Why do smooth, glossy surfaces feel sticky to the touch but a slightly textured surface does not?
In: Physics
“smooth” is very relative, based on what light our eyes can perceive reflecting off the surface. Glass, for instance, is full of ridges and valleys if you zoom in far enough. Our fingers are also full of these ridges, visible as finger prints.
Every two surfaces in the universe interact uniquely when in contact with one another, and we quantify this with a derived constant, called the coefficient of friction. Without zooming in too far for this explanation, your finger experiences more friction when in contact with glass or another “smooth” surface, likely because there is more contact between the tiny ridges. The stickiness you’re feeling is most likely just friction.
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