My three-year-old son Joshua is a bright and curious boy, full of incessant questions and always wanting to get into everything.
The other day he noticed that when he was sucking up juice with a straw, the level of liquid in the cup went down. I pointed to the glass vase of tulips next to him and remarked that they also sucked up water to stay strong.
Joshua then wanted to know if he could see the level of water going down in the vase as well.
I told him that, unlike his juice straw, it happened too slowly for him to see it. But if he liked, we could do a little experiment to test whether it was happening.
Joshua knows what “spare-mints” are because he likes to watch “Nina and the Neurons” on CBeebies – a TV program in which a terrifyingly perky, white-coated host does interesting science with pre-school children.
Joshua was excited about the prospect, so we lined up an envelope on the vase, made a mark at the waterline, and wrote down the date and time next to the line. The envelope went on the fridge, and whenever Joshua wanted, we got it down and made a new mark corresponding to the new water level. As hoped, the tulips drank lots of water, with the level dropping about 3 mm every ten hours or so. We’re now on our second experiment with a new set of tulips, and he seems happy that it’s reproducible.
The staff at Joshua’s nursery has just asked me if I’d be willing to come in one morning to do a small science demonstration or experiment with the kids. This is a completely different brief, as it would have to be something that would have a real impact within half an hour, and which would be robust enough to withstand very short attention spans.
I’m stumped at the moment, so all ideas welcome!