The story begins in 1655. One afternoon, a scientist Isaac Newton under the apple tree to rest. tired want to sleep.
When you sleep with an apple tree fell and struck him in the head. woke up, sat down, looked at the apple to the ground beside him.
Then Newton thought about the apples for many years. Why is an apple fell? This problem has bothered him and he could not think of anything else. Suddenly in 1680 had an answer r. He was excited and started to write a book about his theory.
Finally, in 1687 published a book. The book called Theory of Gravity and became one of the most important books in the history books.