Roger Penrose discusses fashionable ideas in modern physics
zinnia jaswal, contributor
Roger Penrose, a brilliant mathematical physicist and Nobel laureate, has spent a lifetime unravelling the mysteries of the universe. His contributions to general relativity, black holes, string theory and quantum mechanics have earned him a reputation of being one of the foremost thinkers of our time. In his book Fashion, Faith and Fantasy in the New Physics of the Universe, Penrose sets out to challenge and to question one of the most fashionable ideas in physics. Penrose argues about the direction of modern physics, while essential in advancing the field of physics and mathematics, might be leading scientists astray in most of its crucial areas, such as string theory, quantum mechanics and cosmology.
Fashion in this context refers to the tendency for theories or ideas to gain popularity based on trends rather than scientific merits. Faith implies an unquestioning of certain concepts or models where evidence is lacking. Fantasy involves speculative ideas that, while imaginative, might be disconnected from scientific reality. This book is in many ways a continuation of Penrose’s long-standing philosophical inquiry into the nature of reality. The book is an audacious and intellectual critique of the prevailing fashion in modern physics, questioning assumptions that Penrose believes are more akin to faith and fantasy than scientific fact. In this article, I’ll explore the central themes and arguments of fashion, faith and fantasy, examining Penrose’s technique for string theory, the multiverse and the theory of everything.
String theory, being the fashion in modern physics, is a framework that has captured the imagination of physicists and mathematicians for decades. Penrose does not shy away from challenging string theory. He cautions that string theory with its propositions of six dimensions has drifted too far from reality, making it difficult to understand. According to Penrose, there is no testable way to prove the claims of string theory. While the mathematical beauty of the theory has attracted widespread attention, it lacks evidence to back it up. String theory posits that the building blocks of the universe are tiny particle-like vibrating strings that can exist in multiple dimensions, holding the key to the long-sought theory of everything that could reconcile quantum mechanics with general relativity. However, this fails to convince Penrose. For him, string theory is more of a fashion in physics, drawing attention because it answers more of the grand questions in physics.
Turning to quantum mechanics, Penrose acknowledges its extraordinary success in explaining the atomic world. However, he suggests that the overwhelming belief in its applicability to macroscopic physics has led to uncritical faith in its universal validity. In response to this, Penrose argues that quantum theory may need to be reconsidered and adjusted for phenomena at larger scales of physics.
When discussing cosmology, Penrose critiques the current speculative ideas of the origins of the universe, calling them a fantasy and likely incorrect. This leads him to critique the multiverse theory – the idea that our universe is only one of the vast multiverses with different timelines and with different physical laws – as well. Penrose is highly critical of this theory, since it is not scientifically tested. Unlike string theory which at least proposes mathematical models that can one day be tested in principle, the multiverse theory suggests a reality beyond observation or experimentation. Such ideas, while very tantalizing, are more in the realm of philosophy or fantasy than actual science. This section of the book is the most thought-provoking, as Penrose raises fundamental questions about the very nature of science. He asks whether it is acceptable for physics to be based on ideas that cannot be tested, proposing that theories need to meet scientific reality to be accepted. For Penrose, the multiverse theory fails this test.
Another key aspect of Fashion, Faith and Fantasy is the theory of everything which could explain all the forces of nature – gravity, electromagnetism, and the weak and strong nuclear forces – within a single framework. The quest for the theory of everything has been a central pursuit in theoretical physics. Penrose challenges this idealistic goal, suggesting the universe may be too complex for it to be answered in a single, unified theory. He argues that our current understanding of physics, while extraordinary in many aspects, may always be incomplete and the search for the theory of everything might be a misguided effort. This is not to say that Penrose rejects the search for a deeper understanding of the universe but rather that we should be wary of the conviction that a single theory defines all aspects of the universe.
This perspective sets Penrose apart from many of his contemporaries, who are confident that such a theory is within reach. Instead of simplifying the universe into mathematical equations, Penrose proposes that we embrace the reality of the universe. His view is rather humble – we never may fully understand everything and that is okay. Physics is an ongoing exploration rather than a destination.
Throughout the book, Penrose champions mathematical realism and a return to scientific rigor, the idea that mathematics is not just a tool for describing physics but that mathematical structures have an existence independent of human thought. For Penrose, the power of mathematical equations is a reflection of the world. This conviction pins his own work on black holes and the structure of space-time.
In Fashion, Faith and Fantasy, Penrose argues that modern physics has strayed too far away from basic mathematical realism. Theories like string theory and the multiverse prioritize speculative elegance rather than evidence and mathematical rigor. He emphasizes the critical need to return to the foundation of physics, where equations are grounded in what we can observe and test.
My favorite part is where Penrose takes a moment to self-reflect, acknowledging how the forces of fashion, faith and fantasy have shaped his own work. He points to his twister theory, an alternative to string theory which is beginning to take on a fashionable status. He attributes his concept of conformal cyclic cosmology to an idea so unconventional that it may be called conformal crazy cosmology, highlighting the sometimes unpredictable nature of scientific progress.
For readers with an interest in modern physics and cosmology, this book is an essential read. Penrose offers a fresh perspective on the state of physics and raises some important questions on human knowledge, the nature of the universe and our place within it.
