Astronomy 1021 Study Guide - Blueshift, Mass Number, Sunburn
Document Summary
The energy that light carries is called radiative energy. In astronomy, the rate at which carries energy toward or away from us is more important than the total amount of energy it carries. The rate of energy flow is measured in watts (1w = 1 j/s) The primary colours of vision are red, blue and green (directly detected by the cells in your eyes. You can produce a spectrum with either a prism or a diffraction grating. Light can interact with matter in 4 different ways : emission (light bulb, absorption (touching a light bulb, transmission (glass; allows light to pass through, reflection/scattering (mirror) Newton guessed himself that light is made up of tiny particles: other scientists later discovered light behaves like waves. Wavelength: distance from one peak to the next. Frequency: the number of peaks passing by any point each second (cycles per second)(often called hertz - hz) Speed: how fast the energy travels from one place to another.