Was Edison's original light bulb really designed to never run out?
October 29, 2005 9:24 PM   Subscribe

Was Edison's original light bulb really designed to never run out?

I don't know why I'm asking this question. It's weird though because I've always been under the impression the answer to it is yes. Perhaps I heard it while in school or something when I was younger. Yeah, I haven't bothered to Google this one either. I figured someone here would know enough about Edison to state whether this is fact or fiction. Ha! Is this a light bulb conspiracy? Surely not!
posted by sjvilla79 to Technology (14 answers total)
Best answer: From Fascinating facts about the invention of the
light bulb by Thomas Alva Edison in 1879
Edison decided to try a carbonized cotton thread filament. When voltage was applied to the completed bulb, it began to radiate a soft orange glow. Just about fifteen hours later, the filament finally burned out. Further experimentation produced filaments that could burn longer and longer with each test. By the end of 1880, he had produced a 16-watt bulb that could last for 1500 hours and he began to market his new invention.
posted by riffola at 9:49 PM on October 29, 2005

His original light bulb burned for 40 hours, then went out. Maybe he designed it differently, but he didn't do a very good job of it.
You really should have googled this, sweetie.
posted by Juliet Banana at 9:51 PM on October 29, 2005

Um, this thread seems to have been called out. Just letting you know.
posted by Jon-o at 10:15 PM on October 29, 2005

Best answer: This sounds like you've heard one of those "some guy invented a car that runs on water (but the auto industry had him rubbed out)" urban legends -- i.e. that Edison invented a bulb with very long life, but the manufacturers prefer to produce bulbs that need replacement.

There's a grain of truth here, and that is -- well, a bit from Wikipedia:

Incandescent lamps are very sensitive to changes in the supply voltage. These characteristics are of great practical and economic importance.... 5% reduction in operating voltage will double the life of the bulb, at the expense of reducing its light output by 20%. This may be a very acceptable tradeoff for a light bulb that is a difficult-to-access location (for example, traffic lights or fixtures hung from high ceilings). So-called "long-life" bulbs are simply bulbs in which this tradeoff is designed in.... Operating a 100 watt, 1000 hour, 1700 lumen bulb at half voltage would extend its life to about 65,000,000 hours or over 7000 years – while reducing light output to 160 lumens, about the equivalent of a normal 15 watt bulb.

Similarly, there are "light bulb life extenders" that you can insert -- which basically reduce the voltage flowing through the filament to a level which doesn't stress it as much. The article goes on to cite examples such as the firehouse lightbulb that has burned for more than a century -- but the news stories rarely point out that it burns at 4 watts, meaning this is less an inherent property of the bulb as the conditions under which it has been used.

You could probably extend the life of all the bulbs you own in your house right now to the very end of your residence in that building -- but you'd have to live in a pretty dim house.

Despite the math, it doesn't appear to be the case that it's easy -- in Edison's day or now -- to manufacture a bulb at typical cost which will last much longer than the ~1500 hours of a typical incandescent bulb.

Fluorescents, of course, are another matter entirely -- since there is no filament to deteriorate, they can last a great deal longer, and they are also much more efficient due to their lesser reliance on heat energy. I've replaced all but a few "reading" lights in my house with fluorescents, and the difference is astounding -- I almost don't remember the last time I had to change a bulb. At less than 1/4 the power requirements, the extra expense of the fluoros (even subsidized) is easily made back, and there are other savings in terms of less excess heat in the summer that would have to be air-conditioned out (and the lost heat in the winter is easily made up by the furnace, which is far more efficient).
posted by dhartung at 10:28 PM on October 29, 2005

I remember hearing the same sort of thing. I vaguely remember a documentary showing a candelabra in Thomas Edison's home with it original bulbs still intact. After doing a bit of google research I have found evidence of one bulb still burning after 100 years, but it seems to have nothing to do with Edison.
posted by Alison at 10:34 PM on October 29, 2005

Not really an answer but why not throw some Pynchon in for kicks?

"It turns out that the light-bulb is the same identical Osram bulb that Franz Pökler used to sleep next to in his bunk at Nordhausen. Every n-thousandth light bulb is gonna be perfect, all the delta-q's piling up just right, so this bulb is immortal! It is Byron the Bulb, and his story is told. He has great affection for his "mortal" fellow bulbs, and comes to love them through his endless burning hours. He also hates Them, and dreams of a million bulbs flaming out in one grand burst as a Guerilla Strike Force. But even if he avoids the Phoebus light bulb cartel's "hit man," he is doomed both to know and to be ignored, powerless to change anything. In the end, he can only shine his pain-radiance down on the Colonel's exposed jugular while Eddie Penseroso also stands there holding his scissors in a way barbers aren't supposed to..."
posted by rleamon at 11:51 PM on October 29, 2005

Wasn't the vacuum tube / valve invented while trying to extend the life of Edison's light bulb? The way I remember the story, someone (Fleming?) added additional electrodes to experiment with attracting & repelling the carbon atoms emitted by the filament, and the rest is history.

Which would tend to discount the "Edison invented the perpetual lightbulb, and the international cabal of lightbulb manufacturers conspire to keep it hidden" theory. That, and all the other evidence about Edison's personality which point to him being the kind of person who would be ecstatic at the idea of selling you a new lightbulb every other day...
posted by Pinback at 2:06 AM on October 30, 2005

Dang, rleamon beat me to the Pynchon excerpt.
posted by statolith at 6:42 AM on October 30, 2005

What Snopes says.
posted by Miko at 7:49 AM on October 30, 2005

Oops, sorry I didn't notice Alison's link.
posted by Miko at 7:50 AM on October 30, 2005

doesn't pynchon also say in the same book that lightbulbs really suck darkness? is it part of the same riff? if not, is there - gosh - a contradiction?
posted by andrew cooke at 1:01 PM on October 30, 2005

Edison was groping around in the dark, trying out anything he could think of. He did not have a deep understanding of what the materials were doing, he just tried stuff until something worked. He also did not have high precision manufacturing techniques. Someone like Tesla might have come up with something we can't do today, but not Edison.
posted by Ken McE at 5:56 PM on October 30, 2005

Response by poster: This sounds like you've heard one of those "some guy invented a car that runs on water (but the auto industry had him rubbed out)" urban legends -- i.e. that Edison invented a bulb with very long life, but the manufacturers prefer to produce bulbs that need replacement.

Yeah, that's what I was getting at. Sorry for causing such a fuss. Anyway, hope all the MeFi elitists' panties are untwisted now.
posted by sjvilla79 at 6:54 AM on October 31, 2005

Edison was groping around in the dark

posted by Vidiot at 6:55 AM on October 31, 2005

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