AST101H1 Chapter Notes - Chapter 5: Electromagnetic Radiation, Atomic Number, Spectroscopy

• School: UTSG
• Department: Astronomy & Astrophysics
• Course: AST101H1
• Professor: Michael Reid

Document Summary

Light is a cosmic messenger, carrying information from distant objects to earth. Light is a form of energy of which there are three types: radiative (energy carried by light), kinetic, and potential. Light is measured in joules (j) and in science, the rate of energy flow is called power. Power = the rate of energy usage, usually measured in watts. Watt = the standard unit of power in science; defined as 1 watt = 1 joule/s. Light comes in a spectrum of colours (rainbow: roygbv). Light from the sun or a light bulb is called white light because it contains all the colours of the rainbow. Black is what we see when there is no light and no colour. All colours come from mixing a variety of other colours in different proportions together. The three primary colours are red, green (yellow on paper), and blue. Diffraction grating = a finely etched surface that can split light into a spectrum.