In all my life I don’t think I’ve ever seen a lightbulb burn out while it was on, nor have I ever noticed that a lightbulb had shuffled off it’s mortal coil (pun intended) while it was turned off.
It’s always as the light is being turned on, there’s a quick flash, the light comes on for an instant, then there’s an audible “crack”, then the light is out.
So, does it ever happen. Will a lightbulb ever burn out after it’s been on for ten minutes? a few hours?
It’s happened to me. But the burning-out when turning-on phenomenon is much more common.
If a light is left on all the time, then it has to burn out while it’s on.
Are you sure about that?
Yes, it definitely happens. It certainly happened to me, so except if I have some mysterious power making the lighbulbs burn out, it’s probably normal.
How can they do otherwise? When a bulb is off there’s no current flowing thru the filament to cause it to burn out; and if for some reason it did burn out while it was off, you wouldn’t know it. The filament can be broken by rough handling of the lamp, though.
It happens, but it’s less likely to happen than when you throw the switch. Here’s why:
It’s harder for the filament of the bulb to ‘turn on’ than it is for it to stay on. That’s because throwing the switch initiates a surge of electricity through the filament, causing it to suddenly heat up. Once it’s ‘on’, the situation is pretty static and it’s easier to maintain. Over time (i.e., thousands of on/off episodes) the tungsten gradually weakens to the point that it’s unable to continue to handle the sudden surge of electricity that happens when the circuit is completed, but it’s still strong enough to keep the circuit complete). You turn it off, not knowing that it is now too weak to start up again, then the next time you turn it on, ‘pop!’, the bulb burns out.
Anyway, that’s my layman’s understanding. Someone will be along shortly to amplify and correct this.
This feels like the classic “why don’t I ever see dead birds?” question. I’ve had a ton of lightbulbs burn out while I was sitting there reading, say. And I’ve seen a ton of dead birds. But never the green flash at sunset. This makes me feel phenomenologically all alone.
It happens to me fairly regularly. In fact,an ex-girlfriend seemed to think that I generated some sort of field causing it, it happened so often. (She didn’t really think that, she just liked to say it.)
I just KNEW somebody was going to bring up that damned light bulb.
I think they ought to name the bulb “Byron”.
Its certainly less common (for the reasons mentioned above), but I’ve had it happnen once or twice. Usually it flickers for a second or two than just cuts out.
This just happened in my house a couple of days ago. I was sitting in my living room watching TV on the sofa (from which I have a view of the kitchen door and could see the light coming from there.) Out of the corner of my eye I saw a flash and heard a soft POP and then the kitchen went dark.
Green flash? What green flash?
Get a shop light. Then count the number of times you swear while using one. Report the number back here.
Using an incandescent shop light is the true test of a person’s patience. Or sanity. A fluorescent shop light is the way to go.
slight hijack:
thats a good question about the birds id love an answer to 
The old, sick and dying are quickly consumed by local predators. Scavengers take care of most of the rest.
The Master speaks: Where are all the dead pigeons?
Or come to my neighborhood, where the cats kill the birds but can’t be bothered to eat them.