# History of the light bulb



## RIVETER (Sep 26, 2009)

Did not to to the link but I suppose TOM did not invent it..I actually know that he did not invent it. He developed the way that it could be use for normal everyday illumination without blinding you.


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## JRaef (Mar 23, 2009)

RIVETER said:


> Did not to to the link but I suppose TOM did not invent it..I actually know that he did not invent it. He developed the way that it could be use for normal everyday illumination without blinding you.


And more importantly, how to mass produce them inexpensively so that "regular" people (albeit wealthy enough to afford his DC electricity) could afford them. Carbon arc lamps and other filament lamps already existed, but were hand made and hugely expensive so only large commercial enterprises, like theaters, could afford them. Edison figured out that by enclosing the filament in a vacuum, he could make it last longer without having to use a huge filament that needed a big support and protection.


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## telsa (May 22, 2015)

The cited article does have the occasional technical error:

Natural gas was NEVER used to create street lighting. 

The term of art was ILLUMINATING gas -- and since it was manufactured from coal and water -- it was also known as MANUFACTURED gas, or WATER gas.

[ It also known as 'synthesis gas' -- as it's the basis of many fuel synthesis schemes. ]

When gas was found coming straight out of the ground -- it immediately was christened NATURAL gas -- as it certainly was not manufactured -- and it made for a terrible illuminating gas.


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## JRaef (Mar 23, 2009)

telsa said:


> The cited article does have the occasional technical error:
> 
> Natural gas was NEVER used to create street lighting.
> 
> ...


Absolutely right. "Natural gas" is primarily methane, coal gas or syngas was primarily hydrogen, diluted with carbon dioxide. It burned much hotter and brighter than natural gas would have.

I used to live next to "Gasworks Park" in Seattle, where I learned all about coal "gassification" that was used there for street lights up until the "teens" of the 20th century. Huge compressors made the gas from coal and steam. Up to that point I had never heard of it.


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## RIVETER (Sep 26, 2009)

JRaef said:


> And more importantly, how to mass produce them inexpensively so that "regular" people (albeit wealthy enough to afford his DC electricity) could afford them. Carbon arc lamps and other filament lamps already existed, but were hand made and hugely expensive so only large commercial enterprises, like theaters, could afford them. Edison figured out that by enclosing the filament in a vacuum, he could make it last longer without having to use a huge filament that needed a big support and protection.


With his invention, how did he figure out how to secure the glass to the metal base? And by what method?


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## telsa (May 22, 2015)

RIVETER said:


> With his invention, how did he figure out how to secure the glass to the metal base? And by what method?


https://www.youtube.com/watch?v=EzyXMEpq4qw

This Frenchmen has a hobby of making his own triodes. He's amazing to watch.

Within his procedure you can witness the technique used to manufacture an Edison era lamp -- which became the foundation for making triodes, too.

The big difference between a triode and a light bulb is that the former is oriented towards a 'logical' function -- whereas a light bulb is simply a black body emitter.

Evacuated glass enclosures and hot metals are used for both.


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## RIVETER (Sep 26, 2009)

telsa said:


> https://www.youtube.com/watch?v=EzyXMEpq4qw
> 
> This Frenchmen has a hobby of making his own triodes. He's amazing to watch.
> 
> ...


Did not make it to the link but a triode is three electrodes enclosed in a glassed vacuum, unless it is in the form of a transistor. In a filament in a vacuum it is just a metal carrying enough current to heat the metal to "incandescence" ...visable light.


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## JRaef (Mar 23, 2009)

RIVETER said:


> With his invention, how did he figure out how to secure the glass to the metal base? And by what method?


that wasn't the big problem, the big problem was getting the electrodes through the glass and keeping it sealed. That article does a good job of explaining it. he used platinum electrodes because the thermal expansion rate was almost the same as the glass, so they cooled together and didn't introduce a leak or crack the glass. Once sealed, attaching the glass to a base was just a matter of the right adhesive, which I think was a ceramic
cement.


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## cuba_pete (Dec 8, 2011)

I have been to the Spark Museum (Bellingham, WA) where that Edison bulb is on display. It's a pretty cool place even for a Tesla fan (that's me).

They also have a Tesla "cage of death" that my wife bought me a seat in.

She also bought me replica Edison bulb for Christmas...I love the classics and history.


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## fdew (Mar 26, 2009)

from the article 
“Edison didn’t just develop a lamp; he invented a whole system of creating and delivering electricity, including the dynamos, the wiring, the way of measuring the current, and the lamps themselves,” says Jenkins. Edison had soon established a group of companies that would manage each element of the process, making his arrangement the most obvious challenger to the gas-company empire.

The above was his real invention and he deserves all the credit he gets for it. The light bulb by it self is of very limited use.


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## billn (Aug 31, 2011)

Interesting article but, as telsa pointed out, there are some technical errors. One of the major ones is the statement that platinum has a lower resistance than copper. It doesn't, it is much higher - about the same as iron. The reason Edison chose it was probably because it has a very low temperature expansion coefficient. It also has a very high melting temperature.


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## Hawkrod (Mar 19, 2012)

Edison also developed the filament through extensive testing. It was not just a "hey, try this". They started with bamboo filaments which were commonly used by others at the time. Edison's development of a stable low cost filament is what made a lighting network a real possibility.


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## FaultCurrent (May 13, 2014)

Edison is sometimes discredited because some detractors feel he didn't invent anything.

What Edison had, besides the genius of invention, was very keen business acumen. He built a laboratory and staffed it with top craftsmen and scientists. He gave directions, and they got to it. He really had created a small research center able to develop and produce his ideas. That in itself was innovative. The people working for him were smart, they made suggestions and improvements, and Edison ran with it.

He hired Tesla, Tesla did the work, and Edison got the patents. Edison reneged on the payoff, Tesla pouted and left. He made money on his many inventions. He invented the vacuum tube diode, the "Edison Effect", but it was ahead of his time so he didn't see the applications to radio, etc. He also discovered something he called "etheric force" and patented it, a type of wireless communication. Carbon microphone, phonograph, fluoroscope, motion pictures, and so much more. 

Edison stubbornly held fast to his DC system, JP Morgan pulled the plug on him, and he lost control of his own company. Would he be gratified today to see that DC distribution is now a reality again? Really a great American.


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## cuba_pete (Dec 8, 2011)

There is a _huge_ difference between the local block-level DC distribution and today's long distance HVDC.

That would be like saying that Edison gets credit for LED "light bulbs" just because they use the same fixtures.

Does Archimedes get credit for every type of screw ever made?


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## fdew (Mar 26, 2009)

cuba_pete said:


> There is a _huge_ difference between the local block-level DC distribution and today's long distance HVDC.
> 
> That would be like saying that Edison gets credit for LED "light bulbs" just because they use the same fixtures.
> 
> Does Archimedes get credit for every type of screw ever made?


Credit, no, gratified, perhaps.

"Would he be gratified today to see that DC distribution is now a reality again"


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## stuiec (Sep 25, 2010)

fdew said:


> Credit, no, gratified, perhaps. "Would he be gratified today to see that DC distribution is now a reality again"


Only if it had and Edison sticker on it


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## eddy current (Feb 28, 2009)

JRaef said:


> Edison figured out that by enclosing the filament in a vacuum, he could make it last longer without having to use a huge filament that needed a big support and protection.


 Was it Edison himself that made that discovery? Or was it one of the many scientists he employed?


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## Vintage Sounds (Oct 23, 2009)

Very interesting article but it doesn't mention the Nernst Lamp of 1897


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