Messy Science – Water Making Music

Equipment needed

Jars (at least three or four of the same or a similar size); water; spoons; food colouring in a few different colours if you have it
Fill each jar with a different amount of cold water and make each a different colour with the food colouring. Gently tap each jar with a metal or wooden spoon and listen to the different sounds.

Big thinking

Why do the different jars make different sounds? The sounds you hear are caused by sound waves, which are themselves caused by the glass vibrating as you hit it. The frequency of sound depends on how fast the glass is vibrating. When a glass contains more water, the vibration is slower and the pitch is lower. Conversely, when the glass contains less water, the vibration is faster and the pitch is higher. If you're feeling particularly musical, try to work out how to fill the jars to create a musical scale or even a tune. The more jars you use, the more possibilities there are!

You could do this experiment a slightly different way with some plastic water bottles with different amounts of water in. Rather than hitting the bottles, blow over the top of them. Now what do you hear? Which has the highest and lowest pitch? It should be the opposite of what you found when you hit the jars. This is because in this case, it is the vibration of the air in the bottle and not the actual bottle that causes the sound you hear. In the bottle with only a little water in, there is a longer air column and the sound waves in the air vibrate slower so that the pitch of the note is slower. With a lot of water and little air, the sound waves in the air vibrate faster and the pitch is higher.

Big questions

The person who wrote one of the Psalms said, 'Let everything that has breath praise the Lord!' (Psalm 150:6). Sometimes we can praise God through words, but what do you think it means to praise God without words? Do non-humans praise God, do you think? Do trees and rivers? Do animals? How would you praise God silently? Is it possible?

I know that whilst you have been home schooling, many of you have been doing some amazing art and crafts. I'd like to show you two things my Granddaughter Leana has made. Of course, I can't see them at the moment but my son-in-law has sent me some photographs.

The first is of this amazing caterpillar. Can you see what it is made from? Now, I'm sure many of you know the story of the very hungry caterpillar. Well, today I want to tell you a story about a very special caterpillar. He was very hungry, and he munched away on leaves until he grew into a big caterpillar like this one.

And he was a kind caterpillar, so he showed all the other caterpillars where to find the biggest, juiciest leaves, and everyone in the caterpillar community loved him and followed him from leaf to leaf. And then one day, the caterpillar said to his friends, "I'm going away for a little time, I have a very special job to do".

The other caterpillars were dismayed and begged him not to go, but the caterpillar said that he must go, but promised that they would see him again. The caterpillar shuffled away until he found a comfy tree trunk, where he wrapped himself in a silky sleeping bag and went to sleep.

And whilst he was wrapped tightly in his cocoon, he began to change. He grew wonderful wings and long legs and his green coat changed into bright multi-colours and then one sunny day, he burst out of the cocoon as a beautiful butterfly like this one Leana has made.

Wow! The other caterpillars wriggled over to the empty cocoon and began to cry because their friend had gone. They thought he must be dead. Then suddenly they heard a familiar voice and saw a beautiful butterfly hovering above them.

"Don't cry said the butterfly, I'm here, I'm alive". The caterpillars could not believe their eyes. "Didn't I promise you'd see me again?" said the butterfly. "I'll always be with you and one day you'll be beautiful butterflies too and we'll always be together!" Then the beautiful butterfly fluttered away out of sight.
That story reminds us, that like the beautiful butterfly, Jesus is alive, and he is always with us and although we can't see him, we know he is with us when we see the beautiful things in our lives, like butterflies.

And we know he is with us when we are touched by the kindness of other people and feel the love of Jesus in our hearts. Rev Sue