Origin of Universe, Destiny:
-The Sun appears to move across the sky in the say way every day
-Gravity governs motions in the universe
-The solar system is 4.6 billion years old. The universe is 10-20 billion years old
-Early Earth was very different from the planet we live on today
-The origin of the universe remains on of the greatest questions in science.
-The "big bang" theory says the universe began in a hot dense state.
-The "big bang" theory says the universe has been expanding since the beginning