After a century of unimaginable technological change, the incandescent lightbulb is much the same. It may be the most backward technology in use on a large scale, and yet it endures, even inflames.
The federally mandated phase-out of inefficient versions of the incandescent in some of the most commonly used wattage specifications has met with intense resistance, from Tea Party rhetoric to panicked buyers' stockpiling a lifetime of the classic A-Line incandescent, with its "warm" glow.
A fair share of the battle is over shape: More than one hundreds years after Thomas Edison's breakthrough, most consumers still want their lightbulbs in the traditional pear shape.
The story of how the incandescent bulb got that iconic shape is itself a relic of a former manufacturing age. The "ribbon machine" that blows glass bulbs was perfected in the first decades of the 20th century, and the shape developed through a combination of air pressure and the molding process.
At the time, the ribbon machine was a significant breakthrough, allowing manufacturers to make a several thousand bulbs a minute.
"You can take a bulb from the ribbon machine and bounce it on the floor and it will not break," said Terry McGowan, a former manager of the lighting division at GE who now serves as director of engineering for the American Lighting Association. "It will bounce like a ball."
The pear shape no longer represents a vital production but is still what many people want to see on store shelves.
"Lighting is an art and a science. The appearance of fixtures and bulbs becomes part of our culture, and when you try to change culture, you better have a strong reason to do so," McGowan said. The incandescent's classic form also houses several tricky engineering problems (the need for a heat sink and lighting quality that recreates the diffuse, "warm" light to which homes lit by incandescent bulbs have become accustomed). Companies are still working on design and engineering solutions to these challenges within an LED frame.
According to Tom Boyle, chief innovation manager for GE Lighting, the image of a pear-shaped incandescent goes beyond its origins.
"Look at a PowerPoint," he said. "If you pull up icons, you see a lightbulb. It's way beyond engineering at this point, and iconic in multiple aspects, including the psychology of ideas."
The situation has led to division among manufacturers about how to design the 21st-century lightbulb.
The approaches taken by GE and Cree show the extent to which companies are accounting for consumer visual preferences, while Philips Lighting and LED specialist Switch Lighting are pushing the design envelope. The competition is a once-in-an-era opportunity, literally, as LED bulbs can provide up to 25,000 hours of residential use.
"How we transition to CFL [compact fluorescent] bulbs and LEDs is a billion-dollar question," said Todd Manegold, director of LED lamps at Philips.
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There are about 5.6 billion lightbulbs in U.S. residential use, including 4.2 billion incandescents and roughly 1 billion CFLs, according to IMS Research.
"Manufacturers are trying to capture these billions of sockets now residing with incandescent bulbs," McGowan said. "And you have to be the size and shape of what's in those sockets. If you don't get that socket now, it won't be available again until who knows when. It's a desperate horse race."
John Stranick, head of GE's North American consumer lighting business, said the classic A-line shape is one that consumers grew up with. Even though it's inefficient, he added, it does a lot of things well, specifically in diffusing heat and light quality.
GE's experience with CFLs showed that even after the company had worked out start-up time and warmth problems, consumers would reject them based on design.
"Even before we got to LEDs, we had to replicate that iconic shape," Stranick said.
Cree's new advertising campaign carries the tagline, "The biggest thing since the light bulb." Cree ads also include the statement, "Nostalgia is dumb," but it's clear from speaking to Michael Watson, the company's senior director of marketing and product applications, how much thought goes into the bulb's shape and design history, and the irony inherent in the tagline for a product that retains the features of Edison's glass-blown disruptive innovation.
"It was conscious for us to make something pear-shaped for a specific reason," Watson said. "We have to make a sweeping change and want 100 percent adoption as fast as possible, and to drive the velocity of that adoption. It was obvious to us that making the LED look like the classic bulb was a preeminent barrier, along with price.
"Price is still No. 1 on the list, but design is close," Watson said. Consumer awareness surveys put product confusion No. 2, behind price, and that reflects the issue of the bulb's shape, Watson said.
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The approach taken by GE and Cree differs from that of Phillips and Switch. Both of those companies have bulbs mimicking the classic shape and are bringing down costs for bulbs, but they also have high-end LED bulbs that can be compared to the difference between a Toyota Prius and Tesla Model S.
"I think the design has to be consumer-friendly, but my definition might be a little different," said Manegold at Philips. "Mass adoption will be triggered by light effect that people recognize at a price they will pay for. In my house, the effect is far more important than the shape ... and I think consumers recognize that."
McGowan of the American Lighting Association said Phillips has been "carefully treading the line between appearance and function" and has managed to make LED lighting interesting, even if it can be argued that won't be the quickest route to mass adoption.
Mark Costigliola, managing director of Advanced Lumonics and EarthLED.com, said that for Philips, there is an element of "personal pride" in the design and a European aesthetic that may not translate as easily to the U.S. consumer market.
"They [Phillips] want to create a vision for what a new bulb should look like," he said. "They want to drive LED design." That contrasts with more parochial approach of GE, which does not aim to be groundbreaking, he added.
Advanced Lumonics has a museum with two examples of every LED bulb ever made, a kind of Noah's Ark of LED history, including "corncob" and "snowcone" designs. The "scrapped" designs of LEDs' early days also include external "fins" used as an approach to the heat sink issues, and colored phosphor coatings over the bulb exterior as an approach to light diffusion—LEDs by nature emit light in one direction, while a residence typically requires an omni-directional lighting source.
Costigliola said Cree wants most to make a bulb with the Edison shape, and that the company's sales data may show that for mass adoption to take place, the standard shape needs to be a big part of the equation.
"The Cree bulb isn't a show-off," he said, compared with a higher-priced Switch "liquid-cooled" bulb, or a Philips' Wi-Fi-enabled Hue bulb or LED lighting fixture—the latter costing several hundred dollars. Though he stressed that price remains king: When Philips lowered the price on its yellow phosphor-coated LED bulbs, a technical solution Philips has since moved away from in newer designs, EarthLED.com saw a bump in orders, able to "move 4,000 a month on Amazon."
McGowan said that it's easy to lose sight of the historical fact that no light source ever invented has completely disappeared.
"The Amish have nothing but kerosene lamps in their living rooms," he said. "The consumer can't be dictated to in lighting, and the faux old-fashioned bulbs with carbon filaments that glow are very popular now. It's appearance lighting, not efficient lighting."
"LEDs won't take over 100 percent of the market. All these technologies will exist, but comfort level will dictate how much adoption there is, and if you make it familiar it accelerates the comfort level," he said.
—By Eric Rosenbaum, CNBC.com