How fast light travels relative to Earth One of O'Donoghue's first animations shows how fast light moves in relation to Earth. Earth is 24,901 miles around at its center. If our world had no ...

The Earth is really, really old. Over 4 1/2 billion years old, in fact. How do we begin to comprehend a number that large? It helps to put it on a more fathomable scale. Watch to see where Earth's ...