I READ with interest the letter by Anthony Weeden (November 7). Converting Celsius to Fahrenheit is obviously simple, but finding the age of the Earth was very difficult and also contentious.
The age is certainly now accepted as being between 4.5 and 4.6 billion years. The breakthrough came in 1956. It was then known that the age of any rock which had been formed from solidifying magma could be dated from lead isotopes in it which had been formed from the radioactive decay of uranium. This dating can now be done very quickly.
The ages of the oldest rocks on the Earth and also those of meteorites fell into this time slot.
A very readable book on the age of the Earth by Dr Cherry Lewis is called “The Dating Game: One Man’s search for the Age of the Earth.”
Brian Teasdill, Harleyford Lane, Marlow.
