Hello, I am having a hard time understanding the concept of the reciprocal space. Here is my general understanding of it so far: the reciprocal space contains all of the points that light could be diffracted to from the real space. But I don't understand why this is the case from the mathematical definition of the reciprocal space. Why are all of the vectors in reciprocal space normal to planes in the real space? I guess I'm just not making the connection between the two spaces very well.