Astronomy Lecture 11
Why do we bother with telescopes?
- What things did Galileo observe when he pointed his telescope upwards
- Venus rotates just the moon, and that Venus is the brightest planet.
What make a good telescope?
- Size of optical components
- An astronomer with 20/20 vision
Refraction: the bending of light
- Refraction is the behind of a ray of light when it passes through into a new medium
- Light can change direction when interacting with matter
- Prism- white light comes in and it spreads out, light is bending. Short wavelength light bends
more than the long wavelength
- Observation of prisms show refraction depends on the wavelength of light; shorter wavelengths
- Newton’s idea
- A ray of light will reflect from a smooth surface at the same angle that it is incident with
- Special property: for parabolic mirrors, rays of light that are parallel converge at the same point
- A primary or objective lens bends light and brings it to a focu