Pronunciation: [blˈuː ˈa͡ʊ͡ə] (IPA) 
The term "blue hour" refers to a period of time, usually occurring at dawn or dusk, when the sky takes on a deep blue hue. Its spelling is straightforward: the first word, "blue," is spelled with a long "u" sound and an "e" at the end to indicate a silent "e" sound. The second word, "hour," is spelled with a silent "h" and a long "o" sound. In IPA phonetic transcription, "blue" would be written as /blu/ and "hour" as /aʊr/.
Blue hour refers to the period of twilight before sunrise or after sunset, when the sky takes on a distinct blue hue. It is a time characterized by a unique quality of light that creates a serene and tranquil atmosphere. The duration of the blue hour can vary depending on the geographical location and time of year, typically lasting for about 20 to 30 minutes. The phenomenon gets its name from the predominant color of the sky during this time, which appears in various shades of blue, ranging from deep navy to a lighter, more faint tone.
During the blue hour, the sun is positioned just below the horizon, resulting in indirect illumination of the atmosphere. This creates a soft, diffused light that bathes the surroundings, offering a peaceful and ethereal ambiance. The blue hour is often cherished by photographers and artists, as it presents a unique opportunity to capture breathtaking scenes with a captivating blue backdrop. The contrast between the blue sky and artificial lights, such as city lights or the glow of street lamps, adds to the beauty and allure of this picturesque time.
The blue hour has also held cultural significance throughout history. It is often associated with a sense of tranquility, contemplation, and reflection. The calming nature of the blue hour has been explored in literature, art, and poetry, symbolizing a time of magic and mystery. Many photographers and nature enthusiasts also make the most of this time to observe the fleeting beauty of the natural world and appreciate the quiet stillness that accompanies it.
The term "blue hour" originated from the French phrase "l'heure bleue". It was first used by the French poet and essayist, Charles Baudelaire, in his collection of poems called "Les Fleurs du mal" (The Flowers of Evil), published in 1857. Baudelaire used the term to describe the particular quality of light at dawn or dusk, when the sky appears tinged with a bluish hue. The term later gained popularity as a poetic and artistic expression and has since been widely used to describe that period of time after sunset or before sunrise when the sky has a distinct blue color.
