absorption

Definition: (1) Partial loss of light during reflection or transmission. * Light or other radiant energy falling on a material may transfer, and therefore lose, of some energy (usually in form of heat). * Selective absorption of light - i.e. some wavelengths are absorped more than than others - causes phenomenon of colour. * Highly selective absorption is exploited in filters, dyes, colourants, etc. and is central to subtractive methods of colour synthesis. (2) Take up or assimilation of a substance by another e.g. water soaking into paper.

Related Terms: adsorption, unwanted absorption

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