At beggins had nothing. This is an idea very difficult to understand and it cause much confusion between people who have heard about Big bang's Theory. But this is so.
Big Bang is the origin of all that we know. Before there was not mattery, or dark mattery, energy or dark energy, It all started here.
We cann't understand nothing before Big Bang, but we know what happened because echoes have been present in space.
The most important thing to understand Big Bang is to understand Universe's Expansion. This is evidenced at redshift of the electromagnetic waves reaching us from space.
Redshift: Doppler's Effect of electromagnetic waves
Redshift was discovered by Edwin Powell Hubble when in his observatios he observed that celestial objects sent their electromagnetic radiation but they came to us with a lower frequency, or a redshift. Then he concluded these objects away.
Doppler's Effect confimed Big Bang's Theory
Then the scientifics deduced: "if everything away from everything at all times, before everything was over with".
So that the universe originated in the Big Bang.
