QUANTUM PHYSICS EXPLAINED
Take an in-depth look at the unbelievable theories, crazy experiments and practical applications of what may be the weirdest of all scientific subjects
WORDS ANDREW MAY
DID YOU KNOW? Physicist John Wheeler said that if you aren’t confused by quantum mechanics, you don’t understand it
The ambiguity between waves and particles at the subatomic level is central to quantum physics
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Originating early in the 20th century, quantum theory has acquired a fascination and exotic appeal quite unlike any other branch of physics. Movies, video games and comic books regularly invoke it to explain away impossible gadgetry and superpowers, while fashionable mystics and health gurus have appropriated its jargon to their own ends. But it’s important to distinguish between science and pseudoscience and to separate fact from fiction. And surprising as it may sound, true quantum physics is just as rational, level-headed and well-defined as any other field of science. The difference is that it deals with phenomena that only manifest themselves on tiny, subatomic scales that lie way outside our ordinary everyday existence and can often defy all our ideas of ‘common sense’.
Over the next few pages, we’ll demystify some of the most baffling corners of quantum theory, from wave-particle duality and the uncertainty principle to the notorious case of Schrödinger’s cat, which can be both dead and alive at the same time. We’ll also see how present-day scientists are drawing on quantum mechanics to give at least a grain of credibility to long-established science-fiction concepts like teleportation, telepathy and time travel.
But as entertaining as such ideas are, the greatest value of quantum science lies in its practical applications to real-world technology. The LEDs that light our homes, the microprocessors inside our mobile phones, the atomic clocks that make GPS navigation so accurate and even the lasers that power our cats’ favourite toys simply wouldn’t be possible without quantum theory. We’ll take a closer look at these applications, together with more specialised ones like superconducting magnets, electron microscopes and the emerging fields of quantum computing and cryptography.
A photograph of the interference pattern produced by a laser beam passing through a double slit
© Wiki: Bryan Tong Minh