The untold story of the heretical thinkers who dared to question the nature of our quantum universeEvery physicist agrees quantum mechanics is among humanity's finest scientific achievements. But ask what it means, and the result will be a brawl. For a century, most physicists have followed Niels Bohr's Copenhagen interpretation and dismissed questions about the reality underlying quantum physics as meaningless. A mishmash of solipsism and poor reasoning, Copenhagen endured, as Bohr's students vigorously protected his legacy, and the physics community favored practical experiments over philosophical arguments. As a result, questioning the status quo long meant professional ruin. And yet, from the 1920s to today, physicists like John Bell, David Bohm, and Hugh Everett persisted in seeking the true meaning of quantum mechanics. What Is Real? is the gripping story of this battle of ideas and the courageous scientists who dared to stand up for truth.
The untold story of the heretical thinkers who dared to question the nature of our quantum universeEvery physicist agrees quantum mechanics is among humanity's finest scientific achievements. But ask what it means, and the result will be a brawl. For a century, most physicists have followed Niels Bohr's Copenhagen interpretation and dismissed questions about the reality underlying quantum physics as meaningless. A mishmash of solipsism and poor reasoning, Copenhagen endured, as Bohr's students vigorously protected his legacy, and the physics community favored practical experiments over philosophical arguments. As a result, questioning the status quo long meant professional ruin. And yet, from the 1920s to today, physicists like John Bell, David Bohm, and Hugh Everett persisted in seeking the true meaning of quantum mechanics. What Is Real? is the gripping story of this battle of ideas and the courageous scientists who dared to stand up for truth.
Why Copenhagen? Why did we physicists of Earth choose to create the Copenhagen Interpretation of Quantum Mechanics during the wild days of the 1920’s? And why did most of us scientists continue to believe in it for nearly a whole century afterwards? Why would we actually do such a thing to ourselves? Did we have any other alternatives? Do any of the other interpretations of quantum physics make any more sense? Why would anyone want to discover a “correct” interpretation? Why do some of us still seek for a “complete” interpretation? Is quantum physics a real physical thing, that can be physically studied, in a real physical laboratory? Or is quantum physics just a mathematical statistical probabilistic thing, that can only be contemplated intellectually inside our human brains? This brief article attempts to ask some of these important questions, in the hope that it might further encourage others to continue to ask their wise scientific questions, and even to start asking much better questions, until that bright joyful day finally arrives, when we scientists of Earth, can all wisely agree together on the very best answers.
For over nine decades, quantum mechanics has profoundly shaped our understanding of nature, offering explanations for the stability of atoms, the formation of mole cules, the properties of materials, and phenomena such as light or radioactivity. It is essential to modern technologies—from microchips to lasers—and underpins the physics of elementary particles. Yet, despite its successes, it remains a deeply mysterious theory, confronting a central enigma: why does the quantum world behave so differently from everyday reality? Elements such as superposition and quantum entanglement—which allow particles to exist simultaneously in multiple states or remain interconnected regardless of distance—contradict classical world intuitions. This gap between microscopic and macroscopic behavior has given rise to what is known as the “measurement problem,” raising fundamental questions about the nature of reality. Diverging interpretations have led to two major schools of thought: anti-realism, promoted by Niels Bohr, which holds that reality depends on the observer and their interaction with measurement instruments; and realism, supported by Albert Einstein, which argues that quantum mechanics is incomplete and that eality exists independently of observation. Bohr’s complementary philosophy and Heisenberg’s uncertainty principle were central to the formulation of the “Copenhagen interpretation,” which became dominant in the 20th century. However, the persistent opposition of scientists like Einstein and Schrödinger inspired generations of physicists to seek a unification between quantum mechanics and relativity, culminating in new theories such as loop quantum gravity and string theory. Thus, the debate between realism and anti-realism remains alive, and philosophy continues to play a crucial role in exploring the new foundations of physics.
Hi, I’m Adam Becker, PhD, an astrophysicist and science writer. My new book, What Is Real? The Unfinished Quest for the Meaning of Quantum Physics, is about the scientists who bucked the establishment and looked for a better way to understand what quantum mechanics is telling us about the nature of reality. It’s a history of quantum foundations from the initial development of quantum mechanics to the present, focusing on some people who don’t often get the spotlight in most books on quantum history: David Bohm, Hugh Everett III, John Bell, and the people who came after them (e.g. Clauser, Shimony, Zeh, Aspect). I’m happy to talk about all of their work: the physics, the history, the philosophy, and more. FWIW, I don’t subscribe to any particular interpretation, but I’m not a fan of the “Copenhagen interpretation” (which isn’t even a single coherent position anyhow). Please don’t shy away if you disagree. Feel free to throw whatever you’ve got at me, and let’s have a fun, engaging, and respectful conversation on one of the most contentious subjects in physics. Or just ask whatever else you want to ask—after all, this is AMA. Edit, 2PM Eastern: Gotta step away for a bit. I’ll be back in an hour or so to answer more questions. Edit, 6:25PM Eastern: Looks like I’ve answered all of your questions so far, but I’d be happy to answer more. I’ll check back in another couple of hours. Edit, 11:15PM Eastern: OK, I’m out for the night, but I’ll check in again tomorrow morning for any final questions.
Quantum mechanics, the physical theory describing the microworld, is one of science's greatest triumphs. Remarkably, however, after more than 100 years it is still unclear what quantum mechanics means in terms of basic philosophical questions about the nature of reality. While there are many interpretations of the mathematical machinery of quantum physics, there remain no experimental means to distinguish between most of them. In this contribution, I wish to consider the ways in which the enduring lack of an agreed-upon interpretation of quantum physics influences a number of critical philosophical debates about physics and reality. I briefly review two problems affected by quantum interpretations: the meaning of the term universe and the nature of consciousness.
The foundations and meaning of quantum theory became a central issue to Albert Einstein and Niels Bohr since the onset of their impassioned debate in the 1920s, enriched by the contributions of many other distinguished scientists and philosophers.The questions are not settled down at all, despite the great achievements of the theory, its impressive accordance with experiment and predictive power.The fundamental and technological applications range from cosmology to biology, with the development of invaluable instruments and the design of new materials.Is quantum mechanics a complete or an incomplete theory?Is there an objective reality independent of the observer or is the reality created by the measurements?Are hidden-variable theories justifiable?Is there a quantum theory founded in a local-causal and non-linear approach that formally contains the orthodox linear theory as a special case?Can such a formulation unify classical and quantum physics?Are Heisenberg's uncertainty relations valid in all cases?Here, the subject is addressed as an adaptation of our contribution to the Colloquium "Quantal aspects in Chemistry and Physics.