Assertion: radiance's power | /r/HasProperty | constant
Facets:
Source sentences:
text: If a point radiation source emits radiation uniformly in all directions and there is no absorption, then the irradiance drops off in proportion to the distance squared from the source, since the total power is constant and it is spread over an area that increases with the distance squared from the radiation source.
text: squared, since the total power is constant and it is spread over an area that increases with the square of the distance from the source.