The most interesting period of the 24 hours we call a day, for me, is the transition from day to night. Surprisingly, this is something that can be captured in a photograph. The blue sky of day first turns pink (as seen above) in twlight before sinking to complete black at night. What if the Earth always faced the sun as the Moon always faces the Earth? What type of creatures would have evolved on a world with constant sunlight? Everything on Earth is so cyclical. I wonder about a world where everything is constant.