How do astronomers gather light?
Eyes: No permanent record, limited wavelength range, can’t see small details, can’t analyze wavelength.
Telescopes: Bigger than the eye
- Gather more light (proportional to D2)
- Higher resolving power (proportional to ?/D)
- Can be made at wavelengths from gamma rays to the radio.
- Can collect data with electronic detectors for analysis (CCDs, film, etc.)