Universe – Redshift-blueshift concept

What causes Redshifts & Blueshifts? And based on what are they exactly?
We are really getting into the physics of things. These shifts are complicated things to explain, however here goes.

The picture above is a good starting point, so look at it again after you understand more about these shifts, as it will make more sense to you.

It’s all about wavelengths for both Redshifts & Blueshifts. Wavelengths expand for a Redshift, and wavelengths reduce for a Blueshift.

Redshift & Blueshift