Is Water Truly Wet? The answer is more complex than it might first appear.

At first glance, the question of whether water is wet seems straightforward, easily answered by our direct experiences. When caught in the rain without an umbrella, we become drenched—therefore, water must be wet.

However, when considered from a scientific or philosophical standpoint, the question becomes far more puzzling. The answer relies on the properties of water, the definition of wetness, and the extent to which we can trust our senses when determining whether something is wet.

Some suggest that although water can make other substances wet, water itself is not inherently wet. If we define wetness as the ability of a liquid to cling to a solid surface, then wetness becomes an action the liquid performs, not a quality it possesses.

 May the Power of the Forces Be With You

From a scientific viewpoint, an object's wetness depends on the balance between the adhesive and cohesive forces that come into play between liquids and solids. Cohesive forces are what cause molecules in a liquid to cling to each other, while adhesive forces enable liquids to bond with solids. When we fall into water and get soaked, the adhesive forces of our clothes surpass the cohesive forces of the water, making the water adhere to our clothes instead of to itself.

The stronger the adhesive force of a solid, the wetter it becomes. Textiles have greater adhesive forces than metals; most liquids slide right off materials like steel and aluminum. The same applies to the downy feathers of ducks and geese. When they preen, they spread oils from glands near their tails throughout their feathers, which makes their bodies more resistant to water [PDF]. Without this natural waterproofing, water would cling to their feathers, much like it clings to human skin, weighing them down and cooling them off.

The same principle applies to water-resistant or "hydrophobic" materials like Gore-Tex, which have low adhesive forces that cause water molecules to form droplets on the surface, preventing moisture from reaching the inside. Wetsuits, commonly worn by swimmers in cold environments to stay warm, are typically made of neoprene rubber, another hydrophobic material.

On the other hand, wetness also relies on the cohesive forces of a liquid. Water has a high cohesive force due to the strong bond between hydrogen molecules, while liquids like alcohol or acetone have weaker cohesive forces, allowing them to wet solids more effectively. This can come in handy the next time you find yourself caught outside without a raincoat.