Researchers have compressed super-hot liquids between diamonds to demystify how fluids behave under extreme conditions, such as in the interiors of planets.
Physicists have struggled to track how a liquid鈥檚 density changes at extreme temperatures and pressures. To overcome this challenge, at the University of Salford in the UK and his colleagues have used diamonds and lasers.
The researchers compressed several liquids including water, methane and ethane in a millimetre-sized chamber. They did this by heating each liquid up to 240掳C (465掳F) and sandwiching it between two tiny diamonds. This created pressures up to around 120,000 times greater than that of the atmosphere.
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Strikingly, they observed how even extremely hot water could become an ice crystal when the pressure was high enough. Extreme pressure forced the water鈥檚 atoms to bond and form a solid. In separate experiments, the team saw the same happen to methane and ethane. Proctor says this could offer insights into the behaviour of pockets of water that are trapped deep underground, where they can influence seismic activity.
To determine the density of these extra-hot, extra-compressed liquids, the researchers beamed a laser into the chamber. They could infer each liquid鈥檚 density from the way light bent as it travelled in and out of the chamber.
鈥淭his is a hundred-fold increase of what we can do in terms of our understanding of density versus pressure [for fluids],鈥� says Proctor.
at Washington State University says that while researchers have a good grasp on how to study solids under extreme pressures and temperatures, there is a gap in experimental techniques and mathematical theories to study liquids as common as water. The new experiment fulfils a very real need for measurements of liquids鈥� properties that can then be used in other experiments, he says.
In the future, the researchers want to get even closer to emulating the insides of planets like Jupiter and Saturn by filling their chamber with liquid hydrogen 鈥� to make things more realistic, they would also have to increase the pressure up to hundreds of times higher.
鈥淭hat is the dream,鈥� says Proctor.
Physics of Fluids
