In order to support the idea that time is relative, an epiphenomenon, something that just helps us to explain our conscious experiences; it becomes critical to differentiate between ontological time and interval time. This is more difficult than it first appears since both are involved in making sense of our experiences. The writer uses the term ontological time to signify the observation of ‘birth to death’ processes and other time sequences consistent with the second law of thermodynamics and with the arrow of time. Interval time doesn’t have direction, as the interval remains exactly the same whether you are looking forwards or backwards, therefore it does not have to comply with either the arrow of time or the second law of thermodynamics.
Interval time may be defined as ‘the time-gap’ which prevents everything happening at once. In this context time can be viewed as the time-gap between an orderly arrangement of a series of still pictures into an animated sequence of events; similar to the way one may arrange individual frames into a moving picture. The writer suggests that our consciousness is responsible for arranging the sequence of the frames, editing and for bringing our attention to bear on significant events. Continuing with this notion, the next question to consider is whether the pictures form an infinite series, or whether there is a limit established by the Planck limit? Einstein had noted, in one of his famous research papers, that although the emission of radiation from a hot object increased with the temperature of the body as expected, it did so in a series of steps rather than a straight line. Radiation it appears comes in chunks which were later to be referred to as ‘quanta’ by Neils Bohr, heralding the birth of quantum mechanics. In the quantum world there is a limit to the number of times you can divide up the quantities of space and time and you eventually reach the Planck limit,the irreducible dimension of position space, named after the physicist Max Planck.
It has been argued by the physicist Gao Shan that classical continuous motion, based on a simplistic Aristotelian idea, is unsustainable from both a logical and a mathematical perspective. Quantum, discontinuous, motion is proposed as a more viable alternative and this could add some weight to the argument that ontological time is relative. Despite the exceedingly large number of individual frames that are likely to be involved in even the shortest sequence of human experiences, according to the idea of discontinuous motion they cannot be infinite. Fortunately the human eye and the visual cortex provide a smoothing out effect that would be perfectly adequate even if the number of frames were only a tiny fraction of the potential number within the Planck limit.
According to the writer, what is critically important is that the interval between frames is what constitutes interval time, whereas it is the conscious ordering of the frames that results in ontological time. The reason why this ordering appears to proceed in a forward direction, from past to future, is probably determined by the second law of thermodynamics which describes the tendency over time for any complex arrangement of atoms and molecules to break down into its constituent parts. By analogy we can compare this to the observation that although it is relatively simple to smash a ceramic cup into thousands of tiny shards, it is extremely difficult to put it back together again. We spend our lives immersed in a world controlled, at the macro level, by the laws of classical physics so that it appears logical that time should proceed only in a forward direction; we never see the cup spontaneously reforming itself from the broken shards. Despite this our minds can conceive of a world where there is no arrow of time, a world controlled by the laws of quantum physics rather than classical science. Although this world may exist only in our imagination, it is a constant and recurring theme that cannot be entirely ignored.