World Water Day is observed on 22 March annually to raise awareness about the importance of freshwater and the sustainable management of water resources. It promotes global water conservation efforts.

The United Nations declared 2019 as the International Year of Indigenous Languages to raise awareness about the critical loss of indigenous languages and promote their preservation, revitalization, and support for cultural diversity.

The angle between the normal and the reflected ray is known as the angle of reflection. According to the law of reflection, this angle is equal to the angle of incidence at the surface.

The splitting of light into its component colors is called dispersion. This phenomenon occurs when light passes through a prism, separating it into colors like red, orange, yellow, green, blue, and violet.

In the optic nerve, cones are sensitive to bright light and responsible for color vision, while rods are sensitive to dim light, aiding in night vision and detecting motion.

On New Moon Day, the moon is positioned between the Earth and the Sun, resulting in the moon's illuminated side facing away from Earth, making it virtually invisible in the night sky.