Origin of time or origin of space-time?

Question

Are there alternate theories or models that contradicts the idea that big bang is the origin of time ?

Answer 1

Is there any other scientific theory that proves that big bang is the origin of time ?

Here is a gross misunderstanding of what a scientific theory is. A scientific theory can never be proven. It is successful if it fits data and observations, then one says it is validated, and if its predictions are always validated. An invalid prediction requires drastic changes in the scientific theory.

I read in several sources that winding back general relativity equations leads to t=0, origin of time.

Wrong summary. The equations used to model the data and observations for the universe we live in, the Big Bang model, have a singularity at the origin , which we can assume as the beginning , at x=0,y=0,z=0,t=0 . The model has been successfully modified as new observations are made that did not agree with the simplistic singularity model, but it is the dominant cosmological model.

However, it makes sense to hypothesize time as an eternal dimension and big bang merely created space in time and hence the origin of space time.

It cannot be a bang in three dimensions because the data contradicts it. The data show that everything in the cosmos is moving away from everything else. In a three dimensional explosion there is a center to the motion. The raisin bread analogy may help in visualizing this.

Steady state models have been proposed but have not been successful in describing the observations.

Answer 2

Studying big bang itself gives a lot of evidences to believe in it.however redshift ,given by Edwin Hubble , is one of the major theory that supports it by giving evidence of expanding universe.cosmic wave background is also a big point to support it.