink from edge to edge, thanks to the precision of sous vide cooking. Or bringing a platter of roasted root vegetables to the table, their edges beautifully caramelized and their centers tender, prepared in a steam-convection oven. On an induction cooktop, precise, responsive heat helps turn fresh mushrooms into a golden, savory accompaniment.
These technologies put sophisticated techniques within reach of adventurous home cooks, opening the door to new preparations and dishes worthy of special occasions. Experiment with new flavors and rich cuisines that fill your home with enticing aromas and your guests with awe at the first bite.
Nothing says “happy holidays” quite like watching guests discover what you’ve created for them.
The Living Area: Setting the Stage for Connection
Holiday gatherings have a rhythm all their own. The first arrivals are greeted with excitement, conversations pick up where they left off months (or years) prior, and before long, the room is filled with laughter and the pleasure of being together.
Today’s smart lighting systems allow hosts to create and schedule scenes that shift from the sparkle of a festive welcome to the softer, golden glow of an intimate evening. Multiroom wireless audio systems can bring lively music into the kitchen while keeping it a gentle accompaniment to conversation in the living area. Digital art displays can turn a television screen into a gallery of artwork chosen to complement the celebration, bringing holidays past to life as loved ones mingle in the present.
Successful holiday entertainment engages people not merely as observers, but participants. A short film could start an inspiring conversation, the right music might get people dancing and atmospheric visual-audio experiences, like a crackling fireplace or soft snowstorm, can create a relaxing seasonal backdrop for shared activities.
With the atmosphere changing quietly in the background, no one needs to interrupt a favorite story to adjust the lights or lower the music. The host can simply enjoy the company they’ve brought together.
The Bathroom: The Art of Personal Comfort
The most gracious hosts think beyond the rooms where guests gather. Fresh towels, fragrant soaps and a few unexpected comforts can make the guest bathroom feel every bit as welcoming as the rest of the home.
Technology adds a new dimension to that hospitality. Consider a TOTO WASHLET bidet seat, which offers the welcome warmth of a heated seat, the refreshing pleasure of warm-water cleansing and the soothing comfort of warm-air drying. It’s an unexpected luxury that makes an everyday experience feel special.
Hosts can choose an option that complements their home’s character. The S2 offers inviting simplicity with convenient side-panel controls. The sleek S5 pairs contemporary elegance with a wireless remote. Meanwhile, the S7A adds a touch of theater with a lid that opens automatically, a softly glowing nightlight and personalized cleansing settings.
Even the housekeeping benefits from a little ingenuity through automatic PREMIST and EWATER+: One mists the toilet bowl before use to help keep it cleaner, while the other cleans the cleansing wand and, on select models, the bowl itself with electrolyzed water.
It’s another way a thoughtful host can anticipate guests’ needs and make them feel wonderfully welcome.
Long after the last guest has departed, what lingers isn’t the sophistication of the house. It’s the meal that inspired compliments, the conversations no one wanted to end and the little surprises that made everyone feel at home.
Those are the moments that make holiday entertaining special. Behind each one is a host whose warmth, creativity and attention to detail made it possible, with a little help from the house. Explore more sophisticated bathroom upgrade ideas for the holidays and beyond at TOTOUSA.com.
Photo courtesy of Shutterstock (holiday table)
SOURCE:
TOTO
