Theory 17/Phase & ice/Liquid-liquid transition
The Second Transition Is a Fluctuation Ratio
The claim
The proposed liquid-liquid transition in supercooled water appears when the ratio of density fluctuation to correlation length exceeds a threshold, which is why it is hard to observe.
01Mechanism
Two liquid structures coexist over a correlation length; the ratio determines whether they separate into phases.
02Prediction
The transition should appear only in confined or fast-quenched samples.
03Refutation
No transition at any correlation length would remove the picture.