Surface Tension - Glass Plates

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Surface tension - "In physics, surface tension is an effect within the surface layer of a liquid that causes the layer to behave as an elastic sheet. It is the effect that allows insects (such as the water strider) to walk on water, and causes capillary action, for example" (1) .

Meniscus - "A meniscus is a curve in the surface of a liquid and is produced in response to the surface of the container or another object" (2).


Why are these glass plates sticking together? The same principle that allow water skimmers to glide on top of water, or causes water to seem to curve up when in a glass tube, are in effect here. Surface tension!


A meniscus is caused by the attraction of water to glass...are you thinking yet? Water is attracted to water (this is why water beads up on smooth surfaces) and water is attracted to glass. When two plates of glass are sandwiched together with a small amount of water in between them (or an oil, such as finger oils - which is the case above), the cohesion is incredibly strong.

Click here to see a high school science experiment with video

1 - "Surface tension", Wikipedia.org, 22 July 2006.
2 - "Meniscus", Wikipedia.org, 30 June 2006.