NATS 1880 Lecture Notes - Lecture 6: Hard And Soft Light, Blueshift, Redshift
17 Dec 2018
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Document Summary
Distant objects emit light which we can receive and decode. Intensity of light gives some information but analyzing the lights fundamental characteristics or its spectrum reveals a great deal for information. 3 types of spectrum exists: continuous, emission and absorption and all relate to different physical processes. The continuous spectrum of an object allows us to determine its surface temperature. The absorption lines are like chemical fingerprints revealing the identity of the elements in that object that are generating the dark lines. Absorption (dark) lines and emission (coloured) lines associated with the same element have the same wavelengths. Soft light (colour temp t = 2700k) Doppler effect: the apparent change in wavelength (or frequency) of a wave as experienced by an observer that arises from the relative motion of the source of the wave with respect to the receiver (observer).
