Researchers have made a groundbreaking discovery in the world of ice. They have found a new form of ice that is amorphous, meaning it lacks a neatly organized crystal structure. This new type of ice, known as medium-density amorphous ice (MDA), could provide insights into the mysteries of liquid water.
Prior to this discovery, scientists were aware of two types of amorphous ice: high-density and low-density. But there was a gap in understanding how to create MDA. However, when a team led by Christoph Salzmann at University College London placed regular ice, which has a hexagonal crystal structure, in a tumbler with steel ball bearings cooled to -200°C (-328°F), the jostling created the desired MDA.
The researchers were surprised by the results, as they initially expected the ice to simply break down into smaller pieces. Instead, they obtained a fine white powder with a density that fell between the other two known forms of amorphous ice. Remarkably, the density of this MDA was almost identical to that of liquid water.
This led the researchers to propose that MDA could be a water-like substance in a glass phase. The glass phase is a type of matter that retains liquid-like behaviors even at extremely low temperatures. On short timescales, a glass may appear solid, but over longer timescales, it flows like a viscous liquid.
Understanding the properties of liquid water at extremely low temperatures is a topic of great interest in scientific research. Previous studies have suggested the existence of two different liquid phases in supercooled water, with one phase floating atop the other. However, the discovery of MDA raises questions about this hypothesis.
The researchers believe that figuring out the nature of MDA will significantly enhance our understanding of liquid water. Additionally, MDA may play a crucial role in the icy moons of the outer solar system. These celestial bodies experience intense shear forces due to the gravitational pull of their host planets, creating favorable conditions for MDA formation. Furthermore, the researchers observed that when this ice was warmed up, it released an extraordinary amount of heat, suggesting its potential involvement in the geological activity of these icy moons.
Data Section:
Researcher: Christoph Salzmann
Institution: University College London
Ice Formation Method: Collision of steel ball bearings with regular ice
Temperature: -200°C (-328°F)
Resulting Ice Type: Medium-density amorphous ice (MDA)
