Lets start with a simple sentence: "Science is mans attempt to understand the universe in which we find ourselves."
What do we mean by 'understand'?
I propose that to understand something is to have an explanation that makes sense to us. This implies that the explanation is rational and non-paradoxial.
What do we mean by 'universe'?
I propose that we use this word to encompass everything, all that exists, whether currently observed or not observed.
Science has, over the years, formulated a process (scientific process based upon observation, theory, experimentation and proof) and as a result, a number of accepted laws, statements that are held to be true for all time and space.
Some of the oft repeated questions that science attempts to answer are, "what is the age of the universe? and What existed before the universe?" and "what exists outside of the universe?"
One of the 'laws' of science is that energy cannot be created nor destroyed. Another is that matter and energy are different forms of the same stuff (the famous e=mc^2)
So, if we apply our rational thinking approach to this, we can answer the above questions because all energy and matter is what makes up the universe, and as matter and energy cannot be created nor destroyed, then it is what it is and always has been and always will.
The age of the universe is infinite, although it may have gone through some very extreme conditions when it experienced the Big Bang.
This unfortunately is a little difficult to comprehend, the idea that something has always existed does not fall into our normal range of experience. For example, when we ask "where did something come from?" we are assuming that it came from somewhere, it was manufactured, it had a point in time when it did not exist. We anticipate a cause and effect principle, which underlies our every observation of this universe.
So we have an answer which does not really fit in with any known observation, yet it is consistently logical ONLY because of our so called 'laws' which we deem are correct.
In basic science -2 we will look a bit closer at this finding.