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2014 Nobel Prize In Physics Awarded To the Inventors of the Blue LED
grouchomarxist writes with word that "The 2014 Nobel Prize in Physics has been awarded to Isamu Akasaki, Hiroshi Amano and Shuji Nakamura, the inventors of the blue LED." From the organization's press release:
When Isamu Akasaki, Hiroshi Amano and Shuji Nakamura produced bright blue light beams from their semi-conductors in the early 1990s, they triggered a fundamental transformation of lighting technology. Red and green diodes had been around for a long time but without blue light, white lamps could not be created. Despite considerable efforts, both in the scientific community and in industry, the blue LED had remained a challenge for three decades. They succeeded where everyone else had failed. Akasaki worked together with Amano at the University of Nagoya, while Nakamura was employed at Nichia Chemicals, a small company in Tokushima. Their inventions were revolutionary. Incandescent light bulbs lit the 20th century; the 21st century will be lit by LED lamps. White LED lamps emit a bright white light, are long-lasting and energy-efficient. They are constantly improved, getting more efficient with higher luminous flux (measured in lumen) per unit electrical input power (measured in watt). The most recent record is just over 300 lm/W, which can be compared to 16 for regular light bulbs and close to 70 for fluorescent lamps. As about one fourth of world electricity consumption is used for lighting purposes, the LEDs contribute to saving the Earth's resources. Materials consumption is also diminished as LEDs last up to 100,000 hours, compared to 1,000 for incandescent bulbs and 10,000 hours for fluorescent lights. The LED lamp holds great promise for increasing the quality of life for over 1.5 billion people around the world who lack access to electricity grids: due to low power requirements it can be powered by cheap local solar power.
But I'm ok with that.
The bulbs need to come down in price a bit yet
I've spent many a joyful hour gazing at the blue LED. My little blue pals.
It is a pity that their work inspired one of the most horrible trends in consumer electronics design... Seriously, the power light, on the front of the TV, where I'll be staring directly into it while trying to watch something?
Blue is pretty much necessary for LED illumination that doesn't look like some sort of emergency-power-failsafe-lighting scene; but damn is it ever overused...
It seems every single damn device that I purchase these days feels the need to have a blue LED or five on it. Sometimes, for no other reason than to indicate that yes, it is indeed plugged in.
There is no doubt that the blue LED is a great engineering achievement but I'm struggling to see how this really advances the science of physics.
I've lost count of times I had to cut tiny pieces of electrical tape to cover these damn useless LEDs, especially on gadets in my bedroom where I try to sleep.
Blue LEDs exist, but true "white LEDs" do not. So-called "white LEDs" are blue LEDs with a phosphor over them. They're little more efficient at making "white" light than CFLs.
Red and blue LED light are great for plants, but human eyes are most sensitive to the middle of the visual spectrum, peaking around green. And unfortunately there's still no technology that produces an efficient green LED. That is what is really waiting for a prize. Such an invention could eliminate somewhere in the ballpark of 5% of human energy consumption.
Beautiful Blueberries
because some designers decided blue is the new green - the future is blue so let's make our product futuristic. Bah. Very overused.
Shuji Nakamura already won the Millennium Technology Prize in 2006 under the same topic. I bet there have been more recent developments in science that would have deserved more a Nobel Prize in Physics. Right?
As about one fourth of world electricity consumption is used for lighting purposes, the LEDs contribute to saving the Earth's resources.
Efficiency does not mean lower consumption. Efficiency remains a useful goal but not "to save the planet's resources". The latter can happen only if overall consumption is reduced. What will happen is that as electricity used for lighting purposes is consumed less, it will get cheaper to direct it elsewhere.
You are talking about an LED tech that's still being developed. There was an article on it just a couple months ago, in fact. It's got some viability to it but the efficiency is still rather low.
Since we've had much more success in the past year or so understanding the watercooler effect on LEDs, we've hit incredible efficiencies with current InGaN blue LEDs, to the point where we can make white LEDs with almost 50% efficiency (as noted by the 300 lm/w noted in TFS, which was hit by Cree at a correlated color temp of 5150K, 85C junction temp, 350mA forward current.)
Right now, thanks to that, development on the nano-tech LED stuff is really lagging behind.
Still waiting on Serviscope_minor to wake up to fucking reality and realize that Jessica Price isn't going to fuck him.
Aaaand you're probably reading this from an LED screen. Ain't that great?
If you know how photons are generated at the atomic level, it is actually very difficult to get an electrical circuit to turn into a full spectrum of all visible colors that make up white light.
It's the first Nobel for a Blue Light Special!
Yes, we do have true white LEDs. The problem is the efficiency isn't up there, and it's based on a new nano-material (I can't remember if it was selenium or tungsten-based.)
We've got remote phosphor tech that works great for producing green - otherwise Cree wouldn't be hitting 300+ lumens per watt (given the lumen is weighted at 550-555nm green)
Also, green light is great for plants. Don't let old science fool you. Why do you think an HPS lamp works so well despite about 80% of its visible light output being green and yellow?
Still waiting on Serviscope_minor to wake up to fucking reality and realize that Jessica Price isn't going to fuck him.
I've seen alarm clocks that supposedly have blue LEDs; I will never buy one.
Given that blue light has the strongest disruptive effect on circadian rhythm (no idea whether it's just because blue photons are relatively energetic, or whether we evolved to respond strongly to lights that look rather like the sky during the day, I have no idea; but that's what the research says), you'll really start to need the alarm function after a few nights trying to sleep with one of those....
And I bet that tube is BLACK on the ends. Probably won't re-start after you turn it off.
Still waiting on Serviscope_minor to wake up to fucking reality and realize that Jessica Price isn't going to fuck him.
I've got plenty of LED lights, consumer-grade, that have already hit 50Khours operation and are still going strong at 90% original light output.
Don't get shit power drivers.
Still waiting on Serviscope_minor to wake up to fucking reality and realize that Jessica Price isn't going to fuck him.
Watercooler effect? Scientists are more productive with a watercooler in their office?
Support my political activism on Patreon.
Because it's just so hard to cover that LED with a small piece of tape?
Why OpalCalc is the best Windows calc
My TV has a white power light, which CAN be disabled in the menu! :D
Been waiting for this one for a while. Fully deserved.
If they're practicing soniluminescence, I'm sure they are, assuming they haven't killed the thing with high-energy sound waves!
Still waiting on Serviscope_minor to wake up to fucking reality and realize that Jessica Price isn't going to fuck him.
We have the lowest concentration of blue sensitive photoreceptors in the fovea centralis, so reading blue lights (or things lit with blue light) is relatively difficult. Indeed, the localization of blue point sources is difficult, making bright blue LEDs look hazy and indistinct even while being blinding.
I can't wait for this trend to end either. I hope my green VFD and LCD alarm clocks hold out. So soothing and easily readable.
If you want a vision of the future, imagine a youtube comments section scrolling - forever.
yup, that's the big issue. People need to consume, so a led lamp that lives forever is just totally stupid to make
better put some poor electronics behind it that'll burn out a bit after the warranty expires.
http://www.lednews.org/eu-rese...
Sadly, they're way out of date with their math. We're hitting almost 50% with blue-based white LEDs right now.
Still waiting on Serviscope_minor to wake up to fucking reality and realize that Jessica Price isn't going to fuck him.
> Red and blue LED light are great for plants, but human eyes are most sensitive to the middle of the visual spectrum, peaking around green
Yellow. The color of the sun. Obviously.
> no technology that produces an efficient green LED
Sigh.
This was a big breakthrough in condensed matter and optical physics. We learned a lot about how materials doping effects the bandgaps through the development of these GaN/InGaN diodes. The blue LEDs have also been used to build cheap 405nm solid-state lasers for quantum optics experiments without the need for frequency doublers. Nobel prizes in physics usually go to a discovering that generates a lot of follow-up research and shifts the field. Blue LEDs did that in both materials/condensed matter and optics.
The invention of the blue LED could garner both a Nobel AND an Ignobel for the abusive implementations.
Gamingmuseum.com: Give your 3D accelerator a rest.
LEDs are practically by definition monochromatic. They are pn junction diodes. The energy of the photons (aka color) corresponds to the bandgap, and are thus monochromatic. So I'd like to see what you're talking about.
Cree's lab demonstration is not a commercial product; lab demonstrations of all techs are way ahead of commercial realities. Many things you do in the lab simply *can't* be done in the real world at any price. For example, you could gain a couple percent efficiency on metal halide lights by omitting the UV shield, but then you'd be causing permanent vision damage to your consumers. Cree's best commercial LED is 200 lumens per watt, the XLamp XP-L. And FYI, Cree's lab announcement was said to both be "single LED" and "white", which means phosphor, not multiple LEDs of different wavelengths.
As far as I'm aware, the most efficient green LED today yield around 100 if driven nominally, up to around 130-140 if underdriven and well cooled. That's not a figure you'd get in an actual lamp, nor would you use such expensive LEDs in commercial lighting solutions anyway.
LED lightbulbs may very well someday well exceed CFLs. But that day is not today.
No, green light is not great for plants, and I don't know where you got this idea or that it's "old science". There's countless modern peer-reviewed research to support it. The reason plants appear green is because chlorophyl reflects green light. The fact that leaves look black under red or blue LED light is a very good thing. You usually get 2-3 times higher growth per input watt on LED compared to HID, including HPS. HPS has little green, it's mostly yellow, with green and red as the next biggest components. And the worst type of light that exists for growing plants is LPS, which is virtually all yellow. The effect of LPS on plants is terrible.
Yes, the long-term standard for commercial greenhouse light supplementation has been HID, but that's been changing as LEDs drop in price. I know the founder of a company that started a company that produces greens in stackable self-contained "farms". They evaluated different light sources and found that LED gives by far the best bang for their buck. They're hardly the only ones, there's lots of companies switching over.
Side note: I raise a large number of tropicals in Iceland under supplimental lighting.
Beautiful Blueberries
There's about 1 blue receptor to every 60 of the others.
I'm just going to put this out there; you must be REALLY ignorant of what the blue LED has done for optics, solid-state lasers, understanding the Auger effect, crop production under artificial lighting, photobiology, understanding the circadian rhythm, and a whole slew of other things if you think this isn't worthy of a Nobel.
This invention SERIOUSLY helped humanity along.
Still waiting on Serviscope_minor to wake up to fucking reality and realize that Jessica Price isn't going to fuck him.
Even worse: The STANDBY LIGHT!!
Lights up your bedroom when you want to sleep at night. Oh yes, of course you could switch on the device to switch to the much darker gree power light....
bickerdyke
No the OP is correct. Plants use red and blue light for photosynthesis, not green. Green does very little for the plants and in fact very little is absorbed by the plant, some more than others. That's why plants look, um, green. An HPS lamp may work because it puts out sufficient red wavelengths for the plant to absorb. The rest is completely wasted. So yes it works, but not very efficiently. Most of the light just bounces off the plant.
Yellow. The color of the sun. Obviously.
If that's true, why is it obvious? It's not like we need to be especially sensitive to the colour of the sun. It's pretty hard to miss.
systemd is Roko's Basilisk.
Just to nuance my answer a bit more... not completely wasted. Fruit, flowers, and other things do absorb other wavelengths. And there are other things in a full spectrum light that probably help the plant too, such as UV, infrared. Light that does bounce off the plant, though, is "wasted" and that is most of the full spectrum light, or the HFS light.
There are several experiments in growing crops in green houses under magenta lighting with success. It's the most efficient way to artificially light plants.
As we transition to LED lighting, make sure you buy Dark Sky friendly lights. It's great that LED streetlights are hooded and point down now. We need to stop wasting money creating unnecessary light pollution just for aesthetic reasons.
According to this document from the Nobel committee, white LEDs emit more than 300 lm/W, while CFLs are at 70 lm/W. This suggests white LEDs are more than 4 times as efficient than CFLs.
That is used as a diagnostic device. Usually in the form of a blink code.
Still waiting on Serviscope_minor to wake up to fucking reality and realize that Jessica Price isn't going to fuck him.
Also, green light is great for plants. Don't let old science fool you. Why do you think an HPS lamp works so well despite about 80% of its visible light output being green and yellow?
When I GIS "photosynthesis spectrum", I see a million different curves, but they all peak in red and violet-through-blue-green. Even if you don't look at emission and absorption curves, just look at a plant. Its leaves are green. That means that it's reflecting more green light relative to other colors. That should be a clue that green light isn't the most efficient choice for feeding plants. (It's not conclusive, of course; nature's paths aren't always optimized for efficiency.)
Why do HPS lamps work so well? I don't know, but here are some possibilities:
They're many times more efficient than incandescent grow lamps, so you get more usable light per watt even if its spectrum isn't ideal.
HPS grow lamps are tweaked to produce more red light.
HPS lamps put out a huge total radiant flux, so they're just brighter than alternatives, in both useful and wasteful wavelengths.
Can you provide some supporting evidence that "green light is great for plants", when it's near the bottom of the photosynthetic absorption spectrum?
I haven't seen any LEDs dying in one or two years. My oldest LED lamp is now 7 years and still excellent. (Doesn't show the kind of degradation that fluorescents often do after a couple of years.) And the cost is dropping fast. A few years ago, I bought a couple of LED bulbs for about $3 each, and they give excellent light.
The really cool thing is that they don't have to be bulbs. LED strips are popular, and can be programmed for different colours or patterns. You can have flat or other surfaces that emit light. The only real problem is that there's no good standard for it yet, so you get lots of different custom solutions with wires all over the place, but I'm sure that problem will eventually be solved, and then we'll have real SciFi lighting in our homes.
Slashdot ate the last link.
pcp.oxfordjournals.org/content/50/4/684.full
Still waiting on Serviscope_minor to wake up to fucking reality and realize that Jessica Price isn't going to fuck him.
None of them were based out of Harvard.
If you really want to save resources you have to find a way to reduce the number of people on the Earth.
We already know how to do that: education. Highly educated people tend to have less kids than people with little education. So we need to invest in more accessible education for everybody in the world.
I would think that after 15 years you would have finally finished doing the dishes. ;-P
Probably not.
That's not the reason for the eyestrain, though.
Blue light actually triggers/worsens macular degeneration. It's such a high-energy photon that it causes physical damage. Long-suspected, recently experimentally confirmed by researchers in Spain.
This is why all of my monochromatic blue/red LED panels come with an eye hazard warning and always have. As soon as you go past sun levels of luminous flux in the blue range, you start hitting levels of retinal damage from photon overexposure in the blue wavelengths.
Still waiting on Serviscope_minor to wake up to fucking reality and realize that Jessica Price isn't going to fuck him.
What if the device fails when you power it down and it runs its pre/post power diagnostic?
That's why it's on.
Still waiting on Serviscope_minor to wake up to fucking reality and realize that Jessica Price isn't going to fuck him.
No, that's an announcement for a project to try to invent a way to make one. An announcement most notably short on the "how" aspect.
Any particular reason you linked back to this very article yet gave it a different title that only appears on the internet in your comment?
Beautiful Blueberries
Has the inanimate carbon rod ever won anything?
"There are several experiments in growing crops in green houses under magenta lighting with success. It's the most efficient way to artificially light plants."
No, it's not. Red and blue are more efficiently absorbed AT FIRST. You make the mistake of thinking green light is primarily reflected. What happens is it passes through the leaf tissue and is more efficiently absorbed by the inner chloroplasts.
You can somewhat determine this fluorescence for yourself experimentally. Get a test tube full of extracted chlorophyll. Take an incandescent light source, look at the test tube from varying angles in relation to your eyes from the light source. Sometimes it appears red, some times it appears green.
See here.
Still waiting on Serviscope_minor to wake up to fucking reality and realize that Jessica Price isn't going to fuck him.
Can you point to a place where the Nobel site is incorrect? Note that the Prize is for "efficient blue light-emitting diodes", not the first. Also if you look at this document is specifies that the work was in efficient blue LEDs and mentions earlier work on blue LEDs.
To be fair, that 300 lm/w barrier only got breached a few months ago.
But it wouldn't have been possible without the blue LED helping us in figuring out the Auger effect, which is the biggest limitation on LED efficiency right now.
Still waiting on Serviscope_minor to wake up to fucking reality and realize that Jessica Price isn't going to fuck him.
My alarm clock had a blue hue, even on the dimmest setting it was enough to illuminate the room after a few minutes when my eyes adjusted to the low light level.
Maybe instead of being a terror, my cat was actually trying to give me a better night's sleep by chewing through the cord rendering it useless.
"Action without philosophy is a lethal weapon; philosophy without action is worthless."
The key part of the phrase which is so often overlooked in "laws/effects/rules" such as this is "tends to." I think that LEDs replacing CFLs is one of those cases that would clearly be an exception to this rule. I'm not going to light up my house like a Christmas tree because LEDs have some efficiency gains over CFLs.
The argument that an increase in lighting efficiency would increase the demand for lighting just doesn't make sense in a society where no one is deprived of lighting because it's outside of their means. The efficiency gains of using LEDs aren't so great that my electric bill is going to significantly drop -- but they are great enough that total electricity consumption throughout the country will (which would mean less coal burned).
From the article you linked:
This argument is usually presented as a reason not to impose environmental policies, or to increase fuel efficiency (e.g. if cars are more efficient, it will simply lead to more driving).[7][8] Several points have been raised against this argument. First, in the context of a mature market such as for oil in developed countries, the direct rebound effect is usually small, and so increased fuel efficiency usually reduces resource use, other conditions remaining constant.[6][9][10] Second, even if increased efficiency does not reduce the total amount of fuel used, there remain other benefits associated with improved efficiency.
"From the depths of my skeptical and rationalist soul, I ask the Lord to protect me from California touchie-feeliedom."
Thats about 40W incadescent bulb, the minimum many people require for evening reading. They just couldnt get a single white LED or small sets of them to work for long periods of time at this intensity. So they offered a "X Prize" and Philips won a few years ago. I've started to see some 1000 lumen LED bulbs around now.
What do you have against Android Application Packages?
Cuts power consumption 80% over alternatives. A careful recipe of light durations accelerates harvests to under two months. I saw these for about $300 at the Denver County Fair. Pays back by about third harvest of commercial herb purchase.
And the award for misinterpreting research goes to...
Did you actually read the paper? It's about the benefit of adding different kinds of light in strong white light and finds that green helps most in such a situation because the oversaturation of the outer chloroplasts from red and blue light. There are, of course, countless papers out there that show the main actually tested usage of light is poorer for green, including research that cites that paper (the one I linked found that in some circumstances giving more green light can actually decrease growth - so hey if you like burning more energy to decrease your plants growth...)
Beautiful Blueberries
My external disk has a blue power LED. While covered with duct tape, it's still visible.
Yep.
For large sets, this will be our guide even unto death, for the LORD will work for each type of data it is applied to...
No, the simplest solution would be to realize that you can simply make an array of blue LEDs to match mains frequencies within a given engineering tolerance (since LEDs nowdays, in the blue range, have a reverse-breakdown voltage about double-triple their forward operating voltage) and act as a rectifier. Use a phosphor with emission persistence and no flicker concerns for visual lighting unless you're relying upon a shutter timing-based system like a video camera, which will only see a dimming and not flickering of the light at certain frequencies.
God I developed this a year ago and despite practically giving the knowledge away for free people are still screwing around. Do I need to patent this shit and shut the entire market out entirely?
Still waiting on Serviscope_minor to wake up to fucking reality and realize that Jessica Price isn't going to fuck him.
As I understand it, our eyes can differentiate the frequencies of visible light into the colors of the rainbow, but the rainbow is a continuum frequencies. There's not just one frequency that's perceived as 'red' for instance, but rather a band of frequencies perceived as 'red'. So, does the 'white' light from these newfangled things produce one red frequency, one green, and one blue, or is there a band of frequencies, such as you get from incandescence? And if there isn't a band of frequencies, will it matter to our eyes?
In theory, theory and practice are the same; in practice they're different. (Yogi Berra & A. Einstein)
Wars work better.
Actually this comes at a interesting time for me. I am looking for an LED lamp. Basicallly something that can focus bright light on something or provide low ambient light for a work area. I found some interesting lamps ( uncluding "solar powered" lamps --Wha? ), many even poweredc by USB.
The thing is when I look at reviews I often read things like " was great for the first two/three/four months, then just died.".
According to Nobel's will the prize should be awarded for the "greatest benefit on mankind". Important inventions, even without scientific advances, are valid reasons to be awarded.
Any particular reason you linked back to this very article
He just messed up and made the link relative.
Green Light Drives Leaf Photosynthesis More Efficiently than Red Light in Strong White Light: Revisiting the Enigmatic Question of Why Leaves are Green
IANAB, but I think the crux of this article is on the phrase "in strong white light".
Because green light can penetrate further into the leaf than red or blue light, in strong white light,
any additional green light absorbed by the lower chloroplasts would increase leaf photosynthesis to a
greater extent than would additional red or blue light.
So perhaps green light is more effective outdoors, but in an environment only lit by artificial light, green light is probably not the most effective (unless maybe you use both a powerful white light AND a green light?).
"What do you despise? By this are you truly known." --Princess Irulan, Manual of Muad'Dib
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We bought a Samsung Induction range which came with a blue LED clock. You can't read it from halfway across the room.. Something about the contrast or whatever but nobody's eyes can focus on it... It's completely useless.
Currently using an inexpensive single-led backyard white light. 6 inch square solar panel. Small battery hidden somewhere inside. Stays astonishingly bright all night illuminating a rose tree (pointing a bit down, not up at the sky). Way more than enough to read by. Something to free much of the world from darkness.
This has been my go to solution for years.
But lately, yes, it actually is becoming difficult! The culprits:
- lights that have a big piece of plastic in front of them (i.e. a monitor bezel) meaning you have to tape a huge section to block all the light
- this new smart touch crap where the light comes from the same place you have to touch to turn the device on / adjust settings
- lights that leak out through cracks / vent holes
I've gone to the extreme of opening things up and physically removing/cutting the LED, but even that is getting difficult as they are sometimes very tightly integrated with a control board and occasionally glued in place.
Why anyone wants a bright blue LED practically blinding them all the time I have no idea.
Who diagnosis a DVD player these days beyond "it's broke, have another". Certainly not something a consumer would be doing.
And anyone stupid enough to need a light to tell them a device isn't plugged in deserves to pay for a service call.
No, I'm really not; I'm looking at graphs from references and tutorials, some at a pretty introductory level, some at a more advanced level. None of them are from sites trying to market anything -- unless you're implying that Big Grow Lamp has infiltrated and corrupted biology texts stretching back decades.
You raise interesting points (in other subthreads here) about green light penetrating further into a growing plant, and I'll certainly grant that the absorption curves don't reach zero in the yellow-green range.
I'm not in a position to watch or listen to a video; can you link to any other information about the "ZERO LIGHT growing technology" you mention?
No wonder microwave radiation is harmful, then. It is even higher energy than blue light.
Microwave energy is lower than blue light.
A blue light photon is about 4.4 x 10**-19 J. Microwaves have photons at about 0.6 x 10**-24 -- 1.6 x 10**-24 J. That's 5 orders of magnitude difference.
He effected a bored affect.
Little more efficient than CFLs?
Sure the stimulated phosphor emission of white light isn't any more efficient, but you're aware how a CFL generates the photons to excite the phosphor, yes?
Now how does an LED do it?
Tell me again about efficiency.
These people are not inventors of the blue LED. This specific kind of blue LED was invented in Soviet Union in the 1960's by the team of Zhores I. Alferov (the winner of 2000 Nobel Prize in Physics). Nobody disputes the priority on the invention itself.
After that the issue was to develop the manufacturing process that would make the mass-production of such blue LEDs feasible. The Japanese team did exactly that: they came up with the technology that allows one to mass-manufacture the Alferov's device cheaply.
You're confusing lab scale demonstrations of individual LEDs with full commercial LED lightbulbs. The two are not comparable.
Don't look at lab tech announcements. Go compare bulbs available at the store, you'll see what I mean.
Beautiful Blueberries
I am interested in this too. I have seen both LED bulbs and strips die, both with the same failure mode - a low-intensity flicker. In the former case I'm almost certain it's the ballast (cheap chinese capacitors), but I have no idea how the strip that takes 12V would fail assuming it's not being over-driven.
The diode junctions should last for many thousands of hours if driven with the correct current.
"Nine times out of ten, starting a fire is not the best way to solve the problem." - my wife
Only temporarily.
Khyber has posted the link to that article before, and fundamentally misunderstands the result. The big thing he keeps missing, is that the efficiency in the paper is referenced against the amount of light absorbed in the leaf. In other words, it ignores the light reflected by the leaf, so does not factor how much green light is reflected by the leaf into the efficiency values. The paper shows that in very intense light, the marginal efficiency of green light increases above red light. Basically, as the red and blue light saturate the photosynthesis of the upper layers of the leaf, more blue or red light becomes inefficient, and more green works as it gets to places not saturated. This doesn't change that fundamentally red and blue light get into the leaf better, and as a whole drive the majority of photosynthesis and are more efficient in general. But arguing with Khyber over it is pointless, when he values being an LED salesman and misunderstood papers too much... and IAABiophysicist.
Utilize red/green instead of blue/green.
http://www.thinkspain.com/news...
The University and Professor are named in the article. Finding the study itself shouldn't be too difficult, I can't find it this moment as I'm at work.
Still waiting on Serviscope_minor to wake up to fucking reality and realize that Jessica Price isn't going to fuck him.
"it ignores the light reflected by the leaf"
No, it doesn't. Did you even read and comprehend the entire thing? Light that either passes through or is reflected is still eventually absorbed if it continues to be reflected towards and transmitted through leaf tissues.
And that is where the higher quantum efficiency comes in.
This is why an HPS lamp can provide such a huge yield and grow far larger-sized plants.
And I don't sell LEDs any more - I run direct fabrication of junctions, now, along with the designing and building of hydroponics buildings. EcogroLED is no longer my business, hasn't been for... two years.
Try again.
Still waiting on Serviscope_minor to wake up to fucking reality and realize that Jessica Price isn't going to fuck him.
"That's why plants look green."
Uh, have you ever encountered a purpurea? Any variegated style of plant? Guess what color most of those tend to NOT be?
Green.
Still waiting on Serviscope_minor to wake up to fucking reality and realize that Jessica Price isn't going to fuck him.
Two things make me think the whole red/blue thing is wrong.
A. Shelf life of plants grown under red/blue only light. So far, I have results from the UK and Australia regarding leaf lettuces grown under full-spectrum and red/blue LEDs. The shelf life of plants grown under white light is almost double that of the shelf life of plants grown under red/blue. The plants grown under red/blue tend to have weaker stem/water transport systems.
B. While red/blue LEDs are getting closer and closer, they are still not providing the yield nor huge plants the cannabis industry expected versus HPS. While I loathe this rating, everyone uses and 'understands' it, so I'll use it here. An HPS has been shown, even in the lower power ranges, to provide over 3-4 grams per watt of rated lamp power. Red/Blue LEDs with some of the best methods are only really hitting ~2 g/w. I fixed that somewhat by increasing the blue output (because blue is needed for biomass production) but that only helped with about a 5% gain.
Still waiting on Serviscope_minor to wake up to fucking reality and realize that Jessica Price isn't going to fuck him.
Wasn't there a Slashdot article a little while ago about bulbs being regulated so they never lasted longer than some specific number of hours or that company would get a fine? How does that work out?
Great, now you got a deeper meaning to this song: Adolphson & Falk - Flashing Blue https://www.youtube.com/watch?... :-) /Eric
DId you read the fucking press release? Did it mention any of that other shit? NO.
It was all about political happy "green" talk.
Can we sing Kumbaya now?
If blue LED's were the first LED made, I would not object. But which was a bigger first? Blue LEDs or
wikimedia
So my point again - this was a dreadful choice of Nobel prize. And just because something was hard to do and took a technological breakthrough to do is not reason for a Nobel prize. If it were, we could give them out like candy.
My Caddy has what many newer cars have for headlamps - leds. Damn things burn out the ballast, or lamp. Car isn't that old. My 2000 chevy's laps lasted for about 12 years. Even then the plastic was frosted over, the lamps still worked. Even if they didn't, less than $50 at any auto shop and about a minute to replace it. The caddy and the Beamer - what a PIA to get to! Expensive! Ballast for them are around $500 a pop. Headlamp assembly around $800, then you have to get it installed.
Yea, progress.
I thought blue LEDs were cool when they first hit the scene but you're right, they're INCREDIBLY overused. Even on my PC case, they chose insanely bright blue LEDs for both power and HDD activity. It's really obnoxious when I'm trying to sleep. It also doesn't make much sense. Blue was supposed to be yet another color of LED, not replace all other colors of LED because a few retards think it looks neat.
Soraa LEDs might be reaching about 66-75% conversion efficiency (LED die only, not incl. phosphor). I will be sampling some soon to test this.
This is becoming a truly remarkable and world changing technology.
My experience is that the lights are fine, but the cheap wall wart power supply is what is actually dead. My guess is that they tend to get a power supply that is rated just high enough to run the lamp, and unlike most things that use a wall wart the light is going to be drawing the full amount of power any time it is on. Find a working power supply at the right voltage (most use 5 or 12V which is luckily common) that preferably has a higher amperage rating and you can usually revive these lights.
reading the comments written by most people i wonder how many of them actualy read the whole article ? due to the massproduction of blue LED's it became possible to make white leds !! thus saving a lot of electrisity ! before that blue due to its expense of production was used only in medical devices and needless to say military apps . i also feel that the people complaining about blues being overused , while true , has nothing to do with the overall achievement !!! lets face it why blame the people who made it possible for the way the invention is missused . on the subject of missuse the people making rediculus large and loud speakers that some idiots must have in their cars , making it almost impossible ( when the car next to you has them crancked up so high ) that normal people can not make use of their ears in traffic . i blame the people who have these things in the cars for deafening me , not the people who invented them , or even the manufacterer , cos once the item is sold , it is out of their control !
the power of men in charge of words over men in charge of machines surpasses all wondering S WEIL
Yellow. The color of the sun. Obviously.
No, the light from the sun is white. The reason why it appears yellow in the sky is that a good portion of the blue-ish spectrum is spread in the atmosphere, making the sky blue, but hindering most of the blue light coming directly from the sun. The aggregated daylight during mid-day is indeed white, being the sum of direct sunlight plus the other parts of the spectrum reflected in the atmosphere from other directions. Sunlight's not a certain colour in the spectrum, more or less by necessity it's a mix of *all* visible colours.
The human eye is most sensitive to green light a lower intensities, and yellowish-green at higher intensities. This is due to the nature of the colour receptors in our eyes. Observe the visibility of equally powerful red, blue and green laser beams to verify this.
Are you a grammar Nazi? I'm trying to improve my English; please correct my errors!