Learning based on a tutorial right now on Raycasting, guy is explaining it pretty well, however, I was wondering, in the script he says.
local myFirstRay = Ray.new(part.Position, Vector3.new(0,50,0)
So this is supposed to cast a ray 50 studs up from the center of the part, but I was almost certain that you'd have to do something along the lines of
local myFirstRay = Ray.new(part.Position, part.Position + Vector3.new(0,50,0)
Did he just have the part centered on the baseplate or am I wrong? Please explain.

2 comments
By the way, I know I forgot to close the ( in both instances, I just wrote up a quick example.
Creating a ray takes 2 arguments, the origin (where it starts), and the direction (0,50,0) is the Y which is the direction, and 50 is the destination. So, the Ray will start from the parts position, and go up 50 studs, and that is it's destination.