Way back on A Slime By Any Other Name, our first O Wow Moments episode, I showed off a fun slime concoction called Oobleck that we regularly make here at the Children’s Museum of Houston. To make Oobleck at home, combine 2 cups of corn starch +1 cup of water + food coloring (I recommend coloring the water first, then adding the corn starch). After mixing it well, you get a bowl of slime that acts like a liquid as it oozes through your fingers but feels like a solid when you hit/poke it.
This is because Oobleck, like ketchup and Silly Putty, is a Non-Newtonian fluid, meaning its viscosity changes based on rules that were not laid out by Sir Issac Newton. Because of these properties, we can bring Oobleck to “life.”
What You Need:
- Tone Generator – there are a number of apps available for mobile technology as well as several free tone generators available for download online if you choose to use a computer. However, most computers and mobile devices do not have enough power for the big speakers we want to use, so you will also need…
- Amplifier – your basic stereo amplifier/receiver will do the trick.
- Audio cable – to connect the audio jack from your mobile device/computer to the stereo (you can usually get them at Radio Shack or similar places)
- Speaker – I recommend a large woofer or subwoofer for this activity – you need to be able to generate a lot of bass tones
- Speaker wire – to connect the speaker to the amplifier
- Baking Pan – I’ve seen videos where they pour the oobleck directly into the speaker, which can ruin the speaker. I’ve also seen them with plastic wrap but, again, I wanted to protect my speaker with more than just a piece of plastic.
- Oobleck – see recipe above
What To Do:
- Mix up the Oobleck. I’d suggest keeping it white for now and add food coloring once you bring it to life – very cool visual
- Hook up the tone generator to the amplifier
- Hook up the speaker to the amplifier
- Set the tone generator to 50 Hz
- Turn on the sound and crank up the volume
- Pour a thin layer of Oobleck into the baking pan (too much and it won’t work)
- Place the pan onto the speaker and hold it in place. You should start to see the tendrils forming. You may need to help get it started using a finger or a pencil.
- If it doesn’t work, try adjusting the tone and/or volume level.
Remember that sound is vibrations. Those vibrations create pressure on the Oobleck causing it to stiffen. The stiffened Oobleck rises with the pressure allowing fluid Oobleck to flow underneath, whereby it stiffens and adds to the tendrils. If a tendril gets too high, it starts to reform a fluid and falls, rejoining the other Oobleck. Try adding some food coloring and watch what happens!
Special thanks to our friends at Region’s Bank for making our O Wow Moments possible!