Why an electric bulb needs to be vacuumed? Can we light up a bulb in the
space without enclosing in the glass bulb?
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.
Paul Walorski, B.A., Part-time Physics Instructor
'Wisdom is the daughter of Experience, Truth is only the daughter of Time.'