A small team of researchers from Spain and Mexico made a discovery, almost by accident, which
was later published in the renowned journal
Physics Review Letters .
Thousands of cubes randomly poured into a glass align themselves perfectly when the mixture is subjected to "oscillating rotation," that is, alternately accelerated clockwise and counterclockwise.
The researchers poured 25,000 plastic cubes into a transparent cylinder. They then tested various shaking techniques to determine which resulted in the highest compaction of the cubes.
They found that alternating rotation (left-right-left-right) worked best. However, the individual rotations had to be performed at high speed.
This caused the cubes to align themselves from top to bottom, forming concentric circles in each layer.
At an acceleration of 0.52 g, the pile of cubes reached its maximum density after 10,000 alternating angular impulses.
This seems to work significantly better than a simple "jerking," because at a state of medium density, the latter causes the cubes to wedge themselves together and remain stuck.
If the rotational impulses are too slow, the compaction and alignment of the cubes could potentially take years.
The researchers now hope that their findings will open up a potential new way to compact materials during the manufacturing process.
