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.
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Daily News
Major Construction Begins on Metro’s East San Fernando Valley Light Rail Line
LA Metro has moved the East San Fernando Valley Light Rail Transit Project into major construction. The 6.7-mile Van Nuys Boulevard line will add 11 stations, connect with the G Line and regional rail services, and is now targeted for completion in early 2032.
After years of utility relocation and planning, LA Metro is moving into major construction on a new rail line along Van Nuys Boulevard. The milestone also comes with a revised early-2032 completion target.
LA Metro has officially marked the beginning of major construction on the East San Fernando Valley Light Rail Transit Project, moving one of the region’s most important rail projects from preparatory work into full-scale construction.
Metro held a groundbreaking ceremony on October 19, 2026, for the 6.7-mile line, which will run along Van Nuys Boulevard from the G Line busway north to San Fernando Road in Pacoima. The project will add 11 light-rail stations serving Van Nuys, Panorama City, Arleta and Pacoima.
This was not the project’s first groundbreaking. Metro held an earlier ceremony in December 2022 when crews began relocating utility infrastructure. The new milestone is more consequential for riders: the major-construction phase covers the guideway, stations, traction-power substations, rail systems and a maintenance and storage facility.
From utility work to a new rail corridor
The project has spent several years in utility relocation, property acquisition, design and other early work. Metro’s current construction timeline shows major work continuing from 2026 through 2032, with phased traffic changes and K-rail installations expected along Van Nuys Boulevard.
When completed, trains are expected to operate every seven to 10 minutes during peak periods. The line will connect directly with the G Line and provide access to the Van Nuys Metrolink and Amtrak station. It is also expected to become an important transfer point for the future Sepulveda Transit Corridor and a planned Metrolink station in Pacoima.
The corridor already has a substantial transit market. Metro reported that bus Lines 233 and 761, which serve Van Nuys Boulevard, recorded nearly 20,000 boardings in September 2026. The agency also says approximately 19 percent of households in the project area lack access to a car, compared with about 8 percent countywide.
Those figures help explain why this project matters beyond its construction footprint. It is intended to give residents in some of the Valley’s most transit-dependent communities more reliable access to jobs, schools, healthcare and the wider regional transit network.
The opening target has moved to 2032
Metro’s current project page lists an estimated completion date of early 2032. That is later than the 2031 opening forecast the agency publicized when it celebrated an $893-million federal grant in September 2024. Earlier plans were more optimistic still: when utility work began in 2022, Metro said the first segment could open between 2028 and 2030.
The project’s financial scale has also grown clearer. In May 2026, the Metro Board established a life-of-project budget of approximately $3.999 billion and authorized the next phase of its progressive design-build contract with San Fernando Transit Constructors, a joint venture of Skanska and Stacy and Witbeck.
That authorization increased the construction contract’s value to roughly $2.431 billion. Funding for the larger project combines federal, state and local sources, including revenue from Los Angeles County’s Measure M transportation sales tax.
Rail returns to Van Nuys Boulevard
The East San Fernando Valley line will restore passenger rail to Van Nuys Boulevard for the first time since Pacific Electric ended streetcar service there in 1952. It will also become the first major new Metro rail project in the San Fernando Valley since the subway reached North Hollywood in 2000.
The historical parallel is significant. Van Nuys Boulevard once developed around electric railway service before the region shifted heavily toward automobiles and buses. Metro is now rebuilding rail in the same broad corridor, but as part of a modern network designed to connect local riders with bus rapid transit, regional rail and future high-capacity projects.
The current project ends in Pacoima. Metro continues to study a separate 2.5-mile northern extension that would reach the Sylmar/San Fernando Metrolink station. That extension is not included in the segment now entering major construction.
For riders, the October groundbreaking does not mean trains are imminent. Several years of disruptive and technically complex work remain, and the schedule has already moved beyond earlier forecasts. Still, it represents a tangible transition: the East San Fernando Valley line is no longer primarily a planning exercise or utility-relocation program. Metro has begun building the infrastructure that will carry trains.
That makes this a major step in Los Angeles County’s long effort to restore frequent rail transit to communities that lost it generations ago—and another chapter in The Long Track Back.
Primary sources
- LA Metro: Major construction will soon be underway
- LA Metro project page: East San Fernando Valley Light Rail Transit
- LA Metro Board meeting, May 28, 2026 — project budget and contract authorization
- LA Metro: $893 million federal grant announcement, September 6, 2024
- LA Metro: Advanced utility-work groundbreaking, December 2, 2022
This article is part of The Long Track Back, STM Daily News’ continuing coverage of how Los Angeles is rebuilding and expanding a passenger-rail network after decades of automobile-centered grow
For generations, the Santa Monica Pier sign has marked the start of a day at the beach. Now, the familiar blue neon landmark is preparing for a journey of its own.
Santa Monica scheduled removal of the 1941 sign for October 20–22, with shipment to Las Vegas anticipated October 26. The timetable is subject to change, according to the city’s October 19 announcement.
The temporary removal accompanies replacement of the aging bridge connecting Ocean Avenue to the pier. It also creates an opportunity to preserve the historic sign.
YESCO will restore it at its Las Vegas facility. The company’s experience includes work on the “Welcome to Fabulous Las Vegas” sign.
Crews will repair neon tubing, treat rust, repaint components and address structural needs while retaining historic features. The sign will remain in secure storage during bridge construction.
Once the project is finished, it will return above the new bridge at a slightly greater height for visibility and vehicle clearance. The city’s latest announcement targets project completion by 2028, ahead of the Los Angeles Olympics and Paralympics.
Meanwhile, visitors can photograph a lighted, half-scale replica near Pier Burger.
For anyone who associates that glowing arch with Southern California memories, its absence will be noticeable. The restoration is intended to ensure future generations can make memories beneath it, too.
Source: City of Santa Monica — October 19, 2026 announcement
Related Links
- City of Santa Monica: Official sign restoration announcement — October 19, 2026. Primary source for removal dates, shipment to Las Vegas, YESCO’s restoration work and the sign’s planned return.
- Santa Monica Daily Press: Sign restoration during bridge rebuild — October 20, 2026. Additional local reporting on the project and visitor access.
- LAist: Sign removal and how to watch — Reporting on the removal schedule and public viewing opportunities.
Follow more Southern California stories at STM Daily News.
Automotive
Slate Truck Gets Real: First Experience Center Opens Ahead of Planned Deliveries
Slate Auto’s first permanent Experience Center gives consumers an up-close look at its customizable electric truck ahead of planned customer deliveries.
Slate Auto’s new Chicago location gives prospective buyers a permanent place to see the minimalist electric pickup, explore customization options and learn about demo opportunities—but it is not yet proof that customer deliveries have begun.
CHICAGO — October 20, 2026 — The Slate Truck is moving out of computer renderings and temporary roadshow stops and into a permanent retail setting. Slate Auto opened its first Experience Center on October 15 at 1053 W. Grand Avenue in Chicago, giving consumers a year-round location to get an up-close look at the company’s highly anticipated electric pickup.
The Near West Side facility occupies a former Tesla location and includes showroom, retail and garage space, along with electric-vehicle charging infrastructure. For Slate, the opening represents an important step in turning strong online interest into a more tangible buying experience as the startup works toward launching its first vehicle.
Visitors can examine the truck’s compact dimensions, deliberately simple cabin and accessory-driven design in person. The center also showcases Slate’s personalization strategy, including exterior wraps, add-on accessories and digital design tools intended to let owners configure the truck around their needs.
Slate has also promoted demonstration opportunities connected with the location, although availability may be limited or appointment-based as the company continues to prepare its fleet. Early media access included passenger rides rather than unrestricted customer test drives, so prospective visitors should confirm current availability before making a special trip.
Why the Chicago opening matters
Until now, most consumers have encountered the Slate Truck through online reservations, media coverage or temporary appearances. A permanent showroom gives buyers a chance to judge details that are difficult to evaluate on a screen, including seating position, bed access, cabin materials and the overall size of the vehicle.
That is especially important for a product built around an unconventional value proposition. Slate is promoting a basic two-seat, two-door electric truck with manual crank windows and no factory-installed infotainment screen or stereo. The company’s strategy is to keep the starting price low and let buyers add features later through accessories and conversion kits.
The physical location also gives Slate a place to explain that approach directly. Rather than presenting the truck as an unfinished vehicle, the company can demonstrate how its modular accessories, wraps and planned SUV-style conversion components are meant to expand the vehicle’s usefulness over time.
Chicago is a logical first market for that effort. The city offers access to a large Midwestern customer base and is within the broader region of Slate’s planned manufacturing operation in Warsaw, Indiana. Reusing a former Tesla store also gives the startup a space already suited to displaying and servicing electric vehicles.
The roadshow continues beyond Chicago
The Experience Center is opening as Slate expands its public demonstration schedule. The company’s events calendar lists a Boston-area demo ride event from October 21 through October 25 at The Shops at Chestnut Hill, followed by an appearance at RADwood in Alameda, California, on October 24 and a New Jersey demo ride event in Freehold from October 28 through October 31.
Slate also lists future stops in Washington, D.C., Raleigh, Atlanta, Miami and Orlando. Together, the permanent Chicago center and the traveling events suggest the company is moving into a broader customer-education phase ahead of planned deliveries.
What has—and has not—changed
The showroom opening does not change Slate’s headline pricing or range claims. The truck is still advertised with a base price of $24,950 before taxes, registration and destination charges. With the currently listed $1,450 destination fee, the entry price would be approximately $26,400 before other costs or optional equipment.
Slate also continues to advertise an estimated range of up to 205 miles. That figure remains an estimate rather than a final EPA-certified rating.
Most importantly, Slate has not publicly confirmed that regular customer production has started or that the first retail deliveries have occurred. Limited deliveries have been reported as possible before the end of December 2026, while many reservation holders may receive later delivery windows in 2027. The Chicago opening is therefore a commercialization milestone, not a manufacturing milestone.
For customers and industry observers, the next major signals will be the start of production at the Warsaw factory, final specifications and EPA range ratings, and confirmed handoffs to paying buyers.
The bottom line
Slate Auto now has a permanent place where consumers can see and evaluate its unusually simple electric truck. That makes the product feel more real and gives the company a platform to explain a customization-heavy business model that may be unfamiliar to traditional truck buyers.
Still, the biggest questions remain unanswered. Opening a showroom demonstrates progress in marketing and customer engagement; producing vehicles at scale, holding the promised price and delivering a 205-mile truck to reservation holders will determine whether Slate can convert enthusiasm into a viable automotive business.
Sources and more information
- Slate Auto events and demo schedule
- Electrek: Slate opens its first Experience Center in Chicago
- Autoblog: Slate opens its first U.S. showroom
- Slate Auto
Category: Consumer Corner / Automotive
