PHYS 183 Lecture Notes - Lecture 3: Nanometre, Electromagnetic Spectrum, Continuous Spectrum
Document Summary
Astronomy is generally limited to only three types of measurements. Unlike most other sciences: require indirect proxy measurement of physical properties. Three types of astronomical data involve collection of light or photons. Note rarely we also receive actualy samples of matter: lunar, martian, asteroid landers, meteoroids. Newton was also the first perso to show that white light is really a spectrum of many colors. Index of refraction is different for different colors. Light is part wave and part particle called a photon. This dual nature is at the heart of quantum mechanics (beyond this course) There exists a broad range of colors having wavelengths beyond what the eye can see. A color is a certain wavelength and energy (shorter wavelength = higher energy) Wavelength is distance form crest to crest. Can also characterize wave-nature of light by its frequency f (measured in 1/s or hz)