Reason for the Sun appearing red at sunset and sunrise:

Scattering of sunlight:
- During sunset and sunrise, the sunlight has to pass through a thicker layer of the Earth's atmosphere.
- The Earth's atmosphere scatters shorter-wavelength light (blue and violet) more than longer-wavelength light (red, orange, and yellow).
- As a result, the shorter-wavelength light is scattered out of our line of sight, leaving behind the longer-wavelength light to reach our eyes.

Effect on the color of the Sun:
- The scattering of shorter-wavelength light causes the colors of the sky to change.
- Since the shorter-wavelength colors are scattered out, the sky appears red, orange, or pink during sunset and sunrise.
- The Sun, being a bright light source, also appears redder because the shorter-wavelength light has been scattered away, leaving only the longer-wavelength light to reach our eyes.

Angle of sunlight:
- During sunset and sunrise, the sunlight has to travel through a larger portion of the Earth's atmosphere at an angle.
- This increases the distance that light has to travel through the atmosphere, leading to more scattering of shorter-wavelength light.
- The longer path through the atmosphere at these times results in the Sun appearing larger and the light appearing redder.
In conclusion, the Sun appears red at the time of sunset and sunrise due to the scattering of shorter-wavelength light by the Earth's atmosphere, leaving behind longer-wavelength light to reach our eyes.