Have you ever seen sound? In this activity, we’ll explore how invisible sound waves move and how God uses sound in amazing ways.
Supplies:
- Cylinder container (mason jar, cooking pot, oatmeal tub)
- Plastic wrap
- Large rubber band
- Salt
Instructions:
- Stretch a piece of plastic wrap over the top of your cylinder. You might need an adult’s help because plastic wrap can be tricky to handle.
- Use the rubber band to secure the plastic wrap to the cylinder. Carefully adjust the plastic wrap under the rubber band to make sure it is stretched very tight and does not sag.
- Sprinkle a small pinch of salt crystals right in the middle of the plastic wrap.
- Get close to the salt crystals and speak loudly. What happens?
- Experiment with shouting, whispering, singing, or tapping the side of the cylinder.
- Observe what happens to the salt crystals.
Reflect:
- What happened to the salt crystals when you shouted? Whispered?
- Try speaking with a low pitch voice and then a high pitch voice. How do the different pitches affect the salt crystals?
- Try repeating the experiment with another cylinder made of a different material and compare your results (e.g., glass vs. metal vs. cardboard).
It would be easy to assume that it’s the air from our voices causing the salt crystals to move, but it’s actually the result of sound vibrations. All sounds are made up of tiny vibrations that travel in waves through air, water, or solids. When those sound waves hit the plastic wrap they cause the surface to vibrate and the salt crystals to bounce and scatter. Sound might be invisible, but it is powerful and sound waves visibly affect us every day.
Throughout the Bible we encounter all sorts of verses and stories about sound. God spoke the world into existence (Genesis 1). The Israelites shouted and blew trumpets and the walls of Jericho collapsed (Joshua 6:20). God spoke to Elijah with a still, small voice (1 Kings 19:11-13). Ezekiel has a vision of heaven and describes the sound of wings as like the roar of rushing water and Revelation uses the same sound to describe the voice of God (Ezekiel 1:24, Revelation 1:15). The Psalms are full of songs reminding us to use our voices and instruments to praise God (Psalm 98:4-9). Jesus spoke with authority as he healed, cast out demons, and called Lazarus from the grave (John 11:43). We look forward to the sound of a loud command and trumpet proclaiming that Jesus is coming again (1 Thessalonians 4:16-17). And when we are all together in heaven we will lift our voices and shout in praise and worship of our amazing God (Revelation 19:1-8).
What other Bible stories can you think of that use sound? Can you think of a time when God used a sound or even silence to speak to you personally? This week, pay close attention to the sounds around you, whether it’s the wind, music, laughter, or stillness, use your voice to thank God for the way He speaks through it all!
Bonus:
Back in the 1700s, scientist Ernst Chladni discovered something amazing about seeing sound. He used a violin bow to stroke the edge of a piece of metal sprinkled with sand. The grains of sand would dance and collect into amazing patterns depending on the amount of sound vibrations. The faster the vibrations, the more intricate the patterns. Scan this QR code to watch a video showing you the amazing sight of sound. Isn’t it incredible that even in something invisible like sound waves, God has designed beautiful artistic patterns? Every sound we hear bears witness to our Creator and we can celebrate the Master Artist.
