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A light-year: Distance Not Time!
•speed of light = c = 3.0 ´ 108 m/s
•
•distance =   speed   ´   time
•d =      c                     ´     t
•light-second =  3.0 ´ 108   m/s     ´    1 s
=  3.0 ´ 108   m
•light-minute =  3.0 ´ 108   m/s      ´   60 s
= 180 ´ 108   m
=  1.8 ´ 1010  m
•
•light-year      =  3.0 ´ 108   m/s      ´  3.14 ´ 107 s (i.e. 31.4 million s) =  9.4 ´ 1015  m
=  9.5 ´ 1012  km
=  9.5 trillion km
=  9,500,000,000,000 km