Lightbulb

Once too precious to use, now too cheap to notice – the significance of the lightbulb is profound. Imagine a hard week’s work gathering and chopping wood, ten hours a day for six days. Those 60 hours of work would produce light equivalent to one modern bulb shining for just 54 minutes. The invention of tallow candles made life a little easier. If you spent a whole week making them – unpleasant work – you would have enough to burn one for two hours and twenty minutes every evening for a year. Every subsequent technology was expensive, and labour-intensive. And none produced a strong, steady light. Then, as Tim Harford explains, Thomas Edison came along with the lightbulb and changed everything, turning our economy into one where we can work whenever we want to.Producer: Ben Crighton Editors: Richard Knight and Richard Vadon(Photo: Electric lightbulb, Credit: Science photo library)