Heijastuva

Heijastuva is a Finnish adjective that describes something that reflects or is capable of reflection. It is formed from the verb heijastua with the participial suffix -va/-vä and is used to describe properties related to reflection of light, sound, or other waves. The term is common in scientific, technical, and everyday contexts when referring to surfaces or phenomena that return part of an incident wave back toward the source.

In physics and optics, heijastuva describes surfaces or objects that reflect radiation rather than absorb or transmit it. Examples include a heijastuva pinta (reflective surface), which can direct light back toward the original direction, and heijastuva valo (reflected light), which has been redirected after striking a surface. The concept is closely related to the noun heijastus (reflection) and to devices such as heijastin (a reflector), which uses reflective properties to improve visibility.

Usage notes on Finnish style: heijastuva tends to refer to the passive property of reflection—what is reflected—while other forms like heijastava can describe agents or processes that cause reflection. In technical writing, the term helps distinguish reflective properties from absorptive or transmissive ones.

Related terms include heijastus (reflection), heijastin (reflector), and heijastava (reflecting, active in producing reflection). Heijastuva thus functions as a concise descriptor of reflective behavior across physical and metaphorical contexts.