TENSION

News media tend to report frequent instances of tension in the world--whether tension between countries or political groups or in businesses, schools or even families. Such tension is not necessarily beneficial or good.

There is tension in water, too--a physical phenomenon called "surface tension." Because water molecules are more attractive to each other than to other molecules. water molecules are forced inward so as to contract water surfaces.

Surface tension enables me to carry my morning full cup of coffee from the kitchen to another room without disaster to flooring and furniture and causing serious spousal tension. Other examples of surface tension include beading of rain drops on leaves, slow drops of water from a leaky faucet that should have been repaired long ago, and the ability of insects literally to walk on a pond surface util grabbed by a frog or a fish.

Now, Yale engineers have discovered that surface tension of a liquid can strengthen a solid.* Ordinarily, substituting some liquid particles for particles of a solid can be expected to weaken the solid. However, researchers have discovered that, if the embedded liquid drops are sufficiently small, their surface tension creates a stiffness in the liquid that makes the solid more strong. Using silicone as a solid, the embedded liquid made it up to 30% stronger, it was reported.

Apparently, size does matter in the case of surface tension--the smaller the better.

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*McCray, "Engineers Use Liquid Drops To
Make Solids Stiffer", Yale News,
December 15, 2014.