In Our Time

Melvyn Bragg and guests discuss one of the deepest problems in contemporary physics. It’s called the measurement problem and it emerged from the flurry of activity in the early 20th century that gave rise to Quantum Mechanics. If the most famous fruit in physics is an apple, the most famous animal in physics is a cat. Schrödinger’s cat is named after Edwin Schrödinger, a theoretical physicist who in the early 20th century helped to develop the radical theories of Quantum Mechanics. The cat does not actually exist – it is the subject of a thought experiment – in which the rules of quantum mechanics make it appear both dead and alive at the same time.The problem of a cat that is both dead and alive illustrates the challenges of quantum physics and at the heart of this apparent absurdity is a thing called the measurement problem.The measurement problem arises because we don’t really understand how the atoms that constitute our world behave. They are fundamentally mysterious to us, even shocking, and they defy o