Today in Astronomy 142 - Astro Pas Rochester
Today in Astronomy 142 - Astro Pas Rochester
Today in Astronomy 142 - Astro Pas Rochester
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Mean free pathκopacity units g -1 cm 2κρ units cm -1amount of light go<strong>in</strong>g miss<strong>in</strong>g per unit lengthabsorption per unit lengthκρ = n σn particles per unit volume (cm -3 )σ cross section (cm 2 )l = (n σ) -1 = (κρ) -1 (cm) how far a photon goes before gett<strong>in</strong>g absorbedthe mean free path<strong><strong>Astro</strong>nomy</strong> <strong>142</strong> 7