The average incandescent bulb lasts around 300 hours. Doubled, this would be 600. The typical fluorescent lasts 10,000 hours and uses half the energy. Its a nice idea, but the math doesn't really add up. What about working on a cleaner-burning candle?

there's no reason why it won't work. However, it just won't be applied to the mass market anytime soon other than a "gimmick" or audience appeaser.

However, what is not commonly known is that the filaments that all light-bulbs have inside them are designed to be "time-dependent", there's a built-in obsolesce. Each filaments are specifically created to fail at a certain X amount of hours.

Yes, as amazing as it is, those light bulb companies can easily design light-bulbs that would run forever, but it doesn't make a great economic practice/sense for them. They would be literally putting themselves out of business.

The money is in replacements of the individual light-bulbs.

It doesn't require a lot of engineering ingenuity to develop a fail-proof filaments. In fact, it has already been done, patented, and hidden away. It all is dependent upon the very material used to drive the current/heat (the filament itself). The answer is just to simply swap the material itself with a stronger form of alloy with a single cell lattice. Job done.

think of it this way. .

if you were going to take an aluminum paper clip, and bent it continuously , it will eventually snap apart, right? That same concept applies to the Filament. Now. . imagine you had a paper clip made out of rubber, you would just keep on bending it . .will it snap? . .no. . why? . .different properties, different characteristics, and different results :)

I'm an engineer btw :) Any engineer with a basic knowledge of material science will tell you this :)

WILLIAM

If you really wanted some interesting light bulbs. Look no further than LEDS. They last 500K hours. If you can put them in a cluster, you have LED cluster that's as bright as an incandescent bulb, that sucks 1/8th the power of a typical fluorescent. They're nearly indestructible and emit almost no heat.

automotive bulbs often have two filaments, one for high beam, one for low... No reason you could not have two equal filaments.

"Yes, as amazing as it is, those light bulb companies can easily design light-bulbs that would run forever, but it doesn't make a great economic practice/sense for them. They would be literally putting themselves out of business."

That's a false economy. Clearly any company which did release an infinite-lasting light bulb, would steal all the business from every other company selling light bulbs. It would be the _other_ companies which went out of business, before the company which did it.

I agree with 100% William...

Instead of spending time re-inventing the light bulb, non-filament, solid state devices are the future of lighting.

Bulbs are cheap, easy and readily available, but filaments based lighting creates light as well as heat.

As we all know, heat equals loss of power.

LEDs emit very little heat aren't bothered by heat, cold or vibration. LEDs don't produce RF, UV or EMF "and" within this year will be as efficient as incandescent and fluorescents.

Although pricing for LED devices often scare away consumers, expect cost and energy requirements to decrease as output increases.

I await the day when filament based lighting will be phased out, but most likely won't live to see it.

Actually, they've said that if you take a UK bulb that normally withstands 250V current, and use in the US with only 120V, the bulb should last indefinitely. I think the math was around 1000 or more years... So if you want an everlasting bulb, just import from the UK.

It's not going to work most of the time.

The reason most of these bulbs go out is the vacume or the gas thats inside is leaking.

Multi filament lamps aren't new (think tri-lights). Rotating the bulb to change filaments would require an adapter socket (in North America at least) and it could be tricky to use.

Flourescents are a better idea to save money and minimize bulb changing; halogens if colour balance is important or if flouresents won't fit.

Heat. Simple. The long life bulbs were made from great items that withstand heat. Having two items in the bulb will allow you to swap heat source. But while the other one is waiting arounf for its day as the sun, it will be subject to, yes, heat. Reduction in the overlife of the spare is the result. Edison had a bulb that is still going. Why? Heat Management!

LED lights are already here and will be cost effective before long.

Well, you always hear about how company X could make a bulb that lasts forever but they won't because they want to be able to sell you more bulbs later --

You hear this about incandescent bulbs and it is an outright lie. While you can make very long lasting incandescents, they have serious drawbacks making them unappealing for either the manufacturer or the consumer. They will either be very low lumen, very fragile, very expensive (due to materials), or take a very long time to warm up to their full light output.

If you want a "forever" bulb, buy LED fixtures/bulbs. If you want the best tradeoff for economy without an initial purchase price that breaks the bank, go with CFL. If you want the widest selection of bulbs, go with incandescent/halogen/whatever.

I'm all for thinking different about the lightbulb, and I applaud the designers for thinking it up -- it's creative; however, the idea is half baked at best:

1) The design would not work in many (maybe most) light sockets. Requiring a specific socket design with the contact either on a centerline or offset around the ring limits the existing sockets this would work with. In other sockets, it may be impossible to prevent both filaments from having contacts at the same time - meaning twice the light; twice the heat; half the life. There's no way to argue economy if you have to replace your fixtures just to make the bulb work.

2) Bulbs fail mainly due to heat, oxidation, or vibration. Both filaments are going to be worn due to heat whenever the other one is on. If you hit a bulb hard enough or vibrate it long enough to break one of the filaments, you'll likely break them both. If a bulb has a very slow leak, poor seal, etc. or othrwise allows oxygen into the bulb, the filaments are going to burn out faster. Both of them will.

3) It already exists. 3-way bulbs contain two filaments that are activated either seperately or together at each of the three light levels. They require special fixtures, but essentially so does this design.

A practical implementation of this idea would be to produce an adaptor to screw onto the bottom or a 3 way bulb to activate one or the other filament seperately from a normal (non-3-way) base; however, the economics don't actually stack up.

Umm, ok, twice the light, half the materials, UNTIL you run into every house on the planet and rip out the existing light sockets and toss them in the land-fill.

To be a good solution, you must take into account existing infrastructure.

Let's work more on efficient flourescent or LED lighting. Try to get the cost of LED lighting down and more people will use it.

Are you guys stupid.

Normal light bulb socket
VVVVVVVVVVVVVVVVVVVVVVV
Adaptor socket sold with the lightbulb
VVVVVVVVVVVVVVVVVVVVVVV
New bulb with 2 filiments or three.

Then just have the option to buy the lightbulb with or without an adaptor.

ROFL at throwing out all the current sockets.

look, the problem with this idea is it doesn't solve the main gripe people have with incandescent bulbs. I don't give a flying rat's ass if I have to change a bulb in my desk lamp. What pisses me off is when I have to change a bulb in my stairwell. If I have to get up on a ladder to give this bulb a half-turn then wtf am I actually getting? This design offers people nothing in the situations they actually care about: bulb longevity in hard-to-reach places. It will fail.

omg i have this great idea where you put 7 filaments in the lightbulb;
i call it lightbulb 7.0, and it's 3.5x cooler than your idea

Dual filament bulbs used to be quite common in the US, with a light fitting that allowed you to use (say) 40W only, 60W only or both 40W+60W as a three-way dimmer.

But I'd guess the economics favour long-life fluorescents today, and white LEDs soon.

By the way, you can always extend the life of a burnt-out bulb by putting it in the microwave (Google for details first, can be dangerous if done incorrectly.)

You may have cut the cost of materials by approximately 50% by doubling the life of the bulb (which still doesn't stand up to the efficiency of CFL and LED lighting, as others have pointed out), but you've done pretty much nothing to the cost of labor for bulb replacement, which is one of the major costs of incandescent technology. You still need a guy to come by every X hours to give the bulb a turn, where X is the same as it was with a more traditional incandescent bulb design.

Wow, who would have thought a lightbulb to sollicit so much conversation... how many treehuggers does it take to screw in a lightbulb? Technically, a second filament would be subject to the same stress as the first, even while standing idle. So chances are the second filament wouldn't last nearly as long as the first once put to work. The design objection to fluorescents to me had always been its brash whiteness. But today you can get fluorescent that are tuned to mimick the yellowish glow of incadescent. In fact the way to really spare the bulb, is to revert all lights to DC, as it is the constant AC flicker that stresses bulbs the most. Incadescents can run on either AC or DC without modification... but fluorescents, because of their electronic ballast, need to be designed for either one or the other. Most mobile homes and boats all run on DC power. Tesla never advocated AC for inside homes or office... ONLY to allow the electricity to travel long distance. Reverting back to DC once at destination would save an immense amount of energy... ALL computers for example, have a built-in transformer that alters the 110 volt AC current into DC current. There's a big statue of Tesla near the falls in Niagara. I'll never forget the tour guide saying he had invented alternative currency... as if the only thing she was thinking about was how to spend her pay check in Canada!

All the efficiency arguments are accepted. Just a technical point; you only need one extra contact for the two filament solution, that is three contacts not four.

One contact can be common to the two filaments.

I would like to know, what lightbulb company can make a lightbulb that would last for 40 years and be located in the family bathroom, where it is turned on and off 3-8 times a day conservatively speaking, not to mention the condensation. If you can't build one then someone can. Because I own a lightbulb that is approximately 40 years old and has been in constant use since purchased in the early 60's. I'm sure someone out there who builds lightbulbs would like to see this bulb to duplicate it, if you would like to see this lightbulb please contact me, 1-604-295-3632 British Columbia, Canada.

That a real cool idea.
Let lots of it come.
it is high time more of Indians and world citizens participate in the design boom competions.
a develping country and for that matter all countries and the underdeveloped need to save.
Hope to one in the corner shop in due time.

William is talking toffee.
An infinite incandescent is of course possible - just reduce the voltage.
But then the efficiency drops so low as to completely negate any saving on replacement light bulbs.
CCFL and, eventually, LEDs are the way to go - not conspiracy theories about magic filament materials etc.

I have been working with common 40 and 60watt incandescents for a little over three years now and have found a single problem that seems to be constistent and very common with with most of the major manufacturers. I have been able to overcome the built in, planned obsolescence with some experimenting. My problem now is to find a maufacturer who will work with me to get it to market. My modification can be incorporated in the assembly of the bulb with very minor changes in the production process.

CFL's are presently the optimum choice for lightbulbs. They are cheap (prices are between $0.99 and $9.99) and some of them (not all) produce a remarkably high quelity white light. In comparison, LED's are are expensive. However, the greatest drawback of LED's is the poor quality of light produced. It tends to be very cold and bluish. Morever, the light is highly directional.

I've written about this before and thought it had been put to rest by now, but I guess not. Think about the last 100 times you changed out an incandescent bulb: were you reading when it faded out, or did it go *pop* when you flipped the switch? 99% of the time, it was when you flipped the switch. The problem isn't heat, it's a sudden change in temperature. The filament heats up quickly, but not evenly, so part of it stretches more than the rest and *pop*. It isn't leaking gas, or heat exposure. To solve this problem, you could make the filament thicker and restrict the current. That's the secret behind the Centennial Light, a lamp that has burned since 1901. The problem? It's 4 FREAKIN WATTS!!! You can't even tell that it's on if the other lights in the room are on.

http://www.centennialbulb.org/photos.htm

Planned obsolesence? Only if idiots that like to lose money are running Philips and GE. If they had a long lasting light bulb, they would have brought it out to compete with CFLs by now. Where is it?!?!

The lamp described in this article is okay, but I'd prefer a CFL and, when the prices drop, an LED. They can tweak the effective color temperature and directionality of LEDs, but at $200+, who cares? The two advantages that this incandescent has over a CFL is that it requires fewer resources to manufacture (CFLs still use trace amounts of mercury, IIRC, as well as the fluorescing gas, and remember that you are still going to need 2-3 of these 2x bulbs to outlast a CFL) and incandescents can be used in common dimmer and sensor-controlled sockets. But the resources to operate a CFL are still much lower, so I would guess (without running numbers) that the CFL is the winner over its lifetime. If you don't need the control circuits, use a CFL and fuggetaboutit.