GENERAL KNOWLEDGE

Detailed explanation-1: -When an object is moving away from us, the light from the object is known as redshift, and when an object is moving towards us, the light from the object is known as blueshift. Astronomers use redshift and blueshift to deduce how far an object is away from Earth, the concept is key to charting the universe’s expansion.

Detailed explanation-2: -This is equivalent to the Doppler shift of an object moving away from us, so we often describe this as the recessional velocity. The redshift can be measured by taking the light of the object and spreading it into a rainbow to measure the amount of light at each separate wavelength.

Detailed explanation-3: -The Doppler red-shift of light observed from distant stars and galaxies gives evidence that the universe is expanding (moving away from a central point). This allows for Big Bang Theory, because after a “bang” occurs all of the matter moves away from the point of origin.