More from our crazy junior scientists - image  on https://www.johncolet.nsw.edu.au

More from our crazy junior scientists

2012-sciencesound

The topic last week was Sound. The children were quick to realise that sound involved movement through the air, and we saw this movement as vibrations by making rice dance on a drum after much shouting (not so successful) and banging of pans (more so).

We also discussed why we see lightning before hearing the thunder: sound waves travel at a nimble 1200 km/hour, but light whizzes ahead at 1 billion km/hour!

The children did two hands-on investigations:

– Showing that sound waves can travel down a string with the classic string-and-cup telephone (if you try this at home, remember to keep the string tight);

– Showing that tapping a drum sends out a sound wave by using it to blow out a candle.

We then thought about why we have two ears. The children could point to me even with their eyes closed because their ears worked together to locate my voice. So I tried out an experiment using an ear-swapping invention (pictured) to confuse the brain. Alas, the experiment failed.

But therein lay an important lesson: Sometimes a scientist has to deal with failure, have a bit of faith, and keep trying to improve their experiment.

We’ll see whether the experiment works better when the year 2 members give it a try next week.

Bryn Jeffries
Science Club facilitator