Does skin that is perpendicular to the sun’s rays burns faster than skin that is closer to parallel to the sun’s rays? I was certain that it does but a very smart friend/engineer is certain that it doesn’t and was incredulous that I thought it did. I really would like to know the physics behind it if he is right. I haven’t been able to find an answer to this question online, because most of the information online is about the intensity of the sun relative to the angle of the sun through the atmosphere, versus the object on the ground changing orientation. If he is right, would it mean that if you want to collect the sun’s energy in a small area, it would be best to place collectors at close to parallel to the sun’s rays as possible without overlapping, sort of like louvers? I haven’t seen any solar collectors like that. Thanks!