Magnets in the village
In the latest of our shortlisted entries to the 2011 Wellcome Trust Science Writing Prize, Keith Warren describes a typical day in the office.
There is a general complaint in Southern Africa that schools have no laboratories or scientific apparatus. As a result, the majority of them do not study practical science, only teaching theory that the students find uninteresting or have trouble understanding. My colleagues and I work as a small group in Mozambique, trying to interest people in science and technology. Our group’s speciality is to show that not teaching practical science die to lack of facilities is perhaps the wrong way to look at it. There is an alternative – to find opportunities to teach using local resources for the experiments.
We like to arrive in the village where we will be demonstrating science with nothing in our hands, as we do not want to import any non-local things to the area except ourselves.
“Let’s go and buy a battery,” we say to the small group of children we meet. We wander with them to the market – two little stalls, one with vegetables and fruit, the other with common things like soap, matches and batteries. We buy a torch battery, which will be our only investment for the day.
We bargain for a three-inch nail. The stallholder wants to sell us a dozen but we settle for just two. “Go on, take them,” he says, “We know you are helping to teach our children.” Kindly, he throws some smaller nails in as well.
On our way back, the group passes a piece of rather rusty chicken wire. “Let’s use that,” we say to the children who laugh and salvage it. Two of them undo some of our prize to obtain a yard of individual wire – fiddly work, but not difficult – and smooth out its wrinkles over the edge of the log we are sitting on.
The children wrap a piece of newspaper round the shank of the nail, which acts as insulation. They then wind the wire over the paper, making sure adjacent turns do not touch. When the nail is full, another layer of paper followed by another winding of wire. This is repeated until the wire runs out. We connect the ends of the wire to the battery and… The children have created an electromagnet that can pick up smaller nails.
Everybody has a go. “Magic!” they shout, delighted.
“No,” we explain (with mock grave faces), “Science.”
By the next day several of the children had made electromagnets at home, with some of their fathers complaining about flat batteries in family radios.
Occasionally, the nail used is semi-steel, able to retain a little magnetism. In this case, we ask the children to pull it out of the coil of wire and hang it from a thread of hair from a girl’s plaits – fixing it with a bit of chewing gum. We explain to the children that the nail should point North to South. Of course, it does nothing of the sort and just swings in the breeze. To improve the design we cut a clear plastic bottle to make a cup, half-fill it with water and hang the nail in the water from a pencil across the top. The water settles the movement of the nail, which soon comes to rest North to South. A real working compass. The children are delighted, and so are we.
Making another permanent magnet allows us to demonstrate how magnets can both attract and repel one anther. “Ah, yes!” they cry – that exclamation every teacher loves, as it signifies the arrival of understanding. “We learnt about this in the book, but we never understood it,” they explain. After this the children will never forget – you can see some of them are beginning to feel like real scientists already.