Posted on 10/22/2005 8:12:55 AM PDT by ZGuy
The main light source of the future will almost surely not be a bulb. It might be a table, a wall, or even a fork.
An accidental discovery announced this week has taken LED lighting to a new level, suggesting it could soon offer a cheaper, longer-lasting alternative to the traditional light bulb. The miniature breakthrough adds to a growing trend that is likely to eventually make Thomas Edison's bright invention obsolete.
LEDs are already used in traffic lights, flashlights, and architectural lighting. They are flexible and operate less expensively than traditional lighting.
Happy accident
Michael Bowers, a graduate student at Vanderbilt University, was just trying to make really small quantum dots, which are crystals generally only a few nanometers big. That's less than 1/1000th the width of a human hair.
Quantum dots contain anywhere from 100 to 1,000 electrons. They're easily excited bundles of energy, and the smaller they are, the more excited they get. Each dot in Bower's particular batch was exceptionally small, containing only 33 or 34 pairs of atoms.
When you shine a light on quantum dots or apply electricity to them, they react by producing their own light, normally a bright, vibrant color. But when Bowers shined a laser on his batch of dots, something unexpected happened.
"I was surprised when a white glow covered the table," Bowers said. "The quantum dots were supposed to emit blue light, but instead they were giving off a beautiful white glow."
Then Bowers and another student got the idea to stir the dots into polyurethane and coat a blue LED light bulb with the mix. The lumpy bulb wasn't pretty, but it produced white light similar to a regular light bulb.
The new device gives off a warm, yellowish-white light that shines twice as bright and lasts 50 times longer than the standard 60 watt light bulb.
This work is published online in the Oct. 18 edition of the Journal of the American Chemical Society.
Better than bulbs
Until the last decade, LEDs could only produce green, red, and yellow light, which limited their use. Then came blue LEDs, which have since been altered to emit white light with a light-blue hue.
LEDs produce twice as much light as a regular 60 watt bulb and burn for over 50,000 hours. The Department of Energy estimates LED lighting could reduce U.S. energy consumption for lighting by 29 percent by 2025. LEDs don't emit heat, so they're also more energy efficient. And they're much harder to break.
Other scientists have said they expect LEDs to eventually replace standard incandescent bulbs as well as fluorescent and sodium vapor lights.
If the new process can be developed into commercial production, light won't come just from newfangled bulbs. Quantum dot mixtures could be painted on just about anything and electrically excited to produce a rainbow of colors, including white.
One big question remains: When a brilliant idea pops into your mind in the future, what will appear over your head?
Nikola Tesla would not be impressed.
Cool! What a bright idea.
Thanks for the chart. I was thinking of practical lighting for the home.
also this:
"The Vanderbilt researchers are the first to report making quantum dots that spontaneously emit white light, but they arent the first to report using quantum dots to produce hybrid, white-light LEDs. The other reports one by a group at the University of St. Andrews in Scotland and one by a group at Sandia National Laboratories describe achieving this effect by adding additional compounds that interact with the tiny crystals to produce a white-light spectrum. The magic-sized quantum dots, by contrast, produce white light without any extra chemical treatment: The full spectrum emission is an intrinsic effect. "
Example. "How many pollacks does it take to got ( screw in light bulb) stir quantum dots into polyurethane and coat a blue LED light.
(grab slide rule pocket)HAR HAR HAR
"A stupid question from someone with no technology aptitude. How does one turn the light off, particularly on the silverware example?
Better still, what happens if one were to swallow one of those dang things?
This is why I continue using vacuum tubes. There is nothing like them.
Oh my God, then how is anyone going to know when I have an idea?
lol
How much power plant electricity goes to lights as opposed to other uses?
If these lights allowed us to reduce the demand for electricity for light usage by 90%, how much impact would it have?
Would it have a significiant impact on the demand for oil? the demand for natural gas?
There would be some offsetting trends, people would leave lights on more, there would be more outside lighting, etc.
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Posted by Paul Cruce On News/Activism 07/17/1999 7:23:22 PM CDT self | 17 July, 1999 | Kauf E. Beenz Q: How many FReepers does it take to change a light bulb? A:1,343 - 1 to change the light bulb and to post to the mail list that the light bulb has been changed; 14 to share similar experiences of changing light bulbs and how the light bulb could have been changed differently; 7 to caution about the dangers of changing light bulbs; 27 to point out spelling/grammar errors in posts about changing light bulbs; 53 to flame the spell checkers; 41 to correct spelling/grammar flames; 6 to argue over whether it's "lightbulb" or "light bulb"; another 6 to ... |
Good chart - thanks.
Personally, the one thing I liked was 'led lights don't produce heat' That would seem to indicate that you could have savings in other areas, maybe not in a home, but in industry that uses lights 24/7 and also cooling. Less energy to produce the same light combined with less heat...would there also be energy savings in the cooling? Perhaps not significant in one place but if all industry did that? I don't do science, I just ask questions and let those knowledgeable in the area tell us :)
That's obviously a "good thing", as I've used white LEDs as spectoscopy sources, and in various flashlights, and the current "cool blue white" isn't really practical for "everyday" lighting use.
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