Respuesta :
Answer:
One is the expanding model, which says that the universe is Constantly increasing in size.
Explanation:
I believe its that
Answer:
In a short way, if an object is moving away, the light that comes from that object will have a red shift (it seems a little more reddish than it actually is)
If the object is moving towards us, the light that comes from the object will have a blue shift (it seems a little more blueish than it actually is)
Those shifts can be observed from the Earth, so from that is safe to conclude that the expanding model is actually correct.
Explanation: