Quantum mechanics raises questions about the nature of the universe through several interpretations, including the Copenhagen interpretation, the many-worlds interpretation, and the theory of hidden variables. The debate about whether the states of particles are only determined probabilistically, whether parallel universes exist, and whether there are hidden variables we don’t know about is still ongoing and evolving across the boundaries of physics and philosophy.
Quantum mechanics, along with relativity, is a major paradigm shift in modern science. It shattered our seemingly ubiquitous belief in Newton’s classical mechanics and has had a profound impact on the development of technology in our daily lives, both in theory and in applications. For example, the theories of quantum mechanics are at the core of modern electronics and semiconductor technology, which has enabled the development of devices such as smartphones, computers, and GPS. Despite these everyday applications, however, quantum mechanics remains counterintuitive, with many different interpretations, and new theories continue to emerge as areas remain unexplained.
To understand why quantum mechanics is so difficult and why there are so many different interpretations, it’s important to understand what it means to be a “mathematician” in physics. In physics, we use math as a language to describe phenomena and problems because formulas are logically consistent without contradiction. The mathematical process of developing equations and functions seems perfect in itself, but the question of how to interpret them in the real world adds another dimension to the debate. For example, the Schrödinger equation, the most famous equation in quantum mechanics, results in a “wave function” that describes the state and energy of matter, and depending on how you interpret it, it can lead to very different interpretations.
The most common interpretation of quantum mechanics is the Copenhagen interpretation. This interpretation, advocated by Bohr, Heisenberg, Born, Dirac, and others, includes the Schrödinger equation, the wave function, and the idea of uncertainty, and is based on probabilistic thinking: the positions and states of quanta are not specific, but are probabilistically distributed over a large region. This leads to the use of “probabilistic models” to predict the outcome of events, as opposed to the certainty we often experience in everyday life. In other words, we can only suggest the possibility that a quark exists in a certain location, and it is only when observation is involved that the location is determined with certainty. This description marked a major turning point in the interpretation of physical phenomena and provided a very useful framework for predicting many experimental results.
Next, the many-worlds interpretation is another interesting interpretation of quantum mechanics. While the Copenhagen interpretation describes the occurrence of probabilistic events within a single world, the many-worlds interpretation describes all possible events as actually happening in each world. For example, if there is a world in which I lose when playing rock-paper-scissors with my friend, there is also a world in which I win. The many-worlds interpretation has been popularized by the concept of parallel universes, and it’s a theory that often appears in science fiction novels and movies. The concept of quantum decoherence, which suggests that the world is divided into many branches, is a theory that is difficult to verify experimentally, but it has provided a way to explain the counterintuitive nature of quantum mechanics.
Finally, the hidden variable theory argues that the uncertainty in quantum mechanics is actually due to “hidden variables” that we don’t know about. In other words, the uncertainty in quantum mechanics is simply due to the fact that we don’t understand all the variables in a phenomenon, and all phenomena are actually perfectly predictable. Albert Einstein supported this theory with his famous quote, “God doesn’t play dice.” However, when Bell’s inequality experiments in the 1960s failed to produce the results predicted by the hidden variable theory, confidence in the theory fell. Nevertheless, this interpretation is still considered a meaningful attempt to challenge the perfect explanation of quantum mechanics.
Despite these different interpretations of quantum mechanics, there is still a need for research that is based on verifiability from a physics perspective. Since scientific progress comes from verification through experimentation and observation, verifiable interpretations take on greater importance. Indeed, the experimental success of quantum mechanics has explained many phenomena that could not be explained by classical physics, and has laid an important foundation for applications in various industries. The Copenhagen Interpretation is relatively highly regarded for these empirical achievements. For example, the orbital problem of the hydrogen atom explains why electrons stay in certain orbits, and the tunnel effect proves the existence of particles that cross energy barriers that cannot be explained by classical physics.
The influence of interpretations of quantum mechanics on philosophy and other disciplines cannot be ignored. The many-worlds interpretation has sparked philosophical discourse on topics such as parallel universes, and has influenced various theoretical studies, including superstring theory, paving the way for the convergence of math and science. Philosophers have also pondered the meaning and nature of quantum mechanics, which has enriched discussions of epistemology and ontology. Interpretations of quantum mechanics have crossed philosophical and scientific boundaries, each fostering the development of the other.
Quantum mechanics is still not fully explained, and there are many different interpretations. While the mainstream theory, the Copenhagen interpretation, has shown strength in empirical terms, many-worlds and hidden variable theories are still being explored by scientists and philosophers. With more experiments and theoretical reviews, we hope that the mysteries of quantum mechanics will become clearer. Ultimately, these studies will contribute to a deeper understanding of the truth we seek: the fundamental laws of the universe.
