3 ms·...or you could put the concave side on the North. That also solves the problem.by jcampbell1 13y ago...or you could put the concave side on the North. That also solves the problem.bodhi 13y agoThen you build one in the southern hemisphere. Oops!dsuth 13y agoIn the southern hemisphere everything is upside down too, so the rays would reflect off into the atmosphere, I expect.