After the beginning, perhaps not the beginning, after the first fraction of a second, perhaps not the first fraction of the first second, after our universe began, still without us, then the universe was like seething water without land and without air, like a fire without wood and without cold. The universe, as small as it was, created itself space, matter, and the cool of the day.

There always will remain questions; existence does not explain itself ('mystery', see p. 18). However, if we only stress the inexplicable, we would lose sight of the integrity of the universe, the reliability of phenomena. It is not as if something unexpected and incomprehensible can happen any moment. Rather the contrary; the universe in its development turns out to behave according to regularities (laws of nature). If the universe is seen as a gift, the present is a complete one; it has its own integrity. It is not a puppet on a string, with someone else pulling the ropes, or an incomplete product that needs supplementation or correction from time to time.

In earlier times, this seemed different. Newton's theory of gravity explained the movements of the planets in our solar system, but not completely. The system seemed to run off the track from time to time, needing a special act from the creator to keep it on course. The French mathematician Pierre Simon Laplace (1749-1827) showed that the deviations did not accumulate disastrously. This is captured well in the following anecdote, of which the historical veracity is doubtful. Laplace presented a copy of his book on the movements of the planets to Napoleon. Napoleon is said to have remarked that Newton in his treatise referred to God, whereas Laplace did not do so. Upon which Laplace is supposed to have replied: 'Your Majesty, I do not need that hypothesis.'

Indeed, contemporary cosmology does not need a God-of-the-gaps. In that sense, the situation is quite far removed from ordinary experience. When we maintain a fire, we need to supply it continuously with new wood, and we need an environment that is cooler than the fire - an environment to which the fire gives of its heat. The universe seems to do without such input and without such a receptive environment - a fire without wood and without cold; it creates itself space, matter, and the cool of the day.

That there is no need for the difference between the hot fire and the cold night is just one instance of the very fundamental issue of asymmetry arising out of symmetry. In the physics of ancient Greeks such as Aristotle, the Earth was at the centre, a very special place. Heavy objects 'by nature' fell to the centre; that was their 'natural place'. Over time, we have become more modest with respect to our own position. Neither the Earth, nor the Sun, nor our Galaxy is the centre. There is no centre. There is no cosmic discrimination of this kind; all places are equal. At least, equal in principle. In practice, places can be extremely different - from the hot interior of the Sun to the extreme cold of intergalactic space.

When there is no discrimination - with respect to place, time, orientation, or otherwise - physicists speak of symmetry. Newton's law of gravity did away with the concept of 'natural place', and thus with discrimination by place - masses such as the Moon and the Earth attract each other, depending on their distance, but where in space this couple would be makes no difference. Discerning symmetries has been a very powerful technique in physics, since symmetries are closely related to the existence of conserved quantities. If processes are not sensitive to place, there is a conserved quantity, momentum

(velocity x mass). If processes do not discriminate with respect to time - an experiment being performed today or tomorrow is expected to produce the same results - there is another conserved quantity, energy. Theories in fundamental physics are characterized by the symmetries that are built into them.

Symmetries can be spoilt. In the language used by physicists, symmetries can be broken; and they have been broken. Think of traffic. In principle, there is no reason why driving on the right or on the left hand side of the road would be preferable. If you are the only one driving around, it is attractive to keep to the middle of the road. However, once there are more cars around, the symmetrical solution (driving in the middle) becomes unattractive. If some drivers agree to drive on the right side of the road, others will follow, since the asymmetrical pattern is more viable than the symmetrical one. What triggers the choice may be minute. Indonesia was for many years a Dutch colony - and the Dutch drive on the right-hand side of the roads. However, the first car bought by the Sultan was a British Rolls Royce. Thus, driving on the left became the rule in Indonesia. To understand how a symmetry has been broken, we need history. Contingent facts may make a huge difference.

In the perspective of physicists, the fundamental rules of the universe have many symmetries built into them, even though the universe has become a world with many particular features which spoil those underlying symmetries. In biology, it is often the other way round; the symmetry is in the product, but not in the underlying process. For instance, the human body appears to be symmetrical with respect to left and right. However, underlying this appearance, there are all kinds of asymmetries, with respect to the heart, with respect to control over fine hand movements, and deeper down with respect to the way fundamental molecules are structured in space.

Now let us forget about life on Earth for the moment, and concentrate on the universe as it starts to develop. The early universe was homogeneous, whereas we nowadays distinguish cold and hot places, e.g. the night sky and the Sun. Through the expansion of space, the universe cooled. Clumps of matter, formed by gravity, generated hot spots. Thus, matter and gravitational contraction fuel the fire, while the expansion of space allows the fire to radiate away its heat.

We may not need to provide the universe with hot places and a cold environment, but we do seem to need matter to make our universe be what it is. However, according to modern cosmologists, for our universe it is not necessary at all to have an explicit input of mass or energy 'in the beginning'. This is amazing, since we see a lot of matter around us - the ink and paper of this book, our bodies, the house we are in, the Earth, the Sun and all those stars - that cannot be just nothing?

For physicists, it is all mass, and mass is a form of energy. Energy can take the form of movement, heat, and mass. Something can also have energy since you have lifted it; when one drops a stone, that energy is released again. Some objects may have a negative energy; it takes energy to bring a stone up from the basement to ground level. It also takes energy to launch a rocket into outer space, to free the rocket from the Earth's gravitational attraction. It takes even more energy to launch a rocket so that it escapes the solar system. And we need again more energy to free a rocket from our Galaxy. How much energy would be needed to launch a rocket that not only escapes from the Earth, the Solar System and the Galaxy, but even from the universe? That requires a lot of energy. It may take all the mass-energy that the rocket represents. But once the whole rocket is used as fuel to overcome the negative gravitational energy of the universe, there is nothing left to escape - the net energy of the rocket may be zero.

This thought experiment can also be used in reverse. Perhaps our universe is, as far as energy is concerned, 'nothing'. There is an enormous amount of mass (which is equivalent to a huge amount of energy), but that mass is subject to gravitational forces - and this implies an enormous amount of negative energy as well. The same applies to electrical charge. When there is a thunderstorm the clouds and the surface of the Earth have a different electric charge, but taken as a whole the system may well be neutral. The universe needs no input of charge, mass or energy; the conserved sums might be zero.

This self-sufficiency does not imply that nothing is needed. For a thunderstorm to arise, positive and negative charges must become spatially separated out of a neutral whole. The emergence of a material universe presupposes a reality in which matter can form out of energy. Quantum physics describes that process. According to this theory, there may be a fluctuation during which two opposites form, for instance a positive and a negative charge. Empty space is like a seething ocean, with waves rising and falling. After matter has formed, the universe is still like a seething sea in which combinations of matter form and fall apart.

If matter forms in space, then where does space come from? If we find ourselves in an expanding universe, as the Big Bang theory has it, should there not be an environment into which the universe expands? Space seems to be an external, pre-existing resource made available to the universe continuously.

Cosmologists have given an amazing answer to questions concerning the origin of space. The universe expands, and thereby creates its own space. The image of the Big Bang as an explosion, with bits and pieces flying apart, is misleading. There is no centre nor an environment in which the pieces move.

Let me try to explain this with an example. A balloon with dots is inflated. An ant on the surface, near one of the dots, sees all the other dots moving away. And the further away another dot is, the faster it recedes. However, the ant's dot is not the centre of the dots; from the point of view of any dot, all others recede. If we only pay attention to the surface of the balloon, we have an analogy for the cosmological case - the surface expands, but not by adding new material. Space (the surface) itself is stretched. The dots do not move over the surface (nor the galaxies through space), but they move with the surface. The inflation of the balloon shows itself in the increasing distances between the dots, just as the expansion of the universe shows itself in the increasing distances between galaxies. Perhaps a cake with raisins might be a three-dimensional analogy for the two-dimensional surface of the balloon - from the perspective of any raisin, all the other raisins seem to be moving away as the cake rises during baking.

It is hard to imagine, but according to current theories the universe may have created its own space. With the expansion of the universe it cooled down (except for hot spots like the Sun). Temperature differences, including the decreasing temperature of outer space, drive the formation of structures that would not have been stable at higher temperatures.

The universe has its own integrity; it stands on its own feet, without a supply of mass, energy or space flowing in from elsewhere. We speak of 'laws of nature' describing the development of the universe. These laws are the invariant elements in our descriptions; they are what holds everywhere, always. There is no dictator who occasionally brushes his own laws aside and decides otherwise. No shifts from the automatic pilot to manual control. No miraculous interventions. The universe develops itself; it has integrity.

Responses to this integrity of reality are different. Some see it as a basis for atheism, the conviction that there is no God. This interpretation passes silently by the limit questions considered above (see scene 2). The integrity of the universe does not imply that everything is understood; it is something other than self-sufficiency.

Others see the integrity as a basis for deism, the idea that a god started the universe but is not involved in it anymore. However, fundamental limit questions are not only questions about the beginning; they are also questions about existence and lawfulness. The question why the universe is as it currently is, is not answered merely by saying that this is so now since it was yesterday as it was yesterday. It is also necessary that the laws of nature are effective at every moment, that reality has existence at every moment.

As long as we speak in terms of cause and effect, we assume the ordinary notions of time and space. God can be thought of as the creator of the first moment; then and there the fuse was lit. However, since space and time are difficult concepts when we speak of the universe as a whole (see scene 1), we can and should distance ourselves from the image of God as an engineer who started the whole business. In the theological tradition God has been referred to as the 'First Cause', who is the cause of the 'secondary causes', that is, of natural processes and natural laws. Perhaps we should take even more licence from our concepts of time, space and cause. In this context, I prefer to think of God as the sustaining Ground of Being who is also the ground of the natural order and its integrity. To use an image from the novelist John Fowles, one might perhaps say that like the silence that contains a sonata and the white paper that contains a drawing, God sustains our existence. God would be considered as a sense of potentiality, of non-existing, a 'dimension in and by which all other dimensions exist'.

Was this article helpful?

0 0

Post a comment