Atomsphere

In this model the Universe:

• Is expanding
• Has unchanged density
• Spontaneously created matter, espically hydrogen, from empty space to maintain density
• Had no beginning and will never end

In this model the Universe:

• Is expanding
• Is finite and ever-changing
• Was created about 14 billion years ago from an event called the Big Bang
• May have an end, depending on its density

Most scientists believe that the Big Bang Theory is correct, because it explains red shift and cosmic microwave background radiation