The discussion centers on the relationship between gravity and surface tension, specifically how gravity overcomes surface tension in a scale model of Earth. The Bond number (Eotvos number) is identified as the key metric, representing the ratio of gravitational to interfacial energies. When the Bond number exceeds 1, gravity dominates over surface tension. Participants suggest calculating the Bond number for a given model to determine the critical mass at which gravity prevails.
PREREQUISITESPhysics enthusiasts, educators, and anyone interested in the principles of fluid dynamics and gravitational effects on surface tension.
physnoct said:I want to demonstrate to flat earthers...
physnoct said:I want to demonstrate to flat earthers that water does indeed stick to a ball. If we want to do a scale model of the earth, at which radius will gravity overcome the surface tension?
For FEers, maybe. The question itself is worth an answer, as it is an interesting physics challenge and I would like to know the answer.CWatters said:That would be a waste of time.
That's a good start! I'll check that. Thanks!Andy Resnick said:The Bond number (Eotvos number) is the ratio of gravitational and interfacial energies: when the Bond number is high, gravity dominates and vice-versa. So all you need to do is write down the Bond number for your scale model and determine what the critical value of 'planetary' mass is (when Bo = 1)
Is there a formula that I can use?CWatters said:Put a drinking straw into a glass of water and the water will rise up the straw until gravity "overcomes" surface tension.