>>Lightyear is much tougher, I never completed one, so I don't have any idea how much time would four take.
>
>Hmm, wondered about that. According to http://www.enchantedlearning.com/subjects/astronomy/planets/earth/Speeds.shtml the rough sum of all our speeds in the Local Group inertial frame approaches 600 km/s. That's about 1/500th of the speed of light, so if you lived a Biblical lifespan of 500 years you'd travel about 1 ly. Two thousand for four.

Good! I didn't found that, but I know there was something like that. Thank you for the link.