Chilton pulls out a prop to illustrate his point: a glass bulb about two inches high.

WSJ: Gen. Kevin Chilton: Sounding the Nuclear Alarm

In the light from the overhead bulb with its old glass shade, mixed with sunlight from the window on the nearby landing, I saw myself reflected clearly.

NEWYORKER: Miracle Polish

The solution was a vacuum cap that sits over the whole unit, much like the glass globe surrounding the tungsten filament in a flashlight bulb.

FORBES: Pip-squeak Power Plant