[OT] Exploding Light Bulb

"Tom Lucas" wrote in message news: snipped-for-privacy@iris.uk.clara.net...

Is it possible that water dripped onto it while it was still hot? Anything leaking down there?

I was once sat in a bar when a glass with nobody within 20 feet of it shattered into thousands of pieces (like a car window does). That was spooky.

Regards, Richard.

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have got same once the bulk broke at the place it joins the bajonet socket thermal expansion did it.

It is a converted cellar used as a study so it is heated there is no damp in there and the room above it contains no water sources. Whilst I can't completely rule out the possibility it is a long way down the list of candidates. I think what Sagaert suggested is more feasible and it was just coincidence that on this cooling cycle the stress was too much for the bulb. Still odd though. The production manager here used to work for a firm making light bulbs and he reckoned he's never heard of anything like it happening before.

The haunting idea is looking most likely ;-) The kitchen is on the same floor and last year, as I walked into the kitchen, a cracked pint glass that had been sat on the side for several days violently shattered - exploded would be a better term. Even the base was fragmented and in all my years drunkenly dropping pints onto tiled floors I've rarely seen the glass base break. Perhaps there is an indian burial ground somewhere nearby...

Do you drink in neighborhoods that have drive-by shootings?

Chances are that there was a defect in the glass and the contraction during cooling propagated a small crack to the breaking point. Retained stresses in the glass did the rest. It would have been stranger if it had shattered while it was at a relatively constant temperature (hot or cold).

Best regards, Spehro Pefhany

It seems that glass objects can have (or develop) some fairly amazing internal stresses. Not too long ago, I had an ordinary 8-oz. glass tumbler "blow up" in my hand as I was unloading it from the dishwasher. I accidently tapped it against another glass (not hard at all) as I was moving it. It didn't just crack or chip -- it literally exploded into thousands of shards that flew for several feet in every direction. Fortunately, I was holding it lightly by my fingertips and wasn't hurt at all, but it took some time to make sure all of the glass was cleaned up and didn't get into anything edible.

-- Dave Tweed

Glass is a liquid... slow moving, but still a liquid. If you measure an old window it is thicker at the bottom than at the top.

Maybe the light bulb has been there a while and got thin enough by the bayonet fitting that vibrations or thermal changes caused it to give way.

Eric

When the light was cooling the stress caused it to implode.

"Tom Lucas" wrote in message news: snipped-for-privacy@iris.uk.clara.net...

Those windows are thicker at the bottom because they're made that way. It would take thousands of years for the glass to do that on its own.

I could have understood it if I had knocked the glass or if there was a recent heating event such as dishwashing but this glass had been sat untouched for a number of days (shows how lazy I am about bagging up broken glass) following its intial cracking. It had been sited nearish to my combi-boiler but that hadn't been on so any thermal effect from it was minimal. It was within view of a window so I suppose sunlight could be a factor but who knows?

I guess so. Never heard of it happening before though. Perhaps most bulbs have their filaments fail before the glass does and so the effect is not often seen? Perhaps this bulb had an unusually long lived filament and an unusually weak area of glass?

I think I'll get a Priest, a Rabbi and an Imam round just in case ;-)

Thousands of years isn't even enough. Glass doesn't flow under normal temperatures. You can find chips of obsidian that are hundreds of thousands of years old that still have nice sharp edges and haven't turned into puddles.

Years ago, I saw a demonstration of a problem a researcher was working on. A piece of optical glass was exposed to the beam from a 60W CO2 laser for a bit, then the laser was turned off. Some time later the glass literally exploded. The researcher was trying to find out why.

A popular urban legend.

Sulfur is low cost , run lite bulb at very low heat and put in sulfur .

Experiment with various sulfurs like Amonium sulfate etc .. It could explode , be careful .

Sulfur passes thru the glass bulb . Low Pressure sodium lamps have a problem with sulfur passing thru glass , so it must be special glass .

If you succeed in passing sulfur into the bulb , You can screw it in a fixture and when it is turn on it will probably explode ,

but NOT like TNT etc ....

Let me guess....people that don't put 'Sulfur' in their bulbs are Luddites....am I right?

Regards, Richard.

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ppl who dont know how to pour /put piss out of a boot are Luddites ( See Luddite below )

....

UK , about 1810 , General Ned Ludd , gathered his covert army and planned to burn factories , assasinate owners because he was a trade unionist ( they do that here too ) ..

He wanted to weave cloth by hand , cause it employed more of his trade unionists , so he burned mechanized weaving looms ... The King caught and hung 84 of his "union members" ....

It died slowly .... But UK still likes that "hand made" stuff like Jaguar motorcars , but car factories burn slower than wood weaving looms ....

The question is thus begged that, in the following years, did the researcher find out what caused it?

Even _further_ off topic: