Teaching science at home

I have in the past been accused of being horrible about autonomous educators, a suggestion containing more than a grain of truth. Time now to remember that there are also some prize fatheads in the world of orthodox education. Somebody commented on the piece by Alan Thomas in the Guardian, saying;

'I teach science and point out to parents that homeschooled science isn't a patch on school experiments.'

I won't go deeply into the fact that hardly any interesting or stimulating experiments are now carried out during science lessons in maintained schools, due largely to health and safety fears. Nor will I explore the fact that the practical aspect of chemistry, say, contains only 20% of the marks at IGCSE. One could gain an A without doing a single experiment. I want instead to talk about how richer and more extensive the scientific experiments conducted at home can be.

Take the small matter of teeth, for instance. Students need to know about the different types of mammalian teeth. This is usually done at schools from pictures in a textbook, with the occasional handing round of an animal skull. Hardly likely to grab a child's imagination. In our house, the collecting of animal heads and the examination of their teeth covered a period of almost a year. We began by collecting a few road-kills; a squirrel and hedgehog. After sawing off their heads, we buried them in the compost heap in order to strip the flesh from them. This enabled us also to observe the nitrogen and carbon cycles in action as insects and bacteria went to work on the flesh. We dug them up regularly to watch this in detail. A dead snake gave us the chance to compare mammalian and reptilian dentition. This was followed up with a visit to the dental museum ay the Royal College of Surgeons in London. Then we found a dead fox, dragged it home and hacked off its head with a spade. This caused slight irritation in the household as I forgot to dispose of the headless body and it became a feature of the garden for months. On a trip to the seaside, we were fortunate to find a dead seal on the beach but my wife went mad when she found us dragging this back to the car and we were forced to abandon it. None of these experiments required any equipment nor cost any money.

Even more important than the information about biology, chemistry and physics which was learnt in this way were the wider lessons about the nature of the world. Here is an example. Many children's books about science tell the story of Galileo dropping a large weight and small weight from a high place in order to see what would happen. This is given as a brilliant example of the triumph of practical science over old and false theory. There is a delicious irony about this.

First, here is a question. When Galileo dropped those two weights from a high place, what happened? Did the big heavy weight reach the ground first or did both hit the ground together? Everybody who said that they reached the ground simultaneously loses one mark. Here is the sort of experiment which is never conducted at schools, because everybody knows the answer. However, when my daughter was eleven I was in teaching mode and we were studying physics. I decided to recreate this famous experiment and show my daughter what would happen. I wonder what readers think might have happened when I demonstrated this? In fact when I dropped a weight weighing fourteen pounds and another weighing four ounces from the top of a stepladder, the heavy one reached the ground first. We repeated this with different weights and varying heights. It was no good; the heavy weight always hit the ground first. Every book which describes this experiment by Galileo is quite simply wrong.

I was absolutely shocked by this because I have grown up like everybody else, reading this story and learning how Galileo disproved the old ideas of Aristotle. In the end, having found that literally every mention of this story in books in the local library repeated the same untruthful description of the experiment, we found Galileo's own account of the matter in The Two New Sciences, published in 1638. In this, Galileo actually acknowledges that the heavier weight strikes the ground before the lighter one.

It is impossible to overstate the impact which this episode had upon my young daughter. She learnt that even though every book in a library says the same thing, it is not necessarily true. She would not have made this discovery had I not been pursuing a structured course of instruction in physics. She went on to get an A* for physics, but the most important things she learnt as a result of the lessons had nothing at all to do with science!

This is one small example of the advantages of teaching science at home rather than at school. If the same thing happened at a school, the observation would be ignored and the pupils told to write in their books that the two weights actually did hit the ground together. Incredible as it may seem, I have actually seen this done in a school lesson. The experiment in this case involved covering a leaf from the sun and then testing it for the presence of starch. In theory, there should be no starch present, but every time I have seen this experiment done there has been just as much starch in the leaf kept in darkness as in the control left in the light. The teacher just told the children to write down that after they tested the leaves with iodine, the one from the dark tested negative for starch! The reason for this is that they might later be expected to describe this experiment in an examination and it was important to know what the 'correct' result was. This single incident tells me all I have ever needed to know about the teaching of science in schools and explains why I preferred to teach it myself at home.