question: why some things get wet and others don't?
comment: "Wetting" is a specific type of chemical interaction between a liquid and a surface. It is **not** soaking, where a fabric like a cotton shirt absorbs the water. Wetting is the ability for a liquid to spread out over the surface of a material, getting very thin and not clumping up into droplets. A surface will wet because the adhesive force between it and the liquid is stronger than the liquid's surface tension. If the liquid "wants" to interact with the solid more than it wants to interact with itself, it'll spread out to maximize that liquid/solid interaction, and become wetness. If the liquid wants to interact with itself more, it'll stay clumped into droplets and wet partially or not at all. Things get more complicated when a surface is bumpy on a microscopic level, but this is the basic idea. Wetting varies from liquid to liquid and surface to surface. Most glass gets partially wet, with fairly-flat droplets; however, gallium, a metal which is liquid at 30C/85F, will wet glass completely until there are no droplets left. Neither material can wet paper very effectively, but paper will absorb water, whereas metallic gallium is not absorbed by paper at all.
passages: Section::::DRY vs WET solutions.
   Section::::Non-ideal rough solid surfaces.:Cassie–Baxter model.:"Petal effect" vs. "lotus effect".
   Section::::Methods.
  
  Section::::Methods.:Qualitative Methods.
  
  Qualitative methods use changes in information that cannot be quantified to detect a change. This can include a change in color, smell, texture, etc.
  
  Section::::Methods.:Qualitative Methods.:Chemical Tests.
   Section::::Methods.:Quantitative Methods.:Volumetric Analysis.
   Section::::Process.
   Wet
  
  Wet usually refers to:
  
  BULLET::::- Moisture, the condition of containing liquid or being covered or saturated in liquid
  
  BULLET::::- Wetting (or wetness), a measure of how well a liquid sticks to a solid rather than forming a sphere on the surface
  
  Wet or WET may also refer to:
  
  Section::::Arts and entertainment.
  
  Section::::Arts and entertainment.:Games.
  
  BULLET::::- "Wet" (video game), a 2009 video game
  
  BULLET::::- "", a 2003 video game
  
  BULLET::::- "", also titled "Wet: The Sexy Empire", a 1998 computer game
  
  Section::::Arts and entertainment.:Music.
  
  BULLET::::- Wet (band)
  
  BULLET::::- "Wet" (album), by Barbra Streisand
  
  BULLET::::- "Wet" (Nicole Scherzinger song)
   Section::::Physical properties.:Water, ice, and vapor.:Density of saltwater and ice.
   BULLET::::- By change in electrical resistance between two metal conductors in an alternate finger or double spiral configuration on a flat surface, either flat or cylindrical. The conductors are usually gold plated for corrosion resistance. An issue with this method is that measurements depend on droplets being large enough to bridge the gap between the conductors. A surface coating of for instance hygroscopic latex paint may be applied for more consistent results. Resistance measurement is often by alternating current excitation.
   The surface tension of a liquid directly affects its wettability. Most common liquids have tensions ranging in the tens of mJ/m, so droplets of oil, water, or glue can easily merge and adhere to other surfaces, whereas liquid metals such as mercury may have tensions ranging in the hundreds of mJ/m, thus droplets do not combine easily and surfaces may only wet under specific conditions. 
  
  The surface tensions of common liquids occupy a relatively narrow range of values, which contrasts strongly with the enormous variation seen in other mechanical properties, such as viscosity.
  
  Section::::Mechanical properties.:Flow.
   Here γ is the Cassie–Baxter surface tension between liquid and vapor, the γ is the solid vapor surface tension of every component and γ is the solid liquid surface tension of every component. A case that is worth mentioning is when the liquid drop is placed on the substrate and creates small air pockets underneath it. This case for a two-component system is denoted by:
   Section::::Non-ideal rough solid surfaces.:Cassie–Baxter model.:Precursor film.
   Wet gas is a particularly important concept in the field of flow measurement, as the varying densities of the constituent material present a significant problem.
   Section::::Classification and uses.:Earth and agricultural sciences.
  
  In soil science, hydrology and agricultural sciences, water content has an important role for groundwater recharge, agriculture, and soil chemistry. Many recent scientific research efforts have aimed toward a predictive-understanding of water content over space and time. Observations have revealed generally that spatial variance in water content tends to increase as overall wetness increases in semiarid regions, to decrease as overall wetness increases in humid regions, and to peak under intermediate wetness conditions in temperate regions .
   Section::::Water on Earth.
  
  Most water is found in one or another natural kind of body of water.
  
  Section::::Water on Earth.:Oceans.
   Section::::Physical properties.:Water, ice, and vapor.:Miscibility and condensation.
  
  Water is miscible with many liquids, including ethanol in all proportions. Water and most oils are immiscible usually forming layers according to increasing density from the top. This can be predicted by comparing the polarity. Water being a relatively polar compound will tend to be miscible with liquids of high polarity such as ethanol and acetone, whereas compounds with low polarity will tend to be immiscible and poorly soluble such as with hydrocarbons.
   The central theme of hydrology is that water circulates throughout the Earth through different pathways and at different rates. The most vivid image of this is in the evaporation of water from the ocean, which forms clouds. These clouds drift over the land and produce rain. The rainwater flows into lakes, rivers, or aquifers. The water in lakes, rivers, and aquifers then either evaporates back to the atmosphere or eventually flows back to the ocean, completing a cycle. Water changes its state of being several times throughout this cycle.
   Aristotle wrote in Metaphysics, "Thales, the founder of this school of philosophy, says the permanent entity is water (which is why he also propounded that the earth floats on water). Presumably he derived this assumption from seeing that the nutriment of everything is moist, and that heat itself is generated from moisture and depends upon it for its existence (and that from which a thing is generated is always its first principle). He derived his assumption, then, from this; and also from the fact that the seeds of everything have a moist nature, whereas water is the first principle of the nature of moist things."
   The table shows some calculated values of this effect for water at different drop sizes:
  
  The effect becomes clear for very small drop sizes, as a drop of 1 nm radius has about 100 molecules inside, which is a quantity small enough to require a quantum mechanics analysis.
  
  Section::::Surface tension of water and of seawater.
  
  The two most abundant liquids on the Earth are fresh water and seawater. This section gives correlations of reference data for the surface tension of both.
  
  Section::::Surface tension of water and of seawater.:Surface tension of water.
   One of the important areas of hydrology is the interchange between rivers and aquifers. Groundwater/surface water interactions in streams and aquifers can be complex and the direction of net water flux (into surface water or into the aquifer) may vary spatially along a stream channel and over time at any particular location, depending on the relationship between stream stage and groundwater levels.
  
  Section::::Themes.:Precipitation and evaporation.
   Moisture
  
  Moisture is the presence of a liquid, especially water, often in trace amounts. Small amounts of water may be found, for example, in the air (humidity), in foods, and in various commercial products. Moisture also refers to the amount of water vapour present in the air.
  
  Section::::Moisture control in products.
   Section::::Discovery.
   Wet chemistry techniques can be used for qualitative chemical measurements, such as changes in color (colorimetry), but often involves more quantitative chemical measurements, using methods such as gravimetry and titrimetry. Some uses for wet chemistry include tests for:
  
  BULLET::::- pH (acidity, alkalinity)
  
  BULLET::::- concentration
  
  BULLET::::- conductivity (Specific Conductance)
  
  BULLET::::- cloud point (nonionic surfactants)
  
  BULLET::::- hardness
  
  BULLET::::- melting point
  
  BULLET::::- solids or dissolved solids
  
  BULLET::::- salinity
  
  BULLET::::- specific gravity
  
  BULLET::::- density
  
  BULLET::::- turbidity
  
  BULLET::::- viscosity
  
  BULLET::::- moisture (Karl Fischer titration)
   Section::::Methods.:Colorimetry.
  
  Colorimetry is a unique method since it has both qualitative and quantitative properties. Its qualitative analysis involves recording color changes to indicate a change has occurred. This can be a change in shading of the color or a change into a completely different color. The quantitative aspect involves sensory equipment that can measure the wavelength of colors. Changes in wavelengths can be precisely measured and help indicate changes.
  
  Section::::Uses.
   Section::::Implementation and operation.:Operation technique.
   Many materials which we encounter during the day are dispersed media. For example, milk consists of oil drops dispersed in water, fog contains tiny water drops dispersed in air, shaving cream contains bubbles dispersed in a liquid, sand consists of solid grains in air and a kitchen sponge of bubbles dispersed in a solid.
  
presuppositions: Wetting is the same as absorption.  Some things don't get wet.
corrections: Wetting does not mean absorption.  Everything gets wet in varying degrees.
raw_presuppositions: Wetting is the same as absorption.  Some things don't get wet. Some things don't get wet.
raw_corrections: Wetting does not mean absorption.  Everything gets wet in varying degrees. Everything gets wet in varying degrees.