The Amazing Universe

The Amazing Universe — page 3
CHAPTER 1 THE MASSIVE UNIVERSE The universe is a mysterious place It contains everything that exists This includes space matter energy and time No one knows exactly when the universe began But many scientists believe it is about 14 billion years old No one knows how big the universe is either However scientists have found evidence that the universe is constantly expanding Scientists also don't know the shape of the universe for certain Most believe it is flat However some scientists believe the universe curves outward like a balloon And others believe it curves inward like a saddle DID YOU KNOW The only known universe is the one we live in But some scientists believe that there are many different universes seat