Do you think plants breathe only at night? Or that plants absorb food through their roots? If your answer is yes, you’re not alone! These are just some of the misconceptions people often have about the world around us. On 13 October 2025, Assoc. Prof. Mila Bulić helped us unravel these misunderstandings in the best possible way. And not only that — through micro-experiments using red cabbage and toothpaste, we spent the day on the fun border between science and discovery.
As part of the project Sailing into STEM – A Map for 2030, we visited the Faculty of Humanities and Social Sciences in Split, where Assoc. Prof. Mila Bulić welcomed us. Her cheerful approach quickly put us at ease and opened our eyes to the fact that much of what we think we know is actually incorrect.
Her workshop focused on “Misconceptions among children and students – difficulties in constructing knowledge.” In short, if children do not receive clear and precise explanations from the beginning, it becomes difficult for them to build new knowledge later. The examples she presented were incredibly relatable to everyday life.
Plant respiration and other surprises
One of the most common myths is that plants breathe only at night. The truth? No, plants breathe continuously, day and night. During the day they also carry out photosynthesis, producing oxygen, but at the same time they use oxygen for their own respiration. Plants are our allies in keeping the air fresh, not our competitors. So feel free to keep a plant in your bedroom it will produce far more oxygen than it consumes.
Another interesting misconception Mila pointed out is the belief that plant roots “absorb nutrients” or “take in food from the soil.” Children (and many adults) often think plants take ready-made food from the ground, as if they were eating from a plate. In reality, plants manufacture their own “food” through photosynthesis, using sunlight, carbon dioxide from the air, and water. Roots do not take in food; they absorb water and minerals — raw materials, not ready-made food. The actual food for the plant is produced later, in the leaves.
This is a perfect example of how a misunderstood word (“food”) can create a false picture of how plants actually function. And that is exactly why it’s so important to construct knowledge properly from the start, so children can understand nature in the right way.
Mila strongly emphasized the importance of building quality foundations of knowledge. If students adopt an incorrect explanation, it becomes difficult for them to understand more advanced concepts later — like building a house on shaky ground.
When red cabbage becomes a scientific detective
In the second part of the workshop, the real search for knowledge began! Through experiments led by Assoc. Prof. Bulić, we explored the invisible world of acidity, plastics, and ocean issues learning things we will remember much longer than the formula for water.
The first experiment involved believe it or not, red cabbage! It contains a natural pH indicator that changes color depending on the acidity or alkalinity of a solution. In several test tubes we mixed cabbage extract with different substances: lemon juice, baking soda, vinegar, oven cleaner, and degreaser. The results? A real rainbow of colors! From pink to blue and red — each sample revealed its pH. And from there came the lesson about ocean acidification.
As oceans become more acidic due to increasing carbon dioxide (CO₂), water pH decreases, making life harder for many marine organisms. Those that rely on carbonate ions to build their shells — such as mollusks, snails, and corals — are especially affected. Acidified water reduces the availability of these ions, causing shells to weaken or fail to form.
To better understand this, we conducted a simple but striking experiment: an eggshell was placed in vinegar, an acid. We watched the shell slowly dissolve, releasing gas bubbles. This is similar to what happens to marine shells in acidifying oceans. Through this and similar experiments, like the red cabbage pH indicator, we realized how small environmental changes can have large and long-lasting effects on nature.
Toothpaste, microbeads and microplastics on our plate
And then — toothpaste. We didn’t expect it to be the star of the next experiment, but it surprised us! After dissolving toothpaste in water, something remained, tiny beads that did not dissolve. These are plastic particles, also known as microplastics. These microbeads are sometimes added to cosmetics and toothpaste for their abrasive effect, helping with mechanical cleaning. Unlike the toothpaste itself, they do not dissolve because they are made of non-biodegradable plastics such as polyethylene.
These microscopic particles easily pass through wastewater treatment systems and end up in rivers, seas, and various organisms including us. It’s frightening to think that something so small and almost invisible can have such a significant impact on the environment and our health.
Yes, microplastic can travel through water into organisms, and then up the food chain to our own plates. In everyday life, we unknowingly ingest it from cosmetics, packaging, and even clothing washed in washing machines.
The final experiment demonstrated how microplastic bioaccumulates in organisms. We observed a model showing how tiny particles eaten by small organisms end up in larger ones, in fish, and eventually — on our plates. It was a quiet but powerful reminder of how connected we are to the sea and how much we must protect it.
STEM with a message: science is all around us
This one-day visit to the Faculty of Humanities and Social Sciences was both an educational experience and a wake-up call. We learned that STEM is not reserved for laboratories and scientists in white coats — it is all around us: in cabbage, toothpaste, the sea, and even in a potted plant on a windowsill.
Assoc. Prof. Mila Bulić managed to bring science closer to us through the lens of everyday life, breaking down entrenched misconceptions and encouraging us not to take information for granted. Asking questions, investigating, comparing — that is the foundation of true learning.
And it left us with only one question: when is the next STEM workshop?
We invite you to join the project “Sailing the STEM – A Map for 2030”, which aims to popularize science and bring STEM closer to everyone — teachers, volunteers, students, and activists.
The project is implemented with financial support from the European Union through the European Social Fund Plus (ESF+), under the “Effective Human Resources 2021–2027” Programme. It is carried out under the Call for Proposals “Strengthening the capacity of civil society organizations for promoting STEM”, with the goal of improving the ability of CSOs to design and implement educational activities in science, technology, engineering, and mathematics (STEM).
The views and opinions expressed are solely those of the author and do not necessarily reflect the official position of the European Union or the European Commission. Neither the European Union nor the European Commission can be held responsible for them.
The views expressed in this material are the sole responsibility of Sunce and can in no way be taken to reflect the views of the Government Office for Cooperation with NGOs.