Max Planck and Faith in Invisible Light
Gabriella Greison - For the discoverer of quantum mechanics, faith was not an alternative to reason but its root. His spirituality? Resisting the darkness.
Max Planck did not like the limelight. He was not interested in heroism or front-page headlines. He had a discreet, almost austere demeanor, like a professor who prefers to go unnoticed. Yet, from that austerity came a revolution that changed the history of knowledge forever: the birth of quantum mechanics. Planck was not seeking fame; he was seeking truth. And truth, for him, was not a prize or a perfect formula, but a moral condition. He believed that the world had a logical structure, an internal coherence, a music that could only be heard in silence. He said that science was a way to approach order and that order—rational, invisible, harmonious—was the sign of God. Not a God who intervenes in human destinies like a director, but a God who rules the scene with invisible, precise, wonderfully coherent laws. A God who does not need to appear to be believed.
His discovery, the one that changed his life, came almost out of desperation. At the end of the 19th century, physics was in crisis: there was a problem, “black body radiation,” that no one could explain. The classical formulas had hit a wall. Planck was only looking for a way to make the numbers add up, not to revolutionize physics. In 1900, he tried a method that seemed like a temporary expedient: he hypothesized that energy did not flow continuously, but in packets, in “quanta.” It was a small mathematical gesture, almost a trick to make the formula work. Instead, with that act of humility and genius, he opened a door. The world was not continuous but granular. Reality was not a uniform fabric but an invisible mosaic of energy fragments, pulsing like notes in a symphony that turns on and off. Classical physics cracked, and quantum physics was born.
Planck himself struggled to believe his discovery. He said it was as if he had opened a door to a territory he did not yet want to explore. And in fact, for years he tried to go back, to close that door, to restore order to the chaos he had created. But the universe had spoken. And from then on, nothing would ever be continuous, predictable, or definitive again. Yet Planck remained Planck: calm, reserved, almost wary of the clamor of his younger colleagues. He did not have Einstein's visionary élan nor Bohr's taste for paradoxes. He was a man of rigor, method, and consistency.
Furthermore, he thought that science was a slow, progressive approach, a journey made up of small steps. And within that journey, he found room for faith. “Faith is a precious heritage of humanity,” he wrote. “Science and religion are not in conflict but complement and condition each other.” He was not talking about dogmatic faith but about an act of trust. Because every scientist, when writing an equation, makes an act of faith: he believes that the universe has meaning. He believes that the laws of nature are not arbitrary but consistent. He believes that the human mind is part of that order, not alien to it. In this sense, for Planck, faith was not an alternative to reason but its root. It was the belief that the world is not absurd, that every fragment of reality bears traces of a common logic.
But behind the professor's calm exterior, Max Planck's life was marked by pain. He lost two daughters and his wife and finally saw his last son, Erwin, executed by the Nazis for participating in the plot against Hitler. He was over eighty years old. Likewise, he had seen everything collapse: his country, his generation, and his faith in mankind. Yet he never stopped believing, neither in science nor in God. He never raised his fists to the sky to demand explanations. He did not turn pain into resentment. He continued to write, to teach, and to search. Because this was his spirituality: to resist the darkness, to keep the light of intellect burning.
There is a phrase of his that haunts me: “To believe in science, you have to believe in the rationality of the world.” It is a manifesto, a secular prayer. Because every time we experiment, we are already performing an act of faith. Not that of dogma, but the faith that tells us that the world has meaning. That it is not a game of chance. That we are not thrown into chaos but immersed in a logic that precedes us.
And here, if you'll allow me, I'll add a personal note. Because this part concerns me closely. I, who elaborate on physics on stage, why do I do it? Because it's no longer enough for me to say “cold” things, only with numbers. I am searching. I move between equations and stories, between archives and the stage, but what I am chasing is meaning. A meaning that cannot be written with chalk on a blackboard but can be sensed in a breath, in a word, in a gesture. For me, physics has never been just a technical subject: it is a lens through which to look inward, not just outward. It is my way of staying in the question. And spirituality—the free kind, without dogma, made up of questions rather than answers—is the natural territory in which these questions breathe. I don't know if I will ever find a definitive answer. But I know that this journey, this constant oscillation between particles and mystery, is my way of searching.
And every time I talk about Planck, I also talk about this: that mystery is not a failure, but a destination. Planck knew this. He knew that you cannot possess the truth; you can only remain faithful to it. That faith is not a closed package of certainties but the courage to continue searching even when everything seems to be falling apart. Perhaps his true legacy is not just quanta, Nobel Prizes, and formulas that bear his name. Perhaps it is this: the certainty that science and faith are not enemies, but sisters. Two paths that do not cancel each other out but look each other in the eye. Two roads that separate and then meet again, like two waves that interfere and create a new figure.
Max Planck did not talk about miracles. He talked about constancy. He spoke of fidelity. He believed that God was the root of the logic of the universe, the silent foundation of every natural law. And in his sober, unemphatic voice, there was already a profound spirituality: believing that the invisible is real. That the strongest light is not the one you see with your eyes, but the one that illuminates the mind and comforts the heart. His faith in invisible light is an invitation not to stop searching, even when everything around us is darkness. To believe that knowledge, if done with humility, is a form of prayer. That every successful experiment is a genuflection to the beauty of the world. And that every discovery, even the smallest, is a way of saying thank you.
Question for us today: if even Planck, the most sober of physicists, reminds us that all knowledge comes from an act of faith, are we willing to admit that we too live by faith in the invisible? And that perhaps true greatness lies not in having answers, but in remaining faithful to the search—even when it hurts, even when it seems useless, even when everything around us is falling apart? Because science, like life, does not promise certainties. It only promises that, as long as we continue to search, the invisible light will never go out.
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