Introduction to Non-Newtonian Fluids: Oobleck and Slime
Educational and Fun Activities
Written by Jack Roberts
04 November 2024
🕓 7 min
When it comes to the world of science activities, few things capture children's curiosity quite like non-Newtonian fluids. These fascinating substances—like oobleck and slime—don't behave according to the typical rules that govern liquids. Unlike Newtonian fluids, such as water or oil, non-Newtonian fluids change their viscosity or flow properties under stress. Oobleck, a mixture of cornstarch and water, becomes solid-like when pressure is applied and reverts to a liquid state when the pressure is removed. Slime, on the other hand, has an entirely different texture and reaction to pressure, flowing slowly under gravity but stretching or snapping depending on the force applied.
In a science session, contrasting oobleck and slime offers children a vivid demonstration of how these two types of fluids respond differently to pressure, flow, and force. By introducing sound vibrations as an added factor, we take this experiment a step further, exploring the unique way these fluids interact with external vibrations. Sound waves, especially low-frequency vibrations, can affect the structure and behaviour of these non-Newtonian fluids. The differences in how oobleck and slime respond to sound allow children to observe the principles of sound energy and its impact on matter firsthand.
The Science of Sound and Vibrational Properties:
Sound is a powerful force that travels in waves, creating areas of high and low pressure as it moves through a medium such as air, water, or solid materials. When these sound waves encounter a surface, they cause vibrations that, depending on the material, will either be absorbed, reflected, or passed along as energy. The Science of Sound explores these vibrations by using devices like speakers and Chladni plates, which vibrate at varying frequencies. For children, a Chladni plate is an exciting tool to visualise sound: as it vibrates, patterns appear on the plate’s surface, showing how sound waves shape the environment around them.
When sound waves hit materials like oobleck or slime, the energy from the vibrations can create unique reactions in these fluids. Oobleck, with its high sensitivity to pressure, will harden momentarily, forming shapes and ridges that mimic the energy of the vibrations. Slime, however, behaves more fluidly and is less likely to form distinct patterns. Instead, it might ripple or deform slowly as it absorbs and spreads the vibrational energy. By setting up a controlled environment where sound interacts with these substances, children can explore how different materials respond to energy inputs, an essential concept in physics and material science.
Observing Oobleck on a Speaker or Chladni Plate:
When we place oobleck on a vibrating surface like a speaker or a Chladni plate, we witness a remarkable transformation. Oobleck’s unique rheological properties mean it behaves both as a solid and a liquid depending on the pressure applied. As the speaker or plate vibrates, oobleck’s particles come together and create fascinating shapes, almost as if it’s “dancing” to the rhythm. At lower sound frequencies, which generate more intense vibrations, we may see oobleck harden and form spiky, solid shapes that align with the vibration patterns. As the frequency increases, the oobleck will alternate between solid and liquid states in rapid succession, creating a dynamic, pulsing movement that children find captivating.
This reaction occurs because the cornstarch particles in oobleck have difficulty moving past each other quickly under sudden pressure, causing the mixture to act solidly. When the vibrations ease up or the sound frequency changes, oobleck returns to its liquid state, flowing back to its original shape. Observing this dance of particles gives children an exciting demonstration of sound energy’s physical impact and teaches them how force and energy transfer can change the properties of non-Newtonian materials. Through experiments like these, children gain insights into the world of physics in a tactile, visually engaging way.
Slime’s Reaction to Sound Vibrations:
Compared to oobleck, slime reacts quite differently to sound vibrations. Slime is made up of polymers, which are long chains of molecules that can stretch and flex. This structure makes slime less reactive to quick, intense forces and more resilient under gradual pressure. When placed on a speaker or a Chladni plate, slime will not produce the sharp, solid-like structures that oobleck does. Instead, it may move in slow waves or simply ripple along the surface, depending on the intensity and frequency of the sound.
At lower frequencies, slime might stretch and deform, absorbing much of the vibrational energy rather than reacting to it with distinct shapes. Its flexibility allows it to move with the waves rather than against them, making it less likely to produce dramatic visual effects. This response teaches children about the properties of polymers and the role of molecular structure in determining a material’s behaviour. The experience of observing slime on a vibrating surface shows how different materials distribute and absorb energy in unique ways, giving children a deeper appreciation for the science behind everyday materials.
The Science of Sound’s Role in Understanding Non-Newtonian Fluids:
At The Science of Sound, we integrate these experiments into our sessions to offer children a hands-on understanding of sound, energy, and material science. By contrasting oobleck and slime’s responses to sound vibrations, children can learn about non-Newtonian properties, molecular structure, and the physical impact of sound energy in one engaging experiment. Using tools like speakers and Chladni plates, we guide children to explore scientific principles actively, helping them grasp abstract concepts through tangible experiences.
The non-Newtonian dance-off between oobleck and slime serves as a perfect introduction to topics like physics, chemistry, and the science of materials. Not only do children witness the effects of sound and vibrations on different substances, but they also learn to ask scientific questions, form hypotheses, and observe outcomes. This experiment exemplifies the Science of Sound’s commitment to using interactive learning to inspire curiosity and a love for scientific discovery. Through our multi-sensory approach, children not only learn but also experience science, making the concepts memorable and meaningful in their educational journey.
Conclusion: Embracing the Wonders of Non-Newtonian Fluids
The exploration of non-Newtonian fluids, particularly through the captivating behaviours of oobleck and slime under sound vibrations, offers children a rich, hands-on experience that links physics, chemistry, and sound science. At The Science of Sound, we leverage these experiments to reveal the marvels of sound energy and material properties in ways that are as educational as they are entertaining. By observing how oobleck stiffens into jagged peaks or ripples in response to bass frequencies, while slime gently flows or stretches, children gain a foundational understanding of scientific principles that extend beyond the lab.
Anchoring Attention: Sounds, such as Tibetan singing bowls or chimes, can serve as focal points for meditation, helping to anchor the mind and prevent distractions.
This “dance-off” between oobleck and slime doesn’t just educate children on how materials behave under pressure and sound; it sparks a deeper curiosity about the world around them. When we see children light up with wonder at these effects, it’s a reminder of why interactive science activities are so crucial in early education. These engaging lessons can lead to lifelong interests in STEM fields, instilling confidence and curiosity.
If your child enjoyed this experiment or wants to explore more about sound, science, and fun, they’ll love our upcoming sessions at The Science of Sound! Designed to captivate and educate, our programs introduce complex concepts in the most accessible ways, helping young minds connect with science naturally. Join us in our next adventure—where sound and science meet to make learning an unforgettable experience.
