So this experiment is the Chladni plate experiment. Specific frequencies vibrate the metal plate so that it creates areas where there is no vibration. The sand “falls” into those areas, creating beautiful geometric patterns. As the frequency increases in pitch, the patterns become more complex.
How to Draw a Circle Perfectly Freehand?
How to draw a circle perfectly? Learn this simple technique to help you draw a near-perfect circle freehand. It could be useful for drawing charts.