Sunday, 8 January 2017

God's amazing universe: 1. Space and Time

Prior to the discovery in the 20th century of the Big Bang creation event it had been assumed by people of all faiths that the universe was, is and so always would be eternal. It was not created. It just is. Some still cling to this belief.

Big Bang Star Hyperspace Wars
The only real creation metaphor, story, poem or myth that refers to the universe being created by God, rather than fashioned out of eternally existing chaos by various gods, was Genesis 1:1

In the beginning God created the heavens and the earth.

According to Hebrew scholars the expression 'the heavens and the earth' is ancient Hebrew for everything, i.e. the universe. It is extraordinary that some 3 thousand years ago the author of Genesis could make this statement and others equally prophetic. He was writing in a pre-science culture. Genesis is not written as a scientific document. It is written poetically and historically to yield, when read with humility and after prayer, divine truths about humankind and its relationship to God.

It is now established by theory and observation that not only did all energy and matter originate from one infinitesimally small point which then expanded at an unimaginably high rate to give us the stars, galaxies and clusters of galaxies which we see today on Hubble photographs, but something else had to be created. Mass and energy cannot exist without somewhere to exist in. They have to have extent; so God provided the three dimensions of space. For things to exist they had to have space to extend in. But for things to happen there needed to be time. Only with coexistent matter, energy, time and space could God bring about humanity and the universe we see today, 13.8 billion years later.

Our space-time realm is well named. Even what sight and touch deem solid, like the wall in front of you or the chair you sit on, is actually ethereal, consisting of well over 99.99% space permeated by configurations of energy. Things have been set up to give us the experience or illusion of living in a solid world. You could call it a stage, as did Shakespeare ('the world is a stage on which every man must play his part').
The Oxford Dictionary of Physics defines space as a property of the universe that enables physical phenomena to be extended into 3 mutually perpendicular dimensions. So it is not just an empty expanse. It is a property in the same way as mass and gravity. Like other properties it is a concept or metaphor which allows mathematicians to describe the way the world works and calculate what happens under certain conditions.

The universe is often visualised as the surface of an expanding balloon. This, however, is only a 2-dimensional representation of a 3D space. It  is visualised in this simple way just to show how space expands with time - that is, as the balloon is blown up all positions on its surface get further and further apart. The billions of galaxies etc. of the real universe would be represented here as dots on the balloon's surface. The  start of the Big Bang would correspond to the balloon before it started to be inflated. Our Milky Way galaxy would be one dot and, like all the other dots, could be considered a centre of the universe but not, in any visual sense, the centre. However, as future posts will strongly suggest, we could well be the only centre with conscious observers. If that is the case, then humankind can go back to thinking of itself as the centre of creation.

How fast is this space-time regime expanding? According to the theory of inflation, which is not yet proven and during which all kinds of strange things have been surmised, in the first extremely small fraction of a second it grew from virtually nothing to a diameter of 10 metres. After that it expanded at a lower and slowing rate until about 5 billion years ago it started to accelerate. Today, 13.8 billion years after the creation event, it is expanding faster than light. When Einstein said that nothing can travel faster than light he was talking about entities inside the universe, not the edge of  the theoretically observable universe itself, some 46.5 billion light years from earth in any direction. At this distance the stars are receding faster than the light they emit, so no information from them can reach us.

Recently it was determined that the space which we and everything in our universe inhabit is flat and infinite. All this means is that two parallel lines never meet and the Euclidian geometry  taught at school (e.g. the Pythagoras theorem) is correct on any scale, providing there are no local gravitational fields to bend the space.

The balloon analogy seems to contradict this until you remember that the curvature of the balloon surface does not apply to the real universe for which the balloon is serving only as a 2D simplification so that we can visualise the expansion that continues as time proceeds.

Although space has the mathematical property of being infinite the actual universe has a boundary at 46.5 billion light years (see above).   This boundary is equal in all directions so the universe is spherical even though the space within it is flat in its geometrical properties. Anything setting out from beyond that distance would never reach us and so is beyond any conceivable scientific observation.

John Sears

John Sears

I am a layman who follows science. As far as I know the above is factually correct. Please let me know if you find an error or have issues.