Science, Maths & Technology
Build a thunderstorm predictor
...works: The idea is simple. Just before a thunderstorm, the air will be highly charged with static electricity and this will collect on the unearthed bell. The charge bell will then attract the ringer because if the bell is say positive, the ringer (which is insulated) will be relatively negative. However, when the ringer touches the bell (making it ring) it will...