Recent content by Pilpellon

My book states that "irradiance at a point on the outer sphere is less than irradiance at a point on the inner sphere." The formula is simple, it's flux/area. So in case of a sphere its flux/4π*r^2. But my question is what exactly does this formula give? does it give the total flux that...

It's from the book Real-Time Rendering. Does it help understanding why the cos(theta) is there?

I read this interesting thread trying to find an answer to my questions (and I got even more confused). I study radiometry units in context of computer graphics. I have a few questions, starting from the basic ones: 1. Following AlexS's note, why is speed=distance/time and not distance*time? 2...

[Mentor's note: This question was split off from: https://www.physicsforums.com/threads/meaning-of-physical-quantities-and-division.880214/] What does this differential "d" mean? Why say dE instead of E? or