Age of the Earth? How do we know?

Our latest ELI has just been published - 'Working out the age of the Earth - moving backwards as time moved forwards'.  Ask pupils to link up the ‘headlines’ about calculating the age of the Earth, to show how ideas about the age of the Earth have changed over time from 1650 when Bishop Ussher gave a calculation of 6000 years to 1956 when radioactive uranium/lead dating of meteorites gave an age of 4.55 plus or minus 1.5% billion years. In recent years radiometric dating has given the most reliable figures. They all cluster around 4.6 billion years, more easily remembered as near 4,567 million years.
This activity is another ELI which gives a good example of 'How science works'. Others include the work of Charles Darwin, James Hutton, Mary Anning and Alfred Wegener. All of these can be found using 'Search activities' on the home page of our website.