Same as how a fly can walk on water. As long as you don’t break the surface (like a flat bottomed glass) it can slide across the water til it hits a dry section of table.
When a glass moves around on a wet table, it’s usually because of a thin layer of water creating less friction between the glass and the surface. The water also forms a bit of suction, and when you bump the glass or there’s even a slight slope on the table, it can glide around pretty easily. It’s like how a puck slides on an air hockey table — just with water instead of air.
It’s quite low friction, as most of the glass’s weight ends up supported by the air trapped inside the glass, rather then on the edges. The water also greatly reduces friction, allowing the glass to ‘wander’ as it’s weight shifts and condtions around it impart a little energy
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It’s surface tension.
https://en.wikipedia.org/wiki/Surface_tension
Same as how a fly can walk on water. As long as you don’t break the surface (like a flat bottomed glass) it can slide across the water til it hits a dry section of table.
When a glass moves around on a wet table, it’s usually because of a thin layer of water creating less friction between the glass and the surface. The water also forms a bit of suction, and when you bump the glass or there’s even a slight slope on the table, it can glide around pretty easily. It’s like how a puck slides on an air hockey table — just with water instead of air.
It’s quite low friction, as most of the glass’s weight ends up supported by the air trapped inside the glass, rather then on the edges. The water also greatly reduces friction, allowing the glass to ‘wander’ as it’s weight shifts and condtions around it impart a little energy