Plant & Animal Cell Model Activity Set
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 a halogen gas actually inhibits this deterioration, allowing higher filament temperatures and brighter light bulbs. So the glass globe can also help enhance a bulb's capability.
More info on light bulbs:
Tungsten filament close-up image by Dr. Howell at PSU, Material Science Dept.
Answered by: Paul Walorski, B.A., Part-time Physics Instructor
'You cannot hope to build a better world without improving the individuals. To that end each of us must work for his own improvement, and at the same time share a general responsibility for all humanity, our particular duty being to aid those to whom we think we can be most useful.'