And he hovered water– Toward a New Vision of the Physical World?

Conclusion:

In my previous book, What if Einstein Was Wrong on a Key Point in His Analysis Leading to Special Relativity?, and at the beginning of this one, I questioned certain conclusions Einstein had drawn from his train thought experiment, which led to the conception of time in special relativity. Once we move away from the block universe conception and acknowledge that there must necessarily be a present moment for the Universe, our approach to space-time and motion is profoundly altered. One may then ask: on which concepts could a general theory of the Universe be based? I claim that by discovering the mode of action of the Universe’s prime mover, we can uncover the most fundamental conceptual postulate possible. From there, a thought experiment can be constructed to approach the coherence of the structure and motion of the physical world in the most fundamental way.

In Newton’s conception, a certain relationship between kinematics and dynamics is established. The Moon, on the one hand, exhibits inertial motion, and on the other hand, is attracted by the Earth. This emancipates physics from Aristotle’s framework, as inertial motion is considered to be motion that requires no actual cause. Thus, there would no longer be a need for the efficient cause by which Aristotle traced back to the unmoved first mover. It was indeed necessary for physics to free itself from Aristotle’s approach, as it led to a mechanical view of forces (1) and was incompatible with the concept of inertia.

Einstein’s approach advocates for a new relationship between kinematics and dynamics. Indeed, the Moon is not attracted by the Earth but instead follows a geodesic in space-time. In this conception, gravitation is no longer a force, which seems to move us even further away from the necessity of an efficient cause in order to understand motion. We observe that general relativity adopts a partially relational approach to space. Bodies, through their mass, alter the curvature of space — although we do not exactly explain how — and this curvature is supposed to affect the trajectories of bodies.

However, general relativity is not a fully relational conception of space, for at least two reasons. First, according to relativity, there is no present moment for the Universe. Yet, to have a fully relational conception of space, the bodies that enable space to extend must be currently in relation, which implies the existence of a universal present moment (2). Second, in a relational conception of space, motion and the evolution of spatial configuration go hand in hand. This means that every movement must result from the current evolution of the actual relations between bodies. In other words, in a fully relational conception of space, every motion implies an actual cause: the evolution of the present relation between bodies. This entails a redefinition of the concept of inertia in relation to momentum.

Since the existence of a universal present moment is certain, we must evolve our conception of space and motion. The important question then becomes whether we should move toward a fully relational conception of space — and thus of motion. One might wonder whether such an approach is compatible with what Einstein discovered in his elevator thought experiment. In Chapters 10 and 11, I considered whether the equivalence principle can be grounded in a fully relational approach to space. From my point of view, such an approach necessarily implies a prime mover acting immanently and through interrelation according to the determination of elements, because the relation between bodies cannot be mechanical in all cases. This, ultimately, would be the deeper reason why we must distinguish between bodies and fields.

My approach includes elements from Newton’s perspective, from Einstein’s, and from Aristotle’s causal framework. In my view, Aristotle did not understand the mode of action of the Universe’s prime mover. Likewise, the approaches of Newton and Einstein — as well as modern science in general since the emergence of the concept of inertia — have not acknowledged that even if no force acts on a body in a state of inertia, that does not mean there is no actual cause for its state of rest or motion. In fact, if an actual cause is required for motion, it must also be responsible for the state of rest. And it is only within a fully relational conception of space, I believe, that these two perspectives can be reconciled. Indeed, in such a framework, both rest and motion result from the current relation between bodies. And this is only possible if a prime mover acts immanently and by interrelation, because a mechanical cause cannot be responsible for the inertia of a body.

Once the mode of action of the Universe’s prime mover has been identified, and once we adopt a fully relational conception of space, I invite physicists to a thought experiment, considering the mode of action of the prime mover as a foundational conceptual postulate from which to approach the full range of physical phenomena. The goal is to progressively uncover, through the development of a certain vision of space and motion, the various consequences of this postulate for the definition of certain foundational concepts. This is why, behind the analysis of five key concepts — mass, space, inertia, momentum, and time — lies a general theory of the Universe.

Note 1: For Aristotle, the first mover acts through a first moved body, which is responsible for the motion of all other bodies. This leads to a mechanical conception of forces, as the first moved body can act on others only through contact. If, however, it is eventually shown that non-mechanical action is necessary, the first moved body becomes unnecessary.

Note 2: For two reasons: for bodies to be in relation, their existence must be actual, as must their relations — otherwise, space would cease to exist. Once we accept the existence of non-mechanical relations, and if space is defined relationally, we must accept the possibility of an actual relation between distant bodies. A relation between instantaneous distant bodies would therefore be established through the prime mover.

Philippe de Bellescize