The sky gives people a broad vision, so that you have endless space to fly your dreams. The sky symbolizes vastness, profundity, freedom and dream. A figure of speech often used as a metaphor for friendship or as a measure. Clouds can symbolize nothingness, sadness, confusion and uncertainty. It can also symbolize purity and change. It depends on white clouds or dark clouds.
People can observe meteorological or astronomical phenomena in the sky, so as to know weather changes, the passage of time or their own position. Sunrise and sunset can tell the time of the day, and the moon's gain and loss can know the time of a month at night. The sky is blue because sunlight is made up of seven kinds of light.