[007]

Does anyone know why when you put a swatch of cheesecloth over a cup, you can pour water through the holes, but water won't come through the holes the oposite way?

Thanks

[007]

 Liquid can pour through cheesecloth holes one way, but not the other. Does anyone know the secret of the one way holes?

[Yggdrasil]

It's probably not the cheesecloth that's doing it, but the surface tension of water since breaking the surface tension of water is necessary to get water to go through the holes in the cheesecloth.  So gravity is strong enough to force a large mass of water through the cheesecloth's holes, but the weight of the cheesecloth is not great enough to force the cheesecloth down into the water.