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Watch Water Freeze
Freezing water forms a spiky kaleidoscope of colorful crystals.
Ordinarily, water freezes too slowly to be appreciated. Here, polarized light and an ultra cold slab let you watch water crystalize rapidly in real time. The colorful mosaic of ice that forms is different every time.
What’s going on?
You can see colors in this ice thanks to special light filters called polarizers. The various colors appear for two reasons: slightly different thicknesses in the ice, and tiny stresses that develop within the ice as the crystals form and collide.
Chilled by coolant from below, the glass is so cold that when you squirt water on it, the water freezes into crystals.
Going further
On some lucky occasions, you may witness a sudden, abrupt freezing of all the water on the slab. Ice crystals needs a surface or seed crystal on which to form. If none are present, the water becomes supercooled—cooled to well below the freezing point—until a seed crystal forms and ice suddenly spreads.
More to explore
Charles Sowers and his Watch Water Freeze Exhibit
Supercooled Water Drops
Touch supercooled water drops with an ice crystal and trigger them to freeze instantly.
Fostering Active Prolonged Engagement
APE was a four-year Exploratorium project to explore strategies and tactics to shift the role of visitors from passive recipient of information to active participant in the exhibit experience.
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