[Paper Review] "Autothixotropy" of Water - an Unknown Physical Phenomenon

Bohumil Vybíral, Pavel Voráček|ArXiv.org|Jul 9, 2003

Experimental and Theoretical Physics Studies3 citations

TL;DR

The paper proposes that water exhibits a previously unknown phenomenon called autothixotropy—where water develops transient, structured networks of hydrogen-bonded molecules that resist shear and exhibit memory-like behavior. This leads to anomalous mechanical resistance in suspended objects, explained by ephemeric polymerization of water molecules into fragile, elastic networks that form more readily in deaerated, still water, with critical rotation angles increasing over time and depending on immersion conditions.

ABSTRACT

A complex of until now unknown phenomena ongoing in water was discovered in laboratory experiments, where it made impossible gravimetric measurements with the necessarily extreme precision. This behaviour of water, which we call autothixotropy, was the issue of the presented experimental research. We are also proposing a possible explanation.

Motivation & Objective

• To investigate unexplained anomalies in high-precision gravimetric measurements involving water.
• To understand the origin of persistent mechanical resistance in water-suspended systems after prolonged rest.
• To explore whether water can develop transient, structured networks with memory-like properties.
• To determine the influence of water treatment (e.g., boiling, deaeration) and immersion geometry on these effects.
• To propose a physical mechanism—ephemeric polymerization—for the observed phenomena.

Proposed method

• Reconstructed a high-precision torsion balance setup with a fine phosphor-bronze filament and a stainless steel plate suspended in distilled, air-free water.
• Conducted long-duration experiments (days to weeks) with the system at rest to observe mechanical response to controlled rotation.
• Varied experimental conditions: complete vs. partial immersion, use of fresh vs. previously rested/deaerated water, and post-rest stirring.
• Measured critical rotation angles at which the suspended plate abruptly repositioned, indicating a threshold in resistance.
• Observed and recorded time-dependent behavior of the critical angle and damping of oscillations.
• Proposed a hypothesis involving transient, dynamic networks of hydrogen-bonded water molecules (ephemeric polymerization) to explain the observations.

Experimental results

Research questions

• RQ1 Why does a suspended plate in still water resist rotation and only release at a critical angle that increases over time?
• RQ2 What causes the observed time-dependent increase in the critical rotation angle after prolonged rest?
• RQ3 Why is the phenomenon more pronounced in deaerated (boiled) water compared to fresh water?
• RQ4 How does partial immersion affect the mechanical resistance and critical angle compared to full immersion?
• RQ5 What physical mechanism could explain the transient, memory-like behavior of water under these conditions?

Key findings

• The critical rotation angle at which the plate abruptly repositions increases from near zero to several tens of degrees over days of rest, indicating a time-dependent structural evolution in water.
• The phenomenon is significantly stronger and appears earlier in deaerated water, suggesting dissolved gases inhibit the formation of transient networks.
• Partial immersion leads to a higher critical angle and more prominent quick rotation than full immersion, indicating surface effects or interfacial tension play a role.
• Stirring previously rested water accelerates the re-establishment of the resistance effect, implying partial preservation of the transient network structure.
• The system exhibits damped oscillations around new equilibrium positions after mechanical pulses, indicating elastic-like behavior of the water structure.
• The observed phenomena are absent when a rotating cylinder is used instead of a flat plate, suggesting the effect is sensitive to geometry and shear stress distribution.