On Thomas Edison Bulb Anniversary, Lighting Breakthrough

Timed to mark the 131st anniversary of the invention of the light bulb byThomas Edison—whose birthday is marked by aGoogle doodletoday—General Electricon October 21 unveiled an illumination breakthrough: a high-efficiency LED bulb that employs jet-engine technology to keep cool.

But while the company founded by Edison was announcing this highly technical development, its rivals were aiming at a lighting achievement by the end of 2010 that would be far more tangible to consumers—a high-efficiency LED bulb, bright enough for reading, that can be screwed into an ordinary home lamp socket.

BothOsram SylvaniaandPhilipshad LED bulbs designed to replace the popular 60-watt incandescent bulb on store shelves at the end of 2010. GE had a 40-watt LED bulb on the market by the end of 2010, with its 60-watt entry to the market available in by the end of 2011.

GE says its thermal management breakthrough is key for removing an obstacle to wider LED use. Because LEDs produce light through the movement of electrons through semiconductor material, they are sensitive to heat.“LEDs are basically chips you can use in your computer, and are temperature-sensitive,” says GE engineer Mehmet Arik, who led the cooling technology project. “Thecooler you run them, the more efficiency you get.” GE said it has adapted airflow technology used in its aviation and energy businesses to achieve a low-cost solution in a small enough package to work in LED lighting.

GE said it was able to demonstrate the technology at work in a 1,500-lumen prototype—a bulb that stays cool while producing as much light as a 100-watt halogen bulb while using one-third of the energy. GE announced the development at a lighting symposium at the company’s research laboratories in upstate New York at an event to highlight the Edison light bulb anniversary. To mark “Lighting Appreciation Day,” GE encouraged consumers to post photos or videos of their favorite lighting to the social networking site, Twitter, using the hashtag #weheartlighting.

But it was too early for GE’s development to be employed in the first generation of LED home bulbs that the company put on store shelves at the end of 2010, or in the 60-watt bulbs it will market in 2011, the company said.

Replicating the Warmth of Thomas Edison's Invention

It hasn’t been easy to design an energy-efficient lighting appliance that consumers embrace as warmly as the gadget that Thomas Edison first fashioned 131 years ago in a Menlo Park, New Jersey, laboratory with carbonized thread from his wife’s sewing kit.

Edison’s technology so transformed the candlelit world that his lightbulb has stood for years as the iconic image of a new idea. And it’s a shape that 21st-century consumers are reluctant to leave behind, even though Edison’s incandescent lightbulb wastes energy by literally giving off more heat than light.

(See related fromNational Geographicmagazine,"Light Pollution: Our Vanishing Night.")

“We think consumers want a lightbulb that looks like a lightbulb,” says Stephanie Anderson, director of communications at Osram Sylvania, of Danvers, Massachusetts, part of Germany’s Siemens AG. Osram Sylvania already has had an LED bulb designed as a replacement for the 40-watt incandescent in Lowe’s stores for several months.

The twisty look of the main energy-saving home bulb now on the market, the compact-fluorescent (CFL), is seen by the lighting industry as one of a series of stumbling blocks that has prevented the product from gaining deep acceptance.

A U.S. government survey in 2009 found that only 11 percent of household sockets have CFLs. Even though CFLs easily save consumers money through lower utility bills, because they use 75 percent less energy than incandescent bulbs and last five years instead of a few months, consumers have numerous issues with the new bulbs: their color, premature burnout, the expense of dimmable CFLs, and the need to take extra care disposing of them because they contain a small amount of mercury.

Lighting experts tout long-lasting, ultra-low-energy light-emitting diodes (LEDs)—first seen as indicator lights on appliances—as the remedy for virtually all of these issues. LEDs are common in thousands of applications, from traffic lights to jumbo television screens to intense flashlights. Years of research have produced ever-brighter and ever-whiter LEDs, with lighting manufacturers now prepared to offer products they say are good enough for the living room lamp.

“Sixty watts is the holy grail of the LED replacement game,” says Anderson. “We are absolutely in a race to be the first to deliver America’s most popular lightbulb.”

Willing to Pay More for Edison-Bulb's Replacement?

Cost will be the biggest remaining hurdle for consumers, with incandescent bulbs going for about 25 cents and household LED bulbs on the market for about $35 or $40 each, says Anderson.

Manufacturers will have to convince consumers that the up-front cost is worth it for a bulb that will last for 20 years and will reduce utility bills. According to the U.S. Department of Energy, the average U.S. household uses about 40 lightbulbs and spends $200 a year on utility costs for lighting, or 20 percent of their electric bill.

U.S. consumers won’t have the choice of cheap incandescent bulbs much longer. As part of energy-saving legislation three years ago, Congress mandated a phaseout of the Edison incandescent lightbulb beginning in 2012. In the same legislation, Congress sought to spur development of more alternatives, including authorizing a $10 million prize to the developer of the first high-quality LED bulb that could replace the 60-watt household incandescent.

But so far, only one company—Philips, the largest lighting company in the world and a division of Royal Philips Electronics of the Netherlands—has entered its product for consideration in theL-Prizecompetition sponsored by theU.S. Department of Energyand numerous utility company partners.

Philips’ year-old entry is still being run through rigorous testing to see that it meets brightness and durability standards—with 200 bulbs being tested for 6,000 hours each at temperatures as high as 113º F (45º C). And 1,300 samples are being tested by utilities across the nation in real-world settings; it was important that the company be able to produce a large number of samples, said Kelly Gordon, program manager with Pacific Northwest National Laboratory, which is providing lead technical support to the Department of Energy’s solid-state lighting program. “We didn’t want something they could put together in the lab without being really close to market,” she said. Gordon said the department is expecting more entries, and the contest will continue until a product is found that can meet the test.

Anderson, of Osram Sylvania, while praising the L-Prize competition, said her company was keeping its focus on producing a bulb for the market rather than for a prize.

There are other LEDs entering the home markets aside from the 60-watt replacement bulb. LED manufacturerCree, in Durham, North Carolina, is selling a replacement for home recessed light fixtures at a price of about $50 a unit at Home Depot stores. The Cree bulb, which is integrated with a fixture the consumer installs, attempts to tap into one of the most common lighting features in U.S. homes, where there are 500 million recessed downlights.

Still, all the research to put a new generation of bulbs in living rooms, kitchens, bedrooms, and baths is aimed at capturing just a small portion of the lighting industry pie. Commercial lighting dominates the $108 billion world lighting market, with residential lighting just 12.5 percent. But Al Safarikas, director of marketing for Cree, says that it’s an inevitable focus for manufacturers.

“While the home market is not the biggest lighting market, it is the way we relate to lighting, the same way we relate to food by eating it,” he says. “The home market is a very intimate way to reach the individual.”

This story is part of aspecial seriesthat explores energy issues. For more, visitThe Great Energy Challenge.

RELATED

• "Imminent‘Lighting Revolution’ Could Save Trillions of Dollars, Researchers Predict"
• "Inventor Turned Up Energy Savings By Dimming The Lights"
• Thomas A. Edison Papers Project
• Why Thomas Edison's Legacy Includes Starless Nights

Note:An earlier photo of this story used another image.

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Squid Get Violent After Touching Eggs, Study Says

More than a few men have fought to the death to win a woman. Now it appears there's a biochemical force driving the duels—in squid, at least.

According to a new study, when male longfin squid touch recently laid eggs, the males rapidly shift from calm swimming to extremely aggressive fighting (see raw video above).

(Related:"Global Warming Making People More Aggressive?")

Researchers first noticed this effect while studying male squid arriving at breeding grounds where females had already started laying egg capsules.

Each egg capsule contains 150 to 200 eggs. A female squid will lay 20 to 30 capsules over a period of up to several weeks, during which time she will mate with multiple males, according to the National Oceanic and Atmospheric Administration.

The scientists noticed that, when male longfin squid saw egg capsules laid on the seafloor, the squid would swim toward the eggs and wrap their arms around them.

"This struck us as a very weird behavior,"said study co-authorRoger Hanlon, of the Marine Biological Laboratory in Woods Hole, Massachusetts. The team then saw that as soon as the squid contacted the capsules, the males became highly aggressive, violently beating and grappling with each other.

(Related:"Large, 'Glamorous' New Glowing Squid Species Found.")

Keen to take a closer look, Hanlon and colleagues presented 57 pairs of male squid with egg capsules and closely monitored their behavior in the lab.

Upon touching the capsules, the males attacked one another, even in the absence of females, the researchers found.

Squid Discovery to Stimulate Semen Research?

To better understand what was causing the effect, the team chemically analyzed extracts from the surfaces of the capsules. They found a number of proteins and suspected that one of them might be acting as a pheromone that could trigger aggression in squid.

Hanlon and colleagues painted each protein on the outsides of glass containers, placed squid eggs on the inside, and presented the chemical-coated objects to male longfins. Attracted by sight of the eggs, the squid touched the glass containers.

The results showed that contact with a chemical calledβ-microseminoprotein caused the male squid to become aggressive within seconds.

Hanlon and colleagues think the pheromone helps squid by spurring extreme fights, allowing the fertile females to chose the strongest and fittest males for mating.

(Related:"Mouse Tears Are Aphrodisiacs.")

"We don't know of anything like this that exists in humans,"Hanlon added."But when we researched microseminoproteins in the literature, we found that they occur in mammal semen and, more importantly, that nobody has looked at what functional effect they have.

"We hope that our discovery stimulates research in that direction."

The squid-pheromone study appears in the February 10 issue of the journalCurrent Biology.

forNational Geographic News

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Frogs Evolve Teeth—Again

Lower-jaw teeth in frogs re-evolved after an absence of 200 million years, a new study says. The discovery challenges a"cornerstone"of evolutionary thinking, according to experts.

Of the more than 6,000 species of frogs, only one, a South American marsupial tree frog calledGastrotheca guentheri,has teeth on both its upper and lower jaws. Most frogs have only tiny upper-jaw teeth.

A new analysis of the frog family tree reveals that the common ancestor of frogs, which long had lower-jaw teeth, lost them more than 230 million years ago before eventually going extinct.

The marsupial frogG. guentherididn't have lower teeth, then"boom, around 5 to 15 million years ago, it got them ... ,"saidJohn Wiens, who authored a recent study on the phenomenon.

The discovery runs counter to a principle called Dollo's law, which states that physical structures lost during evolution are never regained, according to Wiens, an evolutionary biologist at Stony Brook University in New York State.

In fact, the teeth's reappearance may have exposed the law's loophole: That it's"much easier to re-evolve things if you're already making them somewhere else,"Wiens said.

In other words, the frog"didn't have to make teeth on the lower jaw from scratch, because they're already making them on the upper jaw."

(See"Evolution in Action: Lizard Moving From Eggs to Live Birth.")

"Unassailable"Evidence for Teeth Re-evolution?

In general, losing complex features is common in evolution. Humans and frogs have lost their tails, most snakes have lost limbs, and birds and turtles have lost teeth, according to the study.

But in the past eight years or so, more studies have found evidence of these advanced characteristics springing up again—for instance, wings in stick insects and fingers and toes in lizards.

(See"Sharks Have Genes for Fingers and Toes.")

In his study, Wiens used statistical methods to trace the evolution of teeth on the family tree of 170amphibianspecies to frogs' common ancestor. The scientist used a combination of data, including DNA sequences, from modern frogs as well as amphibian fossils.

An alternate theory is that lower-jaw teeth were lost in hundreds of other frog species but notG. guentheri."It is not impossible, but it is just much, much more likely that teeth were lost once and regained once,"said Wiens, whose study appeared online in January in the journalEvolution.

Gunter Wagner, an evolutionary biologist at Yale University, said that, of all the recent research questioning Dollo's law,"this is probably the one that is least disputable."

Some of it was luck, he noted: Wiens found an animal that is isolated enough on the family tree that the results are strong and"unassailable,"said Wagner, who was not involved in the study.

"It's a very clear case of reacquisition of a lost complex morphological structure, which, according to current thinking, should not be possible."

Frog-Teeth Re-evolution a Mystery

Less certain, however, is why the teeth came back, both scientists say.

In many frogs teeth aren't that crucial: The animals generally rely more on their tongues than their teeth to catch insects, study author Wiens said.

But for some carnivorous frog species, including a group known as the Pac-Man frogs, teeth are more crucial for catching prey, Wiens said. These animals have fanglike teeth on the upper jaw and have in some cases evolved toothlike spikes on the lower jaw. But, unlikeG. guentheri, these lower-jaw spikes are not true teeth.

(Related:"Giant 'Frog From Hell' Fossil Found in Madagascar.")

The fact that toothlike structures appear more often than real teeth means that tooth evolution doesn't automatically occur when the need arises, Yale's Wagner noted.

With that in mind, natural selection—the process by which favorable traits become more common over time within a species—is"not enough to explain"why the marsupial tree frog regained its lower teeth.

"I can confidently say that we don't know,"Wagner said."It's an extremely interesting question."

National Geographic News

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Pictures: Nine Surprisingly Gassy Cities

Workers refurbish a cruise ship in Rotterdam,Netherlands, in 2005. According to a new study, Rotterdam is one of the"dirtiest"cities in the world when it comes to emissions of carbon dioxide (CO2) and methane. The two are by far the most plentifulgreenhouse gasesemitted by cities and major contributors toglobal warming, according to study co-authorDan Hoornweg.

The study, which analyzed emissions figures for 100 cities in 33 countries, determined that, for every one of its residents, Rotterdam is responsible for the annual emission of about 29.8 tons of CO2 and methane, combined.

The figure"reflects the large impact of the city's port in attracting industry, as well as fueling of ships,"according to the report.

The study looked at how much CO2 and methane a city produces each year based on consumption by residents and industries within city limits. Still, Hoornweg cautions against seeing the report as an indictment of cities in general.

"Differences in production and consumption patterns between cities and citizens mean that it is not helpful to attribute emissions to cities"to the exclusion of suburbs and rural areas, Hoornweg, lead urban specialist at the World Bank in Washington, D.C., said in a statement.

Around the world, emissions per person per year were found to vary from 5 to 25 tons of CO2 and methane for cities in industrialized nations to less than half a ton per person per year in some South Asian cities.

—Ker Than

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Pictures:"Ominous" Japan Volcano Erupts Again

Ash gushing from an eruptingvolcanoinJapancovers a downtown area of the city of Takaharumachi in Miyazaki Prefecture on Monday.

The Shinmoedake volcano awakened last week, spewing ash, lava, and lightning (see pictures of last week's volcanic lightning). The biggest explosion yet occurred on January 31, with a bang that shattered windows five miles (eight kilometers) away, according to BBC News.

Residents living near the 4,662-foot-tall (1,421-meter-tall) volcano have been advised to evacuate to a shelter.

(Also seepictures:"Merapi Volcano Ash Smothers Indonesian Villages.")

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Pictures: Ancient Egyptian Artifacts Damaged in Looting

Tanks roll into Tahrir Square outside theEgyptian MuseuminCairoon Sunday, January 30, 2011. During the chaotic protests two nights before, would-be looters broke into the 108-year-old building through a skylight, according to official reports. The vandals damaged mummies and artifacts but were arrested before they could make off with anything.

(See"Egypt Treasures Looted, but Public Strikes Back.")

—Ann R. Williams,National Geographicmagazine senior writer and regional editor

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Six New Planets: Mini-Neptunes Found Around Sunlike Star

NASA's Kepler space telescopehas uncovered six newplanetshuddled around a sunlike star—odd worlds that astronomers have dubbed mini-Neptunes, scientists announced Wednesday.

Five of the new planets are closer to their parent star than Mercury is to the sun. The sixth world lies farther out, within a region that would fit inside the orbit of Venus.

"This is the most closely packed known planetary system,"said study co-authorJonathan Fortney, an astronomer with the Lick Observatory at the University of California, Santa Cruz.

(Related:"New Planet Found; Star's Fourth World Stumps Astronomers.")

The planets are relatively small—ranging from roughly 2 to 4.5 times Earth's radius—but they are also surprisingly lightweight, indicating they are made mostly of gases. Based on their densities, four of the planets appear to have thick atmospheres of hydrogen and helium.

The two planets closest to the star have higher densities, suggesting these bodies have atmospheres of mostly water, with just a thin skin of hydrogen and helium.

Finding so many planets around the same star and being able to calculate their properties is a scientific boon, Fortney said. Like paleontologists studying related dinosaur species, astronomers can look at multiple worlds that were born together to get a better understanding of planetary transformations.

"We can do comparative science and ... we can think about how the evolution of the planets has diverged over time,"he said.

New Planets Found Via Orbital Dance

The Kepler space telescope was designed to look for Earth-size planets that transit—or pass in front of—their host stars, as seen from Earth.

(Related:"Five New Planets Found; Hotter Than Molten Lava.")

"We're basically targeting 100,000 to 150,000 stars next to the constellation Cygnus,"said Fortney, who is a member of the Kepler science team."Kepler just stares at that patch of sky unblinking for four years."

With enough time, astronomers can tease out periodic dips in the light from stars as planets pass. (Find outhow you can help hunt for planets using Kepler.)

Fortney and colleagues found six signature dips in light from a star called Kepler-11, about 2,000 light-years away. The star is almost the same size, temperature, and brightness as our sun:"It's very much like a solar twin,"Fortney said.

At such a distance, though, the star is very dim, making it hard for astronomers to use other planet-hunting techniques to verify the find. Instead the Kepler team confirmed the discoveries using a method called transit timing variations, or TTV.

"Think about one planet that transits,"Fortney said."If its orbital period is ten days, every ten days it will pass in front of the parent star. But if multiple planets transit, they'll affect each other {via gravity}. A planet may transit early or late."

Similar calculations of planets affecting each other's orbital timing are what allowed French and German astronomers to find Neptune in 1846.

The outermost planet in our solar system, Neptune was barely visible to telescopes of the time, and those who could see it thought it was a star. But astronomers knew that Uranus wasn't orbiting as it should, based on laws of physical motion.

Uranus's odd orbit led mathematician Urbain Joseph Le Verrier to predict Neptune's position and mass to account for the discrepancies.

(Related:"Uranus, Neptune Swapped Spots, New Model Says.")

In the case of the Kepler-11 star, the gravity-driven choreography of dips in starlight is almost certainly the product of multiple planets, the team concluded. Further studies, detailed this week in the journalNature,allowed astronomers to calculate with significant accuracy the masses, positions, sizes, and densities of five of the new worlds.

The sixth planet is far enough away from its siblings that it doesn't affect their orbital dance. Instead astronomers had to run through a suite of calculations to be sure the planet exists. While the team is confident it's there, they weren't able to tease out as many details about the outlying world.

"We know the radius is about 3.6 times that of Earth,"Fortney said,"and it's probably less than 30 Earth masses."

"Super Earth"Among New Planets?

The new planetary sextet is remarkably similar toanother tight-knit set of worlds found around the sunlike star HD 10180, which was announced last fall. That star lies a mere 127 light-years from Earth.

A team of scientists based in Europe found five Neptune-like worlds close to the star and a larger sixth planet farther out.

They also saw a faint signature of a much smaller world very close to the star that may be a"super Earth"—a rocky planet much larger than our own.

One key difference between the two newfound systems is that"the 'packing' is much more pronounced in the new Kepler system,"HD 10180 study leader Christophe Lovis, an astronomer with theObservatory of Genevain Switzerland, said in an email.

"At first glance I was very surprised that such a system could be dynamically stable on the long term,"he said."Planet masses in the Kepler system are lower than in HD 10180 ... which probably makes it possible to have an even more compact configuration."

Lovis and colleagues had found the planets around HD 10180 using the High Accuracy Radial velocity Planet Searcher, or HARPS, instrument in Chile. The radial-velocity method measures wobbles in starlight caused by the gravitational tugs of orbiting bodies.

"The fact that HARPS and Kepler, using different techniques, find similar things is reassuring in itself and shows how complementary both approaches can be."

Lovis notes, however, that he'd prefer to have the planetary properties of the Kepler-11 system confirmed by other techniques.

"In this particular case, radial velocities would be helpful to measure the masses, probably more precisely than is feasible with TTV,"he said. The problem is that the Kepler-11 star"is almost too faint for precise radial velocity followup and would require a lot of telescope time.

"This will remain the main contrast between the Kepler survey and a typical radial velocity survey like the HARPS one: Kepler looks at tens of thousands of distant stars, whereas HARPS looks at a few hundred nearby, bright stars."

Even More New Planets Waiting for Discovery?

For now astronomers aren't sure whether the Kepler-11 system hosts any rocky Earthlike worlds like the one circling HD 10180.

"It's possible that there are smaller planets that we haven't been able to see yet,"said Fortney, co-author of the new Kepler study.

"With a few more years of data, one may emerge. It's also possible that TTV will show us there's another planet in the system that doesn't transit. ..."

(Related:"New Planet System Found—May Have Hidden 'Super Earth.'")

What the existing data do reveal is that the closely orbiting group around Kepler-11 most likely formed very quickly.

"The way we think that big gas giants like Jupiter form is that first a protocore of ice and rock forms that's like ten {times Earth's mass}. Through its gravity, the core pulls tremendous amounts of gases on top"—notably hydrogen—Fortney said.

In the disk of planet-forming materials, free hydrogen gas lasts just five million years or so before stellar wind—charged particles flowing from the host star—blows it all away. That means the gassy planets around Kepler-11 must have grown up quickly for them to be full of hydrogen.

The Kepler-11 system is also a good case study for what happens to gas planets that move in close to their stars. Based on their sizes and orbital dynamics, the Kepler planets formed farther from the star and migrated inward, the team thinks.

The two mini-Neptunes closest to the star may once have had thicker hydrogen-helium atmospheres like their siblings, but as the two nearer worlds cuddled close to the star, its powerful radiation began to strip away the outer layers.

Looking at the differences between the two sets of planets can help astronomers understand exactly how such worlds lose mass over time.

"In the long term, I think we're going to find that multiplanet systems are common,"Fortney added."With transits limited to seeing edge-on systems, we're always going to be finding the minimum number of planets—a system could have an alignment so that we measure three planets when really there are five."

But overall, he said,"when you see one planet, you're probably going to find another."

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