Scientists examine the light spectra from distant stars to determine if the size of the universe is changing. Why do astronomers believe the size of the universe is changing?
options:
The red shift indicates that distant galaxies are moving away from each other.
The red shift indicates that distant galaxies are moving towards each other
The blue shift indicates that distant galaxies are moving away from each other
The blue shift indicates that distant galaxies are moving towards each other
Red shifting occurs when objects move away from each other. You can think of the light wave being "stretched." A stretching of the wave causes a higher wavelength, and less energy, which are the characteristics of red light.
