How Old Is the Earth?

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Source:  Richard Dawkins, YouTube
Excerpt: …People long believed the Earth had only existed for several thousand years. Then, in the 1800's, a study of geological features (including fjords) led scientists to the conclusion that the planet must be … at least millions of years old. Later, the discovery of radioactivity provided a mechanism by which the Earth's core could be continually heated. This meant it was much older ... Earth is roughly 4.54 billion years old!

 www.youtube.com/watch

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