After viewing YouTube videos of people chilling water in a bottle and then freezing to death, something solidified for Matthew M. Szydagis, assistant professor of physics at the University of Albany at New York State University especially when he saw her again during the Disney movie "Frozen".
During the American Physical Society 201
Wenn water clean enough – little impurities such as dust particles – and placed According Szydagis, the container in refrigerate a sufficiently smooth container without freezing below the freezing point of 0 ° C.
"This is referred to as" subcooling "and is similar to that of water that can be slightly overheated in the microwave heated substantially above its boiling point, without actually It's just the opposite, "he said." In both cases, the water ends up in a state called "metastability," neither unstable nor quite stable . "
In this case, a perturbation can trigger phase transition, freezing, and crystallization. "This is not an ordinary freezing and white snow is forming instead of clear ice," he added. "In our laboratory, we cooled liquid water to -20 ° C without freezing it, and it's not the same thing as lowering the freezing point, like salting your sidewalk, because the water was pure and did not purposely contaminate with impurities."  The group showed that certain forms of particles that hit the water can freeze microscopically (subatomically) when first subcooled. "Some particles, such as neutrons, can even disperse in the water several times," Szydagis said. "We were able to show this not only with commercially available particle sources, but also with a radioactive red 'Fiestaware plate' with orange-colored uranium-based paint from the 1950s."
They created a new detector based on supercooled water. It's called the "snowball chamber" because it fits in well with "bubble" and "cloud" chambers, which are technologies from the early to mid-20th century that use cooking and condensation.
Subcooled water is certainly not new; It has been studied for decades by chemists and physicists of condensed matter down to -40 ° C. There are even more than 100 years old releases about it.
"However, we have discovered a new property of subcooled water," said Szydagis. "To our great surprise, we found that some particles (neutrons), others (gamma rays) do not cause freezing, because this is basic research that has never been done before, there was no guarantee that it would work Try it and see '- the scientific method in its most basic form. We not only have a new detector for fundamental particles, but possibly also for dark matter, because we believe that neutrons mimic them. " The group sees many other potential implications for their discovery, including finding nuclear weapons in the cargo for the security of the homeland, understanding cloud formation, and pointing out how certain species of mammals hibernate and somehow overcool their blood.
Deformation of the waterdrop surface can increase the likelihood of the drops freezing
The presentation, "The Snowball Room: Using Chilled Water to Find Lesser Matter of Dark Matter," took place on Sunday, April 14, at Governor's Square 11 at the Sheraton Denver Downtown Hotel. Summary: meetings.aps.org/Meeting/APR19/Session/J09.8
"Snowball Chamber" Helps Researchers Find Dark Matter with Undercooled Water (2019, April 15)
retrieved on April 15, 2019
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