April 14 marked World Quantum Day, a global initiative aimed at public understanding of the quantum science and technology that shapes our modern existence. The date itself is a tribute to the fundamental physical constant that birthed this revolution: 4.14 (April 14), representing the first digits of Planck’s constant (eV·s). As India navigates the 21st century, this day serves as a critical juncture to reflect on the transition from classical determinism to a quantum reality ~ a reality that finds a surprising resonance in ancient Indian thought. The story begins in 1900 with Max Planck.

Attempting to solve the ultraviolet catastrophe of blackbody radiation, Planck made a radical assumption: energy is not continuous, but packetized into discrete quanta. This discovery shattered the foundations of classical physics. Planck’s constant became the scale of the universe’s granularity. It was the key that unlocked the door to the subatomic world, leading to the development of quantum mechanics by Bohr, Heisenberg, and Schrödinger. World Quantum Day honours this numerical foundation, reminding us that at the most fundamental level, our universe is governed by discrete values rather than smooth transitions.

For decades, quantum phenomena like superposition ~ where a particle exists in multiple states simultaneously ~ and entanglement ~ the spooky action at a distance where two particles remain connected regardless of separation – were treated as philosophical puzzles or mathematical oddities. Today, these are no longer mysteries; they are experimentally determined facts. Recent breakthroughs in quantum computing and Bell’s theorem experiments have proven that the universe is non-local and probabilistic. We have moved from observing these phenomena to engineering them.

Whether it is through the development of qubits in quantum processors or secure quantum key distribution (QKD) for communication, the weirdness of the quantum world is now the engine of a new industrial revolution. The rise of quantum mechanics signalled the death of Newtonian deterministic materialism. In the Newtonian view, the universe was a giant clockwork mechanism; if........

© The Statesman