It is remarkable that, despite Computing being introduced in the statutory National curriculum Programmes of Study from Year One in primary schools from 2014, electricity and electrical safety is not included until year 4. Of even more concern is that when electricity is introduced it doesn’t refer to switching or digital electronics and it encourages children to be taught that all materials may divided into two discrete categories ‘conductors’ and ‘insulators’. This is bad science, it is a false dichotomy and in practical terms it is also a very dangerous assumption to make. Children should be taught about electricity much better and earlier.
Three Crucial facts about Electricity and Safety
- There is no such thing as a perfect insulator
Every material can conduct electricity under some conditions. While pure water is a poor conductor, dirty water can be a very good one. Even air conducts electricity at times as can be seen in lightening and the insulation qualities of rubber and plastics around electrical cables may be reduced through age and damp conditions.
“…there is no sharp division between conductors and insulators; insulators can be thought of as poor conductors.” Valkenurgh, p14)
- The Human Body conducts electricity
According to the Royal Society for the Prevention of Accidents (ROSPA) there were as many as 2,788 accidents involving electricity in the home every year. In 2002, 27 deaths were recorded to have been the direct cause of electrical injury, and 24% of all electrical injuries involved children under the age of 14. When a strong current flows through your body it blocks the electrical signals between the brain and you muscles. In some conditions 50 Volts is enough to cause this ‘electric shock’:
- It may stop your heart beating
- It may stop you breathing
- It may cause a muscle spasm that leads to serious injury
- Electricity + Water = Danger
The seriousness of an electric shock depends on the size of the voltage, which parts of your body are involved, how damp you are, and the length of time the current is flowing through you. From an electrical safety point of view, the bathroom is probably the most dangerous room in the home. There are special regulations limiting the fitting of electric sockets in bathrooms and electrical devices such as hairdryers, heaters or radios should never be used. Another major site of accidents is in the garden where electrical equipment should never be used in wet or damp conditions.
For a much more adequate and relevant approach to teaching basic electricity than found in most texts see: https://327matters.wordpress.com/2012/06/05/computer-science-and-the-blatchford-buzz-box/
For information on how to obtain your own Buzz Box contact: John@327Matters.org