Abstract:  We shall reconsider the pressure within a bubble, when we take into account all the cohesive forces within a liquid, which surrounds a bubble. These principles will be applied to maximum bubble pressure method, providing a new plausible explanation as to why measured bubble’s pressures do not correlate with traditional Young-Laplace based theory. Finally, we shall explain why probes do not measure increased pressures within bulk liquids

 

Conclusions: Traditionally, we do not consider the cohesive forces perpendicular to a tensile, when considering the pressure in liquids, and/or bubbles. Herein, we were able to show: When we consider all the liquid’s net cohesive forces, then we can clearly explain why maximum bubble pressure method (MBPM) consistently measures the pressure of a bubble at values, which are significantly lower than that predicted by the Young-Laplace equation. I.e. a bubble’s pressure is approximately:

Pb=1.64 (@/rb) + Patm

 

Of course the above being the case, then we also need to understand that the liquid’s affinity to pressure gauges/probes will also affect the pressure that we measure within a liquid. Therefore, when we measure a liquid’s pressure, the net result is simply due to the weight of the overlying atmosphere, and liquid.