What has changed after 250 million years?

Earth's tectonic plates are constantly moving, making the Earth's surface change over time. After millions of years, the Earth's appearance changed dramatically because the continents were split or merged.

1. How did scientists determine the age of the Earth?
2. What is left of the Earth after 100 nuclear warheads are detonated at the same time?
3. If the Earth swells twice, how will humans and plants and animals change?

The video below will help us better visualize the process of changing the face of the Earth for another 250 million years as predicted by scientists.