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The disappearance of ice in oil (Heather Ploeg, Gabriel Hanna, Matt McCluskey)

This video was taken by Heather Ploeg, a Research Experiences for Undergraduates (REU) student at Washington State University, sponsored by NSF/AFOSR. The video shows a sample in a moissanite anvil cell. Two moissanite anvils press on a sample, which has been loaded into a hole drilled in a stainless steel gasket.

The hole is a half millimeter in diameter, filled with mineral oil, and under a pressure of 1 GPa. A ruby chip, for pressure calibration, is at the top. At the bottom is a drop of water – actually ice, due to the pressure. The pressure is released. When the pressure goes below 0.9 GPa, the ice melts and disappears!

Help us solve this mystery! Some possibilities are (1) the water somehow dissolves in the oil, (2) the water escapes out of the gasket, or (3) the water coats the gasket walls.

Ice VI (Heather Ploeg, Gabriel Hanna, Matt McCluskey)

Using a moissanite-anvil cell, pressure is applied at room temperature to freeze water. The pressure is 10 kbar (10,000 atmospheres – over 70 tons per square inch). The diameter of the hole is 0.6 mm.

Water becoming ice VI. The ice begins to form on the outer ring of the sample and progresses towards the center. The entire sample is converted to ice VI in less than a second. The ruby chip, used for pressure calibration, is visible in the upper left of the sample.

Ice VI becoming water. After the pressure is slowly released, the ice cracks and the phase change begins. The pressure continues to drop inside the gasket. The ice breaks up into smaller pieces that coalesce into larger ones, but the total mass of the ice gets smaller. Eventually only liquid water remains.

Watermelon versus liquid nitrogen (Matt McCluskey, Gabriel Hanna)

July 4, 2007: An uneaten (obviously) watermelon is sacrificed to science. Matt McCluskey pours liquid nitrogen into a plastic soda bottle. After the bottle is sealed, the pressure inside increases as the liquid nitrogen turns to vapor. Then – well, see the video. “Emmy-winning” videography and color commentary by Gabriel Hanna, with off-camera cameos by Slade Jokela and Ryan McCluskey.