Critical Opalescence

A blog about cutting-edge physics

  • Why is Quantum Physics So Freakin’ Hard to Write About? [Video]

    Every area of journalism presents its challenges, but quantum physics is in a molecular orbital of its own. It demands more time per word than anything else I’ve written about. Why is that? Earlier this month I offered some thoughts to fellow science journalists attending a philosophy-of-physics workshop at the University of Leeds.     […]

  • If You Think Quantum Physics Is Weird, Try These Theories

    It’s quite a trick to picture a theory even weirder than quantum mechanics. Yet many physicists think the best way to make sense of quantum mechanics is to imagine what might have been. Within a vast radiation of conceivable theories, they look for principles that single out the quantum. In so doing, they aim to […]

  • Demonstrate Quantum Encryption With a Flashlight and Pair of Sunglasses

    “Are you telling me that this could be of practical use?” exclaimed the Irish physicist John Bell. He had shown in the 1960s that quantum entanglement burrowed deep into the foundations of physics, but even he hadn’t thought it could have real-world applications. That was the brainstorm of Artur Ekert, then a graduate student at […]

  • How to Demonstrate “Twisted Light” Using a Laser Pointer

    In November 2003 I published a short news story in Scientific American about the orbital angular momentum of light and how you can glimpse it with a laser pointer and an overhead transparency. The article is no longer available at scientificamerican.com, so, as a service to fellow makers and citizen scientists, here are the instructions: […]

  • The Twelve Varieties of Consciousness

    I have an essay in Aeon magazine on the possibility that machines might become conscious without our realizing it and possible ways to test for that. A huge variety of physiological and behavioral tests of consciousness might be adapted to machines, and Spanish AI researcher Raúl Arrabales Moreno and his colleagues have systematized them as […]

  • The Universe Is a Big Layer Cake

    Is the universe deterministic or indeterministic? A clockwork or a craps table? In this month’s issue of Scientific American, I have an essay arguing that the answer is: both. The world can be deterministic on some levels and indeterministic on others; these two categories are not mutually exclusive. To me, this is the essence of […]

  • Living in a World of Illusion

    My favorite optical illusions are motion illusions: static images that appear to spin, shimmer, and shimmy, like Piet Mondrian’s Broadway Boogie–Woogie or the psychedelic pinwheels of Japanese psychologist Akiyoshi Kitaoka. So I was pretty pleased to come across a new class of them, known as fuyuu, or floating, illusions. I visited their co-creator, mathematician Hitoshi Arai, […]

  • A Hologram Shows How Space Could Pop Into Existence

    I remember buying my first hologram as a college student in the mid-1980s. It showed a bed of nails. I came across it at a gallery in what was then the world’s capital of spacey trinkets, Haight Street in San Francisco. When I picked it up, the hologram looked like a featureless sheet of film, […]

  • Why Bother with Ordinary Fireworks When You Can Have Black Hole Fireworks?

    Theoretical physicist Carlo Rovelli, one of the creators of loop quantum gravity, and his collaborator Hal Haggard have just come out with a new paper on black holes. Ever attuned to puns, Rovelli calls it the “fireworks” model, alluding to the firewall argument that has consumed black-hole theorists over the past two years. As if […]

  • Physicists Look Beyond the Large Hadron Collider, to the Very Large Hadron Collider

    In 1954 the renowned physicist Enrico Fermi did a simple but depressing calculation about future particle accelerators. To create particles with an energy of 3 teraelectron-volts, he estimated, you’d have to build a ring 8,000 kilometers in radius at a cost of $170 billion. It was a rare instance of Fermi being wrong. The Large […]

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