Researchers from University College London and the University of Cambridge have discovered a new type of ice that looks more like liquid water than any other known ice and could revolutionize our understanding of water and its many anomalies. The newly discovered ice is amorphous, meaning its molecules are in an irregular shape rather than in an orderly arrangement as in normal crystalline ice.

Amorphous ice, although rare on Earth, is the main type of ice found in space. This is because in the colder environment of space, ice does not have enough thermal energy to form crystals. For the study, published in the journal Science, the research team used a process called a ball mill, which vigorously shakes steel balls with regular ice in a jar cooled to -200 degrees Celsius.

They discovered that instead of producing small chunks of ordinary ice, the process produces a new form of amorphous ice that, unlike all other known ice, has the same density as liquid water and is similar to solid water. They named the new ice medium density amorphous ice (MDA).

The team hypothesized that MDA (which looks like a fine white powder) might exist on the icy moons of the outer solar system because tidal forces from gas giants like Jupiter and Saturn could exert shear forces on normal ice similar to those created by global ice. The team also found that when MDA is heated and recrystallized, it releases an extraordinary amount of heat, meaning it can trigger tectonic movements and “ice earthquakes” in miles of ice sheet on Jupiter’s moons like Ganymede.

“We know of 20 forms of crystalline ice, but only two main types of amorphous ice have been identified previously, known as high-density amorphous ice and low-density amorphous ice. There is a huge density difference between them, and the consensus is that there is no ice in this space. “It shows that the density of Earth is precisely within this density gap, and that this discovery could have far-reaching implications for our understanding of liquid water and its many anomalies.”

The difference in density between the known amorphous ices led scientists to propose that water actually exists as two liquids at very low temperatures, and that two liquids could theoretically coexist at a given temperature, with one type floating on top of the other, like mixing. oil and water. This hypothesis has been demonstrated in computer simulations but not confirmed by experiment. The researchers say their new study may cast doubt on the plausibility of this idea.

Professor Salzmann said: “Existing models of water should be reexamined. They should be able to explain the presence of moderate density amorphous ice. This could be the starting point for a definitive description of liquid water.” The researchers hypothesized that the newly discovered ice could be a true glassy state of liquid water, an exact replica of liquid water in a solid state, just as the glass in windows is a solid form of liquid silicon dioxide. However, another scenario is that MDA is not glassy at all, but in strongly fragmented crystalline form.

Co-author Professor Andrea Sella (UCL Chemistry) said: “We’ve shown that it’s possible to create what looks like stop motion. It’s an unexpected and quite surprising discovery.” D., who conducted the experiments while working at the UCL University of Chemistry. Alexander Rosu-Finsen said, “We shook the ice like crazy for a long time and disrupted the crystal structure. We realized that instead of ending up with smaller chunks of ice, we found a whole new kind of thing with some great properties.”

The team also created a computational model of MDA by simulating the ball milling procedure using repeated random cutting of crystal ice. Performing computational simulations as a PhD student in the ICE (Interfaces, Catalytic and Environment) Laboratory at UCL and Cambridge University, Dr. it is therefore very important to understand the exact atomic structure of MDA.