Cornstarch Monsters - Science Minute

Key Concepts:

• Non-Newtonian fluid: A fluid whose viscosity changes under stress.
• Cornstarch and water mixture: A common example of a non-Newtonian fluid.
• Frequency generator: A device that produces electrical signals of specific frequencies.
• Vibration: The mechanical phenomenon of oscillation about an equilibrium point.
• Amplifier: An electronic device that increases the power of a signal.

Experiment Setup and Procedure:

1. Creating the Non-Newtonian Fluid: Mix cornstarch and water to create a non-Newtonian solution. The mixture exhibits properties of both a solid and a liquid, behaving like a solid under stress and a liquid when relaxed.
2. Adding Color (Optional): Add food coloring to the cornstarch mixture for visual appeal. In the video, orange food coloring is used.
3. Speaker Preparation: Obtain a speaker, preferably one removed from an old stereo cabinet (found at a garage sale or thrift shop).
4. Amplifier Connection: Connect the speaker to an amplifier, also sourced from a garage sale. The amplifier will boost the signal from the frequency generator.
5. Frequency Generator Setup: Use a frequency generator to create specific frequencies that will vibrate the speaker.
6. Bag and Tape: Cover the speaker with a plastic bag and tape it securely in place. This prevents the cornstarch mixture from directly contacting the speaker.
7. Cornstarch Placement: Pour the cornstarch mixture into the bag on top of the speaker. The amount should be enough to cover the speaker surface but not too much.
8. Initiating Vibration: Turn on the frequency generator and adjust the frequency. The vibration will cause the cornstarch mixture to form unusual shapes and patterns.

Observations and Results:

• Shape Formation: As the speaker vibrates, the cornstarch mixture forms dynamic shapes and patterns, described as "cornstarch monsters."
• Frequency Dependence: Different frequencies produce different vibration patterns and shapes in the cornstarch mixture.
• Messiness: The experiment is prone to creating a mess, with cornstarch potentially scattering around.

Scientific Principles:

• Non-Newtonian Behavior: The cornstarch and water mixture's unique behavior is due to its non-Newtonian properties. Under vibration (stress), the particles in the mixture pack together, causing it to act like a solid. When the vibration stops, the particles relax, and it flows like a liquid.
• Resonance: The specific shapes and patterns formed are influenced by the resonant frequencies of the speaker and the cornstarch mixture.

Notable Quotes:

• "It's a solid and a liquid at the same time. It has these crazy properties." - Describing the non-Newtonian fluid.
• "When we add vibration, look at what we get. We get these corn starch monsters that just appear as they move around." - Highlighting the visual effect of the experiment.
• "Why? Because it's a Steve Spangler experiment." - Acknowledging the messiness often associated with his experiments.

Technical Terms:

• Non-Newtonian fluid: A fluid that does not follow Newton's law of viscosity, meaning its viscosity changes under applied force.
• Frequency: The number of occurrences of a repeating event per unit of time, measured in Hertz (Hz).
• Amplifier: An electronic device that increases the amplitude of a signal.
• Frequency Generator: An electronic device that produces repeating electronic signals of a specific frequency.

Logical Connections:

The video logically connects the creation of a non-Newtonian fluid to the demonstration of its behavior under vibration. It explains how to set up a simple experiment using readily available materials to visualize the effects of frequency on the fluid's properties. The experiment serves as a hands-on demonstration of scientific principles related to fluid dynamics and wave phenomena.

Synthesis/Conclusion:

The video demonstrates a fun and engaging science experiment using a cornstarch and water mixture to visualize the properties of a non-Newtonian fluid. By vibrating the mixture with a speaker and frequency generator, the experiment showcases how the fluid behaves differently under stress, creating dynamic and visually interesting shapes. The experiment is presented as an accessible STEM project that can be done with readily available materials, encouraging young scientists to explore the wonders of science.