i just need a little help with a relatively easy lens question A small fish is cast into the center of a glass sphere of radius R=5 cm and n=1.5. Where will an observer see the fish? Where will the observer see a decorative pattern painted on the back side of a sphere? So, I thought I could use the formula to find the image distance i=n-n1/R; and i subtracted 1.0 (n of air) from 1.5, then divided by the radius to find the distance of the image of the fish. For the background pattern, I used 10 cm as the value of "R", because it is the length of the diameter away from the observer. Am I right in my thinking? I feel like I am just plugging and chugging, rather than really understanding the concept...(so i am not sure it i am even evaluating correctly) Thank you.