GMAT
Becquerel's discovery of radioactivity, and thereby radiometric dating, not only indicated a much older age of the Earth than Lord Kelvin's thermal calculation of a "young Earth," only 20 million years, but providing the mechanism of extra heat as well which would keep Earth's core so warm even billions of years after Earth's creation.
Becquerel's discovery of radioactivity, and thereby radiometric dating, not only indicated a much older age of the Earth than did Lord Kelvin's thermal calculation of a "young Earth," only 20 million years, but also provided the mechanism of extra heat, which keeps Earth's core so warm even billions of years after Earth's creation.
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