The wire telephone

I joined the Integral Enrichment Programme (IEP) conducted by Sri Aurobindo Society, Singapore, as a facilitator this year after completing my GCE ‘A’ level Examinations. I came for the first week at my mom’s (also a facilitator) request to co-ordinate an activity on her behalf, but joined as a full-fledged facilitator after seeing all the friendly faces of the children and the facilitators. Though I have been involved with reading activity for children with SINDA since 2002, this is the first activity I have conducted for the IEP children.

To kindle the awareness and the knowledge that simple articles found in the house can be used to create creative and fun science experiments that can explain science concepts such as sound, light and states of matter, I chose to work on the ‘wire telephone’, which is made as follows:

Things you will need:

1. Three empty paper/plastic cups
2. A ball of thin, strong string
3. Scissors
4. A needle

Instructions:

Method:
1. Use a needle to make a small hole in the end of each cup. Thread an end of the string though.

2. Tie a knot on the inside to keep it in place. The plastic pot acts as both the mouthpiece and the earpiece.

3. If you make sure that the string is stretched tight, you can use the string telephone to talk to someone in another part of the room.

The string must be kept tight. If the string is loose, the vibrations from your voice are lost into the air. If it is tight, they cannot escape easily and so move down the string to the other end.

If there are three of you, you can make a third string telephone and use it as an extension. Tie the string to the first line in a convenient place.

On that day that I was to facilitate for the first time, not only the children but also the facilitators and even the accompanying parents took part where they were split into pairs and given the materials. Many of the children were doubtful if the contraption would work but after some demonstrations with a model I had prepared earlier, they got down to making their own ones with a little help from us. Although the older children knew how sound travels in air, they forgot that the same principles apply to solids which in this case was the thread stretched between the two cups. In fact they could feel the thread vibrate when they touched it while talking. In no time the children had their own models and the room was crisscrossed with threads as the they passed ‘secret messages’ and sounds. Even the 1+ year old child of one of our facilitators had fun saying “allo” to her older sister!

I was gratified to know that it even reached the toddler
- Aravind, Facilitator