How Blue LEDs Changed the World

very short but delightful video on discovery of blue LEDs

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@Josh_Melnick - You spilled the beans on my favorite trivia question during my Arduino classes: Why did the inventors of blue LEDs get a Nobel prize when the developers of red and green did not?

Excellent post!

I have occasionally given away Throwie components in my classes (LED, CR2032 battery and magnet). What is interesting is that the battery will run down for most colors in a few days, blue will still be throwing off a bit of light weeks later. This is because the forward voltage drop for blue is higher than others so the current flow is less. To see it after a week, put it on your night stand and look at it after your eyes adjust to dark.

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Are ‘throwies’ not just littering under a colorful veneer?

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Without blue LEDs we wouldn’t have the Matthew McConaughey Blue Light story. I can’t find a good video but here’s audio:

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At $0.50 each they are too expensive for me to litter with them. I salvage the LED and magnet.

I am guessing we listen to the same radio station from time to time, and this was the first thing I thought of as well when I saw this thread… Hehe.

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I light my house almost exclusively with LED, which thanks to the overwhelmingly dominant blue die pumped phosphor method has a strong blue spike no matter the color temperature, CRI, etc. As a former shift worker I’ve developed some methods to cope. One of the more important ones is a wind down process where I reduce lighting in the 30 minutes before turning in and spend the last 5-15 minutes of the day using the absolute minimum amount of light possible. I compliment this by resisting the urge to do anything more than ensuring my alarm is set on the phone before going to sleep. I also still have blackout curtains up so the bedroom stays pretty dark at all times without artificial lighting.

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I absolutely need to follow suit.

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I’ve come across a great deal of alarmism about LED lighting in recent years - probably a consequence of any new technology.

Alongside it is often the junkiest of junk science. Nonsense like expose rats to about the angriest blue-white light (i.e. 6500K or higher, which is hard to find outside of flashlights) at intensities >double what you’d find in an operating theater for 12+ hours a day for weeks on end. Spoiler alert - expose a largely nocturnal animal that avoids daylight to light like that, it will experience eye damage.

On the behavior side, there’s some legitimate concern about added blue spectrum, but the Mental Health America article puts most of the emphasis on conscious choices and also notes that this is a far longer-rolling phenomenon than LED lighting/backlighting. Walk along a residential street during prime time TV viewing hours and look at living rooms and note that the average color of light being emitted is typically blue - something that’s been a constant since the advent of color TV. I imagine that we’re all well aware of the ability of a small bright screen to keep us awake in a dark room so long as it’s on and we’re refreshing that page just one more time. Suspect that consciously focusing on sleep hygiene
would do a good order of magnitude more than fixating on light sources.

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Much like “feed rats several thousand times the amount of saccharin a human would consume in a day, and guess what? stomach cancer!”

Saying something"may increase _____ risk" by itself is about as informative as furniture stores with their “up to 50% off!” sales.

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like anyone could even know that

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