25 Euro Quantum Physics Coin SU
Quantum physics reveals that the world has much more to offer than meets the eye. It explores the fascinating domain of the tiniest constituents of matter – electrons, photons and atoms – which defy the laws of classical physics and exist in a realm of possibilities rather than certainties. Only through observation or interaction with a system does one of these possibilities become an actual, measurable state. Quantum physics teaches us that nature is not fixed but governed by probabilities. It replaces the predictability of classical physics with a universe where chance, superposition, entanglement and uncertainty are fundamental principles. These findings sparked a profound revolution in our understanding of space, time and the very nature of reality. As abstract as the quantum world may seem, it has long influenced our daily lives. Technologies such as lasers, computer chips, LEDs, MRI scanners and atomic clocks – essential for GPS – all rely on the principles of quantum physics. Now, a second quantum revolution is underway, paving the way for quantum computers, tamper-proof communication and next-generation quantum cryptography – technologies that research teams at the University of Vienna are helping to advance. The obverse of *Quantum Physics* features Schrödinger’s cat, the thought experiment illustrating quantum superposition. The cat’s face dominates the niobium core, its eyes representing the superposition of the states ‘alive’ and ‘dead’. Around the cat, extending to the edge of the coin, are an unstable atom, a Geiger counter scale, a radioactivity symbol and the observer. The abbreviation of Schrödinger’s equation can be seen at the top of the coin. The coin’s reverse celebrates Anton Zeilinger’s experiment on quantum entanglement. The simplified experimental set-up shows the measuring stations ALICE (A) and BOB (B), which are connected via a quantum channel and a classical channel. The niobium core illustrates the entanglement of two particles with opposite spin directions.