How big was the universe at the time of the Big Bang?

There is no way to find out if there even was a universe before , therefore no one knows the answer on your question. We don't even know how big...

My estimate is attributed to other estimates. Our universe has had expanded through 13.8 billion light years in 13.8 billion years. So, I have reference for okaying my estimate.....

The Universe (as we know it) did not exist before and it was a singularity. (here the laws of physics are indeterminate). The Universe came into existence at Planck time...

In Big Bang cosmology, the Planck epoch or Planck era refers to the earliest stage of , before the time passed was equal to the Planck time, tP, or approximately...

As I understand now, it was speeding out of matter, from a point source, at the speed of light, with consequent formation of the systems of our universe,...

I know this is frustrating to say but cannot be easily visualized, because we instinctively think in Newtonian terms. Matter was not blown during the big bang, it was space...

Not to oversimplify this but the very nature of "theory" means that an absolute proof does not exist. In the case of the development of the early universe, it will...

Even determining "facts" is a difficult, on-going process, with many errors along the way. BUT, the point of the "Scientific Method" is to KEEP questioning and looking for supporting EVIDENCE,...

This is a question that still lies outside of our knowledge, and may always continue to do so. Physics today can do a creditable job of outline the events that...

The Big Bang means that the Universe evolved from a singularity and the Universe is inflationary, it being finite and unbounded, Einstein had originally postulated the need for a cosmological...