Corn starch "oobleck" is a non-Newtonian fluid that reacts wildly to heavy vibrations!


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Teachable Topics

  • Non-Newtonian Fluids
  • Resonance
  • Cymatics

Theory

Oobleck is the 50-50 combination of corn starch and water.  Once mixed, the oobleck exhibits many fascinating qualities, the most significant of which is that it has a viscosity proportionate to the velocity of the object moving through it.  If you move slowly through the oobleck, you will pass with little resistance.  If you try to move quickly, the oobleck almost solidifies against you.

When the oobleck is placed on a vibration plate, weird stuff happens!  The standing waves created in the fluid causes areas of high and low viscosity which eventually creates standing "fingers" of material.  


Apparatus

  • Corn starch Oobleck
  • a pie plate
  • audio speaker
  • frequency source

Procedure

  1. Mix the corn starch and water.  50% corn starch to 50% water.  Mix thoroughly.
  2. Pour the oobleck into the pie plate and place it onto the speaker.  Use tape to affix it so it won't move.
  3. Turn on the speaker and ramp the amplitude as high as you can stand it.  Ear protection may be required!
  4. Cycle through various frequency ranges until you see the "creepers" appear!

Search 'em up!