The blue hour is the period of twilight each morning and evening when the sun is a significant distance below the horizon and the residual, indirect sunlight takes on a predominantly blue hue. This effect is caused by the relative diffusability of short blue wavelengths of light versus the longer red wavelengths. During the blue “hour” (typically the period is about 40 minutes in length), red light passes straight into space while blue light is scattered in the atmosphere and therefore reaches the earth’s surface. Because of the quality of the light, this period is treasured by artists . . . .
The blue hour is famous for its romantic connotations, particularly in the arts. A colloquial French saying dictates that the blue hour is a time of confusion and mystery, since it is impossible to determine whether it is really night or day.
Mr. Violin sheds light on curious facts about Brazil – but he also touches on issues that somehow connect Brazilians to world topics, making his audioblog an invaluable link between South America’s powerhouse and the rest of the globe.