Conspiracy theory and the light bulb

[Sylvester]

DId you know there is a light bulb that has been burning for 112 years? That light bulbs were meant to last, until a cartel decided they could make more profits by making bulbs cheaper. Here is the link to the theory, and a link to the 112 year old still burning light bulb.

http://conspiracy.wikia.com/wiki/Light_bulb_conspiracy

http://www.centennialbulb.org/

Have we been kept in the dark?

[ruckman101]

Planned obsolescence. Nylon socks were the example my high school teacher used. The first ones never wore out.

neal

[glasseye]

Light bulbs run at undervoltage last a long time. I have a 22O V bulb running on 110V in a lamp that's been running 24/7 for over 20 years. Nice warm glow.

[Amskeptic]

Light bulbs run at undervoltage last a long time. I have a 22O V bulb running on 110V in a lamp that's been running 24/7 for over 20 years. Nice warm glow.

You gotta get out more . . . but still, that is pretty cool.
Where is this lamp, and what is its purpose?
Colin

[Sylvester]

Which lamp, Glasseyes or the Centennial Bulb?

[SlowLane]

Where is this lamp, and what is its purpose?
Colin

It's at a fire hall here in Livermore, just about a mile from my house: http://en.wikipedia.org/wiki/Centennial_Light
It's pretty darn dim, though. You wouldn't want to tweak an AFM by it.
Its purpose, as far as I can tell, is to have an entry in the Guinness Book of Records. And to justify the Web-cam aimed at it.

[hippiewannabe]

It's pretty darn dim, though...

Exactly.


A heavy filament glows softly orange because it is converting a much higher percentage of it's energy to heat rather than light, and not making much light besides. But because it's running so cool, it is not boiling off metal as fast, and so will last a long time. When you are heating a wire to make light, energy efficiency is inversely proportional to life span. Think about being at Home Depot and seeing a bulb that advertises "as much light as a conventional 50 watt bulb, using only 100 watts!". I'm confident that's what's going on with those communist bulbs, but I'd love to see the data.

Incandescent is over anyway, LED is here.

[hippiewannabe]

I wish I had a dollar for every time somebody spent a few minutes posting some little claim on the Internet and it sent me off to spend 20 times as long to prove it wrong, or just research it for my own satisfaction.

"Long-life" lamps are an example of lamps with thicker, stronger filaments that can last much longer than a standard service lamp, but they are less energy efficient.

http://energy.gov/energysaver/articles/ ... t-lighting



Somebody forgot to tell these damn capitalists about the the conspiracy; you can pay your money and take your choice:

Uses 65 watts for 685 lumens of brightness
2000 life hours

http://www.lowes.com/ProductDisplay?par ... &cId=PDIO1

Uses 65 watts for 510 lumens of brightness
Bulb life is 4000 hours

http://www.lowes.com/pd_302043-3-15952_ ... facetInfo=

Bulb Wattage 60.0
Rated Life (Hours) 1000.0
Lumens 855.0

http://www.lowes.com/pd_62793-3-10489_4 ... facetInfo=



http://www.livescience.com/14700-longes ... ornia.html

the 60-watt bulb has been alight 24 hours a day, operating at about 4 watts, to provide night illumination of the fire engines.

Mystery solved. Spent some time playing with these equations: http://www.zap-tek.com/webpage/Elect/ls ... p_res.html and got crazy numbers. They warn you the coefficients get less reliable as the differences between rated and actual power/voltage get larger, but very conservatively, a bulb with a design life of 2000 hours (three months of continuous usage), will last over one thousand years if you run it at such a small fraction of it's design power.

As they point out: "In the case of excessive "undervoltage" burning, the theoretical life of lamps calculated by the exponential relationship of life and voltage is seldom realized because handling, cleaning, vibration, etc. introduce breakage factors that reduce lamp life." The life of this bulb has as much to do with careful handling as with extremely low voltage.

[Amskeptic]

I wish I had a dollar for every time somebody spent a few minutes posting some little claim on the Internet and it sent me off to spend 20 times as long to prove it wrong, or just research it for my own satisfaction.

“The truth will set you free, but first it will piss you off.”

[SlowLane]

running so cool, it is not boiling off metal as fast, and so will last a long time.

Have another read of the bulb's official website. It's a carbon filamant bulb, so there is no metal to boil off at all.
Jeez, the frickin' thing even has a Facebook page.

[hippiewannabe]

It's a carbon filamant bulb, so there is no metal to boil off at all.

Right you are. Same principle, though.

[glasseye]

Incandescent is over anyway, LED is here.

Too true. I just bought three 60W equivalent LED luminaires from Costco. I can confirm by my well-trained eye that it's pretty close to an incandescent 60W bulb in light output. (and colour, for that matter)

Its lifetime is listed on the packaging as 23.8 years. Interesting that they know to the tenth of a year how long it will last.

It draws 7W. Amazing. Fully dimmable, too.

[Amskeptic]

Its lifetime is listed on the packaging as 23.8 years. Interesting that they know to the tenth of a year how long it will last.

I don't think they do. I DON'T THINK THEY DO.
AMskeptic

[glasseye]