Molecules/Matter & Energy

Supersized Rubik’s Cubes solved
Solving a Rubik’s Cube with more squares than the original toy requires fewer moves than expected. A new algorithm developed by MIT computer scientist Erik Demaine and colleagues spots situations in which several squares can be put in place at once with a few simple twists. This efficient strategy outperforms the usual approach for solving supersized cubes — which concentrates on one square at a time — and challenges the prediction that the minimum number of moves needed is proportional to the number of squares on one side, the researchers report online June 28 at arXiv.org. —Devin Powell

Tibetan singing bowls levitate water
Drops of water can levitate inside a Tibetan singing bowl — a bronze vessel that produces a ringing sound when rubbed around the edge by a leather mallet. Physicists found that this rubbing creates vibrations that can churn up liquid inside the bowl, forming Faraday waves, which move up and down at half the speed of the bowl’s vibrations. Drops of water that break off these waves can sit on the liquid’s surface and skip like stones. Similar fluid dynamics should also be possible — but more difficult to spot — in a wine glass rubbed with a wet finger, researchers at MIT and the University of Liège in Belgium report online June 29 at arXiv.org. —Devin Powell

Soda cans squeeze sound
A new use for empties: focusing sound just as an optical lens focuses light. Blow across the mouth of an empty Coke can, and you’ll hear a sound as the can resonates. Arrange a group of cans into a grid, and they can all resonate together. In a simple experiment, French researchers demonstrate that such a lens can squeeze a sound wave down to a spot smaller than its wavelength — a feat once thought to be impossible. This “resonant metalens” could be built out of a variety of materials, opening up new ways to use sound at small scales, the researchers report in an upcoming Physical Review Letters. —Devin Powell