AST101H1 Lecture Notes - Lecture 5: Electric Field, Radiography, Diffraction
31 May 2016
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AST101H1 Full Course Notes
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The universe is made of two things: matter and radiation, two forms of energy. Matter - mass energy - atoms - electrons, nuclei. Radiation - energy - oscillating electric and magnetic elds. Astronomers learn almost everything about planets, stars, galaxies from the radiation these objects either emit, re ect or absorb. Astrophysics is about how matter, radiation and gravity work together to produce different phenomena e. g. like stars, interstellar gas clouds (nebula). as are radio. Visible light is a form of waves, infrared and ultraviolet light, x-rays and gamma rays. Waves are disturbances which move through space carrying both energy and information. they are i. e. oscillating. Waves interact with objects (obstructions) and each other. Diffraction tendency for waves to bend around corners . Electricity particles possess electric charge electrons negative charge protons positive charge charged particles attract (or repel) each other following a force law like gravity like charges repel - different charges attract electric charge create an electric eld.
