About This Lesson
Here’s a neat experiment you can try at home. All you need is a glass of water, a sewing needle, and a small slip of paper. Place the sewing needle on the little slip of paper and very gently rest the paper on the surface of the water. The paper will absorb water and soon sink to the bottom of the glass, but the needle itself will remain on top of the water after the paper has dropped away! How is this possible?
