The first moment

I will first deal briefly with the question of the origin of time.
Most present day religions teach of a moment of creation when the Universe came into being. They may differ from each other in the ‘how’, ‘why’ and ‘when’, but the basic idea is the same.

most physicists (some of whom are themselves
devoutly religious) now also believe that the Universe began at a
definite moment, about 15 billion years ago. But can we say that
the Big Bang ‘happened’ at some definite moment in time?
The problem is that time itself is thought to have started at the
Big Bang and is part of the fabric of the Universe. The Big Bang
cannot even be considered as the ‘first event’ since that would
require it to have happened within time. This idea is not unique
to science and many religions have a Creator who exists outside
time, leaving Him free to create time itself.
Physicists are now trying to understand why the Big Bang
happened in the first place. What caused it? Unfortunately, cause
and effect are notions that require time, and since the Big Bang
marked the beginning of timewecannot say that something ‘prior’
to it caused it. It may have just ‘happened’.
And as if this is not enough, remember that in order to
understand the world of the very small we need to apply the ideas
and concepts that arise from the theory of quantum mechanics,
and you don’t get much smaller than singularities. The Big
Bang singularity must therefore be treated as a quantum ‘event’.
Physicists have yet to sort out many of the details but nevertheless
argue that, in the quantum world, things get fuzzy and indefinite,
even the ordering of events. Strangely enough (or conveniently
enough depending on your viewpoint)quantummechanics allows
things to happen without a cause, including the Big Bang itself.
Oneexplanation which physicists are fond of using to describe
how the Universe came into existence is that the rules of quantum
mechanics would have allowed the Big Bang to happen on the
understanding that the Universe should quickly ‘pop back out’ of
existence again. For reasons we do not fully understand yet, what
mayhave happened next was that the Universe quickly underwent
a brief period of extremely rapid expansion after which it became
a permanent fixture, still expanding but at its current, more sedate,
rate.
So if it wasn’t the Big Bang, what was the first event in the
now created Universe? Physicist and author Paul Davies, who has delved as much as anyone into the nature of time, explains that
there cannot even have been a first event. He likens it to asking
what the first number is after zero. We must consider all numbers
and not just whole ones (the integers) otherwise the first number
after ‘zero’ would be ‘one’. It does not matter how small a number
we choose, we can always halve it to get a smaller one. In the same
way, there was no first event after the Big Bang. However early
the event, there will always have been an earlier time closer to the
Big Bang to consider.
However, as soon as quantum mechanics is brought into the
debate, we find that there is indeed an ‘earliest time’ after the Big
Bang. At the tiniest length and time scales, everything gets grainy
and fuzzy, including time itself. Just as the concept of the ordering
of events no longer applies at these extremes, neither does the idea
of continuous time. At this scale, an interval known as the Planck
time can be considered as the shortest possible meaningful slice
of time. Of course we are unaware of such a departure from the
smooth flow of time because the Planck scale is so tiny. In fact,
there are unbelievably more units of Planck time in one second
than there have been seconds since the Big Bang. Anyway, the
point is that if you go back in time to one unit of Planck time after
the Big Bang, it makes no sense to ask what happened before it.