The change from day to night is primarily caused by the rotation of the Earth on its axis. As the Earth spins, different areas of its surface move into and out of sunlight, creating cycles of day and night.
During the day, when our part of the Earth is facing the Sun, we experience daylight, which allows us to see and engage in activities. As the Earth continues to rotate, our location eventually rotates away from the Sun, resulting in nightfall in that area.
This rotation takes approximately 24 hours to complete a full turn, which is why we typically see day and night last for about 12 hours each. However, this duration can vary with the seasons and our position on the globe.
In summary, day and night are caused by the Earth’s rotation, with the Sun illuminating one side of the planet while the other side remains in darkness.