The filament can be blocked by an index card to show that the image is projected upside-down. The lens can be partially blocked by an index card to show this does not block parts of the image. Mount ...

A concave mirror reflects a real, inverted image of a light bulb filament onto the wall. Covering parts of the filament or mirror with an index card illustrates the nature of image formation under a ...

Bright, twisted light can be produced with technology similar to an Edison light bulb, researchers at the University of Michigan have shown. The finding adds nuance to fundamental physics while ...