Parents from all walks of life have, at some time, been asked questions about Heaven from their children: "Where is Heaven?" or "Is Heaven up in the sky?"
Where is Heaven? It is a question that was easily answered prior to the development of advanced scientific knowledge. The answer was as simple as it was primitive: Heaven was up above, while hell was below.
Today, with the modern understanding about the physical universe, that question about Heaven is not so easy anymore. Heaven is not simply a place beyond the earth’s atmosphere. Space is not the place where the prophets of old simply lifted up in chariots, or floated up into space. Unless we are to believe that they left here to be taken to another planet called "Heaven."
Children of a Different Breed
Children are also more knowledgeable. In school they learn all sorts of things. They learn how the earth revolves around the sun - a view once held as heretical in Europe. They learn that the planets spin on their axis and children no longer believe that angels or boats cause the rising and setting of the sun and moon.
Children learn that there is no thunder god who brings the storm and no demons living in the closet or bathrooms. They learn that mental illness is the cause of psychological diseases and that there are no evil spirits invading their souls.
Thus parents in some traditions appear to be raising children who will soon make departures from their traditionally-held belief system; viewing it as archaic and filled with beliefs best left to comics.
Heaven and Paradise are not the Same in Islam
In Islam, this question about paradise and Heaven is easy to answer. The Quran states, “Be quick in the race for forgiveness from your Lord, and for a Garden whose width is that (of the whole) of the heavens and of the earth, prepared for the righteous...“ (Quran 3:133)
The first thing that's significant in this verse is that there are separate words for Heaven (Samawat) and paradise/Garden (Jannat). This relates that Heaven and paradise are different and should not be confused.
As such, Islam has never held the belief that paradise is somewhere up there in space. Furthermore, this verse states that paradise is bigger than the whole of the heavens and earth. Therefore paradise is not confined to, or a part of, the physical universe. It stretches beyond somewhere into the infinite creation that God has made.
Physics of Dimensions
Children also learn that they exist in only one of several dimensions. The world they live in is only one in a multitude of possible universes. In comparison, Islam states that God created worlds and heavens one above the other.
In Islam, children (in most cases) are taught that science and religion are one and the same. This creates what Muslims believe is a healthy outlook of life that is rooted within a person, eliminating the disparity of having to choose one over the other.
As such, heaven or the heavens is the beautiful artistry of the physical universe we see in the sky. Furthermore, it is relative to perception. In the west we see certain features of the sky that are not seen in the east and vice versa. Also, upon traveling to the moon, mars, or beyond again a person’s perception changes and she will see other things not visible from earth. However, there is nowhere she can travel to view the paradise that God has in store for the believers. It is a place and state of being invisible to those in the physical universe.
Accordingly, science is an investigation into the majesty that is God's Creation in this universe and paradise lies beyond what is accessible by modern technology.