A lamp used to be simple thing: just stick a filament in a glass bulb, pass a current through it and behold! Let there be light. A bigger lamp meant a larger filament, taking more power and a larger ...

It’s an age-old riddle: if you have a perfect sphere with a perfectly reflective inner surface, will light bounce around inside it forever? The answer is pretty obvious when you think it through, but ...

An integrating sphere is a hollow spherical cavity that features a highly reflective white coating. These devices can be used to measure the total luminous flux from lamps or the power of laser light, ...