By using lead isotopic data from the Canyon Diablo meteorite, he calculated an age for the Earth of 4.55 billion years, which was a figure far more accurate than those that existed at the time, and one that has remained largely unchanged since 1956.
Menggunakan data isotop timbal dari meteorit Canyon Diablo, ia menetapkan usia Bumi di angka 4,55 miliar tahun, jumlah yang lebih akurat ketimbang yang sudah beredar pada waktu itu dan menjadi permanen sejak 1956.