is it possible for something like the universe, consists of many stages of formation,atoms,elements,compounds, biological systems, to exist by one single bang?

The Big Bang isn't actually a bang. It's a model that describes the inflation of the universe from a hot dense state to a cooler less dense state. There was no explosion and considering that the inflation is ongoing, the universe is technically still "banging" as we speak.

Edited October 23, 201411 yr by Delta1212

the model is supposed to describe an early universe that already exists and its evolution. it isn't a description of the origin of the universe.

the model is supposed to describe an early universe that already exists and its evolution. it isn't a description of the origin of the universe.

 

if I understood clearly, the universe did not come to existence from nothing by a bang. it already exists. Thank you

if I understood clearly, the universe did not come to existence from nothing by a bang. it already exists. Thank you

According to the model of the Big Bang, the universe was once extremely hot and extremely dense to the point that it was opaque and impossible for anything even as complex as an atom to form. This obviously changed as it expanded and cooled.

 

Where that initial hot, dense universe came from is still something of an open question.