This week marks the start of the Oxfordshire state school holidays. Currently I plan to continue this blog for the time being, but will take a short break while I'm on holiday in August. Do let me know if there's a topic you'd like me to cover before the schools go back in September.
Also, for those of you looking for holiday clubs, there's a guide on our intranet pages (SSO needed). For those of you who are unable to get a place in a local club or who prefer to stay at home, Science Made Simple is running an online holiday club with live activities all day.
This week I've picked one or two tricks/activities for each sense.
Most people have two eyes which each receive a 'picture' of the world about them at the same time. Our brain then cleverly puts the two pictures together so we only see a single picture. This trick uses that process to fool us into seeing something that isn't there. Better still all you need is your eyes and a sheet of paper - why not give it a go! Smaller children often find it difficult to understand what to do for this trick. Try doing it yourself first and talk them through it. It is vital that you keep both eyes open (many people automatically close one eye when looking down the tube).
As discussed in a previous blog, sound is a vibration. Some things vibrate too slowly for humans to hear and some things vibrate too fast for us to hear. Humans can hear sounds between roughly 50 vibrations per second (a very low rumbling sound) and 20,000 vibrations per second (a very high pitched sound). Most adults can't hear as high as 20,000 Hz (Hz=number of vibrations per second) but lots of children can. Test how high you can hear yourself here (NB Your sound equipment may not be able to cope with frequencies above a certain level as some headphones etc aren't designed for frequencies at the top of the hearing range). Generally speaking children can hear much higher than adults (as a child I could hear the lower calls that bats made, now I can't) and like doing something where they are better than the adults in the room.
Sound Pelmanism - many of us will have played that memory game where you turn over two face down cards each turn and try to collect pairs (if not the rules are here). Why not have a go at creating a pelmanism game that uses sound by putting different objects into pairs of matchboxes or other small identical containers and shaking them. Some good things to try might include: Uncooked rice, sand, paperclips, plastic beads, bits of lego, cotton wool, a marble etc
Different parts of the body are more sensitive to touch. You can have a go at the two point discrimination test in this set of touch experiments to find out which parts are most/least sensitive. Another quick experiment is to fill three bowls with water. One very cold, one hot (not too hot or you'll burn yourself) and one with warm water in it. Put one hand in the hot bowl and at the same time the other hand in the cold bowl for 30 seconds and then put them both in the warm water bowl together. Even though both hands are in the same temperature water, they'll probably feel different. In general we're better at knowing if things are hotter or colder than something else rather than being able to tell specifically how hot/cold things are. Finally, another trick I learned from James Piercy - for this one you'll need a partner.
Collect together some different smelling objects and challenge someone to identify the smells (make sure they're not allergic to anything first though!) I have done this with film cannister pots in with holes punched in the lid, but any small containers work well (eg small play dough pots). For smelling liquids it's probably easiest to pour a small amount onto cotton wool or toilet roll to hold the smell. Some strong smells to try might be: mint/toothpaste, coffee, vanilla essence or other flavourings, washing powder/liquid, scented soaps/shower gel etc. You could also have a go at creating a smell version of the pelmanism game above.
A lot of what we think of as taste comes from our sense of smell. Have a go at this experiment to see how much difference it makes if you can't smell your food. Again be careful that the person tasting the food isn't allergic to anything before trying it.
Although we tend to learn about the five senses above at school we have other senses too such as our sense of balance, or how hungry or thirsty we are. One of these additional senses is called proprioception and it is to do with our ability to know where our body is in space. Try this simple trick, close your eyes and try to touch your nose. Even if you don't get it right first time you were probably pretty close - we have a sense of where our nose is relative to the rest of our body. There are some great proprioception experiments on this sheet from the Ri - the 'arms through the floor' experiment feels really weird.
And finally ...
Please let me know if you have tried any of the experiments from any of the blogs. I'd love to know if you have or not and perhaps what your favourites were.
Meanwhile here's another picture of my kittens.