Back when different theories were presented, the Earth’s age was different due to varying opinions of different people – readers of the Bible calculated Earth’s age by counting Adam’s offspring. It wasn’t until 1898 when Marie Curie proposed the phenomenon that is called radioactivity. Several years later, physicist Ernest Rutherford discovered radiometric dating stating that radioactive elements are broken down into several elements in a predictable series and proposing that Marie Curie’s phenomenon can be used as a clock for dating rocks.
With these different theories combined, Arthur Holmes was able to develop the uranium-lead method – a technique which can be used to date rocks accurately. With radiometric dating, scientists and geologists were able to calculate Earth’s age – today, the Earth is 4.543 billion years old.
