Why Water Is Wet

The word "wet" is a technical term. If you spray a water repellent like Scotchgard on your clothes, they will become hydrophobic, and water won't cling to the cloth, nor penetrate its surface. In other words, hydrophobic materials are hard to wet. Waxy surfaces are also hard to wet. See "wetting" on wikipedia (not to be confused with nocturnal enuresis ;-).

Wetting is a verb. Maybe the title should have read "Daddy? Why does water wet?" That might have resolved the confusion, at the risk of angering grammatical pedants.

> “Daddy? Why is water wet?” And the proper answer is: strong tetrahedral hydrogen bonding, which they then related to their teachers for years afterward whenever the subject of water came, they’d say, “Strong tetrahedral hydrogen bonding!” But that’s the correct answer. That’s what makes water wet. I think this answer the HOW water is wet question not the WHY water is water question.

Nothing is actually true by definition. That's a very sloppy cop-out.

I certainly don't know the answer to your question, but I believe you not only feel the difference in temperature, but also the fact that water is a better conductor of heat and will draw the heat from your body better than the air - and that difference in heat transfer is one of the things you "feel".

I forget what they are called, but I have heard of places that immerse you in total darkness and total silence and have you float in water that is the same as your skins temperature so that you feel like you are floating in nothingness. I never went but want to try it sometime. So I cannot say if it works or not but at least according to these places you would not feel the water. I wish I could remember what they were called. We have one here in Atlanta.

EDIT: found it based on SCHiM's comment: http://flo2s.com/floating/what-is-a-float-tank/

At least skin hair will act differently when immersed in water so I'd expect that you will notice a difference for body parts immersed in water.

We don't have any receptors that detect water, so it's the combination of temperature (cold from evaporation) and tactile properties.

I believe some frogs do have such receptors: http://booksandjournals.brillonline.com/content/journals/10....

>Can we actually feel wetness or only the temperature difference of wet vs dry?

In my experience if you put your hand in water with similar temperature to your hand it's hard to notice if there is any water there or you are just still touching air. You have to rule out other senses to make this work.

If these things are any indication [0]. Then no.

[0] https://en.wikipedia.org/wiki/Isolation_tank

I believe the viscosity difference would give you a hint.

The professor disagrees with you:

"When water freezes into ordinary ice, which is the kind that makes the ice cubes that float in our highballs, this happens at what we would call zero degrees centigrade, at atmospheric pressure. When water freezes into ice it creates a very open structure. That form of ice comprises arrays of six membered rings that are stacked on top of one another to make channels and most of that ice is actually empty space."

The strength of hydrogen bonding in the original answer refers to the strength relative to other kinds of molecules. It is kind of implicit in the question that we are at room temperature, or more precisely a state where water is liquid.

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?

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.