How a lineage of scientists pieced together the puzzle revealing the dual nature of the universe.
Ever since Heisenberg stood on the shoulders of giants to pave the way for quantum mechanics, this captivating branch of science and its central fact — that light can behave both as a particle and as a wave — has challenged us to grapple with the perplexing duality of the universe, inspiring everything from critical questions about the future of science to mind-bending meditations at the intersection of theology and astrophysics to philosophical children’s books.
That central mystery of quantum mechanics is what particle physicist Chad Orzel, author of the illuminating and intelligently entertaining How to Teach Quantum Physics to Your Dog (public library), explores in this animated primer from TED Ed.
Orzel writes in the book:
Classical physics is the physics of everyday objects — tennis balls and squeaky toys, stoves and ice cubes, magnets and electrical wiring… Modern physics describes the stranger world that we see when we go beyond the everyday… Modern physics is divided into two parts, each representing a radical departure from classical rules. One part, relativity, deals with objects that move very fast, or are in the presence of strong gravitational forces… The other part of modern physics is what I talk to my dog about.
He points out that quantum mechanics is woven into the very fabric of modern life:
Without an understanding of the quantum nature of the electron, it would be impossible to make the semiconductor chips that run our computers. Without an understanding of the quantum nature of light and atoms, it would be impossible to make the lasers we use to send messages over fiber-optic communication lines.
Quantum theory’s effect on science goes beyond the merely practical — it forces physicists to grapple with issues of philosophy. Quantum physics places limits on what we can know about the universe and the properties of objects in it. Quantum mechanics even changes our understanding of what it means to make a measurement. It requires a complete rethinking of the nature of reality at the most fundamental level.
Quantum mechanics describes an utterly bizarre world, where nothing is certain and objects don’t have definite properties until you measure them. It’s a world where distant objects are connected in strange ways, where there are entire universes with different histories right next to our own, and where “virtual particles” pop in and out of existence in otherwise empty space.
Quantum physics may sound like the stuff of fantasy fiction, but it’s science. The world described in quantum theory is our world, at a microscopic scale. The strange effects predicted by quantum physics are real, with real consequences and applications.
Those consequences and applications are what Orzel goes on to explore in the wholly fascinating How to Teach Quantum Physics to Your Dog. Complement it with Alice in Quantumland, an allegorical explanation of quantum mechanics inspired by Lewis Carroll, then revisit TED Ed’s stimulating animated primers on what makes a hero, how you know you exist, why playing music benefits your brain more than any other activity, how melancholy enhances creativity, why bees build perfect hexagons, and Plato’s parable for the nature of reality.