Quantum mechanics challenges our intuitive understanding of the world, as it allows for superpositions and collapses to single outcomes upon observation.
Entanglement, the phenomenon where particles become connected regardless of distance, is a key feature in quantum mechanics, used in quantum computing and secure communication.
Deep dives
Quantum mechanics and its counterintuitive nature
Quantum mechanics is a theory that describes nature on the small scale of particles and atoms. Unlike speculative theories such as string theory or multiverse, quantum mechanics has been extensively tested and is used in everyday technologies. However, the mystery lies in interpreting the theory. Does it accurately represent how nature behaves? Quantum objects can exist in superpositions, holding contradictory features or being in multiple places at once, but this collapses to a single outcome upon observation. The randomness and uncertainty inherent in quantum mechanics challenges our intuitive understanding of the world.
The phenomenon of entanglement and its practical applications
Entanglement is a phenomenon in quantum mechanics where particles can become mysteriously connected, even if they are light years apart. For instance, measuring the state of one particle instantaneously determines the state of the other, regardless of the distance between them. This property of entanglement is utilized in quantum computing and secure communication. Researchers are experimenting with entangled particles, such as photons, to explore their correlated properties and develop innovative technologies based on this quantum behavior.
The measurement problem and the role of consciousness
The measurement problem in quantum mechanics revolves around how a superposition of quantum states collapses into a definite outcome upon observation. There are various interpretations of this process, ranging from the Copenhagen interpretation to more extreme views like Cubism. While the role of consciousness in measurement is a topic of debate, some argue that consciousness is not necessary for the collapse of the wave function. The physics of observers suggests that any measurement apparatus, including machines, can act as an observer in the quantum world.
Bridging the gap between quantum mechanics and macroscopic world
One of the mysteries in quantum mechanics is why we don't see quantum effects in the macroscopic world. The transition from the quantum to the classical is still not fully understood. While large objects theoretically can exhibit quantum behavior, the difficulty lies in controlling the interactions and decoherence caused by the constant monitoring from other particles and objects. Researchers are exploring the limits of quantum effects in larger systems and investigating fundamental connections between quantum mechanics and gravity through experiments.
It is hard to shake the intuition that there's a real and objective physical world out there. If I see an umbrella on top of a shelf, I assume you do too. And if I don't look at the umbrella, I expect it to remain there as long as nobody steals it. But the theory of quantum mechanics, which governs the micro-world of atoms and particles, threatens this commonsense view.
Featuring Chiara Marletto, Research Fellow of Physics, and Christopher Timpson, Professor of Philosophy of Physics, both at the University of Oxford, and Marcus Huber, Professor of Physics, TU Wien.
This episode is presented by Miriam Frankel and produced by Hannah Fisher. Executive producers are Jo Adetunji and Gemma Ware. Social media and platform production by Alice Mason, sound design by Eloise Stevens and music by Neeta Sarl. A transcript is available here. Sign up here for a free daily newsletter from The Conversation.