I was in the shower last night when one of the lightbulbs started flickering a bit. Nothing unusual, I thought. It’s probably just buring out. So when I heard a loud crack, I figured it was just an unusually loud lightbulb burnout. :rolleyes: Then I smelled something burning. That was just not normal. I jumped out of the shower, water going everywhere, and felt around for my glasses (I’m blind without them). I then saw that the lightbulb had broken, and the burning smell was a piece of it melting one of my makeup tubes. Little shards of glass were everywhere. I was really lucky that I had been in the shower at the time, and therefore protected from flying pieces of glass.
With very high powered bulbs such as car headlights and stage spotlights, it is important not to get any oils from your hand on the glass, because the oil heats at a different rate than the glass and causes a thermal imbalance. The thermal stress eventually cracks the bulb. With lower-quality bulbs it’s not as important, because they never get that hot; the glass is therefore of lower quality.
My guess is that the humidity from the shower (or other weird bulb mojo) caused a short of some sort, making the bulb much hotter than it is accustomed to being. If there were any oils on it (and/or because it was made of lower quality glass) the heat caused it to shatter from thermal stress.
So, the cheap answer to your question is “your bulb overheated, and that’s why it broke.” But other than some kind of humidity-induced short, I can’t think of what would cause the overheating. If you’re looking to get down to the root cause, keep looking. I’ll hand this over to someone who knows electricity.
My WAG is that a manufacturing defect (or careless handling) caused one particular spot on the glass bulb to be weaker than the rest of the bulb, so that over a period of time exposed to heat it finally got overstressed and cracked.
What you’re saying about the humidity causing the problem makes sense, but it’s not like this is the first time we’ve been showering while that lightbulb was on. Why would it happen now?
