He showed that light striking a metal surface releases electrons from the metal with violet light producing more energetic electrons than red light. He showed that light passing through two narrow, closely spaced slits produces a pattern of dark and light bands on a screen by wave interference. He showed that the speed of light decreases when it enters a denser, transparent medium. He showed that the speed of light in a vacuum is the same for all observers.
Angular resolution depends only on the diameter of the telescope and is independent of wavelength.
The Sun would not rise or set because Venus rotates synchronously, always keeping one side toward the Sun. It would rise in the north because Venus has a spin axis parallel to the plane of its orbit. Earth and Mars possess two properties in which they are very similar. It has geyser-like plumes of nitrogen gas. The total mass of all asteroids is much smaller than the mass of the Earth.