Thursday, 28 February 2013

Physics is either super accelerating particles to beyond the speed of light, or it's melting ice in a bucket

 Here we are exploring ice.  Ice is a brilliant medium for home experimenting as it is easy to make and very tactile.  At it's most basic form of experiment, kids love handling ice and seeing how it changes.  Ice cubes can be a choking hazard though, so for Toby I first wrapped some cubes up in a tea towel and smashed them to bits with a rolling pin.  Also, don't let your kids chew ice as it is now known that this can cause micro-fractures in the enamel of their teeth.

I use simple experiments like this to develop Ollie's descriptive skills and vocabulary.  Questioning method is the key here: "what does it feel like?" can be tricky for a little one to answer when they're first getting going, but 'or' questions can help them to frame their ideas "is it slippery or rough?".  If you're keen on written logs (as by now you know I am, mainly because Ollie feels like he's doing real science if it goes in his book) you can make a little table for them with the descriptive word pairs in, and
help them to highlight the word they think is the best description of the sensation they're experiencing.

Predicting outcomes is often tricky too, and is a lovely way for us adults to step back and realise that our little one's don't magically know the information we take for granted.  Ollie's response to "what do you think the ice will turn in to when it warms up?" was "bugs, or a really big cow".  A three year old has very few preconceptions about the world, and having seen that a caterpillar turns into a butterfly, why shouldn't an ice cube turn in to a cow?  Although in this case I think he was being facetious as he thought I was asking a silly question, since the next thing he said was "I'm off to play with my toys while we wait for this ice to melt".  I've not sat him down with ice cubes before, so it took me by surprise :)

Since I was apparently being to simple for him, the next thing we did was test to see if adding salt had any effect on how quickly the ice melted.  Ollie counted the ice cubes, and then I explained we needed the same number in each box, and how many we needed to count out for it to be half.  Ollie counted half the ice cubes into the box, then added as much salt as he wanted (which was all of it).  He thought that the ice with no salt would melt faster, so when he saw the opposite happened it was really interesting to him.  This allowed us to then come back to a discussion we'd had last week about why the car was so dirty - salty grit put on the road to melt the ice spraying up on to the car.  I kept the salt well away from Toby though, as it's very tempting to eat and not good at all for babies.  He seemed pleased sliding the tiny chips of ice around, and again this was good for a new topic to talk to him about "brr Toby, that feels cold and wet" etc...