500
Name the three advantages a reflecting telescope has over a refracting telescope.
1) The mirrors can be very large and allow reflecting telescopes to gather more light than refracting telescopes.
2) Curved mirrors are polished on their curved side, which prevents light from entering the glass-therefore, any flaws in the glass do not affect the light.
3) Mirrors can focus all colors of light to the same focal point, so all colors of light from an object can be seen in focus at the same time.