A recent discussion on Reddit’s r/nostalgia sparked a wave of memories and a fascinating exploration of a simple science experiment: creating a non-Newtonian fluid with cornstarch and water. The thread, centered around childhood experiences, quickly evolved into a shared recollection of the peculiar properties of this mixture – a substance that can feel solid one moment and liquid the next.
This seemingly simple concoction, often referred to as “oobleck,” isn’t just a nostalgic trip; it’s a tangible demonstration of complex physics. Non-Newtonian fluids defy the typical behavior of liquids, exhibiting a viscosity that changes under stress. This means their resistance to flow isn’t constant, unlike water or oil. The cornstarch and water mixture is a prime example of a “shear-thickening” fluid, becoming more viscous – more resistant to flow – when force is applied. Understanding these fluids has implications across a surprisingly wide range of industries, from food processing to petroleum engineering.
What Makes Oobleck So Unique?
The magic of oobleck lies in the way cornstarch particles interact with water. According to the University of Utah’s Chemical Engineering department, when gentle pressure is applied, the cornstarch particles are able to slide past each other, allowing the mixture to flow like a liquid. Although, when sudden force is applied, the particles lock together temporarily, creating a solid-like structure. This is why you can quickly strike the surface of oobleck and it will feel firm, but slowly sink your fingers into it like a liquid.
This behavior is a key characteristic of non-Newtonian fluids. As LittleBinsForLittleHands explains, unlike stirring water where the resistance remains consistent, stirring a non-Newtonian fluid changes its behavior. Ketchup, for example, demonstrates this property – it’s tricky to obtain out of the bottle until you apply force, then it flows easily. Slime is another common example, stretching like a liquid slowly but feeling more solid when pulled apart quickly.
The YouTube video from dArtofScience visually demonstrates this phenomenon, showing how a coconut can be broken on a bed of cornstarch and water, yet a finger can easily penetrate the surface with sluggish, gentle pressure.
Beyond the Fun: Applications of Non-Newtonian Fluids
While oobleck is a fun and accessible science experiment, the principles behind non-Newtonian fluids have significant real-world applications. Chemical engineers encounter these fluids in various industries, including food processing, cosmetics, and plastics. A petroleum engineer, for instance, needs to understand how to keep oil flowing efficiently through pipelines, a task that involves managing the behavior of non-Newtonian fluids. Similarly, cardiologists study blood flow, which also exhibits non-Newtonian properties.
Researchers have also been investigating more complex behaviors within these fluids. Studies, as cited by the University of Utah, have explored “persistent holes” in these fluids and how they self-replicate when vibrated, offering insights into fluid dynamics and material science. These investigations highlight the potential for utilizing these unique properties in advanced materials and technologies.
Safety Considerations
The University of Utah’s Chemical Engineering module emphasizes the importance of adult supervision when conducting experiments with non-Newtonian fluids. All procedures should be carried out under the guidance of a responsible adult familiar with potential hazards. While the materials are generally non-toxic, proper supervision is crucial, especially when working with minors.
The enduring appeal of the cornstarch and water experiment, as evidenced by the Reddit thread, lies in its ability to build complex scientific principles accessible and engaging. It’s a reminder that fascinating science can be found in the simplest of materials, sparking curiosity and a deeper understanding of the world around us.
As research into non-Newtonian fluids continues, we can expect to witness further innovations and applications emerge, building on the foundation of this surprisingly versatile and intriguing phenomenon. Share your own experiences with oobleck and other science experiments in the comments below!
