Space and time play a special role in all physical theories, because they are implicitly assumed in all physical theories. Physical theories can only be applied in practice if we know what 'here' and 'now' mean.
Most physicists use an understanding of space and time that philosophers refer to as "container theory. Space and time provide the stage on which world events take place. Physical theories explain what is observed in space and time. However, we may need to leave this familiar frame of mind and turn the explanatory approach around: Instead of implicitly presupposing space and time, it should follow from the basic laws of physics how what we tend to call space and time comes into being. A philosopher familiar with the terms 'explanandum' (= that which is to be explained) and 'explanans' (= that which is explained) would describe the task to be solved as follows: Switch the roles of explanans and explanandum - reverse the direction of the explanation!
If we are to follow this path, we must first consider what space and time actually are. Or to put it in the language of ontogenetic thinking, we need to describe space and time phenomenologically as fully as possible and look for an ontological and genetic derivation of these phenomenological properties. Fortunately, we can draw on the insights of great thinkers.
Immanuel Kant (1724-1804) characterised space and time as pure forms of perception: It is certain before any experience that every perception must take place in space and time. Space and time constitute the stage on which the spectacle of the universe is performed for us. With our current neurobiological knowledge, we could also say that our brain organises all sensory impressions in space and time. Space and time are therefore to some extent 'inventions' of our brain. On the one hand, this means that space and time are not necessarily inherent in things themselves, i.e. the basic laws of physics may not take place in space and time. On the other hand, the forms of visualisation of space and time have obviously proved to be excellent ways of interpreting world events over the course of evolutionary history, which means that the basic laws of physics must produce what we know as space and time. In short, it might be worth looking for fundamental physical laws that initially do not require space and time, and whose effects first produce what we know as space and time.
But what are the properties of space and time that need to be explained?
For us, space has three orthogonal dimensions, the three directions of space. Everything accessible to us exists in the same space. There are no holes or separate regions in space, apart from any black holes that may exist. According to our ideal conception, space is homogeneous and isotropic, i.e. the same everywhere and in every direction.
The objects with which we are familiar from everyday experience have a fixed place in space, they are localised. However, a surprising insight of quantum mechanics was that this does not apply to the sub-microscopic building blocks of the material world. The fact that our familiar bodies have a fixed location in space is due to the fact that the material world is organised on several hierarchical levels: elementary particles - atomic nuclei - atoms - molecules - bodies. Only the rules of organisation of the higher levels force the elements of the lower levels to occupy a certain space and not to leave it. In the language of systems theory, spatial localisation is a submergent property. The basic constituents of the material world have no spatial localisation, rather they fill the entire universe. This finding is a strong indication that our proposed reversal of the direction of explanation is correct: the fundamental laws of physics do not describe the motion of localised objects in space, but rather the action of the fundamental laws of physics produces what we know as spatial order.
In today's physics, we equate 'space' with the measurement of distances. But we must abandon this way of thinking. Instead, we should take seriously the realisation of quantum physics that the elementary building blocks of the world completely fill the known space of the universe and are in all places at the same time. Spatial localisation, and therefore the measurement of distances, is only possible at higher levels of organisation of matter. The fundamental laws of physics must not presuppose localisation in space, but must bring about spatial order in the first place.
Let us now turn our attention to ‘time’ and its characteristics. The church father St Augustine (354 - 430) wrote in his Confessiones: ‘So what is time? If nobody asks me about it, I know it. If I want to explain it to someone who asks, I cannot say.’ To this day, time is an elusive phenomenon for which neither physics nor philosophy have a truly satisfactory and comprehensive explanation.
Einstein believed that time is simply what you measure with a clock. Similar to space, today's physics is limited to the measurement of time intervals. Like space, time is regarded as homogeneous and coherent, with the difference that time is only one-dimensional.
Today's physics deliberately ignores the essential characteristics of time: time is constantly passing. What was just the future is now the present and immediately the past. The past is unchangeable, whereas the future is still undefined and, within certain limits, open. No one can escape the present. Today's physical theories can neither satisfactorily explain these fundamental differences between the three time modes of past, present and future, nor the fact that time is constantly flowing.
The new theory we are looking for, on the other hand, should be able to explain these peculiarities of time. However, since the phenomenon of time has so many different and difficult to grasp facets, we should be prepared for the fact that the human view of time combines several effects based on very different physical causes. One indication of this is the fact that the flow of time is permanent and has an effect everywhere, while some temporal phenomena are reversible and others are irreversible. However, the distinction between the three modes of time - past, present and future - can only be made on the basis of irreversible events. The flow of time and the modes of time must therefore have different causes.
In order to arrive at a theory that can explain the described properties of space and time, we must turn to the basic elements of the material world and its laws.
Comments powered by CComment