We know how very large objects move -- and we have theories about how very tiny particles move. But classical physics and quantum theory only take us so far: When it comes to the stuff in between, scientists aren't entirely sure what governs matter's movement. One idea that's been hypothesized, however, is quantum friction, a phenomenon that could slow the motion of quantum particles of its own accord, without any external sources of friction.
The physicist Michael Mazilu and his colleagues at the University of St. Andrews wanted to test whether quantum friction exists. Which is difficult when you're dealing with, you know, quantum particles. So they created something -- a kind of tilt-a-whirl for particles.
Mazilu and his team needed to trap aggregations of atoms within a beam of light, and then get those atoms spinning really, really quickly. Oh, and in a vacuum. So they took calcium and concocted a tiny sphere (really tiny: about of 4 micrometers, or one-tenth of a human hair, in diameter). Then they levitated the sphere in a beam of laser light. They did all this, yes, inside a vacuum. And then! They took their tiny little sphere and whirled it -- at a rate of 600 million rotations per minute. Which (wheeeee!) must have been quite a ride for the particles inside it.
The sphere the team created, in other words, rotates 500,000 times faster than the average washing machine. Making it, yes, the fastest-spinning object ever made.
Mazilu and his co-authors just published their work in the journal Nature Communications -- and it could, LiveScience points out, shed light on the physics of matter. "This system poses fascinating questions with regard to thermodynamics and is a challenging system to model theoretically," Mazilu noted in a statement. "The rotation rate is so fast that the angular acceleration at the sphere surface is 1 billion times that of gravity on the Earth surface — it's amazing that the centrifugal forces (the forces pushing outward due to circular motion) do not cause the sphere to disintegrate."
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