Is Your Flashlight A Lumen Liar? Build A DIY Integrating Sphere

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 large…

Cannonball Mold Makes A Dandy Integrating Sphere For Laser Measurements

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 thro…