Simplify the following text for a Grade 11 native English-speaking person.
Original: This expansion accounts for how Earth-bound scientists can observe the light from a galaxy 30 billion light years away , even if that light has traveled for only 13 billion years ; the very space between them has expanded .
Simplified: This getting bigger accounts for how Earth-bound pople can see the light from a galaxy 30 billion light years away , even if that light has traveled for only 13 billion years ; the very space between them has expanded .