# Can the special theory of relativity explain the strangeness of quantum physics?

Physics has had a problem for some time. Its basic theories, the General and Special Theories of Relativity and theories of quantum physics, have proven correct in many cases. But they don’t fit together – in extreme cases, like in black holes or the big bang, where you would need to use both relativity and quantum physics, the math doesn’t work out. Quantum physics appears to be the more fundamental theory, so scientists have assumed that the theory of relativity would need to be modified to quantum relativity.

But that might not have to be the case. Dr. Andrzej Dragan from the Physics Department at the University of Warsaw (FUW) and Prof. Artur Ekert from the University of Oxford have presented an argument in a paper that leads to a different result. The strange phenomena of quantum mechanics can apparently be explained within the framework of the Special Theory of Relativity. All you need to do is take a certain, rather unorthodox step.

Albert Einstein based the Special Theory of Relativity on two postulates. The first is known as the Galilean principle of relativity and states that the physics is the same in any inertial system (i.e., a system that is either at rest or in uniform, straight-line motion). The second postulate requires a constant speed of light in any reference system.

“Einstein considered the second postulate to be essential. In reality, however, what is essential is the principle of relativity. In 1910, Vladimir Ignatowski had already showed that it was possible to reconstruct all phenomena of the Special Theory of Relativity based only on this principle of relativity,” says Dr. Dragan.

The Special Theory of Relativity makes possible three mathematically correct types of solutions: a world of particles moving at speeds less than the speed of light (subluminal velocity; normal particles with rest mass), a world of particles moving at the speed of light (photons, with no rest mass), and a world of particles moving at speeds greater than the speed of light (superluminal velocity). This third option has always been rejected by scientists, because it didn’t appear to match reality.

“We posed the question: what would happen if – ignoring reality for the time being – we took all of the solutions seriously, including superluminal solutions? We expected that to produce cause-and-effect paradoxes. But, in fact, we discovered exactly those effects that form the deepest core of quantum mechanics,” say Dragan and Ekert.

First, the two theoreticians considered a simplified case: spacetime with all three families of solutions but consisting of only one spatial dimension and one time dimension (1+1). A particle at rest in one system of solutions appears to move at a velocity greater than the speed of light (superluminal) in another system, which means that superluminosity is, itself, relative.

In a spacetime continuum constructed in this way, non-deterministic events, like those known from quantum physics, emerge in a very natural way. If a superluminal particle is generated in one system at point A, which is completely predictable and emitted in the direction of point B, where there is simply no information on the reason for its emission, then from the viewpoint of an observer in a second system, the events run from point B to point A and they assume it to be a completely unpredictable event. It follows that similar effects emerge also for subluminal particle emissions.

The two theoreticians also show that by taking into account superluminal solutions, the motion of a particle appears simultaneously on multiple paths naturally and a description of the course of the event requires the introduction of a sum of combined probability amplitudes that point to the existence of a superposition of states, which was previously associated only with quantum mechanics.

Everything becomes more complicated, however, when you expand to our known spacetime with three spatial dimensions and one time dimension (3+1), which is, of course, our physical reality. Then, the principle of relativity does not hold up in its original form – the subluminal and superluminal systems are distinguishable from each other, which they shouldn’t be. This problem disappears, however, if you reformulate the principle of relativity: “the ability to describe an event in a local and deterministic way should not depend on the selection of an inertial system.” Then only those solutions emerge in which all conclusions from the consideration in the simplified (1+1) spacetime remain valid.

“Incidentally, we’ve determined the possibility of an interesting interpretation of the role of individual dimensions. In the system that appears superluminal to an observer, some spacetime dimensions appear to change their physical role. Only one dimension of the superluminal light has a spatial nature – the dimension along which the particle is moving. The other three dimensions appear to change into time dimensions,” says Dragan.

A characteristic feature of spatial dimensions is that a particle can move in any direction or can remain at rest, while it always propagates in only one direction in a time dimension (in everyday parlance we know that as “aging”). Three time dimensions in a (1+3) system would mean that a particle in this system would age three-times simultaneously. Viewed from a subluminal system (3+1), the aging process would look like the particle was moving like a spherical wave, which would, in turn, lead to the famous Huygens principle (every point of a wavefront can itself be treated as the source of a new spherical wave) and to wave-particle duality (a particle can take two paths simultaneously).

“All the strangeness that appears when considering solutions relating to a system that looks superluminal proves to be no stranger than what has been stated for a long time by quantum theory, which is generally accepted and has been experimentally verified. In contrast, if you consider a superluminal system, it is – at least theoretically – possible to derive some of the postulates of quantum mechanics from the Special Theory of Relativity, which were generally accepted as not resulting from other, more fundamental bases,” says Dr. Dragan.

For almost a hundred years, quantum mechanics has been waiting for a deeper theory to explain the nature of its mysterious phenomena. If the arguments presented here prove to be correct, the wait will have been especially frustrating in retrospect, because the theory that had been sought for decades would prove to have been already known from the very first work on quantum theory. Of course, everyone is always smarter in hindsight. Unfortunately, the conflict between the General Theory of Relativity would still be unresolved. But at least there would finally be an explanation for why the world behaves so strangely at the microlevel.