On the 31st of July, Cool Science was at the Manitou Library Lawn Concert where kids played with “goofy ears.” These are headphones with pop tubes and funnels that let the user alter his or her hearing. The kids also got to pretend they were dragons by combining breakfast cereal with liquid nitrogen. Cool, right? Or…cool science!
Since liquid nitrogen is so cold (-320°F), it chills cereal instantly, and because the food is mostly air and sugar, it’s safe for the kids to pop the now-super-chilled treat right into their mouths. Then as they exhale the cold cereal condenses the water vapor in the air, creating an impressive fog that looks like a dragon blowing out smoke.
Once done with the cereal, the kids put on the headphones, where they learned the benefits of having two ears. Sound waves reach each of our two ears independently, which is how our brain locates a sound source in three dimensional space. By moving the pop tubes and funnels, you can trick your brain into thinking someone speaking to you on your left side seems to be talking on your right.
Both of these activities gave the kids something fun and engaging to do while their parents enjoyed the music at the concert.
-posted by Joshua