Project 7: Magic Hair Hygrometer

Make a Weather-Predicting Arrow!

Hello Spark Times readers,

Is the air dry or damp today? Let your hair tell you!
In this weather-sensing experiment, you’ll build your very own hygrometer using just cardboard, paper, and a single strand of hair. As the air gets wetter or drier, the hair will stretch or shrink, moving your arrow like magic. It's a fun, zero-cost way to track humidity like…