Why an electric bulb needs to be vacuumed? Can we light up a bulb in the space without enclosing in the glass bulb?

Asked by: Muhammad Nasir

Answer

An incandescent light bulb contains a thin wire filament (usually tungsten) that glows hot when an electric current is run through it. In the presence of oxygen, the filament would burn up as a result of the high temperature. A glass bulb, then, is used to keep oxygen away from the filament.

While a vacuum will work, any inert gas that inhibits combustion will also work. Since the vacuum of space would have no oxygen, a bare filament WOULD work as a light bulb without the glass globe.

By the way, even without oxygen present a filament eventually deteriorates as its atoms dissipate. The presence of an inert gas, such as Argon, actually inhibits this deterioration, allowing higher filament temperatures and brighter light bulbs. So the glass globe can also help enhance a bulb's capability.

Answered by: Paul Walorski, B.A., Part-time Physics Instructor