Arthur T Knackerbracket has processed the following story:
A new kind of "phase transition" in water was first proposed 30 years ago in a study by researchers from Boston University. Because the transition has been predicted to occur at supercooled conditions, however, confirming its existence has been a challenge. That's because at these low temperatures, water really does not want to be a liquid, instead it wants to rapidly become ice. Because of its hidden status, much is still unknown about this liquid-liquid phase transition, unlike the everyday examples of phase transitions in water between a solid or vapor phase and a liquid phase.
This new evidence, published in Nature Physics, represents a significant step forward in confirming the idea of a liquid-liquid phase transition first proposed in 1992. Francesco Sciortino, now a professor at Sapienza Università di Roma, was a member of the original research team at Boston University and is also a co-author of this paper.
The team has used computer simulations to help explain what features distinguish the two liquids at the microscopic level. They found that the water molecules in the high-density liquid form arrangements that are considered to be "topologically complex," such as a trefoil knot (think of the molecules arranged in such a way that they resemble a pretzel) or a Hopf link (think of two links in a steel chain). The molecules in the high-density liquid are thus said to be entangled.
[...] "First, their elegant and experimentally amenable colloidal model for water opens entirely new perspectives for large-scale studies of liquids. Beyond this, they give very strong evidence that phase transitions that may be elusive to traditional analysis of the local structure of liquids are instead readily picked up by tracking the knots and links in the bond network of the liquid.
More information:
Andreas Neophytou, Dwaipayan Chakrabarti, Francesco Sciortino. Topological nature of the liquid–liquid phase transition in tetrahedral liquids, Nature Physics (2022). DOI: 10.1038/s41567-022-01698-6
Journal information: Nature Physics
(Score: 3, Interesting) by krishnoid on Tuesday August 23 2022, @04:59AM (2 children)
Or is it even a 2D graph [ergodic.ugr.es] under these conditions?
(Score: 2, Interesting) by khallow on Tuesday August 23 2022, @05:15AM (1 child)
Being a supercooled liquid is not a preferred state. And by necessity, to get to that tricky state the past state of the liquid has to be cooled from a state where liquid is normal to one where it is not.
(Score: 0) by Anonymous Coward on Tuesday August 23 2022, @02:07PM
From memory, I think I've seen some phase diagrams where dotted lines were used to indicate states that required some dynamics or history to achieve? Again, distant memory, this could be supercooling under special conditions (no vibration, no nucleation sites), to avoid crystallization below the normal freezing point.
(Score: 3, Insightful) by soylentnewsfan1 on Tuesday August 23 2022, @12:33PM (2 children)
While simulations are useful as the article states to help determine which physical evidence of a phenomenon to look for, they are not evidence of a physical phenomenon, they are at best approximations and can be in error. The publicist at the University of Birmingham should of known better, even in the scientist whey they are quoted knows to separate the categories by saying "experimental and computational evidence", and though the scientist later says "strong evidence" it is clear from the context that they are implying computational and not conclusive evidence of this occurring in reality.
There is a very strong possibility this does happen in water, our simulations are incredible these days, there are some physical experiments are hinting that it does, but it is not confirmed, the evidence so far is not unmistakable, and we do not yet live in The Matrix, Tron, Reboot, Vanilla Sky, or any other computer world.
(Score: 1, Interesting) by Anonymous Coward on Tuesday August 23 2022, @08:52PM (1 child)
What I enjoyed out of this paper was that it makes use of knot theory. They even describe using a python package that is designed to tell you if something is knotted and if so, what kind of knot it is. The mathematician in me smiled at that.
(Score: 1) by khallow on Wednesday August 24 2022, @11:58AM
I was feeling a bit contrary at first since you can have writhe on an oriented ring (such as a Moebius strip [wikipedia.org] or double twisted strip [github.io] neither which is convertible to the zero twist strip).
(Score: 0) by Anonymous Coward on Tuesday August 23 2022, @03:11PM
See also: https://www.sciencealert.com/physicists-just-discovered-a-second-state-of-liquid-water [sciencealert.com]
(Score: 2) by acid andy on Tuesday August 23 2022, @03:15PM (1 child)
I ordered a glass of water, but you brought me the wrong liquid!
Yes I know it's water, that's what I asked for, I just wanted a different liquid. Bring me a different liquiid! Of water.
Master of the science of the art of the science of art.
(Score: 1) by khallow on Wednesday August 24 2022, @12:00PM
(Score: 2) by Sourcery42 on Tuesday August 23 2022, @04:52PM
Do you want ice-nine? Because this is how you get ice-nine.