Critical Opalescence
A blog about cutting-edge physics

How to Build Your Own Quantum Entanglement Experiment, Part 1 (of 2)

The cheapest and easiest way to do the famous Einstein-Podolsky-Rosen experiment.

Quantum-entanglement experiments are not exactly something you can buy in the science kit aisle at Toys ’R Us. The cheapest kit I know of is a marvel of miniaturization, but still costs 20,000 euros. In the past month, though, I’ve put together a crude version for just a few hundred dollars. It’s unbelievably simple—so simple […]

Physicists Find a Backdoor Way to Do Experiments on Exotic Gravitational Physics

Who’d have thought viscous fluids would act like gravitational waves caroming off a black hole?

The whole point of an explanation is to reduce something you don’t know to something you do. By that standard, you don’t gain much by explaining anything in terms of black holes. Appealing to the most mysterious objects known to science as an explanation sounds like using one mystery to explain another. Yet this is […]

When You Fall into a Black Hole, How Long Have You Got?

Maybe not long at all, if black holes are ringed by “firewalls.”

In chatting with colleagues after a talk this week, Joe Polchinski said he’d love to fall into a black hole. Most theoretical physicists would. It’s not because they have some peculiar death wish or because science funding prospects are so dark these days. They are just insanely curious about what would happen. Black holes are […]

Hacking the Quantum: A New Book Explains How Anyone Can Become an Amateur Quantum Physicist

Quantum physics is becoming the next maker revolution.

For years I’ve been thinking and hoping that quantum physics would become the next hacker revolution. DIYers in their basements, garages, and hackerspaces have already pioneered radio communications, PCs, household robots, and cheap 3-D printers—why not quantum entanglement, cryptography, computers, and teleportation? In recent years, physics educators have streamlined quantum experiments to the point where […]

How to Build the World's Simplest Particle Detector

Foil tray, plastic tumbler, and rubbing alcohol make for a simple cloud chamber, without any dry ice.

In about 10 minutes, using stuff you probably already have lying around your house, you can watch atomic nuclei and elementary particles for yourself using a diffusion cloud chamber—a rudimentary particle detector. There are lots of websites and YouTube videos giving step-by-step instructions to build such a chamber, but all require some component that’s hard […]

How Do You Count Parallel Universes? You Can't Just Go 1, 2, 3, ...

Introducing a whole new breed of number, the p-adics.

Cosmologists have been thinking for years that our universe might be just one bubble amid countless bubbles floating in a formless void. And when they say “countless,” they really mean it. Those universes are damned hard to count. Angels on a pin are nothing to this. There’s no unambiguous way to count items in an […]

String Theory in 26 Seconds [Video]

A weird little video, done on a dare.

SANTA BARBARA—Someone once asked me to describe string theory in 26 seconds, so, a couple of months ago, I went down to Goleta Beach with my iPhone and recorded this little video. It’s kind of spacey, I admit. Soundtrack and dog were entirely unintentional.

As If One Giant Black Hole Weren’t Enough, What’s a Galaxy Doing with Three?

Standard formation models can’t account for this triplet.

Last Thursday, my colleague John Matson described a truly amazing galaxy known, somewhat unromantically, as BX442. It has a majestic spiral pattern while hundreds of its galactic contemporaries were gawky and misshapen—a peculiar and special anomaly which suggests to many astronomers that cosmic pinwheels are ephemeral art forms, like Tibetan sand mandalas. John’s piece spurs […]

Does It Matter If Black Holes Are Popping into Existence Around Us All the Time?

Black holes are not just distant cosmic monsters. Microscopic ones may exist all around us, with potentially momentous consequences.

It may well have been the liveliest hour and a half I’ve ever spent in the company of theoretical physicists. In April, during a workshop I was attending on black holes, Bill Unruh gave a talk that challenged his colleagues on a point almost all of them thought had been settled in the mid-1980s. His […]

What Is the Higgs Boson? [Video]

In 2 1/2 minutes, you, too, can break the symmetry of the electroweak interactions.

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