When physics meets faith: the journey of Dr Chan Man-ho
Propelled by an inquisitive mind since childhood, Dr Chan has explored the realms of science, theology, and philosophy in his lifelong pursuit of truth.
I was born with an inquisitive mind, always eager to uncover hidden secrets. During my primary school years, I developed a strong affinity for astronomy. My interest in astronomy and physics blossomed in senior high school, inspired by a book that raised many unanswerable questions about the universe. The book filled me with awe at the vastness of the cosmos. Naturally, I chose physics at university, despite having achieved excellent results in the HKCEE examination that would have allowed me to pursue any subject. A few years after obtaining my bachelor’s and master’s degrees in physics, I furthered my academic journey by enrolling in a part-time PhD programme to study dark matter. Meanwhile, I earned a living teaching physics at a secondary school.
Dark matter is a captivating subject in astrophysics. Unlike normal or ordinary matter, which interacts with electromagnetic (EM) waves, dark matter neither emits, absorbs, nor reflects them. Because it does not interact with light or other forms of EM radiation, scientists cannot directly observe dark matter using EM-based methods, hence the name. Researchers estimate that approximately 95% of all matter and energy in the universe consists of either dark matter or dark energy, with the remainder being ordinary, visible matter.
Dr Chan describes dark matter as an enthralling subject that attracts many brilliant scientific minds. Scientists estimate that approximately 95% of all matter and energy in the universe consists of either dark matter or dark energy, with only a small portion being ordinary, visible matter.
The study of dark matter has given me profound intellectual satisfaction, marking a milestone in my long journey of discovery since childhood. While my desire to uncover the hidden laws of the mysterious universe led me to pursue a doctoral programme in astrophysics, my Christian faith encouraged me to complete a master’s degree in theology afterward. At that time, I believed that with a PhD in physics and a master’s in theology, I was well equipped to engage in discussions about higher truths, such as whether there is a purpose behind the creation of the universe and whether there is a creator.
That realisation awakened me to the fact that my knowledge was insufficient to answer profound ontological questions. The awareness became a turning point in my search for ultimate truths.
My confidence was shaken when I attended a seminar where one of the speakers talked on science studies (科學學), an interdisciplinary field that draws insights from philosophy and the social sciences to examine how scientific knowledge is created and received. I realised that I had little understanding of this crucial subject, which provides essential insight into the very questions I had long contemplated. That realisation awakened me to the fact that my knowledge was insufficient to answer profound ontological questions. The awareness became a turning point in my search for ultimate truths.
With my perspective broadened by that experience, I came to see that astrophysics examines only the physical aspects of the universe. It does not address fundamental questions such as the origin of the universe or the purpose of its creation. My yearning to tackle these metaphysical questions and the desire to integrate my faith with insights from the humanities subjects prompted me to study philosophy of religion a few years later. Without pursuing a second doctorate in this discipline, my intellectual journey might have remained confined to science alone.
Like many scientists, Dr Chan appreciates the beauty of physics and mathematics. “I am always amazed by the power of physics to explain the physical world, and the elegance and simplicity of mathematical equations,” he says.
As a branch of philosophy, the philosophy of religion employs methods such as logic and epistemological and metaphysical reasoning to analyse central themes in religious traditions and the philosophical questions arising from them. Unlike theology, which seeks to understand and justify beliefs through religious texts and traditions, the philosophy of religion adopts a more neutral and often sceptical approach.
Philosophy stands in marked contrast to physics too, the field from which my earlier knowledge came. In physics, causation refers to the temporal relationship between events where one event (the cause) leads to another (the effect), typically expressed through natural laws and mathematical equations. In philosophy, however, causation explores deeper conceptual and metaphysical dimensions. Philosophical inquiry of causation encompasses definitions of cause and effect, types, mechanisms, and implications of causal relationships in various contexts. I would not claim that one discipline outranks the other; rather, both enrich our understanding of the world by addressing shared questions from different perspectives.
Philosophy of religion has helped me grasp the complexities of abstract concepts. One major insight I’ve gained is “categorisation of concepts”, the understanding of how experiences, objects, and ideas are grouped according to shared characteristics and relationships. In physics, existence is defined in physical terms, referring to what can be observed, described, or measured, either directly or indirectly. The philosophy of religion, however, extends this to encompass non-physical existence.
While physics and theology had taught me scientific and biblical knowledge, my doctoral studies in philosophy of religion opened my mind to a completely new approach to knowledge.
Over four years of study, I re-evaluated my understanding of concepts such as existence, causation, and explanation, previously shaped by physics. This required me to interpret dense philosophical texts, often in English—which posed a challenge as my physics studies had not demanded such intensive reading. While physics and theology had taught me scientific and biblical knowledge, my doctoral studies in philosophy of religion opened my mind to a completely new approach to knowledge, playing a key role in my lifelong search for truth.
Dr Chan remarks that “the end of physics is the beginning of philosophy”. “When physical explanations cannot answer questions about existence, meaning, or reality, philosophy steps in to offer alternative insights into these inquiries,” he states.
I am proud to hold both a PhD in physics and another in philosophy of religion. It is not because two doctorates demonstrate exceptional intelligence, for human understanding is minuscule compared to the vast ocean of knowledge, but because both disciplines have deepened my understanding of the fundamental truths of existence and the nature of the universe. I often use the phrase “the end of physics is the beginning of philosophy” to express their relationship: when physical explanations cannot resolve fundamental questions about existence, meaning, or reality, philosophy offers alternative insights.
Although physics and philosophy adopt different approaches to knowledge, inquiry, and understanding, the two disciplines are not opposites. For instance, science founded in naturalism avoids arguments involving non-material entities, whereas metaphysics in philosophy explores matters beyond the physical, such as “what is love?”. Many philosophical questions focus on metaphysical ideas. Although physics does not employ philosophy’s methods, it does not reject them.
Dr Chan studied fine-tuning theory during his doctorate in philosophy of religion. The theory states that the universe’s physical constants and conditions are precisely calibrated to allow for the existence of human beings. It suggests that even slight alterations in these conditions could render life impossible.
It is the universe’s boundless mysteries that continue to draw me to astrophysics. I further explored these mysteries by examining the fine-tuning theory during my doctoral research in philosophy of religion. This theory proposes that the universe’s physical constants are finely calibrated to support human existence, and that even slight changes could make life impossible. Both philosophy and physics seek to understand the universe, but from distinct angles: physics relies on empirical data and mathematical models, while philosophy probes their implications and meanings.
While my doctoral work in astrophysics equipped me with scientific and empirical knowledge, my training in philosophy honed my critical thinking, reasoning, and analytical abilities. With expertise in both fields, I am uniquely positioned to bridge the gap between empirical science and abstract philosophical inquiry. Moreover, having experienced the same dissatisfaction with science’s limitations, I empathise with fellow inquirers. I understand their questions and know what they may need to reach fuller answers.
Now, as a scientist shaped by faith, I find that the same mysteries inspire humility.
As I continue to explore the cosmos and engage with others who share this curiosity, I hope to inspire more people to pursue their own intellectual journeys. Whether believers or not, many inquisitive minds ask me, through emails or public talks, questions about the origin of the universe, the foundations of scientific knowledge, and the meaning of life. Although I have pondered such questions for many years, I do not claim to have all the answers. Yet, I find great joy in sharing my reflections.
Dr Chan says the mysteries of the universe strengthen his belief in a creator who is behind the brilliant stars illuminating the night sky and the immeasurable vastness of the cosmos. (Photo source: https://depositphotos.com)
Physics, theology, and the philosophy of religion each reveal different facets of truth, all essential in guiding me towards a deeper understanding of the universe and human existence. As a child, I was drawn to the unknown secrets of the cosmos; now, as a scientist shaped by faith, I find that the same mysteries inspire humility. With a humbled heart, I find these mysteries strengthen my belief that there is a creator behind the brilliant stars and the immeasurable expanse of the universe.
For readers who wish to learn more about Dr Chan’s research, see the earlier interview by the newsletter on his study of dark matter and the universe.
Note: Dr Chan Man-ho holds a PhD in astrophysics and another in philosophy. His research focusses on astrophysics, cosmology, philosophy of science, philosophy of religion, the dialogue between science and religion, and STEM education. He has been a Fellow of the International Society for Science and Religion, a Fellow of the Royal Astronomical Society, Expert Adviser (專家顧問) to The Hong Kong Space Museum, and a member of the International Astronomical Union (IAU, 國際天文聯會).
Dr Chan believes that the existence of Planet Nine—a planet possibly hiding beyond the orbit of Neptune. In a paper published in 2023 that drew much public attention, Dr Chan argues that by adopting a benchmark model of planet nine, his research team showed that the tidal effect can heat up the satellites significantly, which can give sufficient thermal radio flux for observations, even if the planet itself is a dark object.
(Dr Chan Man-ho collaborated with Tam Siu-man on this piece.)
