ENVIRSC 1C03 Lecture Notes - Lecture 4: Rayleigh Scattering, Solar Constant, Radiant Energy
3 Sep 2018
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Document Summary
Earth receives energy from the sun (the nearest star) Is a giant celestial furnace and has an extremely hot core (15 million degrees celsius) Here, hydrogen nuclei collide at such high speeds that they fuse together to form helium nuclei. During this reaction, a heavy hydrogen atom is formed as an intermediate step. This thermonuclear process generates an enormous amount of energy, which gradually works it way to the sun"s outer luminous surface (photosphere) where temperatures are much cooler. Energy transferred from the sun to the earth is called radiant energy or radiation. It travels in waves that release energy when they are absorbed by an object (electromagnetic waves) Each wave has a specific wavelength and each wavelength determines the form of energy (ie light or heat) Types of radiation: am radio waves, television waves, microwaves, visible light, ultraviolet waves, x-rays. The sun constantly emits a flow of radiation but only a fraction of it reaches earth.
