Talk:Incandescent light bulb/Archive 2

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Archive 2

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Archive 4

Terminology

The Edison patent is for an "electric lamp" as I would suppose most of these inventions would have been called at the time. I think the current discussion using the term "light bulb" is appropriate as this is the common term used today. However, I also believe it would be interesting to know when the term "light bulb" was first used, or came into common usage. Jbottoms76 (talk) 08:21, 17 August 2008 (UTC)

Tungsten filament

In 1906, the General Electric Company was the first to patent a method of making tungsten filaments for use in incandescent light bulbs.

Wasn't this patent bought from Lodygin? —Preceding unsigned comment added by 71.131.194.102 (talk) 10:29, 13 January 2008 (UTC)

Yes, It was...see http://www.geocities.com/s_fedosov/history/texno.htm —Preceding unsigned comment added by 92.255.179.188 (talk) 17:13, 24 March 2008 (UTC)

The reference cited by 92.255.179.188 is to Geocities, a service which hosts peoples personal webpages, and therefore does not appear to constitute a reliable source. The material is in Russian, which further makes it hard to examine for most Wikipedia editors. Is there a source in English which states what patent Logygin got, from what country, and when, with images and text? Is there a reference which says GE bought that patent? Even if GE bought that patent, they patented their own process for making exteremely thin tungsten filaments via new processes. It would not be possible to buy someone's old patent and then "repatent" it and somehow extend the trerm of patent protection. Did GE sell tungsten bulbs which said they were produced under a Lodygin patent? This sounds suspiciously like a case of someone dabbling in a technology without success, then when someone else later makes a breakthrough and advances the art, claiming that the earlier experimenter "really invented it." This claim should not be in the article without verification through reliable sources. Edison (talk) 15:18, 11 April 2008 (UTC)

What is the alternative

I have fluerescent lights everywhere in my home, *except* my room. Because i work all the time with the computer and look at the monitor, and fluerescent lights make my eyes ake and makes them wet when i look at the monitor 10 minutes or more. Yes i tried to replace light bulb in my room with fluerescent light already so many times. Yes the vertical frequency is the highest, 80 hz, yes the monitor is lcd. But why no one thinks about the simple fact that the fluerescent lights flicker, and the monitor screen flickers as well, and together they generate much more intensive and lower frequency flickering, while banning light bulbs or advocating against them. When they ban light bulbs in EU, would there be any possibility for me to get a light which doesn't flicker? Are there any alternatives, or anyone even ever thought about it? Are there some special lights which are made to flicker less? I think these concerns have to be mentioned in the article for it to be neutral point of view, instead of writing there only the fluerescent lights advocacy, that the light bulbs would be eventually replaced with the flurescent lights, and this is only good. Please consider that, thank you.--Tkorrovi 17:39, 13 July 2007 (UTC)

Tkorrivi, There are other bulbs, known as LED bulbs that are somewhat expensive, but last longer than cfls (Also known as fluorescent bulbs) and use less energy. But, these bulbs do not produce as much light. N:vision cfl's do not flicker. (At least, I think so.) —Preceding unsigned comment added by 75.166.211.132 (talk) 03:33, 6 December 2007 (UTC)

Humphry vs. Humphrey

When I reverted the Nickroxvote3 vandalism, I used "Humphrey" Davy for the spelling, but that was later changed to Humphry. I only came by because Nickroxvotex vandalized one of the sites I monitor so I was curious about what he did here. I also got curious about this Davy guy and did some Googling on him and noted that his named was spelled as Humphrey here and there, which is why I ended up spelling it that way. Whatever. Just some FYI. -BC aka Callmebc 14:10, 12 September 2007 (UTC)

Both spellings were used often during the lifetime of Humphry/Humphrey Davy. Check Google books and you can find both spellings in published works from his time. It is puzzling why the two spellings were both used. One may have been the English version of a Welsh spelling or some such. Edison (talk) 02:42, 11 December 2007 (UTC)

Politics Section II: Just banned in Ireland

Hi, I just googled to find out exactly what an 'incandescent bulb' [as opposed to "a bulb"!] is as they have just been banned in Ireland, and I read the above discussion. So here are the links confirming their banning in Ireland last week. Greenpeace wanted the ban to start in 2010 [1] but the Irish government is banning them from 2009. http://www.belfasttelegraph.co.uk/breaking-news/ireland/article3229273.ece; http://www.greenpeace.org.uk/media/press-releases/ireland-legislates-to-ban-inefficienct-light-bulbs-by-2009-20071206; http://www.scoop.co.nz/stories/WO0712/S00420.htm; 213.202.170.60 (talk) 23:58, 8 December 2007 (UTC)

Is Ireland now the first state to ban incandescent bulbs? 213.202.170.60 (talk) 23:59, 8 December 2007 (UTC)

Swan's birthplace

Someone changed the text recently to say Swan was born in "Sunderland, England" rather than "Sunderland, United Kingdom." What is the preferred usage? Is the present like saying someone was born in "Philadelphia, Pennsylvania" rather than "Philadelphia, United States?" No strong feelings on this, but input from Brits or Manual of Style wonks appreciated. Edison (talk) 23:33, 14 December 2007 (UTC)

Most people this side of the pond would say they were born in England/Scotland/Wales etc or possibly in Britain. The UK is a political construction which has varied in extent, has only existed in its present form since the 1920s, and could disappear in the future if devolution progresses to independence for Scotland, Wales etc. Our governments have always like fiddling with boundaries: Swan was born in Bishopwearmouth, which is now part of Sunderland. Both were then in County Durham, but are now officially in Tyne and Wear. Pterre (talk) 11:28, 6 February 2008 (UTC)

This gets us into another srea of uncertainty: should we use the then-used name of the town, which you say is Bishopwearmouth, rather than Sunderland? And do you go along with calling it Bishopwearmouth, England, or should we have a middle term to state what county etc it was in? Where did Swan himself say he was born? Maybe discussion of his birthplace belongs in his own article and not in the Incandescent light bulb article. Edison (talk) 15:56, 6 February 2008 (UTC)

Sorry, overlooked your reply somehow. I would personally go for "Bishopwearmouth (then in County Durham), England". Pterre (talk) 22:41, 1 March 2008 (UTC)

Vitrit

A diagram in this article identifies insulation at the base of a lightbulb as "vitrit". What is this stuff? A Google search brings up nothing, other than a site that requires you to pay to access it, which identifies it as a mineral:

http://www.mindat.org/min-23479.html

These links seem to be associating it with coal:

http://www.kgs.ku.edu/Publications/Bulletins/102_1/03_class.html

http://www.oxygentimerelease.com/A/Therapies/Germanium/b7.htm —Preceding unsigned comment added by 96.232.126.158 (talk • contribs) 21:51, 19 December 2007

Response copied from Wikipedia Reference Desk: Miscellaneous: :::"The Electrical Engineer" for Oct. 25, 1889 p 322 [2] talks about the "Vitrite Company" as making the insulating glass used in the base of light bulbs. I find a description of the base of the bulb, inside the brass screw-form base, being filled with "vitrite" in pp 68-69 of "Electricity in Mining" By Sydney Ferris Walker, Van Nostrand, New York, 1907, viewable at Google Books [3] . Before vitrite, porcelein was used, and before that plaster of paris, which absorbed moisture and which crumbled from the heat. Vitrite is described in "A Dictionary of Chemistry and the Allied Branches of Other Sciences" By Henry Watts (1869)as another name for vitrinopal, "a matrix of Bohemian pyrope, related to pitchstone, and being 83.72% silica, 3.58% ferric oxide, 7.57% lime, .67% magnesia, and 11.46% water. Unfortunately this adds up to 107%. The 1911 Britannica article on electric lamps [4] calls it "vitrite." Numerous other sources found from Google Book search spell it "vitrite." I have corrected the spelling in the Incandescent light bulb article. Edison (talk) 18:20, 28 December 2007 (UTC)

Lower resistance = higher wattage/higher output?

I wish this article had a little more on the physics of the light bulb. I came to it hoping to solve something. It's common knowledge of course that electricity running through the resistance of the filament causes the filament to get so hot it glows. So the resistance is what makes it work. But then it seems to me, from Ohm's law, that for a given voltage, a lower resistance would pass more current, and therefore the device would operate at a higher power. So it would seem that to get more light output, you'd use a filament with a lower resistance. It's a paradox I've been wondering about for some time. 140.147.160.34 (talk) 19:31, 31 December 2007 (UTC)Stephen Kosciesza

Why is this a paradox to you? What part of P=V²/R is troubling you? Is it not intuitive that if the "resistance" is less, more "something" will be let through and more "stuff" will happen? If not, I'm not sure that an encyclopedia article can dispel the perceived paradox. --Wtshymanski (talk) 20:02, 31 December 2007 (UTC)

OK, it could seem a little counter-intuitive without the math (if someone doesn't know or understand it). We read, in this article for instance, that a light bulb works because electricity is put through a resistance; it has to do work to get through (in elementary terms), so it gets hot and glows. One could think, the more resistance, the more work, ergo the hotter it must get. But then when you plug in the math, it turns out to be more or less the other way around.

And that would be so for any heating element, as well. I'm not sure that really puzzled me so much as it kind of startled me when I first figured it out. Maybe I wanted some confirmation/validation from an authority (if Wikipedia counts as an authority).

But then, it seems to me that the unsophisticated could ask--what about a filament then with almost no resistance? What if you just take a bit of the wire that supplies the light fixture and put that into the bulb as the filament? I suppose that all this must work up to a point. And that point would be somewhere when the resistance of the filament gets to be so low that it compares to the resistance of the supply wires (and the supply wires would always have some). In that case, the voltage drop through the supply wires--which normally we'd overlook--would start to be significant; the work would be done over the whole system, and filament and supply would start getting hot.

If I have this all right, then it might be worth mentioning that, although an incandescent light bulb works by passing electricity through a filament with a resistance, a lower resistance leads--perhaps paradoxically--to a higher power light bulb. 140.147.160.34 (talk) 16:51, 2 January 2008 (UTC)Stephen Kosciesza

The usual relationship applies: you can suck the maximum amount of power out of the power supply if the load resistance (impedance) matches the source resistance (impedance). Practically, this doesn't work, of course, for mains power circuits because power systems have very low source impedance and the maximum amount of power that they can supply far exceeds the ratings of the various circuit breakers and fuses that the power flows through on its way to our hypothetical lamp. Thus, our lamp always operates on that side of the load impedance versus power parabola where reduced resistance leads to higher power being disspiated in the load.

Atlant (talk) 18:13, 2 January 2008 (UTC)

By the way, Wtshymanski, please don't be offended that I fixed the superscript in your answer. That said, I notice that your mathematical definition doesn't appear in the article. I'm thinking maybe it should. 140.147.160.34 (talk) 17:02, 2 January 2008 (UTC)Stephen Kosciesza

Woodward and Evans

[5] Contains a reprint of "Invention of the Incandescent Lamp", Electrical World and Engineer, Vol 35, No 15, Apr 14, 1900, pg 540" which cites predecessors of Woodword and Evans who had superior lamps, and debunks some of the claims made for their priority. I am still trying to figure out the significance of the claim that "Edison bought their patent then patented his bulb." Thisoft-repeated claim makes little sense. If his patent were the same as an earlier patent, then competing and infringing manufacturers would have cited that fact in the litigation, which Edison eventually won, and they would not have been counting down the days until his patent expired. You don't buy a patent from someone then re-patent it and claim it is your own. Edison (talk) 23:06, 31 December 2007 (UTC)

I've taken a look at the artice, Lamp (electical component) and there is a little information that I'd like to add to this article. Where the article states: "The same year, Canadians Henry Woodward and Mathew Evans", I will add: ",working for the Morrison’s Brass Foundry on Adelaide St., West Toronto, Canada" and at the end will amend it to say "obtained a US patent for their light bulb," so in full it will read:

"The same year, Canadians Henry Woodward and Mathew Evans, ,working for the Morrison’s Brass Foundry on Adelaide St. West Toronto, Canada, obtained a US patent for their light bulb."

Within the Lamp (electrical component) article, there is a rather subjective section entitled 'A Brief History' which, whilst not suitable for an encyclopedia, does contain a line or two of useful information. If there is a better wording that anyone can thing of, please don't hesitate. I'm still rather new to editing documents on Wiki, especially in a scientific article. Daniel-James 01:51, 23 March 2008 (UTC)

The article says Edison bought the Woodward/Evans patent. The citation for this claim is to "THE CANADIAN ELECTRIC LIGHT, The Science Corner, by Nigel Bunce and Jim Hunt, College of Physical Science, University of Guelph, Thur. Mar. 15, 1984" There is no indication what kind of document this was. It appears to be one of a series of columns about science. Was it published in a source with editorial supervision, in fact was published anywhere? This seems like an important issue in priority of invention. There has been the unwaranted assumption that if the Edison company bought rights to this patent, then Edison added nothing to the invention. The history of light bulb patent litigation (and other 19th century patent litigation) showed that infringers would buy up someone's unworkable patent and then copy the workable invention asserting rights under the dud patent, and string along litigation for a decade or more. It might have been worth a few dollars to prevent the patent from being used by infringers in litigation. Bunce and Hunt mention ""Canadian Electrical News", from February 1900, so it might be where they got the info, but there should be better history in the 1890's light bulb patent litigation in the U.S. and in England. The magazine is apparently available on microfilm. Their patent drawing shows huge differences from the inventions of Swan and Edison: the glass container lacks an adequate seal to hold in a hard vacuum, they did not use a hard vacuum but surrounded the carbon with nitrogen, and they used a huge piece of carbon which could never be considered a filament. One puzzling claim by Bunce and Hunt is that apparently after "selling their patent" to Edison, Woodward/Evans tried unsuccessfully to form a company to make their lamps, but were "treated as cranks and subject to much public ridicule" which seems unlikely if they had a working lamp, and difficult legally if they had sold their rights to the patent.Edison (talk) 20:20, 17 June 2008 (UTC)

[6] The Electrical Engineer, November 20, 1891 (Published in London) p 496-497 at Google Books discusses the patent, and it shows the patent diagram and specifications. The author thought well of the inventors, but said nothing about them having sold any patent rights to Edison. Edison (talk) 20:36, 17 June 2008 (UTC)

heat output

I've corrected 90-95% heat output statement to 98%. See the table already in the article, which already confirms this figure.

I also removed the existing reference http://www.homefamily.net/index.php?/categories/consumersmarts/light_bulb_energy_efficiency/ because it is

1. wrong
2. not a suitable reference: it is a simple non-technical piece containing elementary mistakes.

Tabby (talk) 07:09, 6 January 2008 (UTC)

The reference you deleted cites a Canadian government site [7] for the 5 to 8% figure. Such a source is not so easily dismissed as that for being "wrong," i.e. not agreeing with your opinions. You 2% efficiency figure is lower than some credible sites state. Edison (talk) 16:20, 26 February 2008 (UTC).

The article now claims 10% efficiency, based on "Incandescent Lamps" publication TP-110, General Electric, Nela Park, 1964. This is higher efficiency than other sources I have seen. This publication is not easy to obtain. Is there a credible online source which has this high an efficiency claim? Edison (talk) 13:51, 9 March 2008 (UTC)

TP-110 says 10% visible radiation, 90% various infrared radition, conductive and convection heat transfer. I think the lower efficiency value comes from comparing a white light source to the theoretical 683 lumens/watt at peak sensitivity of the human eye at 555 nm. I believe this to be an incorrect basis for comparison since no-one wants a house lit by monochromatic green light. I'm trying to find a good equivalent for the luminous efficacy of white light but I've seen several different figures from 230 lumens/watt to 300 and higher. I'll have to check the IES handbook at the office to see if I can get a definitive value. (It's too bad someone named Edison doesn't have good access to the GE publications - although TP 110 is quite old, it's standard in any set of GE product catalogs.) --Wtshymanski (talk) 14:28, 9 March 2008 (UTC)

Edison wrote: "The reference you deleted cites a Canadian government site [6] for the 5 to 8% figure. Such a source is not so easily dismissed as that for being "wrong," i.e. not agreeing with your opinions."

If you want to cite the CDN govt site, then great, but citing the article with basic errors I removed is not a step toward the solution, as that sort of material is not fit for citation. It is neither correct, accurate, scientific, nor written with any particular care for the facts. I don't know if we'll agree on that, but I hope at least you appreciate why I removed it, and why others likely will in future if reinstated. Tabby (talk) 20:46, 9 March 2008 (UTC)

There is an inconsistancy in the article between the "10%" light 90% heat" for incandescent lamps and the later reference to "9% efficiency" for halogen lamps, which was recently modified to 25%. If we are still thinking about the ratio of light to heat 25% is impossible. I believe 9% for (the best) halogen lamps is about right and the GE reference to "approximately 10 % is rather optimistic for ordinary domestic lamps. A 120V 100W at 17 l/w corresponds to a colour temperature of 2900K . A black body at this CT has 5% in the visible. For 9% the CT would need to be about 3200K. Tungsten filaments are not perfect black bodies, generally giving slightly more light, but my figures indicate roughtly the comparison. The figures in the table for efficiency, related to the perfect conversion to light aren't very relevent for other than academics and probably just cause confusion. (Redcliffe92 (talk) 21:06, 27 March 2008 (UTC))

more

The diagram lacks ballotini fuses

GLS filament lighting is normally 2700K Tabby (talk) 07:21, 6 January 2008 (UTC)

Agreed. Patent reference to ballotini fuses added to the article.(Redcliffe92 (talk) 16:14, 10 March 2008 (UTC))

link/inclusion of Edison screw

As there is a section on the Edison screw type socket, we should probably include a reference to Edison_screw which as an overview. Alternatively, Edison_screw could be merged with this article (which is getting very long). Moaltmann (talk) 00:02, 2 March 2008 (UTC)

Don't merge! All the Edison Screw stuff can be moved to that article...only the most patient of readers is going thorough 50+ kB. --Wtshymanski (talk) 16:16, 23 March 2008 (UTC)

International wiki, not US wiki

I've rephrased US policy to international, as the US only accounts for 5% of the world population.

/* Luminous efficacy and efficiency */ Most -> Some safety codes. Most is unrealistic for a worldwide wiki, even among the wealthier countries only some do.

Same applies to mandatory use of LEDs in emergency escape signs, here in UK we usually use fluorescent, claiming LEDs are mandatory does not describe the world situation factually.

If someone is going to revert this to describing only US practices, please give us all a good reason here. Tabby (talk) 21:04, 9 March 2008 (UTC)

Gas filling

In the description of Lamp Construction it is stated "filled with an inert gas to reduce evaporation of the filament and reduce the required strength of the glass". I do not believe "reduce the required strength of the glass" is correct. During manufacture the gas filling is introduced at just below, or even above atmospheric pressure. When the lamp is lit its pressure will rise, so the glass envelope will be under tension. Converesely, in a vacuum lamp it will be under compression. Glass fails under tension, not compression. Even with a wall thickness on 0.7mm in places the bulb is very strong, and bursting is not an issue, (unless it receives a thermal shock). Gas filling does create higher temperatures on the bulb, particulary where the convection stream from the filament reaches it. This has to be taken into consideration when sizing the lamp, for example to keep the base temperature within limits. Does anyone object to the removal of "and reduce the required strength of the glass" ? (Redcliffe92 (talk) 19:40, 11 March 2008 (UTC)) No comment, so deletion made. (Redcliffe92 (talk) 20:50, 17 March 2008 (UTC))

There are glass devices which contain air at up to 300 p.s.i. Then glass isn't particularly thick and they don't fail as suggested. They are covered by a net, but not for strength, just to catch any glass fragments if they do break. I am not aware of any current production lamps where the gas filling is anything more than a couple of p.s.i. 20.133.0.13 (talk) 14:18, 28 August 2008 (UTC)

Ohmic?

No comment on the article. But inviting opinions on whether the lightbulb is an ohmic resistor. I will keep my opinion to myself for now. —Preceding unsigned comment added by 64.238.49.65 (talk) 21:45, 17 March 2008 (UTC)

The resistance of tungsten is temperature dependent,with a posative coefficant, but this does not mean it is not ohmic. The cold resistance of gasfilled lamps is about one fifteenth of the hot resistance, higher for higher efficacy lamps. Carbon has a negative coefficient. (Redcliffe92 (talk) 22:33, 18 March 2008 (UTC))

I'm wary of definitions but if you define "ohmic" as "having a voltage drop linearly proportional to current over some reasonable range" then of course, no, the tungsten filament lamp is not an "ohmic" resistor. But what does this hard-won knowledge gain for us?

--Wtshymanski (talk) 22:45, 18 March 2008 (UTC)

When does tungsten burn?

Can someone fill me in on the details of tungsten oxidation in air? See Talk:Tungsten#At_what_temperature_does_tungsten_burn. — Omegatron 23:49, 8 April 2008 (UTC)

Reverting vandalism

While it's good to go back in the edit history to make sure you've caught all the vandalism, it's probably not a good idea to rewind the article from May 15 back to February 28. It's necessary to keep the good edits as well as getting rid of the bad. --Wtshymanski (talk) 16:48, 19 May 2008 (UTC)

Are those really incandescent flood lamps?

Great picture but I'd be surprised if these were actually incandescent lamps; though some of them do look a little orange in the picture. --Wtshymanski (talk) 13:58, 21 May 2008 (UTC)

[8] says it is a "metal halide lighting system." That makes it a gas discharge lighting system and not incandescent lamps. Therefore I am removing the picture from this article. Edison (talk) 14:16, 21 May 2008 (UTC)

Amazing the stuff you can find on the Web. Thanks for checking that out ( I thought we were going to have to wait for a Texas WIkipedian baseball fan...could be a while). --Wtshymanski (talk) 14:28, 21 May 2008 (UTC)

Respectfully, if the picture is in the wrong place, why not simply move it to the appropriate page? — BQZip01 — ^talk 16:40, 25 May 2008 (UTC)

And what's stopping you? WP:be Bold and all that. If you find a place where it provides value to the encyclopedia, go ahead. But remember, this is supposed to be an encyclopedia, not the world's photo album. Pictures must illustrate the topic. --Wtshymanski (talk) 16:45, 25 May 2008 (UTC)

I already did it while you were typing a response. My point is that there is a deletionist attitude with some contributors ("That isn't in the right place. I'll remove it from Wikipedia") when the material could simply be moved from one place to another and still provide useful information/illustration even when the original material was simply in the wrong place. A single article is not Wikipedia and contributing to the entire encyclopedia would be better. — BQZip01 — ^talk 16:54, 25 May 2008 (UTC)

A much better place for the halide lighting picture. Thus the Encyclopedia grows. --Wtshymanski (talk) 17:36, 25 May 2008 (UTC)

Instead of criticizing a perceived "deletionist attitude" you might remember that this is not a shoebox full of photographs. It is an encyclopedia. If a photo does not contribute to an article, it should be removed. It is not the responsibility of the editor removing an inappropriate photo from an article to place it somewhere else, since not every snapshot someone creates even has a proper place in an encyclopedia. This one really does not illustrate anything; it is just a randon, generic and fungible bank of lightbulbs in reflectors, which could be of any sort at any time. Edison (talk) 18:33, 25 May 2008 (UTC)

I never said it was a shoebox of photos. I never said the photo shouldn't have been removed from this article, but merely that the photo in question could have been moved to another page. If you will look at the page where this photo currently resides, it does indeed show the differences in color as the lighting warms up. I never said it was your responsibility to do anything, but merely to suggest an alternative form of action that might benefit us all. — BQZip01 — ^talk 16:30, 26 May 2008 (UTC)

Is there a source for the differing color appearance illustrating something special about the halide lamps, or is that conclusion original research? And you are quite right that a given illustration would ideally be used in any articles where it is helpful, whether or not it is used in this article. For the halide lamp article I would prefer more of a closeup; it still sems more illustrative of a bank of lamps than of anything unique to halide lamps. Edison (talk) 01:26, 27 May 2008 (UTC)

It is an illustration of the color difference elaborated upon in the text. — BQZip01 — ^talk 02:05, 27 May 2008 (UTC)

The photo would fit well in Floodlights (sport) -JWGreen (talk) 02:10, 27 May 2008 (UTC)

Nitrogen

Nitrogen is sometimes used as a fill gas in light bulbs. See Britannica online [9] and the IEE site on light bulbs [10]. The article said neon and argon were used, without mentioning nitrogen. Edison (talk) 23:49, 8 June 2008 (UTC)

Nitrogen is rarely used as a gas fill. What may not be obvious is that the molecular weight of the gas has a bearing on the rate at which the filament evaporates. Argon has a higher molecular weight than Nitrogen and therefore reduces the rate of evaporation. Krypton has a higher molecular weigh than Argon and therefore can give a brighter or longer lasting lamp. Xenon has a higher molecular weight still and is now being used particularly in motor vehicle headlight bulbs. 20.133.0.13 (talk) 14:18, 28 August 2008 (UTC)

The term "light globe" in Australia

How is mentioning that in Australia "light bulbs" are commonly called "light globes" unencyclopaedic?
If this is true, then mentioning that the term is used in the theatre, television and film industries is also unencyclopaedic (and unreferenced). So I've removed that line and moved the term to the introduction line, because it is used not only in the entertainment industries (and Australia), but elsewhere too. --203.94.135.134 (talk) 23:11, 16 June 2008 (UTC)

It just seemed too prominent a mention of a term or usage peculiar to a single country. I wonder if there are any other country-specific terms? Usually these things divide between North America and the rest of the English speaking world, or between the U.S. and Britain+commonwealth. Are Australians aware that the rest of the English speaking countries call them light bulbs? I find 224 refs for usage of "light bulb" in "The Australian": [11] compared to just 3 for "light globe:" [12]. In some of these the term "light bulb" is also used. The Australian "Herald Sun" has 490 cites with "light bulb" and 8 with "light globe." Clearly there is no need to emphasize the term light globe in the lead so that readers in Australia will understand what the article is about. "Light globe" appears to be a rarely-used term even in the one country which uses it. As for theatrical lighting, I Googled "theatrical lighting" "light globe" -Wikipedia (to avoid finding mirrors of Wikipedia articles and found 175 sites where the two terms appeared, although they only show 12 unique sites, and 2 of these are Australian. Googling "theatrical lighting" "light bulb" -Wikipedia produced 5270 sites. too many to count and check for unique cites. Experts on theatrical lighting or reference to books on theatrical lighting could clarify if the term is really widely used by professionals in that field. Edison (talk) 19:14, 17 June 2008 (UTC)

My grandmother (Western Pennsylvania, USA) calls them "light globes". I had always assumed it was an archaism, rather than a regionalism, but there's probably elements of both. -- Coneslayer (talk) 19:34, 17 June 2008 (UTC)

I checked Google Books for books on theatrical lighting. Most only allow snippet view. "Illustrated Theatre Production Guide" By John Holloway (Focal Press, 2002) does not contain the phrase "light globe" but contains "light bulb" four times. "Theater Technology" by George C. Izenour (1996) Yale University Press [13] contains no instances of "light globe" and 7 instances of "light bulb." I will tag the claim that theatrical folks call them "light globes" and no good ref is provided in a reasonable time I will take that statement out. I note that on the web many sites seem to have picked up the claim from this article. I would like to see a reliable print book on theater which says the term "light globe" is preferred. Edison (talk) 19:51, 17 June 2008 (UTC)

I think the current arrangement (as of 23:22, 17 June 2008 (UTC)) is fine, with just mentioning the term light globe in the introduction sentence with light bulb and lamp. All these terms are commonly used in daily speech wrt region, occupation, culture, etc. --203.94.135.134 (talk) 23:22, 17 June 2008 (UTC)

I haven't seen evidence that "light globe" is commonly used even in Australia. Most instances of "light globe" on Google are literally decorative globes with some sort of lights like LEDs in them, or other sperical light diffusers with some kind of light inside. Most light bulbs are not "globes," either. They are the A series shape. Some of Swans' Edisons' and others early lights were more cylindrical than spherical.Edison (talk) 14:49, 18 June 2008 (UTC)

As I said, in Australia "light globe" and "light bulb" mean the same thing in common speech. I'm not talking about the airy-fairy world of half-arsed Google searches on the internet. I'm talking about the real world where products are labelled "light globes" and when chatting to a person in the street we would more often say "globes" rather than "bulbs". We also have products that are call "light globes" (not trademarked) on the box. Btw most Australian sites that I have visited, which use "light globe" refer the the thing others would call a "light bulb". --203.94.135.134 (talk) 23:29, 18 June 2008 (UTC)

Maybe it is more common in some regions than the ones of the 2 Aussie newspapers I checked, Can't rule it out at all that "light globe" is common in some quarters. There are areas in the U.S. where a fox is called a "wampus." Some folks call a vacuum cleaner a "Hoover" or a phonograph a "gramaphone." Edison (talk) 04:27, 19 June 2008 (UTC)

One of the newspapers (Herald Sun) you mentioned *does* come from a region that commonly uses the term "light globe". --203.94.135.134 (talk) 07:15, 19 June 2008 (UTC)

Humphry Davy + incandescent light

I can't find any sources that agree with the following paragraph, there are several sources that say he created the first arc lamp but nothing about an incandescent lamp. 93.97.115.254 (talk) 23:51, 21 December 2008 (UTC)

"In 1802, Humphry Davy had what was then the most powerful electrical battery in the world at the Royal Institution of Great Britain. In that year, he created the first incandescent light by passing the current through a thin strip of platinum, chosen because the metal had an extremely high melting point."

Davy's research is described in many books about him. Some drill down to the specifics. He certainly passed enough current through wires of many metals, including platinum, to cause them to glow brightly and then flash into molten metal. While the metal was glowing, it was incandescent and thus an incandescent light, although not long lasting enough to be commercially practical. He also caused an electric arc between thin carbon rods. When the rods were initially touched together, they glowed white hot before being separated to create the arc. He never claimed anything he had demonstrated constituted a practical source of illumination, but his work was noted and cited by later 19th century lighting inventors. It may take a few days to find good references for this. Edison (talk) 23:59, 31 December 2008 (UTC)

Here is something:in "The Engineering Magazine," McGraw-Hill publishing company, inc.,New York, Volume VII, April to September 1894, "Development of the incandescent electric light, by John W. Howell, pages 70-77 " page 71 says. "Sir Humphry Davy, in 1808, constructed a very large battery. In his experiments he produced the electric arc between carbon points and electrically heated to incandescence platinum and other wires, and carbon...Metallic wires and pieces of carbon were heated to incandescence in the open air, and in globes which were exhausted, or filled with different gases at different pressures." It notes that Davy had the "carbon burner," the vacuum, and the glass globe with its lead-in conductors, but the vacuum was inadequate, the globe's seal was inadequate, and the "incandescent carbon" was inadequate for a successful lamp. Also the battery was too expensive for practical incandescent lamp operation. Note that this ref pushes the experiment to 1808 from 1802. Other sources have noted 1802 as the date of creating an electric arc and making substances incandescent. The U.S. Supreme Court noted in 1901 [14] that Davy had heated carbon to white incandescence with electric current early in the 19th century. The American Electrical Directory, (1886) p 94, said [15] Davy was "really the discoverer of the incandescent light, and he produced some results with it that to-day would be extraordinary if witnessed." A recent book "The Empire of Light" (1998) says (p 98) "In 1801 Davy attached two carbon electrodes to a massive electrical batteryabd saw a spark jump between them when he held them a fraction of an inch apart. ...Not long after, Davy observed that an electrical current passed through platinum heated the metal until it glowed with incandescence." A lecture by J.A. Fleming in 1893 [16] said that Davy requested funds to build a great battery of 2000 pairs of copper and zinc plates in 1808, and that the production of an electric arc was one of the first experiments. Fleming says Davy had probablyu made an electric arc several years before 1808, and that "according to Quetelet, Curtet observed the arc between carbon points in 1802Other sources noted that as little as 50 volts at several amps will support an electric arc, so a much smaller battery of 60 or so plates would have sufficed to make an arc, although large area of the plates would be needed to provide the current. Making a conductor incandescent when electricity passed through it was a capability of the earliest Voltaic piles of Volta, as noted by [17]. It only requireda basic Voltaic pile and a fine wire of something which did not melt at too low a temperature such as platinum. Volta probably made a fine wire incandesce before it burned up with his Voltaic pile in the infancy of electricity circa 1800, as noted by [18]. See also [19] for an early discussion of wires glowing and arcs. An article from 1805 noted the melting of iron and platinum wire via a Voltaic pile [20], and incandescence is usually a step in the melting process. Edison (talk) 00:54, 1 January 2009 (UTC)

It turns out that experimenter had been using electricity to melt lengths of wire in controlled experiments long before the electrochemical cell was invented in 1800. Abraham Brook, in "Miscellaneous experiments and remarks on electricity" published 1797 (2nd ed) describes work apparently originally published in 1786, in which he devised a meter to measure the charge on Leyden jars, which were charged from typical friction machines of the 18th century, then the stored electricity was used to melt standard lengths of wire made of copper, iron, lead and brass, in various small diameters from 1/50 inch down to 1/170 inch. Sixteen square feet of Leyden jar surface charged to "32 grains repulsive force" could "melt to pieces" a steel wire 10 1/2 inches long and 1/100 inch thickness (p 27). When a lower charge was passed through a brass wire 1/170 inch diameter, " "the wire was heated so red hot, as to be flexible, yet it did not separate, but was shortened near three eights of an inch." (page 30). Later "the charge was sent through ten inches of steel wire, one hundredth of an inch thich, which made the wire red hot, but did not melt it." (page 33) He noted the "calcining" or oxidation of the wire surface from the repeated passage of current. He did some parametric experiments on the heating to redness or the melting as a function of length, diameter, potential of charge, and capacity of the "battery" of Leyden jars, and compared the current carrying abilities. Thus many early 19th century "inventors" of the incandescent light were just replicating 18th century work done with Leyden jars charged by static electricity, having the advantage of a steadier supply of current. Edison (talk) 22:15, 21 January 2009 (UTC)

Joseph Priestley in 1775 [21] page 251 had previously melted iron wire1/70 inch diameter with a battery of Leyden jars, noting the continued glowing of the wire for a bit after it melted, "for some seconds." Edison (talk) 05:12, 22 January 2009 (UTC)

Volta "burned iron wire" with his battery in November, 1800. Pepys in 1802 was able to "fuse and burn the most refactory metals and to produce the most intense light." Davy in 1802 built a battery with 400 cells of 5 inches square and 40 cells of a foot square, with which he could melt platinum wire, and "redden and burn" iron wire 3/100 inch diameter, per [22]. Edison (talk) 04:31, 3 March 2009 (UTC)

Cruto's light.

ehm... why isn't there any reference to Alexander Cruto? (see http://it.wikipedia.org/wiki/Alessandro_Cruto ).

i think that he was an important person to this invention. --87.9.230.97 (talk) 16:35, 30 January 2009 (UTC)

I don't read Italian. But you do...find some references, write the articles - you know, the whole WP:Be Bold routine. This is how the encyclopedia grows. But since there's no English-language article on Alesandro Cruto it seems likely his contributions to light bulb science will never be appreciated by the English-speakers. --Wtshymanski (talk) 19:46, 30 January 2009 (UTC)

ok, i translated italian article, i hope in a pubblication.

http://en.wikipedia.org/wiki/Wikipedia_talk:Articles_for_creation/Submissions/Alessandro_Curto --87.14.250.45 (talk) 07:47, 31 January 2009 (UTC)

formulas for temperature vs light output

At what temperature does the filament in a light bulb first start glowing at all visibly (for example, operated by a dimmer)? Are there formulas for temp vs light output? A table of temp vs. apparent color of the glowing filament? -71.174.182.182 (talk) 14:56, 21 May 2009 (UTC)

There is a good set of formulas here that relate volts, amps, watts, lumens, and life; for General Electric lamps:

• http://www.zap-tek.com/webpage/Elect/lsn_4/014_lamp_res.html

It is said that a wire has to get up to a temperature of about 2000-degC to start emitting significant quantity of visible light. This is above the melting point of copper, aluminum, iron, and steel.

Here is a good source of formulas and examples. It says that the power in to a lamp is proportional to the fourth power of the temperature of the filament in Kelvin, assuming all the power in is radiated from the filament:

• http://www.sci-ed-ga.org/modules/materialscience/light/

-71.174.182.182 (talk) 15:58, 21 May 2009 (UTC)

Mystery bulb caption

The new caption is still gibberish. What's an "E27 bulb housing" ? There's an E27 base, there's an A-shape bulb, but what's a "bulb housing" and where does it show in the picture? Why show this arbitrary lamp at all? The caption should explain the relevance of the picture to the article else it's just a page decoration. The German text in the image description is no help at all. --Wtshymanski (talk) 17:20, 23 May 2009 (UTC)

Well its an example of a replacement bulb. But if you feel that strongly about it I suggest you replace it with another example of a replacement bulb. If you don't like the wording please change it--Thorseth (talk) 21:01, 23 May 2009 (UTC)

I don't know what's in the picture. Whoever wanted it in the article should explain its relevance. --Wtshymanski (talk) 15:40, 24 May 2009 (UTC)

It's a replacement blub! Using a halogen, like the ones refereced in the table. I have elaporated on the use of other light sources and retrofitting in the section, so I hope that clears up the matter. --Thorseth (talk) 08:37, 26 May 2009 (UTC)

Banning Incandescent Bulbs

Why is it considered preferable to use fluorescents, when they contain mercury? Granted incandescents use more power, which is bad for the environment, but isn't mercury worse? —Preceding unsigned comment added by 71.167.114.131 (talk) 01:01, 25 April 2008 (UTC)

Of course mercury is worse. A million CFLs in a land fill is 5 kilogrammes of mercury (at 5 mg per lamp). The environmentalists claim the mercury can be recovered when the lamp is recycled, but this is a myth. Partly because most of the mercury is adsorbed into the glass, phosphor and cathodes as the lamp ages, but mainly because it is completely unecomomical to recycle the lamps. There is no recycling facility anywhere on the planet. 20.133.0.13 (talk) 14:18, 28 August 2008 (UTC)

Although incandescents use more power, they are only less efficient than fluorescents when they are outdoors or are being used in a location with an ambient temperature that is high enough. In other words, when it is anything less a few degrees below room temperature outside, an indoor incandescent bulb can be considered 100% efficient, as the heat it produces is being used (unless it's making noise, which happens sometimes). --driids (talk) 19:09, 19 June 2009 (UTC)driids

Wrong. Define "efficient". You (nearly) always buy a light bulb to make light, not for making heat (aside from niches like Easy Bake and brooders). If you're burning fuel to make electricity, it's always more efficent ( where I mean "efficiency of units of visible light energy and usable space heating energy vs. total energy input") to burn the fuel in your local furnace for space heating, rather than throw away 50-75% of the energy in condensers at the steam plant or hot waste gas off a gas turbine (and a trifle more in transmission losses). A 50% efficient (purchased BTUS in the pipeline gas vs. BTUS that actually make it into the house) household furnace would be a relic of a bygone age, and probably dangerous to use - whereas only the very best modern combined-cycle gas fuelled plants hit 50% efficiency (pipeline energy input vs electrical energy in the wires going out). There's very few parts of the world where a kwh of heat energy for space heating costs as much as a kwh of electricity - after all, they *burn* natural gas and coal to *make* electricity, presumably at a profit. --Wtshymanski (talk) 21:27, 19 June 2009 (UTC)

Who is Edison?

(Help edit this page!!! YOU will be recognized as the writer! Have fun!) —Preceding unsigned comment added by 65.5.190.240 (talk) 22:15, 30 January 2009 (UTC)

Haha, nice one! :-) --Paxcoder (talk) 15:36, 3 July 2009 (UTC)

Make your own light bulb

There are many home experiments possible, making "light bulbs" to learn about the physics. Even a pencil can be used! (But be careful not to burn down the house.)

A pencil lead (carbon) has a resistance on the order of one ohm. Running appropriate current through a mechanical pencil lead produces light by incandesence: www.instructables.com/id/Lead_light_Not_a_LED/ -71.174.182.182 (talk) 00:37, 22 May 2009 (UTC)

Is someone really "learning about the physics" by making something get red (or white) hot by passing current through it? A pencil lead is likely to pop apart and a redhot piece land on something or someone. Note that the video says "Disclaimer: this is a dangerous project.1.This is very HOT up to 300 degrees minimum so be careful.If you get hurt during this project it is not my fault." The video notes it is "up to 300 degrees." Yeah, like a couple of thousand degrees over that celsius temperature! I have tried this in the past with a battery, and the lead is likely to get white hot and explode into fragments. If the fragment flies into an eye, blindness could result. It will burn flesh or objects it lands on before it cools off. We should be very cautious about encouraging readers to perform such a demonstration. Edison (talk) 17:49, 29 May 2009 (UTC)

Could this graph be useful?

The table it comes from is unreferenced, so of cause it would be better with referenced values. But I think it is important to see how the efficiency levels off, and that is better seen in a graph--Thorseth (talk) 09:04, 28 May 2009 (UTC)

The efficacy of practical incadescents depend on the life for which they are designed, whether single of coiled coil filaments are used and the composition of the filling gas, as well as the rated voltage.
 A good indication of the variation of efficacy with wattage for lamps designed for an average life of 1000 hours can be found in IEC Publication 64 - Tungsten filament lamps for domestic and similar general lighting purposes - Performance requirements. My (old) copy gives two tables - "Lamps with normal luminous flux" and "Lamps with high luminous flux"  The former covers single coil lamps and the latter coiled coil.  They list "Minimum Rated luminous flux" for voltages 100 to 250, for wattages from 25 - 200W  Earlier editions included higher wattages in the first table.  

From the High Luminous flux table it can be deduced:

         Watts       25      40    60    100   150    200

      Efficacy

120 V 10.6 12.5 14 15.8 16.1 17.0 230V 9.2 10.4 11.8 13.4 14.4 15.2 From the "Normal Luminous flux talbe: 120V 8.8 10.9 12.7 14 15.5 16.3 230V 8.8 8.5 10.3 12.4 13.8 14.5 The apparent anomoly with the 230V 25W is because this lamp was a vacuum lamp, while all the others would be gasfilled.

It is unlikely these values have changed in later editions.   

These show a flattening off at higher wattages and that the benefits of coiled coil filaments are greatest in the 40 -100 W range. Redcliffe92 (talk) 14:17, 26 June 2009 (UTC)

Material in "Commercialization

I removed some text from the Commercialization section which was not really about commercialization, so much as it was poorly referenced and misleading claims about operating bulbs on DC, and claims that it was simple to make a "permanent light bulb." Even back in the 1890's they knew that there was a tradeoff between light output per watt and lifetime. If a bulb is operated at a low current, its lifetime is extended but the hue becomes more reddish and there is much less light output per watt. Thus more bulbs have to be installed to achieve a given level of lighting, at a higher cost for fixtures and wiring, as well as for the electricity used. with a higher overall cost. The claims about inserting a rectifier in the socket do not make clear whether it is a simple half wave rectifier, which would drastically reduce the RMS voltage and the efficiency. The cite to a scientist was some off the cuff remarks in a blog, and not a book or peer-reviewed journal. Edison (talk) 17:39, 29 May 2009 (UTC)

Trivial statement removed

I have removed the following passage:

As for any other electrical appliance, the hourly cost of operation can be
calculated by multiplying the input in watts by the cost per kilowatt-hour and
dividing by 1,000; for example, a 100-watt lamp operated on electricity that
costs 10 cents per kilowatt-hour will cost 100 × 10/1,000 = 1 cent per hour to
operate.

Not only is it entirely trivial and only tangentially relevant, but it is also highly confusing: I actually spent some fifteen seconds contemplating the meaning of the paragraph, looking for a non-trivial statement, not realising that someone actually wrote an entire paragraph on something so trivial. —Preceding unsigned comment added by 88.77.131.54 (talk) 05:45, 1 June 2009 (UTC)

Initial acceptance by society

I assume that light bulbs replaced candles at some point as the main artificial light source in industrial societies. When did this happen??? Light bulbs combined with electric power in every home presumably radically changed people's ability to work when they pleased. This huge effect on society is completely unmentioned. My main curiousity is when did this happen? (Of course it will vary by region, and many places still have no power, but I think it is still a reasonable question.)

It is very nice to cover the zillion patent history, but even the "commercialization" section doesn't tell me when, say, a typical New York apartment or London flat was lit primarily by candles vs. light bulbs. Did they catch on slowly? Quickly? In what decades? Please, somebody tell us the social history! 130.60.5.218 (talk) 22:05, 29 June 2009 (UTC)

Electric lights did not generally replace candles. Candles had been replaced in most cities by gas lights, before gas lights were replaced by electric incandescent lights. Gas lighting was generally brighter and steadier than candle light, and the cost per unit of illumination per hour was lower with gas lights. In the country, electric lights replaced kerosene lamps. Kerosene lamps (called "paraffin" lamps in UK) were cheaper to operate than candles. In cities, electric lighting displaced gas lights gradually. Some city residents still had gas lights into the 20th century. Electric lights became available in many US cities by the 1890's. The UK lagged a bit behind because of regulations which made the electric industry less profitable. After electric lights, the next main benefits were electric ironing (try ironing a white shirt with a sadiron heated on a stove. A bit of soot and it's back to the washtub). Electricity made electric well pumps possible, electric washing machines, electric fans, and electric stoves(hobs in UK), all in the early 20th century. In cities and factories, electricity allowed more economical factory operation of machinery and elevators, as well as electric trains. It is hard to state what year the average apartment had electric lights, but the slums lagged behind the fashionable dwelling, which had them by the first decade of the 20th century.See [[23] from 1894. In the mid 1890's, electricity was still more used for street lighting than residential lighting. On p 25 it is noted that one gas jet equal to 12 standard candles consumed as much oxygen as 4 people. The initial 60 watt electric light bulb was designed to be brighter than that while consuming no oxygen from the room, and generating no soot, and offering no possibility of asphyxiation, which an unlit gas jet might cause in a small room. The heat generated in the room was shown (p25) to be a tiny fraction of that from the gas jet, which in turn was less than the paraffin lamp, which was less than the equivalent candles. When a city got an electric plant and the mains were extended to someone's neighborhood, those who could afford the wiring got electric lights in their homes. To avoid original research, it would be best to find a modern scholarly review article or book which covers your question rather than integrating info from such older sources, which tended not to take the larger or more historical view. Edison (talk) 04:37, 30 June 2009 (UTC)

Free lightbulbs?

I've heard that in the 1950s lightbulbs were given away for free when you recycled your old ones(I think I heard it was the Edison Company). Then someone decided that they wanted to make a profit off selling lightbulbs so they sued on grounds that the company giving lightbulbs away for free was running a monopoly and that was the end of free lightbulbs? 65.42.26.190 (talk) 20:19, 27 July 2009 (UTC)

Some U.S electric companies, into the 1970's, had a service which exchanged burned out light bulbs for new ones. The idea was that each light bulb in service presented an opportunity to sell more electricity, particularly in residential service at night when the business and industrial load tended to fall off, thus evening out the load curve. There may have been a small monthly fee. Does anyone have a reference in electric company literature to verify this practice, so it could be mentioned in the article? Edison (talk) 06:02, 28 July 2009 (UTC)

I remember that. I think they did charge a tiny fee, maybe to make people use the service more than to earn any money. You would exchange the bulbs at the grocery store, as I recall. A SCOTUS legal case that mentions the practice was Cantor vs Detroit Edison Co., 96 S.Ct. 3110, 428 U.S. 579, 49 L.Ed.2d. 1141. Abductive (reasoning) 01:57, 17 October 2009 (UTC)

Economic inertia and article WP:OWNership

Is the incandescent the first mass-produced electric light source? And does not its continued use, in the face of better alternatives, represent economic inertia by virtue of its position? User:Edison says not to mindlessly edit war, but in his edit summary he said "Candles and oil lamps were also mass produced. Do not mindlessly edit-war. Take it to the talk page." Since my edit said "By virtue of their position as the first mass-produced electrical light source" and he failed to notice that, who is the mindless one? Abductive (reasoning) 03:13, 17 October 2009 (UTC)

But it's wrong. Arc lamps were mass produced and are extinct. I picked up a wonderful pair of books that spend whole chapters discussing the different makes and models of the arc lamp, care and installation, different types of electrodes, AC and DC operation, open vs. enclosed arcs, the magnetite arc, automatic feeders - all gone now. Anyone editing an encyclopedia article should have a knowledge of the topic before making generalizations. Repeating the same actions over and over is what Douglas Hofstadter called "sphexish" behaviour - the anti pole of consciousness. Perhaps after the first couple of reverts, one should consider if one is perhaps indeed in error. --Wtshymanski (talk) 12:18, 17 October 2009 (UTC)

The WP article on arc lamps makes it sound like they started to be commercialized before incandescents, but likely not mass produced before incandescents, perhaps depending on your definition of mass production. So I'm not sure whether the statement is correct or not, but it's not the kind of self-evident statement we should put in without a reliable source.Ccrrccrr (talk) 01:00, 11 November 2009 (UTC)

Exploding light bulb

So much talk on discussion forums all over internet about exploding bulbs. So many photos and videos. Sometime light bulb explosion causes injuries and even suspected cause of, apartment fire, wildfires, fire on train etc. But I am not finding any website to give references. I can't give references of discussion forums. I just don't understand what is going on. Hope that some user knows better references. If so, please add a section to this article Light bulb and redirect article created by me to this article. Thanks! Rāmā (talk) 15:49, 16 November 2009 (UTC)

This isn't a topic for an encyclopedia article - any more than getting wet in the rain is. Incandescent light bulbs break all the time,it's unremarkable and not notable - might as well have an article on cigarette-butt litter on public streets. --Wtshymanski (talk) 16:46, 16 November 2009 (UTC)

It's a real issue, not with regular incandescents but with halogens, which have two factors that make them dangerous in that way: 1) high pressure inside the envelope (10-20 atm if I remember right), and 2) glass runs hot enough to ignite things when the hot shards scatter. Rama and me saying so doesn't make it worth including yet, but nobody proposed putting it in without finding verifiable sources. Here's one [24]; here's another source that doesn't meet standards of verifiability but might be a good start towards finding better sources: [25]. Also note that if we put real info there it can help people sort out rumors. Ccrrccrr (talk) 16:57, 16 November 2009 (UTC)

Article is tagged for deletion by other user. My purpose was to let people know causes of this phenomenon. OK, leave it. Thanks for your reply. Rāmā (talk) 17:24, 16 November 2009 (UTC)

Split history ?

I really like having the history in-line in an overview article, but perhaps the section is large enough to split out? ---Wtshymanski (talk) 02:33, 11 November 2009 (UTC)

Split. Yes, it's gotten big enough that it's not helpful to a typical reader. Ccrrccrr (talk) 03:57, 11 November 2009 (UTC)

Changed my mind, at least - keep the history in-line and moved some of the tables to more relevant articles. --Wtshymanski (talk) 14:04, 26 November 2009 (UTC)

LED efficacy

maybe add mention in the table of comparing efficacies of the recent commercially available Cree XP-G white LEDs of 132lm/watt —Preceding unsigned comment added by 85.83.19.103 (talk) 19:35, 23 December 2009 (UTC)

Planned Obsolescence

Considering its the archetypical example of Planned Obsolescence in engineering and business courses which discuss this, shouldn't their be a section on how lightbulbs are designed to fail by insuring the gas mix inside the bulb will oxidize the filliment? 208.66.124.31 (talk) —Preceding undated comment added 14:45, 27 January 2010 (UTC).

This should be in the article only if reliable sources can be provided which document the claim. When the claim is made that "light bulbs are designed to burn out so you have to buy a new one," it ignores the issues of efficiency and total cost per unit of lighting per hour. You don't get something for nothing in light bulb engineering, a fact which was aready well document by 1890. Basically the filament thickness and length controls the light output and lifetime, and there is a tradeoff between the two. Operating a bulb at a lower voltage decreases the lumens per watt of electricity used, but extends the lifetime. Reduced output could require more bulbs or higher wattage rated bulbs to get the desired light level. The electricity used by a typical bulb over its lifetime is usually many times more expensive than the initial cost of the bulb, so sensible engineering calls for striking an economic balance between bulb life and lumens per watt. At the GE site, specifications can be seen for "GE soft white 100 watt 120 volt bulbs" which provide 1690 initial lumens with a lifetime of 750 hours (product code 41036), and for a similar bulb which runs on 120 volts and provides 50% longer life, 1125 hours, but only provides 1600 initial lumens (product code 97761). This relation between a lifetime and output has been in lightbulb engineering books for well over a century. The bit about "putting gases in the bulb to oxidize the filament" is nonsense. The first practical bulbs, by Edison and by Swan, required excruciatingly long use of improved vacuuum pumps to get out the oxygen which would oxidized the filament in earlier bulbs. Later bulbs used inert gases to get improved performance with metal filaments. I could find no sources saying that manufacturers put oxygen in bulbs to make the filaments burn out. Edison (talk) 16:49, 27 January 2010 (UTC)

If there was enough oxygen in an incandescent bulb to oxidize the filament to failure, that reaction would take seconds the first time the bulb was turned on. And according to the History column written by Hal Wallace in the IEEE Industry Applications Magazine, November/December 2001 issue, page 13, GE chemist Edward Zubler discovered that a tiny bit of oxygen, on the order of 10 parts per million, was required for the halogen lamp cycle to work properly. This oxygen actually *extends* lamp life.

You can make an incandescent "century lamp" that will last 1,000,000 hours but you'll pay a fortune in electricity for any reasonable amount of light from it. (let's see, life/LIFE is as LUMENS/lumens to the 3.86 power...1000 times the life implies the lumens would be about .17 and lumens/watt about .38...if the exponential relations hold at such absurd extrapolations). Bulbs are cheap compared to the energy they use, same as electric motors. As King C. Gillette, Hewlett-Packard and IBM, learned, keep the initial cost low and make your money on supplies. --Wtshymanski (talk) 17:28, 27 January 2010 (UTC)

I thought the automobile was the canonical example of planned obsolescence? Though cars go obsolete at a glacial pace compared with personal computers. --Wtshymanski (talk) 17:33, 27 January 2010 (UTC)

bulb coating

Why not mention "pearl" versions? —DIV (138.194.12.32 (talk) 06:17, 26 November 2009 (UTC))

Why not, indeed? The article mentions Marvin Pipkin and the inside frosted bulb, but if you've got more on bulb finishes, have at it. --Wtshymanski (talk) 14:04, 26 November 2009 (UTC)

This article also briefly mentions coatings. The article says: "Next, the inside of the bulb is coated with silica to remove the glare caused by a glowing, uncovered filament. The company emblem and bulb wattage are then stamped onto the outside top of each casing." Bus stop (talk) 15:17, 20 January 2010 (UTC)

Notes to add

We need a little more on Sawyer and Man's bulb, which was important to Westinghouse getting the Worlds' Fair lighting contract when Edison wouldn't sell him any lamps to use on AC. Sawyer looks like a tragic figure and Man is interseting as a rare lawyer/inventor. I've renamed a section to "manufacturing" which could be considerably expanded. --Wtshymanski (talk) 15:05, 20 January 2010 (UTC)

As we started to discuss above, it might be time to split out the history. Any addition like this would probably tip the balance and make it time to do that. I don't mean that to discourage adding it, just to encourage a split in the process. Ccrrccrr (talk) 21:04, 6 February 2010 (UTC)

Efficiency comparisons

The first sentence reads "Approximately 90% of the power consumed by an incandescent light bulb is emitted as heat, rather than as visible light.[27]"

This should be made more accurate. You cannot speak of emission of heat. Emission (or radiation) is one possible way to TRANSFER heat. The emission consists of photons in the IR part of the spectrum. And if the human skin (or the air surrounding the bulb) absorbs them, they will be perceived as "warmth".

I suggest to change it to "Approximately 90% of the power consumed by an incandescent light bulb is emitted as infrared radiation, rather than as visible light.[27]"

Bj norge (talk) 11:20, 4 February 2010 (UTC)

No, not quite. Some of the wasted energy comes off as IR. Some, however, is in convection in the air around the bulb, and conduction into the bulb socket and through the air. All of those forms qualify as "heat", however. Leave the original word as it was, it is sufficiently precise for our purposes. An encyclopedia is an overview, not a physics text. --Wtshymanski (talk) 13:57, 4 February 2010 (UTC)

Very well. There are of course some heat processes involved. But they are not emitted. This sentence refers to the main processes in play. I don't see why wikipedia should be less precise than other comparable sources. There is a lot of technical language in the article as well as in thousands of other wikipedia articles. And this can quite misleading if one uses technical and collquial language in the same section. There is some room between the suggested text and a physics text.

Are we arguing about the definition of "emitted"? That's a dull argument. I've no idea what your definition of "emitted" is. It's heat that's getting out of the bulb in some way...what word would you use aside from "emitted"? And let's not write a paragraph of heat transfer physics here - one word, please. "Word" gives "produce, release, give off, give out, send out, discharge, emanate, secrete" as possible alternatives to "emit". I think "emitted" is perfectly clear, accurate, and adequately precise. But let's do have an edit war over ONE word in the article, because that's the best way to make Wikipedia great. Let's by all means write painstakingly detailed paragraphs (preferably with a dozen or so Navier-Stokes and Reynolds equations) to show the hapless encyclopedia reader just how incredibly rich and detailed the world of light bulbs is, so that they may be awed and humbled by the display of erudition and sadly turn away in incomprehension and fear. --Wtshymanski (talk) 22:11, 4 February 2010 (UTC)

It was just a concrete and simple suggestion for a possible clarification of the text. But we cannot reach a consensus on this so we'll leave it at that. Bj norge (talk) 08:27, 5 February 2010 (UTC)

Oop ack, I'm all in favor of clarification. But fibbing to the reader about how heats get out of the bulb is not a good plan. "It seems wrong to sacrifice accuracy for expediency". --Wtshymanski (talk) 14:22, 5 February 2010 (UTC)

References

This article refers to 25 General Electric TP-110 pg. 3 26.^ Kane and Sell 2001 page 37, table 2-1 27.^ General Electric TP-110, page 23, table. and several of them are used as references repeatedely.

I get no hits on google for anywhere to view or buy these documents. Are these references available anywhere? And if not, are they appropriate references? Bj norge (talk) 21:33, 4 February 2010 (UTC)

And of course if it's not on the Web, it's not worth knowing. You might be able to get GE TP 110 from General Electric - the bulletin is a standard part of the GE catalog sets and I see it in every Engineering library I visit. I bought my copy of Raymond Kane, Heinz Sell Revolution in lamps: a chronicle of 50 years of progress (2nd ed.), The Fairmont Press, Inc. 2001 ISBN 0881733784 from the publisher a few months ago, after reading a good part of it on Google Books. Look harder. --Wtshymanski (talk) 22:11, 4 February 2010 (UTC)

The Raymond Kane , Heinz Sell book is of course a excellent, valid and appropriate references. I belive we should include the title and ISBN number (at least once), so that it is easy to find and readily apparent that it is a quote from a published book.

I cannot see how to go from the information "General Electric TP-110" to anything that one can use to obtain this. Maybe there is a fuller name that makes it easier to find? GE has numerous documents published on the net but I haven't found anything with this name. Bj norge (talk) 09:03, 5 February 2010 (UTC)

Named references don't work the way I think they should work, or I don't understand them. In a real book, you would footnote a reference once with all the identifications, name it "Foo97", then just say " Foo97 page 17" etc. as you use it. With Wikipedia named footnote markup, even though you can enter something like <ref name=Foo97> page 17, where Doctor Foo speaks extensively about the critical importantance of foot fungus on the outcome of the Peloponnesian War </ref> , you don't get a useable reference. This is either a Wiki software problem or an education problem, not my problem. If anyone ever actually read the footnotes, they'd see the Kane and Sell ISBN etc. listed. As for TP-110, again, it's a great reference by a respected source and should be available from GE or a technical library, even if they haven't put it on a Web site; again, all the description is given in one of the footnotes. --Wtshymanski (talk) 14:16, 5 February 2010 (UTC)

You say about TP-110, "all the description is given in one of the footnotes". All I can find in any of them is "General Electric TP-110". What footnote number gives more? I see it described in a NIST publication as "Incandescent Lamps, Publ. TP-110, General Electric Company, Nela Park, Cleveland, OH (1964)." Presumably we should replace the vague citation with that more detailed one, but I'm not entirely comfortable doing that without having a copy in front of me. Ccrrccrr (talk) 21:20, 6 February 2010 (UTC)

Edison Effect

Current article states, "Study of the problem of bulb blackening led to the discovery of the Edison effect, thermionic emission and invention of the vacuum tube." Although true, this article needs to explain that Edison discovered adding additional metal elements to the lamp envelope and then connecting voltage to them produced a triode vacuum tube (called 'valve' in the UK) which allowed Edison to use a little current flow between two of these elements to control a large current flow between two other elements. Edison named this the 'Edison effect'. Edison noted this control of current in his laboratory notes. Edison promptly dismissed his 'Edison effect' and other inventors later on recognized its possibilities. These other inventors made use of the 'Edison effect' and produced the Audion tube and the triode vacuum tube or valve.

I propose to write in this article, "Edison dismissed his 'Edison effect' and others invented the vacuum tube."

Will also include supporting references.

Would appreciate other editors to comment on how best to combine these two sentences to preserve the historical facts...

http://en.wikipedia.org/wiki/Triode

http://en.wikipedia.org/wiki/Triode_electron_tube

--Sponsion (talk) 06:30, 9 March 2010 (UTC)

No, Edison never put a grid in a bulb. He did patent some kind of meter using the "diode", but I don't recall reading anywhere that Edison ever looked at controlling the flow of current through the device with an additional element. Since this is an article about light bulbs and not the history of vacuum tubes, I don't think the point needs to be expanded here. --Wtshymanski (talk) 13:54, 9 March 2010 (UTC)

It would not be accurate to say Edison "dismissed it." Edison presented it as a new scientific discovery, and patented ((U.S. patent 307,031, 1883) it as an electrical indicator and regulator, but scientists at the time saw nothing significant in the discovery. I do not think the original Edison effect tube was used for anything more than a lab demonstration device and experimental tool, by Preece in England. Edison's was the first thermionic emission device where current was shown to flow unidirectionally from a hot filament to a cold metal piece in a vacuum. They did not understand that it was a flow of electrons, and in the 1890s scientists were still explaining the current as a flow of carbon atoms. Years later John Ambrose Fleming started with the original Edison device, improved it, and said he had "invented" the vacuum tube diode, and patented it in 1904, useful as a detector of radio. Edison's "lamp number 20" Edison Effect bulb, made in 1883,was recently discovered in London where it was an exhibit in patent litigation in the 19th century. Here is a photo of that first Edison Effect bulb. Here is the gap between the filament and plate. Preece as well contributed greatly to the understanding of the effect. Edison did not add a control grid to make a triode. Lee de Forest invented the triode in 1908, although he did not really understand how it worked, thinking that it needed some gas to operate. Edison (talk) 00:00, 18 March 2010 (UTC)

Vandalism

This page seems to be a repeated target of vandalism. Fortunately there are a lot of cops on the beat, but should this article get semi-protected to free them up to do more useful work? Ccrrccrr (talk) 16:40, 17 March 2010 (UTC)

That presupposes that other work is more useful. If we're not reverting bored schoolkids here, we're off changing hyphens to emdashes or quibbling about the spelling of "colo[u]r" and "alumin[i]um". All of these things are equally "useful" to Wikipedia. Most edits don't add any content. --Wtshymanski (talk) 16:47, 17 March 2010 (UTC)

In other words, vandalism is a useful diversion to keep editors out of real trouble? Hmm.... Ccrrccrr (talk) 13:43, 19 March 2010 (UTC)

As an aside, someone cited WorldNetDaily as evidence to the US federal government's phasing out of incandescent light bulbs, but used the article name of a USA Today article. I've since changed the citation to reflect the article name that was cited ("It's lights out for traditional light bulbs") and also replaced "banned" with "phased out" to make the language less inflammatory. Kakomu (talk) 18:40, 25 March 2010 (UTC)

Dangers of CFLs

I have reverted deletion of the comment about slow reaction time of CFLs. This is a serious problem for elderly and disabled individuals especially where their sight is poor. with many "trip and fall" accidents caused by low light levels.Peterlewis (talk) 07:53, 5 April 2010 (UTC)

Every personal care home I've visited has fluorescent lamps in it. You have yet to produce a credible source that shows there's any correlation between falls and lighting. You claim to be a forensic engineer, surely you have access to authoritative studies that sound the warning on this issue - strange that this hasn't made headlines every month, though. --Wtshymanski (talk) 13:10, 5 April 2010 (UTC)

So how many such homes have you visited? Here is one source about "slip and trip" accidents which mentions poor lighting: http://nasdonline.org/document/208/d000006/preventing-injuries-from-slips-trips-and-falls.html. There are many more which say the same thing. CFLs have a small delay before full illumination occurs, and in that intial dimness, a person can suffer a fall. You should avoid groundless criticism and demeaning personal comments. Such accidents are of course among the most common types of personal injury, and many agencies try to improve facilities to prevent such accidents. Peterlewis (talk) 20:32, 5 April 2010 (UTC)

Come on, get serious. You must be able to do better than that, to so strongly hold this point of view. "Adequate lighting to ensure proper vision is also important in the prevention of slips and falls." That's it. Nothing in that about incandescent lamps, fluorescent lamps, or whale-oil lamps for that matter. Could you possibly find something that says seniors don't wait for the lamps to warm up before running down the stairs? --Wtshymanski (talk) 20:40, 5 April 2010 (UTC)

This [26] (table 1 page 5 of the .PDF file) actually recommends fluorescent lamps for the elderly. --Wtshymanski (talk) 21:11, 5 April 2010 (UTC)

Well I suppose ignorance of the problems is a excuse for your curious opinions. I saw my own 106 year old father slip when using a CFL kitchen lamp with slow reaction time. I replaced it immediately. The article gives some good advice but clearly needs some healthy criticism from those of us who have to investigate real accidents. Peterlewis (talk) 21:20, 5 April 2010 (UTC)

Truly unfortunate, but that's WP:OR of the purest quill. I see nothing on the Consumer Products Safety Commission Web site, and Google searching "fluoresecent elederly fall" gives nothing so far. Find some citations that links lamp start time with falls in the elderly. --Wtshymanski (talk) 21:32, 5 April 2010 (UTC)

Also see [27] - not about falls and the elderly, though. --Wtshymanski (talk) 21:35, 5 April 2010 (UTC)

Peterlewis, I appreciate your raising this sincere concern, and I'm sorry the response was sarcasm. Unfortunately, there's really not any way that we can add anything in Wikipedia without a reliable source backing up your assertion. The idea that "instant illumination is vital for their safety" is not self evident. How are people safe for time just before the switch is thrown? Ccrrccrr (talk) 02:55, 6 April 2010 (UTC)

I'm baffled. I've re-read the above and I don't see either sarcasm or demeaning personal comments. I did accuse the correspondent of claiming to be a forensic engineer, but that is clearly stated on his user page; he can't possibly feel demeaned by that!

If it was a real problem, the CPSC and similar organizations would be all over it. (I read of a product recall of toy blocks where one block was slightly undersize and so a choking hazard...the CPSC seems to be pretty intent on this sort of problem.) I can't find anything, I've never read or seen anything (aside from Wikipedia), and so I think it's quite reasonable to ask for a citation that proves there is an issue. Our learned co-editor was unable to come up with any references when discussing the same question at Compact fluorescent lamp, though, and he's got the most motivatino to find a reference...if he can't find it, I suspect it doesn't exist. --Wtshymanski (talk) 14:02, 6 April 2010 (UTC)

Historical Note

The story of how the incandescent light bulb came into being is interesting, to say the least. Anyone today interested enough can read about it today but won't have lived through the exciting days when the battle to produce successful electric light was in full swing. The newspapers of the day were keen to chase the next big development in science and print it. Reporting scientific developments sold newspapers. There is one particular report that many would find both amusing and interesting; printed by the New York Daily Tribune in January, 1880 under the title 'Mr. Edison's New Lamp.' Here's the link to the image, provided by the Library of Congress, Washington, DC. : http://chroniclingamerica.loc.gov/lccn/sn83030214/1880-01-02/ed-1/seq-2/ MZionC (talk) 17:45, 27 August 2010 (UTC) On 9-23-10 Production was officially ended by GE of the incandescent light bulb.

Total Sales

I visited this page hoping to find sales totals for the lightbulb. How many lightbulbs have been sold since its invention? How many are sold annually? I think the page should mention same. --66.222.244.232 (talk) 18:21, 27 September 2010 (UTC)

Health Issues

I'm not prepared to make the actual changes to the section of the article on "Health Issues," until it can be properly sited. I think the issue of UV light emitted by fluorescent bulbs also requires a notation on just how much time humans today spend in doors, away from natural light. UV light is the only method by with the human body makes vitamin D.

In addition, I think it is extremely relevant to add a notation that fluorescent bulbs contain a quantity of mercury (as noted by the Hg symbol on the bulb/packaging).

However, it should be noted that I found this article by typing a search for "Light Bulb." This article is the return, which is clearly about a specific type of bulb - the incandescent light bulb. Unless this article is prepared to include more information on fluorescent bulbs, I feel the "Health Issues" section should be moved to the Discussion Page, rather than the actual article. Christopher, Salem, OR (talk) 17:23, 8 February 2010 (UTC)

But an incandescent bulb causes much more mercury to be released into the atmosphere for us all to breath than a CFL bulb, because the latter uses 1/4 less power for equivalent lumens of light. Thus the mercury argument is a red herring. Of course, incandescents are made of very thin glass to allow them to produce more light, thus making them prone to easy breakage. it is quite difficult to break a CFL, which is made of heavier, thicker, glass tube. Try to break one. I find it almost impossible without seriously focused force. In any case, a red herring concern from most likely the business as usual lighting industry. —Preceding unsigned comment added by 128.32.166.162 (talk) 23:35, 30 September 2010 (UTC)

Quite a collection of very dubious original research. Please do not add it to the article without reliable sources. Edison (talk) 15:49, 1 October 2010 (UTC)

The mercury emission issue is beaten to death at Compact fluorescent lamp#Environmental issues, with a reference. Cheesburgers and SUVs are a bigger threat to health than mercury, anyway. --Wtshymanski (talk) 17:01, 1 October 2010 (UTC)

A CFL is perhaps 4 times as efficacious at producing light as an incandescent bulb. How does the mercury emitted by a coal or oil or gas or nuclear plant, weighted by the present fuel blend, compare to the mercury put into the environment per CFL for the same luminance hours? This should come from a reliable source, and not synthesis or original research. It should take into account the proportion of CFLs which are simply broken and discarded as trash versus the percentage properly recycled at a cost of about 90 cents (US) per bulb. Edison (talk) 00:04, 4 October 2010 (UTC)

Again, this is discussed in context at the CFL article, not here. The US EPA has done this study and is a pretty reliable source, unless one is of the opinion that Big Government is yet another tool of the Conspiracy. Nukes give off very little mercury in their lifetimes, and gas plants not much more. --Wtshymanski (talk)

Edit request from 220.245.94.174, 2 October 2010

{{edit semi-protected}}

For the entry, "Incandescent light bulb", under the section "Manufacturing", could you please fix the following grammatical error.

Original text :

Early lamps were laboriously hand-assembled; cost of lamps fell after automatic machinery was developed.

Proposed, corrected text :

Early lamps were laboriously hand-assembled; however after automatic machinery was developed the cost of lamps fell.

OR

Early lamps were laboriously hand-assembled. The cost of lamps fell after automatic machinery was developed.

220.245.94.174 (talk) 09:21, 2 October 2010 (UTC)

Done elektrikSHOOS 17:35, 2 October 2010 (UTC)

A19 bulb E26 base

Well, I guess the article is locked, so there is nothing I can do about the fact that this key article does not mention the most common light bulb envelope form factor A19 nor the most common one-inch E26 base.-96.237.72.218 (talk) 18:21, 16 October 2010 (UTC)

Edit request from Indytycoon, 14 November 2010

{{edit semi-protected}}

efficacy should be "efficiency"

Indytycoon (talk) 12:50, 14 November 2010 (UTC)

Not done: The technical term is referred to as "luminous efficacy". Favonian (talk) 13:34, 14 November 2010 (UTC)

Terminology and stuff

The use of 'efficacy' in the article seems vague. At some points it seems to be meaning efficiency and other places something else, possibly 'effectiveness' - which is what I'd take 'efficacy' to mean.

Lamps, bulbs and tubes

I was mildly irritated by these terms until the point I read 'tubular bulb'. I guess this is akin to circular squares ?

Tubes are tubular and presumably bulbs are bulb-shaped ;) - hence their name. I think there is much debate about the mix up between 'lamp' and bulb but, based on one of Edison's patents, I think I've worked it out. A 'light bulb' is undoubtedly a bulb-shaped light source. A 'lamp' is a contraption for creating light - with name variations for specific designs. Lamps may use light bulbs as their light source. Alternatives are gas and oil, etc. 'Lamp' variations include 'desk lamp','standard lamp', 'street lamp', 'miner's lamp' ['Davy Lamp'] 'head lamp' (car) etc. A light bulb is what it says on the tin. A lamp includes control gear to manage the light source.

I do suspect 'tubular bulbs' exist - on the ends of thermometers - where the bulb is more a round-ended cylinder. Any envelope with a contact at either end is most certainly a tube. Bulbs are obviously significantly less tubular and have both terminals at one end of the envelope. There may well be a grey area somewhere (due to dim light?) but perhaps definable on the quantity of caps.

I came looking for when 'pearl' bulbs were first made. I note there's a lacking in the article on pearl/frosting of bulbs.

—Preceding unsigned comment added by 81.141.47.192 (talk) 00:47, 22 September 2010 (UTC)

In 1924, Marvin Pipkin, an American chemist, patented a process for frosting the inside of lamp bulbs without weakening them, and in 1947 he patented a process for coating the inside of lamps with silica.

--Wtshymanski (talk) 13:30, 22 September 2010 (UTC)

oh and i forgot to tell you this kind of light bulb can really hurt your skin — Preceding unsigned comment added by Bernster1997 (talk • contribs) 00:06, 9 December 2010 (UTC)

Edit request from 75.30.198.14, 28 November 2010

{{edit semi-protected}} Costs of lighting:

"To compare incandescent lamp operating cost with other light sources, the calculation must also consider the lumens produced by each lamp." Remove the word "also."

Actually this whole section is awkwardly written and should be written from scratch. The costs of industrial lighting are the same for residential except instead of required illumination, you have desired illumination. Just remove the word required and replace it with desired and remove the mentioning of commercial and industrial. I also don't see any mention of the cost of energy used per lumen which would be a primary determinant of the cost--the number of lumens needed times the cost per lumen.

75.30.198.14 (talk) 12:17, 28 November 2010 (UTC)

•  Done My76Strat 04:29, 4 December 2010 (UTC)