The sunrise or sun is instant where the upper edge of the Sun appears on the horizon in the morning. This term can also refer to the entire process of the Sun across the horizon and the atmospheric effects that accompany it.
Although the Sun appears to "rise" from the horizon, it is actually the Earth's movement that causes the Sun to emerge. The illusion of the Sun's moving results from Earth observers is within a rotating reference frame; This real movement is so convincing that most cultures have mythology and religion built around geocentric models, which prevailed until astronomer Nicolaus Copernicus first formulated a heliocentric model in the 16th century.