I would greatly appreiciate some insight into this question to allow me to beter understand the nature of relative simultainety. A rocketship is traveling at v=.5c and passes a tree at the instant a lightning bolt strikes it. Now some time later (in referance to the rocket) say the light wave from the lightning has propegated distance L. As the rocket is traveling at speed .5c will it be at a distance .5L??? This was my first intuitive answer but then i remembered that the speed of light is absolute regardless of which refereance frame you are in Now if this is true does this mean that at some time later (time t) the light wave is C times t meters infront of the spaceship and infact an external observer would not observe the rocket passing the tree and the lightning strike to be simultaneous??? In fact they would see the lightning strike the tree before the rocket got to it?? This entire idea has got me perplexed just because i have so many different possibilities in my head and no intuitive instinct to base a true answer on. Any input will be greatly appreiciated.