3 ms·

Best answer I ever heard was "because it's sticky".

• alejohausner 11y ago
  Nice idea, but I doesn't really do justice to wetting, I think. First of all, water doesn't stick to everything: some materials are hydrophobic, and as Saykally points out, it's that dual ability to attract some parts of molecules and repel others that makes water necessary for life on Earth. That's how cell membranes form spontaneously: long skinny lipid molecules gather into sheets with their hydrophilic ends facing out towards water and their hydrophobic ends facing inward. Second, all viscous fluids are sticky, in the sense that their flow is slowed where they touch stationary surfaces. This boundary phenomenon is responsible for the Coanda effect. Have you ever touched a spoon to the stream of water coming out of the kitchen tap, and watched the water change course towards the spoon?
• agumonkey 11y ago
  It's a blend of something that adheres to you but doesn't stick (easy to remove, or even let it evaporates), diffuses heat and toy with light (shines, magnify, refract...). All this makes wet wet.