The past is real, the future is not, hence time stream from the present
Author unknown
1. Introduction
Time dilation is an intriguing phenomenon. The clocks of satellites need continual corrections in order to match the clock on the ground (Ashby, 2003). A curious part of that scenery is that the satellites stay in our present. They don’t disappear in the past, nor do they get ahead of us into the future. Based on relativity theory, most physicists argue against the present being special. (Rovelli, 2017). However, there exists an alternative interpretation of special relativity, which is often overlooked in the discussion. The purpose of this paper is to investigate this interpretation.
2. Background
Newton placed time outside the universe, but Einstein put it back in (Smolin, 2013). Einstein proved Newton wrong with his theory of relativity where time can dilate. Some physicists even question the existence of time (Rovelli, 2017; Smolin, 2013).
Presentism states that only the present exists, the past and the future do not. Counter to this eternalism (often referred to as block universe) states that the past and future are equally real. This results in a deterministic world view, which is rejected by many; hence an alternative viewpoint has been developed: The growing block universe. Here the past exists, and the future is a void to be filled, but there is no universal present, like in presentism. The debate between presentism and eternalism is most often conducted with the former in defense. Deasy (2019) argues that the debate has become irrelevant. This is disputed by Viebahn (2020), who argues that in order to explain where matter is, we need to combine eternalism and presentism.
Time dilation has been confirmed in many experiments using atomic clocks. Both the special relativity and general relativity have been confirmed with observations. Most famously is perhaps the deflection of sunlight by gravity and the explanation of the planet Mercury’s orbit.
When the topic is time, it is worth noticing that all the above-mentioned observations (like all observations) are made in the present concerning events in the past. There are no direct observations of the future. The relativity theory is there only validated in the domain of the past.
3. Does the future exist?
The time paradigm developed by Newton, Einstein, and others is so strong, that we find it difficult to imagine that future as an illusion. However, the concept of the future is not supported by observations. All we can observe is, that the past increase continually. Paradoxically, science is based on observation, and yet we readily accept a phenomenon of which we have no observation at all. The only indication of a future is the tendency of natural forces that keep working in the present and thereby produce more and more past.
As humans, we are led to believe in the existence of the future because of the inertia working in the present Our experience of the world makes of the automatic projection of the continuous movement of moving objects, hence believe strongly in the existence of the future (Buonomano, 2017). But scientifically, the future is nothing but an illusion.
4. Elsewhere
Relativity theory is based on an observer-centric worldview (Smolin, 2013). The so-called expanded present is one of the strongest arguments against absolute simultaneity (Rovelli, 2017). The rejection is based on the realization, that one observer can only determine the position of a responder positioned the 'elsewhere' if the relative velocity is known. Since the relative velocity cannot always be determined, the responder can be anywhere in the 'elsewhere', hence the universal present is rejected.
But the argument does not hold up. Just because the position of something in ‘elsewhere’ is unknowable, this does not mean that it does not exist on a continuum of three-dimensional space-now in the four-dimension spacetime. The argument is only based on epistemological thinking about the extended present. Ontological, the expanded present could be divided into a past, and a future separated by a continues now dividing the entire spacetime.
5. Absolute simultaneity un-rejected
Absolute simultaneity un-rejected
Einstein's train thought experiment is still frequent uses in introducing the theory of special relativity and rejecting absolute simultaneity. A graphical representation of the train thought experiment can be found in the following resource. https://en.wikipedia.org/wiki/Relativity_of_simultaneity
However, the rejection of absolute simultaneity is only one of two interpretations of Einstein’s train through experiment. The alternative interpretations come about as follows. The two observers disagree about the order of past events. Both the events are past events to both observers – otherwise talking of the order of the events gives no meaning. We can say that the observers disagree about history. The perception of history is distorted by velocity (as well as changes in velocity, hence gravity, according to general relativity).
The implication of this worldview can be divided into two cases. In the case, that the moving observer knows his/her velocity relative to the events, this observer can apply Lorentz transformation to the impression and then agree with the observations made by the stationary observer. If the relative velocity is not known, then the observation of the moving observer is flawed in the same way an object can be observed to grow, when in fact it is merely moving towards the observer. In the case, that an observer cannot report the motion relative to the observed, then observations regarding time are deficient. This should be common sense. By this interpretation of relativity theory, absolute simultaneity is preserved. The 'cost' of preserving absolute simultaneity is the acceptance of unresolvable historical distortion of observers without knowledge of the velocity relative to the events.
Einstein said that time is what clocks measure. But no clock has ever measured the future, hence a more correct statement would be, that clocks measure the duration of the past. The measurement of clocks depends on the relative velocity and gravity, known as time dilation. Many observations, including the satellites mentioned in the introduction, support the existence of time dilation. Conceptually, it would be easier to state, that clocks measure the aging of an object moving alongside the clock, hence exposed to the same velocity and gravity as the clock. The essence of a clock is activity, and so is aging - including the decay of atoms.
To make the point clear, the direction of time is reversed, hence the present is always t=0, and time increase into the past. The so-called future is then measured by negative numbers; an analogy to the future being merely a mental construct. The latter will be discussed in the next paragraph.
6. Rethinking time
Time can be seen as an emergent property of nature, like temperature. Temperature plays no role in Quantum Mechanics (QM) but emerges for the vibration of quanta. Similarly, time can emerge from the quantum world. Here the emergent effect will be a stream based on the continuous pushing as a result of emission. When a given photon has been emitted there is no turning back. The outcome of is irreversible. The arrow of time is not based on increasing entropy, but on the outcome of chance. The emitted wave will expand in all three directions.
One could further postulate that time is created by the emission of photons. This would explain why nothing can travel faster than light, and why matter never can catch up with light. Some implications of this thinking are, that the present movement is always at a time equal to zero. Further, only the past exists, and the future is nothing but a theoretical abstraction. The past exists, not as matter but merely as electromagnetic waves as traces of past events. In this way, the past exists in the present as traces of past events.
With such a word view the QM can be merged with the relativity theory (RT). QM does not need time. The timeless realm could be thought of as space-now, e.g. a domain where the emission occurs. Here time is an emergent property resulting from emission. When light is emitted from space-now, spacetime is the emerging universe giver affordance to the movement of matter in spacetime.