Experimental Soft Condensed Matter Group Harvard University, Prof. D. A. Weitz Cool Picture of the Moment

At sufficient concentration even particles without attractive interactions (hard sphere potential) form a crystal. This phase transition is driven by entropy alone and the only important parameter is the volume fraction. The video is based on experimental data and shows an x/y slice of a sediment forming in a suspension of silica particles. The color of the individual particles depends on the amount of order in their immediate environment, red indicating high order. While the particle density increases steadily, crystallization sets in quite abruptly at some point.

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