With the widespread everyday use of personal electronics in our world today ... it's hard to believe that 'blue light' would be worthy of any extended discussion at all. But it was really only very recently that the synthesis of blue light was made possible. And this breakthrough discovery and it's implications for the advancement of other technologies is little known.
There are two stories to tell here. The first is the 19th century story of blue light ... via white light passing thru blue glass ... and the promises that were made of it's beneficial use. This of course was an unproven claim, but like many of these stories in history (and maybe even some of today) ... the recipients of the claims don't clearly see the facts ... and become true believers.
The second part has to do with the 20th century discovery of the physical principles neccesary to synthesize blue light electronically (which was quite elusive for a long time). This is no hoax ... and will likely serve as a major foundational discovery that will change the face of artificial 'illumination' for generations to come.
These stories together tell a tale of promise, deception, hope, greed, perseverence, fraud, and revolutionary success. Two stories ... one of charlatans ... the other of a dedicated researcher ... who come upon a once in a lifetime opportunity ... to change the world. No possible connection between them ... less the passion for the Blue Light they shared!
The Blue Glass of Augustus J. Pleasonton
It's mid 19th century ... in a backyard greenhouse in Philadelphia a one Augustus J. Pleasonton works busily at planting grapes. There's appears to be nothing special about Mr. Augustus Pleasonton ... and not much all that special about the grapes he planting either ... at least there's nothing to notice as yet.
Looking upward yields a strange curiosity ... a somewhat sporatic and seemingly random appearance of a few squares of blue glass in the roof of Mr. Pleasonton's greenhouse. It is these strange 'blue glass' curiosities that we're here to discuss ... and the passion of one Augustus J. Pleasonton.
Augustus was born in 1808 ... a graduate of West Point by 1826 ... and a Brigadeer General ... the officer responsible for defending the state of Pennsylvania for the Union Army. He'd resigned his army commission in 1836 and gone on to study and practice law in Philadelphia.
Augustus was a voracious reader and had a keen interest in science, physics, electricity, and geology. His reading habit brought him into the center of many a subject and one of his favorites was an 1844 title by Professor Robert Hunt titled "Researches on Light: An Examination of All the Phenomenon Connected with the Chemical and Molecular Changes Produced by the Influence of the Solar Rays". Robert Hunt is often credited as the founder of modern photography but it was his views on the effects of light on organic materials that most interested Augustus. In Hunt's book Augustus fouund references to old cases where it appeared as though different light spectrum (different colors of light) had beneficial effects on carbon dioxide production and the growth rate of plants. Blue light seemed to exhibit a noticable postive effect in Hunt's findings.
Augustus took to this idea immediately. He had always believed there to be a special quality in the color blue which he stated at a later date: "For a long time I have thought that the blue color of the sky, so permanent and all pervading ... must have some abiding relation and intimate connection with the living oranisms on this planet".
Augustus set out on a grand experiment ... to build himself a 2000 square ft. greenhouse in his backyard where he could try this theory of blue light. In April of 1860 Augustus began planting his vine cuttings beneath the panes of glass in the ceiling of his greenhouse ... every eighth pane a cool azure blue.
Augustus spent the next few months tending to his vines w/ a passion not too much different than countless other home gardeners in Philadelphia that year. He was obviously anxious as to how his experiment might turn out.
A few months into the season he gets a visit from the owner of the local plant nursery, Robert Buist, who stopped by to see how Augustus' plants were faring. Augustus takes Mr. Buist to the back of the house and into the greenhouse to allow him to see his plants. After a brief examination of the vines Mr. Buist comments: "I have been cultivating plants and vines for the last fourty years ... I have seen some of the best vineyards and conservatories in England and Scottland ... but I have never seen anything like this growth".
To say the least Augustus was a happy man ... and when Buist visited again a year later for the first harvest he was taken back by the degree of growth within the greenhouse. After a few observations and a few more calculations Buist turned to Augustus and said: "Do you know that you have 1200 lbs of grapes in this grapery?" Following Augustus's surprise Buist indicated his amazement and that he could never publish such a find since nobody would ever believe him.
Augustus had a number of great harvest years from his backyrard greenhouse ... and after reading further works on the benefits of light ... he started to think that maybe these same benefits might apply to animals and people. He lost no time in constructing a pig house w/ one side filtered w/ regular light ... the other with some panes of blue. After some time raising pigs under his new experiment a modest increase in growth was noticed for the pigs raised under the blue light.
Following his successes w/ plants and then subsequently w/ the animal experiments ... he started to get a lot of inquiries from locals who were aware of him and his claims of beneficial results from exposure to blue light. He was invited to speak the to the Philadelphia Society for Promoting Argriculture where he summarized his blue light process and it's successes ... then he shared his novel ideas about electricity and the effect they have on pretty much anything and everything. Following his presentation to the Society group he had his speech published in a pamphlet which he then sent to all the intelligensia in the country.
Shortly after his speech and the publishing of such he received many inquiries and assisted both friends and relatives w/ a variety of ailments ... who all unexplicably improved as a result of the blue light prescriptions he was writing ... which was to buy a pane of blue glass and sit under it for a couple hours a day. These successes gave rise to a new confidence in Augustus and he decided to apply for a patent for his blue light discovery. The patent office was a bit more efficient in these times ... or maybe it was that there weren't as thorough in their assessment of an application. Regardless ... Augustus got the examiner to come out and see the grapery and pig house for himself within a month ... and a month later in September 1871 Augustus is issued US Patent #119242 titled "Improvement in Accelerating the Growth of Plants & Animals".
An article in late 1871 in Gardener's Monthly produces a flurry of requests for information and assistance w/ various issues that his readers were having. These problems ranged from tree growth ... to mute canaries ... to a parlyzed infant. In all cases the maladies or conditions were allegedly improved. His success in these encounters convinces Augustus that he needs to share this w/ the rest of the world and he proceeds to summarize his findings and theories in a full length book titled "The Influence of the Blue Ray of the Sunlight and the Blue Color of the Sky'". This book was published in 1876 and was printed on tinted pages w/ light blue ink and a powder blue cover. His book included the blue glass findings in the first part of the book ... with the second part of the book discussing his unusual theories on electricity. These theories were radical for his time and the whole book was pretty much ignored by all learned scholars ... who viewed his theories as absurd. You can see the online copy of Augutus's book here
Soon after the book is published there's a story out of France about some experiments that were tried in a psychiatric ward where they painted the walls of various rooms with different colors. The blue room showed signs of calming individuals down where the red painted rooms made patients more aggressive. These reports supported the claims that Pleasonton had been making all along and in no time at all his blue glass craze was official.
Up to this point Augustus's critics were either few or chose to remain silent. In mid 1876 following the publishing of his book and the stories of the French experiments Alfred Ely Beach ... the publisher of the weekly magazine Scientific American runs a scathing story that debunks the many claims made to date by AJ Pleasonton. These critical stories had little effect at this point and in 1877 Augustus publishes the second edition of his book in which he now claims the use of blue light is effective in relieving gout, menangitis, paralysis, and pulmonary hemorage. In short order the 'blue' craze spreads beyond glass or light and pretty much covers anything at all ... including color of walls, fabric, water, etc.
In April of 1877 Scientific American publishes another critical piece on Pleasonton's blue glass theories and continues throughout the year each week w/ another critique of his theories and methods. With little effect on the momentum of the blue light craze ... it spreads to Europe and demand for blue glass skyrockets as all are replacing their clear glass w/ panes of blue. Besides the recurring and critical onslaught from Beach's Scientific American ... there were many other books published that either parodied Pleasonton (John Carboy's 'Blue Glass A Sure Cure for the Blues') or took a more analytical view of the claims w/ control tests and exhaustive testing ('Blue Glass Mania' by Thomas Garfield). The Scientific American coverage continues to raise questions about the fundamental theories behind Augustus's claims ... mainly that a pane of blue glass (or any other color for that matter) will pass LESS light thru it than a pane of clear glass ... and that goes for all the spectral elements of the light. Pleasonton had been claiming all along that there was some type of amplificaiton of the light's power as it passed thru the glass (based on his eccentric electricity theories). He was never able to respond to this simple observation made by the SA writers.
After a while the critiques of blue glass began to produce some alternative views than those of Augustus. It was forwarded that the benefits claimed were all a result of what was being called the 'placebo effect' ... and there were some urban legends beginning to cicurlate about dangers associated w/ blue glass ... including a story of a man w/ vision problems who was prescribed a set of eyeglasses fitted w/ blue lenses ... and in a short few weeks the man was completely blind.
As fast as it took the country by storm it seemed to fade into oblivion ... and by 1878 the blue glass craze had reached it peak. There were many follow ups to the craze in the next twenty years or so including an approach in 1890 by John Kellog ... of cereal fame ... who created interest in 'light baths' .. a large lightbox that you would stand in ... w/ the walls fitted w/ an array of light bulbs. Niels Finsen studied effects of light around 1900 .. and published 'Phototherapy' in 1901. And Dinshah Ghandi founded the 'Spectra-Chroma Institute' based on light therapy claims.
Augustus Pleasonton died in 1894 still holding a fervent belief in his blue glass ... when his possessions were sold at auction his library was so large that it required it's own auction catalog.
Reading some of his book today ... which is a bit of a challenge since the tint on the page has darkened and the ink has faded ... it's hard to believe that anyone would have bought into this idea ... but at the same time some (and I stress some) of the claims about 'blue light' were not that far off. Today we know that both the human body and it's elements do in fact respond to light in varying (and sometimes beneficial) ways. White light therapy (Kellog's Light Bath) is used for sleep cycle adjustment and Seasonal Affective Disorder (or Winter Depression). Only the future will tell how close Augustus was to his other blue light benefit claims.
The story above is an edited and consolidated version of a story about Augustus Pleasonton and his panes of blue glass written by Paul Collins in Banvard's Folly. The book contains thirteen different stories which tell the tale of individuals who did things in history that never quite caught on or worked out. This is a great read for both the full story of Augustus and his blue panes of glass ... and the other dozen historic tales as well ... I highly recommend it. Paul Collins is a prolific writer who contributes to the McSweeney Quaterly, has a blog where he ruminates regularly, has a profile on Wikipedia, and has authored quite a few other titles as well.
The Synthesis of Blue Light ... Blue LEDs & the Blue Laser
It's late in the 20th century ... 1988 to be exact ... a Mr. Shuji Nakamura is discussing research projects w/ his employer Nichia Chemical in Shikoku, Japan. He had just finished his last development project related to an imporved process for manufacturing a common LED product that's used in the electronic market.
Nichia Chemical's owners make a very bold business move and tell Mr. Nakamura that they're going to allow him to select the next thing he will work on as the companies lone research scientist. As amaziing as that may sound they clearly had faith and trust in Shuji's judgement for them to give him this responsibility to pick what he'll likely spend the next five to ten years working on.
Mr. Nakamura, a seasoned materials researcher and one who would desire as anyone else would ... knew clearly that the quest for the synthesis of blue light was one that had been in front of some of the largest companies and most skilled teams of physicists and semiconductor scientists for more than two decades. He believed in his own abilities and decided that pursuing the elusive blue light technolgies would be what he proposed for this next challenge.
From Dr. Nakamura's recent experience of improving processes for the manufacture of standard LED product ... but failing to succeed commercially in the marketplace ... he knew that the only means of payoff for any signifigant effort toward an elusive goal would be to use an approach that nearly nobody else was using. He studied the current research on the quest for blue light in detail ... and decided to work on a process to develop a suitable form of the substance Gallium Nitride which had been first identified and developed at RCA in 1969 by Jaques Pankove. Mr. Pankove never got a chance to perfect his processes because RCA was driven heavily by practical application ... and at that time there wasn't as much value placed on alternate light spectrum technologies.
By the late 1980's many in the industry ... and especially the decision makers in the Japanese semiconductor business knew that development of short wavelength lasers (blue, violet, uv) could set the stage for the creation of untold future markets for their tiny chip based products. Revolutionary leaps in communications, medicine, and research science could be made possible by the development of these still elusive alternate light technologies ... and the products that would help make these revolutionary leaps would be built from their components. If only they knew how to produce a blue LED that would last longer than a few minutes.
So off Dr. Nakamura goes in his quest for perfecting the process of developing a usable form of Gallium Nitride. This was a risky move since many in the industry had traveled the Gallium Nitride path before without success ... many who had much greater resources than Nichia ... and signifigantly larger teams of researcher's and scientists ... some of the best in the world.
In the middle of Dr. Nakamura's work on Gallium Nitride ... in 1991 ... researchers from 3M corporation in Minneapolis, MN announced that they had succeeded in creating a blue laser based on zinc selenide. The excitement was followed by trepedation as it was discovered that in order to get their elusive beam of blue they had to intice it w/ a bunch of impractical external stimuli. To put it bluntly ... it was a complete power hog ... with much of this power disipated as heat ... lots of it ... and as such required specifc and complicated means to keep it cool during it's operation. Well ... it wasn't really that complicated ... since despite all the special meaures ... the 3M laser blasted it's ray of photons for no more than a few seconds ... before going up in 'proverbial' smoke.
What ultimately ended up being good for Nichia and Dr. Nakamura ... was unfortunate for the likes of the major players in the Japanese electronics business. Following the 3M announcement ... and despite their inability to show any real reliability in their device ... Matsushita (panasonic), Sony, and Phillips semiconductor moved aggressively in the development of the short wavelength technologies based on the Zinc Selenide material. This now put Nichia on a path by itself in the development of Gallium Nitride for their efforts toward the elusive blue.
In late 1993 Dr. Nakamura finally develops his Gallium Nitride to a point where he succeeds in getting his little blue LED to emit a cool blue beam of light ... under practical and real world conditions ... and w/ a brightness and overall reliability that set everything else on the landscape miles behind him. Nichia makes their announcement and stuns the whole electronics industry w/ it's radical approach ... an approach that pretty much everyone else has given up on years earlier.
While Nichia secured it's intellectual property rights to it's new device and began ramping up it's production of blue LEDs ... the whole industry was now in a race for the blue laser diode and other short wavelength (UV) devices.
At this point it's estimated that the electronics industry as a whole was producing and consuming roughly 20 billion LEDs annually for the wide range of products and devices they were being incorporated into. But the development of short wavelength light technologies ... both as LEDs and laser diodes were likely to dwarf this current production rate for standard LEDs. Markets that didn't exist and applications that nobody has actually considered seriously were now within reach ... and the dollars were astronomical.
Some might compare this major shift in the application of semiconductor technologies in the visible and UV light markets to what occurred w/ the initial development of the transistor is the '50s and '60s ... which started the whole semiconductor and consumer electronics business itself.
It's has been estimated that the profits from the sale of the rights to use the Gallium Nitride process that Dr. Nakamura and Nichia developed have exceeded over 120 billion yen ... or $1.2 billion dollars to date (i did say profit) .
Can you even begin to imagine being Shuji Nakamura that day in his lab in November of 1993 ... the only guy in the world who has a working blue led ... the only guy ... after over 25 years of some of the greatest minds in the industry working toward that goal ... and not succeeding? How long does a high like that last?
The Inventor's Piece of the Pie
Shuji Nakamura spent 5 years in an overall 25 year industry quest in getting the elusive glow of blue to emminate from his lab. Soon after the breakthrough in 1993 he left Nichia for other opportunities.
As is typical for a researcher or other contributor to a companies efforts to develop a product or process that's patentable ... they typically receive a modest award for their efforts (ie. like $1000 dollars). Following the incredible financial success that the rights to the blue light technology produced ... Mr. Nakamura apparently started to re-evaluate the modest award provided for his efforts. He subsequently sued his previous employer for a greater percentage of the royalties associated w/ his breakthrough blue diodes.
A Japanese court made a preliminary ruling that the inventor was due 50% of the net gains from the invention. By this time the rights to the blue LED invention had yielded roughtly 120 billion yen or roughly $1.2 Billion in US dollars in profits. This meant that Mr. Nakamura was entitled to over $600 million! The case was ultimately brought to court w/ Mr. Nakamura suing for $16 million and the case was settled for roughly $8 million.
It's not typical that technical contributors go on to sue for additional rights for their efforts toward some patentable technology. Although it's difficult to determine how Mr. Nakamura's suit would have faired in US courts ... it's likely that he wouldn't have come out as well. Of course, with such a signifigant breakthrough ... and it's astronomical gains ... he may have found a sympathetic judge/jury and came out on top.
There is however one signifigant and high profile case in the US courts in 1978. It started in 1967 in Michigan in the basement of one Robert Kearns. He was an inventor and had dreamed of creating an intermittent wiper system for cars. He tinkered on his pet project for years before he had an intermittent electic motor driven system that he had retrofitted to his 1962 Ford Galaxy. He applied for a variety of patents for his many automatic wiper ideas.
Believing that his wiper system would be appreciated and possibly licensed by The Ford Motor Company ... he drove to their headquarters in his Galaxy equipped w/ the intermittent system. His car met w/ a keen interest from the Ford engineers but after many follow ups w/ Ford he realized they weren't interested in his idea.
Kearns received the first of more than a total of 30 patents for his automatic wiper designs in 1967 ... and in 1969 Ford came out w/ it's first intermittent electric motor wiper system ... followed in the next few years by the other major car manufacturers w/ their own systems.
Through a chance circumstance in 1976 it came to Kearns' attenttion that the designs being used by the 'big three' auto manufacturers was almost identical to his patented design. It was at this point that the remainder of his life's efforts were directed toward those that he felt had shamelessly stolen his ideas. He sued Ford in 1978 for $325 million and ultimately ended up in litigation w/ over 25 car manufacturers. In 1990 he was awarded $10 million in the ford case ... a subsequent suit against Chrysler yielded $20 million. By this time it had pretty much consumed his life ... he had divorced his wife ... had a nervous breakdown ... and had delusions of being the sole manfucturer and supplier of the systems he claimed the rights to .
Rumour has it that in his later years he was seen driving two older model cars ... a '78 Ford and a '65 Chrysler ... neither of which had intermittent wipers. He died in Feb 2005 at the age of 77.
Dr. Nakamura has since moved to the United States and is a professor of engineering at the University of California Santa Barbara. He is currently the Director of the UC Santa Barbara's Solid State Lighing and Energy Center ... working on optical technologies to further advance the state of solid state light devices.
How Blue Makes White ... A Revolution In Artificial Lighting
For over twenty five years before Shuji Nakamura made his groundbreaking discovery there were many who dreamed of the elusive goal of a semiconductor device that could synthesize blue light. Although there were likely many who had a special affinity for the color blue ... their quest for blue was for other reasons ... the synthesis of white light!
This drive for synthesized blue/white light was fed by lighting industry powerhouses such as General Electric, Sylvania, and Phillips. They had long seen an evolutionary progession of lighting technologies that were likely to be solid state in nature and dependent on this synthesis of white light from 'silicon'.
The implications were tremendous when you consider the likely impact of a solid state white light technology ... which will include smaller size ... a magnitude or more lower power consumption ... less heat ... many magnitudes greater reliability ... capability for granular electronic control ... and ultimately lower cost.
For a variety of technical reasons it was clear to all on the 'white light' quest that evolutionary advances in more efficient 'blue light' and ultra violet LED technologies were necessary to reach their objectives.
For many years semiconductor engineers believed Zinc Selenide or silicon carbide would provide the key to blue light ... but it was Shuji Nakamura ... a lone research scientist working with Nichia Chemicals ... and using a totally differnt approach utlizing gallium nitride ... an approach that many others had left behind as ineffective ... that finally layed the foundation for the discovery of a high intensity and high effiency blue light source.
Since Mr. Nakamura's breakthrough pretty much every company interested in these alternate light technologies have shifted their production methods to those employed by Nichia and Dr. Nakamura. To date there are various white light leds that have been incorporated into flashlights, display lighting, underwater lighting, architectural details and other applications. There is signifigant effort toward developing techniques in combining colors to create any desired color of the visible spectrum ... and beyond.
Medical/Therapeutic Uses of Blue Light
Some medical applications of visible, infra-red, and ultra-violet light have actually preceeded the break-thrus relating to blue light ... although the blue light technologies have moved this field forward signifigantly. Some of the key areas where Light Therapy can be beneficial are in treating skin conditions, mood modifiers, circadian rythm shifting, relief from jet lag, and some applications of 'anti-aging'.
For skin treatment application it's been known for many years that regular sunlight provides beneficial relief of acne symptoms in patients. Initially it was believed that the UV elements of sunlight were the key to the observed results. It was later determined that the blue/violet spectral elements of natural light were responsible for undermining the bacteria that's associated w/ acne. These isolated light spectrums are made possible by the advances in blue light technology. It's been shown to be remarkably effective in roughly 70% or more of patients who receive the light therapy for a minumum of three months. Treatments are typically performed in a Deramtologist's office (due to special equip) but home based light treatment systems are within reach and likely to get cheaper as blue light advances drop prices of the components.
Other skin conditions like Eczema and Psoriasis have been shown to react favorably to UV light exposure. The UV radiation acts to suppress the immune system thereby undercutting the adverse effects of the Psoriasis and Exzema. It's not uncommon for a treatment for these types of conditions to include some narrow band UV light exposure ... and a medication to mitigate their symptoms.
As a mood modifier ... natural light has been known to be effective in treating what is known as 'Seasonal Affective Disorder' ... or what is sometimes refered to as 'winter depression' or SAD for short. Bright light therapy is being used w/ many of the patients suffering from this condition. Special bright light devices are utilized in these treatment sessions ... often in combination w/ presribed medications ... where the SAD patient is exposed to the high intensity light for 30 to 60 minute daily sessions.
Another technique known as 'Dawn Simulation' has also be utilized in treating SAD patients ... where the light intensity is increased incrementally within a limited time window in the early am hours just prior to the normally scheduled awakening time for the patient. This technique was developed following research findings at Columbia University in the '80s which showed some wild animals sleep patterns were affected by the gradual blue light predominance in the late hours of night and just prior to the sun's rise. It's believed this has some synchronizing effect w/ the internal circadian rhythms of the body (human or animal).
For sleep therapy situations ... it's been found that blue light sources affect the levels of melatonin in the body ... a key hormone involved in the regulation of sleep cycles. Bright light therapy techniques have been shown to be effective in shifting the internal (circadian) rhythms of the body to bring it back in line w/ normally accepted times of activity (sleed at night; awake in morning).
For those suffering from jet lag ... there's potential relief w/ the utilization of light therapy. Exposure to bright light before, during, and after a long flight has been shown to assist in the reduction of the symptoms typically associated w/ jet lag.
There has been some observed benefits w/ the use of visible red light therapy on skin quality where it seemed to increase collagen production temporarily. Long term gains from these techniques have yet to be obtained but future advances will likely identify other narrow spectrum applications to provide some therapeutic benefit.
The Dangers of Blue Light
To nobody's surprise ... soon after the release of the first blue LEDs ... these strange glowing sparkles of blue started appearing on many electronic designs. Even though these 'cool' blue LEDs were much more expensive than their green and red cousins ... they added a uniqueness to the devices they adorned. It's even believed the color itself may have some inherent quality to it that draws attention ... and likely buyers. This may be due in part to the color blue being more favored than any other single color (zogby poll). As the process to manufacture the blue LED improved and the prices dropped further ... splashes of blue light made it's debut on more and more electronic devices.
In short order the increased use of 'blue' was soon followed by complaints from various users of these devices ... complaints about the light being too bright ... it's too distracting in the periphery ... or it's keeping them awake at night. For some, these distractions became so much of an annoyance ... that they have resorted to covering the light over w/ tape, or paint, or even disconnecting the wires to turn it off. It's not clear if these issues are affecting consumer's buying decisions for 'blue LED laden' product ... but it's only a matter of time before they do if these adverse effects are substantiated and it's found to affect a large number of people.
Is it possible that a little blue LED could wreak so much havoc on the human species? Just when we were all getting to know this 'cool blue' beam of chromatic intensity so well? Are the problems w/ blue light going to undermine the advances that are likely due to it's discovery?
As is the case w/ many aspects of the human species ... we are wired a certain way ... physically, electrically, and chemically .... and this in many ways characterizes the capabilities, strengths, and weaknesses of any given physiology of the body. As such ... despite the many wonders of the human eye and man's ability to see ... it has a variety of issues w/ blue light including chromatic sensitivity, focus, brightness, peripheral effects, and even some adverse effects upon circadian rhythms (ie. sleep patterns).
The term 'blue light hazard' is now part of our vernacular ... and describes a condition where a potential could exist for a retinal injury resulting from ultra violet radiation exposure to wavelengths between 400 - 500 nm (blue LED is approx. 450nm). The process involved is a biological mechanism used to protect the eye tissue from damage when exposed to UV radiation. Blue light seems to short circuit this process enabling a potentially damaging UV exposure of the sensitive tissues of the eye including the lens and retina. The wavelength of the blue light itself (450nm) is very close to the Ultaviolet end of the spectrum w/ violet just above blue at 420nm ... and UV light at 400nm.
Below is a summary of some of the core issues surrounding incidental exposure to blue light and the short term effects that exposure could produce.
- Chromatic Sensitivity
The human eye resolves fine detail in the objects reflecting light back to itself primarily with the green or red elements of the light spectrum. The most sensitive spot on the retina, the fovea centralis, has no blue light-detecting cones.
The human eye just doesn't handle the blue light effectively for proper focus. A common effect when trying to resolve blue light is a fuzzy cloud around the point source ... with a seeming inability to correctly focus on it at all. A popular 'info-mercial' sunglass (BlueBlockers) sold millions w/ the promise that it filtered out the blue light from sunlight ... thereby making everything crisper and cleaner when viewd thru the glasses. It was based on these principles concerning the eyes 'fuzzy' handling of the blue elements of light.
This is mostly an issue in subdued lighting conditions or at night. The rods ... monochromatic light detectors which play a more signifigant role in subdued light ... are most sensitive to greenish-blue light. This creates an effect where the blue elements of light that are present under subdued lighting condition appear brighter.
- Periphery Effects
Many of the same issues relating to brightness also come into play in the periphery. There's a greater concentration of rods near the edges of the retina ... creating a sense of greater brightness and potentially producing a perceived distraction in the peripheral view.
- Circadian Rhythms & Sleep
The hormone known as Melatonin is important in the regulation of the sleep cycle. It's been determined that exposure to blue light diminishes the levels of melatonin in the body. Even levels of blue light emitted by a single bright blue LED could suppress melatonin levels.
I'll bet Augustus had no idea what he was getting into ... this blue light thing ... with those early panes of azure blue glass ... allegedly good for the grapes ... but maybe not so much so for us humans.
Clearly common sense should be applied here to avoid most if not all the issues just discussed. As a start ... don't get your eye in direct line w/ the very directional beam of a super bright LED (especially a blue one). Take stock of any blue LED emitting sources in your bedroom or other places where you sleep ... removing these or obfuscating any direct line of the blue to yourself. Don't read under low light conditions or especially one's where 'bluish' or solely LED white light is being used.
As long as you aren't replacing all the 'white' light in your life w/ blue ... you'll probably be ok. But if you have some strange thing going on ... can't sleep ... recurring headaches ... strange involuntary twitchings about the head and neck? You might want to stop for a moment and check to see if you've got anything 'the color of blue' staring you in the face.
New Discoveries From Blue Light
I've already outlined many of the secondary advances that can be somewhat attributable to the discovery of blue light. However ... to date there has been one other major discovery worth mentioning ... one that was by all measure a completely accidental find ... the emmission of white light from what are known as Quantum Dots
Quantum Dots are nano-sized crystalline semiconductors w/ a protective biological protein coating ... less than 1/1000th the width of a human hair ... and contain a few hundred electrons. They have application as cellular probes that can permeate a nuclear membrane and embed themselves within the cell structure. They're easily excited bundles of energy, and the smaller they are, the more excited they get. 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.
This strange white light illumination emminating from the quantum dots surprised Michael Bowers, a graduate student from Vanderbilt University, who was attempting to elicit blue light from a group of quantum dots that he was exciting w/ a laser. He noted the strange white glow on the table ... and despite the fact that he was expecting blue light ... he and a fellow grad student thought to then mix the dots in w/ some polyuerthane (clear coat) and apply it to the outer surface of a blue LED light bulb. A couple of volts applied to the bulb and they had themselves a warm glow of white from their blue bulb. In this case ... the energy from the blue light is exciting the quantum dots that are spread over the surface of the bulb ... producing twice the brightness and 50 times the life of an equivalent 60 watt incandescent bulb.
Once again, as has been discussed previously ... this discovery has huge implications for the future of artificial lighting ... providing potentially unlimited range in color selection ... dynamic control of that color in real time ... smaller and more efficient packaging, and energy savings that will dramatically change the profile of energy consumption worldwide.
The story of Quantum Dots is much bigger than this discussion of blue light ... or light bulbs for that matter. This nano technology is likely to be at the center of many future advances in medicine and science. In fact ... you may see this subject covered as it's very own Cardboard Illusions 'Strange Stuff' item in the near future.
The Future Is Blue
Well there you go ... there's The Story of Blue Light. I'll bet you didn't think there was that much to it ... did ya?
I think this is a great story ... from Augustus Pleasonton and his blue glass ... to short wavelength laser diodes ... all in the span of roughly 100 years. I'm betting that the future holds much more in store for blue light and it's direct and indirect implications in many aspects of our lives.
It's likely that as time goes by the obvious connections to an actual blue led ... or a beam of blue light will fade ... with the technologies made possible by blue light becoming catalysts themselves for other advances and breakthroughs. This is actually already happening now with many medical and biological instrument advances.
Keep a look-out for all the places where blue light is having some impact in your world ... not just in the form of the obvious bright blue LED on the face of your next electronic gizmo ... but in the most unexpected places ... doing the most unexpected things!
Your Next Encounter With Blue Light
I'm guessing that if you've faithfully read this whole page and had any interest at all in the story ... you'll not look at blue light, blue leds, or blue anything the same way again. Sorry if it makes you crazy ... you're welcome if it enriches your life just ever so little. Go spend some time w/ 'anything red' for a while to counter the likely effects of blue overload that you're now suffering from. I know I wouldn't want to be responsible for creating a 'code blue' condition for anyone.