The discovery of quasars supported the big bang theory and went against the steady state theory.
Big bang theory timeline.
Since the big bang 13 7 billion years ago the universe has passed through many different phases or epochs.
The big bang theory is a cosmological model of the observable universe from the earliest known periods through its subsequent large scale evolution.
The model describes how the universe expanded from an initial state of extremely high density and high temperature and offers a comprehensive explanation for a broad range of observed phenomena including the abundance of light elements the.
According to the steady state theory these quasars should be found all throughout the galaxy but they are only found on the outskirts which supports the big bang theory in which the universe is constantly expanding.
Due to the extreme conditions and the violence of its very early stages it arguably saw more activity and change during the first second than in all the billions of years since.
Models that aim to describe the universe and physics during the planck epoch are generally speculative and fall under the umbrella of new physics.
Timeline of the big bang theory.