You are right that regular mirrors absorb or scatter light energy. However, to get 100% reflection it should possible with a setup where the light is getting re

You are right that regular mirrors absorb or scatter light energy. However, to get 100% reflection it should possible with a setup where the light is getting refracted or bounced off critical angle. http://en.wikipedia.org/wiki/Total_internal_reflection http://en.wikipedia.org/wiki/Total_internal_reflection This is commmonly used in Fibre optics. Its more of an engineering challenge to come up with a setup to view your past than a theoretical one!