The universe is constantly expanding, but we can say that at some point there was a time when everything didn't exist. There are different conceptions of how and why the universe began to exist. One perspective says that something simply popped into existence out of nothingness for no reason at all. Another theory suggests that something cannot come from nothing because it would violate fundamental laws of physics (the law of conservation of energy). Therefore, the universe must have been caused by an external force outside itself. Whatever one may believe, it’s highly likely that there was a start to everything at some point.
I think that in order to properly examine the issue of how and why something exists outside itself, we should first consider the nature of time. There are many views about what time is or means. I sometimes ponder around this topic and there are a number of views that consider time in different ways.
One view is that time is an arrow or perhaps a vector, which means it moves in one direction. This is where we establish that time is moving forwards and cannot be turned back. Yet another view is that time goes around and around like a circle, we might look at a clock and say it’s that time again and certain events may occur once more.
Yet another perspective view time in similar fashion to a train track or other predetermined route. The past and future are fixed in place, but the present moves forward. This might sound like a combination of our arrow on a predestined route. We could also consider that time exists only when there are events taking place. When nothing is happening, we come to a pause. We could also throw all of this out of the window and go with time not existing, all moments of time exist at once in the present.
The nature of time is complicated and mysterious, allowing for a person to think deeply about this abstract concept with great contemplation.