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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News
How healthy is Sodastream?
The SodaStream Sparkling Water Maker is a device that forces carbon dioxide (CO2) gas (stored under pressure in a cylinder) into water, making it sparkling (fizzy)
Sodastream machines have been gaining popularity in recent years as an alternative to store-bought soft drinks. Not only are they more environmentally friendly, but they also offer several health benefits compared to traditional sodas.
Reduced Sugar Intake
One of the most significant health benefits of using a Sodastream machine is reducing sugar intake. Traditional sodas are loaded with sugar, and excessive sugar intake can lead to weight gain, obesity, and other health problems such as Type 2 diabetes. With a Sodastream machine, you can control the amount of sugar you add to your drink, allowing you to enjoy a refreshing beverage without the harmful effects of excessive sugar consumption.
No Artificial Sweeteners
Many store-bought soft drinks contain artificial sweeteners, which can have negative health effects such as headaches and digestive problems. Sodastream machines, on the other hand, allow you to use natural sweeteners such as fruit extracts, honey or agave nectar, giving you a healthier and more natural alternative.
No Preservatives
Another advantage of using a Sodastream machine is that you can avoid preservatives commonly found in store-bought soft drinks. Preservatives such as sodium benzoate and potassium sorbate have been linked to health problems such as cancer and allergies. By making your own drinks, you can avoid these harmful additives and enjoy a healthier, preservative-free beverage.
Eco-Friendly
In addition to the health benefits, using a Sodastream machine is also environmentally friendly. Traditional soft drinks are packaged in plastic bottles or cans, which contribute to environmental pollution. With a Sodastream machine, you can reuse the same bottle multiple times, reducing waste and helping to reduce your carbon footprint.
Variety
Finally, Sodastream machines offer a wide variety of flavors and options, allowing you to customize your drink to your liking. You can mix and match different flavors or create your own unique blends, giving you a healthier and more enjoyable alternative to traditional sodas.
In conclusion, Sodastream machines offer several health benefits compared to traditional store-bought soft drinks. By reducing sugar intake, avoiding artificial sweeteners and preservatives, and being eco-friendly, they offer a healthier and more sustainable alternative to traditional soft drinks. Moreover, with a wide variety of flavors and options, you can customize your drink to your liking, making it a fun and enjoyable way to stay healthy.
Consumer Corner
Behind the Product: What Sustainability Looks Like in Beauty Development
Beauty Development: Shoppers want to know what ingredients are used, how items are packaged and whether the production process includes thoughtful choices. Beauty brands are taking note, and sustainability is increasingly shaping decisions across sourcing, packaging, production, shipping, storage and replenishment.
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(Feature Impact) Shoppers are paying closer attention to the products they bring into their homes. They want to know what ingredients are used, how items are packaged and whether the production process includes thoughtful choices. Beauty brands are taking note, and sustainability is increasingly shaping decisions across sourcing, packaging, production, shipping, storage and replenishment.
Responsible product lines rarely come from sweeping change. They are built through smaller, connected choices made throughout development. Packaging, ingredient sourcing and production planning influence how a product performs, how much waste it creates and how sustainably products can be produced.
Consider this beauty sustainability information from Laura Badcock, Chief Operating Officer of NourishUs Naturals.
Why packaging matters beyond appearance
“Packaging is often the first thing shoppers notice,” Badcock said. “It can shape how someone feels about a product before they ever try what’s inside.”
A package should look appealing, though appearance is only part of the equation. It also needs to protect the product, travel safely, store well and hold up through regular use. Once the product is finished, the packaging should allow easy recycling, refilling or responsible disposal.
There is no single packaging option that works best for every beauty product. A lightweight container may reduce shipping weight. A refillable option may stay in use longer. A recyclable material may work well in one area but create challenges in another if local recycling systems cannot process it. Even packaging that appears sustainable can create problems in practice if it leaks, breaks or requires excess shipping materials.
Why ingredient sourcing matters
“Ingredient lists have become an important part of how people evaluate beauty products,” Badcock said. “Shoppers often look for familiar oils, butters, botanical extracts and information about how ingredients were sourced, which plays a major role in the environmental impact.”
A product’s environmental footprint is influenced by many factors, including shipping distance, processing methods, storage conditions and supplier practices.
These factors can also affect product consistency and ingredient availability over time. Beauty brands working with wholesale skin care suppliers or private label manufacturers often need to balance ingredient goals with sourcing reliability and production needs.
How better planning can lead to less waste
“Packaging and ingredients are usually the first things people associate with sustainability, but how much product gets made, stored and discarded matters, too,” Badcock said.
Overproduction is one of the biggest hidden sources of waste in beauty and personal care. Products that sit too long in storage may eventually expire or remain unsold. Excess inventory can also create additional packaging waste, warehousing needs and disposal costs.
Smaller batch sizes give producers more room to adjust as trends or demand shift, and producing closer to expected sales windows helps reduce long storage periods and unnecessary waste. Testing new products in smaller volumes and restocking based on actual demand makes overproduction less likely.
How sustainable beauty choices are connected
Packaging, ingredient sourcing and production planning are closely connected throughout development.
“A packaging choice can affect shipping weight, storage needs and whether a package can be refilled,” Badcock said. “Ingredient choices can influence sourcing timelines and how products need to be stored. Production planning affects how much material gets used and how much product could eventually go unsold.”
Beauty shoppers want more transparency around sustainability claims
Sustainability claims carry less weight when those claims aren’t explained in practice.
This shift is pushing many beauty brands to focus more heavily on traceability, supplier relationships and clearer product information. Transparency is becoming part of the customer experience itself.
More responsible product lines are built over time
Responsible beauty products come together through ongoing choices around packaging, sourcing, production and inventory planning. For shoppers, those choices influence the products they bring into their homes.
“The brands that build sustainability into early decisions tend to have the easiest time maintaining it later,” Badcock said. “Once supplier relationships, packaging formats and production routines are in place, small adjustments are far easier than major changes. Treating sustainability as part of product development from the beginning, rather than something to fix later, is what makes it work in practice.”
To find more information on the intersection of beauty and sustainability, visitNourishUsNaturals.com.
Photo courtesy of Shutterstock
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Automotive
EPA removal of vehicle emissions limits won’t stop the shift to electric vehicles, but will make it harder, slower and more expensive
The EPA’s move to rescind the 2009 “endangerment finding” and roll back vehicle emissions limits won’t stop the shift to electric vehicles—but it will slow adoption, raise costs, and increase climate and public health harms.
Alan Jenn, University of California, Davis
The U.S. government is in full retreat from its efforts to make vehicles more fuel-efficient, which it had been prioritizing, along with state governments, since the 1970s.
The latest move came on Feb. 12, 2026, when President Donald Trump and the Environmental Protection Agency issued a new rule rescinding the landmark “endangerment finding,” and reversing various emissions limits on cars and trucks. The 2009 finding stated that greenhouse gases pose a threat to public health and welfare. If the new rule stands up in court and is not overruled by Congress, it would undo a key part of the long-standing effort to limit greenhouse gas emissions from vehicles.
As a scholar of how vehicle emissions contribute to climate change, I know that the science behind the endangerment finding hasn’t changed. If anything, the evidence has grown that greenhouse gas emissions are warming the planet and threatening people’s health and safety. Heat waves, flooding, sea-level rise and wildfires have only worsened in the decade and a half since the EPA’s ruling.
Regulations over the years have cut emissions from power generation, leaving transportation as the largest source of greenhouse gas emissions in the U.S.
The scientific community agrees that vehicle emissions are harmful and should be regulated. The public also agrees, and has indicated strong preferences for cars that pollute less, including both more efficient gas-burning vehicles and electric-powered ones. Consumers have also been drawn to electric vehicles thanks to other benefits such as performance, operation cost and innovative technologies.
That is why I believe the EPA’s move will not stop the public and commercial transition to electric vehicles, but it will make that shift harder, slower and more expensive for everyone.
Putting carmakers in a bind
The most recent EPA rule about vehicle emissions was finalized in 2024. It set emissions limits that can realistically only be met by a large-scale shift to electric vehicles.
Over the past decade and a half, automakers have been building up their capability to produce electric vehicles to meet these fleet requirements, and a combination of regulations such as California’s zero-emission-vehicle requirements have worked together to ensure customers can get their hands on EVs. The zero-emission-vehicle rules require automakers to produce EVs for the California market, which in turn make it easier for the companies to meet their efficiency and emissions targets from the federal government. These collectively pressure automakers to provide a steady supply of electric vehicles to consumers.
The new EPA move would undo the 2024 EPA vehicle-emissions rule and other federal regulations that also limit emissions from vehicles, such as the heavy-duty vehicle emissions rule.
The possibility of a regulatory reversal puts automakers into a state of uncertainty. Legal challenges to the EPA’s shift are all but guaranteed, and the court process could take years.
For companies making decade-long investment decisions, regulatory stability matters more than short-term politics. Disrupting that stability undermines business planning, erodes investor confidence and sends conflicting signals to consumers and suppliers alike.
A slower roll
The Trump administration has taken other steps to make electric vehicles less attractive to carmakers and consumers.
The White House has already suspended key provisions of the Inflation Reduction Act that provided tax credits for purchasing EVs and halted a US$5 billion investment in a nationwide network of charging stations. And Congress has retracted the federal waiver that allowed California to set its own, stricter emissions limits. In combination, these policies make it hard to buy and drive electric vehicles: Fewer, or no, financial incentives for consumers make the purchases more expensive, and fewer charging stations make travel planning more challenging.
Overturning the EPA’s 2009 endangerment finding would remove the legal basis for regulating climate pollution from vehicles altogether.
But U.S. consumer interest in electric vehicles has been growing, and automakers have already made massive investments to produce electric vehicles and their associated components in the U.S. – such as Hyundai’s EV factory in Georgia and Volkswagen’s Battery Engineering Lab in Tennessee.
Global markets, especially in Europe and China, are also moving decisively toward electrifying large proportions of the vehicles on the road. This move is helped in no small part due to aggressive regulation by their respective governments. The results speak for themselves: Sales of EVs in both the European Union and China have been growing rapidly.
But the pace of change matters. A slower rollout of clean vehicles means more cumulative emissions, more climate damage and more harm to public health.
The EPA’s move seeks to slow the shift to electric vehicles, removing incentives and raising costs – even though the market has shown that cleaner vehicles are viable, the public has shown interest, and the science has never been clearer. But even such a major policy change can’t stop the momentum of those trends.
This is an updated version of an article originally published Aug. 5, 2025.
Alan Jenn, Associate Professor of Civil and Environmental Engineering, University of California, Davis
This article is republished from The Conversation under a Creative Commons license. Read the original article.
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