Why must an integrating sphere be a sphere? Why can't it be an integrating cube? What is the difference? Could I use a cube to measure total illuminance like an integrating sphere does?
What the name of the evacuated glass gadget with black and white vanes that turn when a light is applied?
I remember a glass device my physics teacher had at high school which Contained some vanes mounted somehow on a vertical axis, which were all black on one side and white on the other Was in a ...