It will around 13.8 billion years ago when our Universe was created from an undoubtedly hot and very dense singularity in space an in time. This hot Universe was created in a fraction of seconds and has eventually calmed down as what we see today. The Universe is gradually expanding, the main reason being the dark energy. This event is described the Big Bang model of cosmology which is the most sought after theoretical explanation in respect of our Universe. This theory is backed by the boatloads of observational evidence. Some of the scientists have even considered the big bang theory as 100 percent true.
But this theory is no wonder when it comes to finding from where the Universe comes from? , what came before this Universe? What reason has caused it to bang in such a huge way? And so on. Carroll has rightly pointed out the fact that this huge bang and the singularity are the main points regarding which we are totally unaware. Moreover it has been pointed out by many scientists that it would be very difficult to even find out the main reason behind such a bang with the current method of observation. The high voltage nature of the inflation has ultimately led to wiping out of any prior information that was available. This was viewed by the astrophysicist Mr. Ethan Siegel said.
According to the MIT cosmologist Alan Guth has said that the universe that we can see around us must have has a beginning. He is the inventor of the cosmic theory of inflation. He has further added that it never implies that this was the actual beginning of the universe. It may have the implications that there might have been some background behind such beginning. Scientists have further viewed that the universe that we see around us is considered to be the region between two membranes of the universe parallel. There is another concept which revolves among the scientists that the universe in which we live have emerged from a black hole and that we are living in the event of the horizon.
All these theoretical concepts are very nice to hear but most of them are rendered unused at the present time. Perhaps we will never be able to unleash the truth behind the beginning of the universe. But still, our human nature will always be eager to find out the reason for our ultimate existence.