How Blue LEDs Changed the World

[Mr. Sparkle]

[targetpractice]

1. I remember reading an article about the blue LED in the 90s...

...that it had been invented... I remember reading this in NYC, and my mind immediately imagined how the lights in Times Square would be transformed. I kept telling my friends what a big deal this would be, and they thought I was weird.

Then there was that period of time afterwards when all electronics seemed to have blue LED displays for years.

Thanks for posting this!!

[Blues Heron]

2. The problem is now LED proliferation

You're not saving energy if you replace one incandescent or florescent with ten LEDs which is what's happening. Also shade those puppys! nobody wants your piercing laser-sharp LED glaring in their eyes. When did appropriate lampshades go out of fashion? Looks like a prison yard around our neighborhood these days.

[greyl]

3. That's very interesting but needs counterpoint re light pollution.

Lots of towns and cities are making uninformed, money-wasting, unhealthy decisions when upgrading to LED.

Outdoor Lighting Basics

Modern society requires outdoor lighting for a variety of needs, including safety and commerce. IDA recognizes this but advocates that any required lighting be used wisely. To minimize the harmful effects of light pollution, lighting should

Only be on when needed
Only light the area that needs it
Be no brighter than necessary
Minimize blue light emissions
Be fully shielded (pointing downward)

...


Color Matters

As the illustration above, it is crucial to have fully shielded lighting, but we now know that the color of light is also very important. Both LED and metal halide fixtures contain large amounts of blue light in their spectrum. Because blue light brightens the night sky more than any other color of light, it’s important to minimize the amount emitted. Exposure to blue light at night has also been shown to harm human health and endanger wildlife. IDA recommends using lighting that has a color temperature of no more than 3000 Kelvins.

Lighting with lower color temperatures has less blue in its spectrum and is referred to as being “warm.” Higher color temperature sources of light are rich in blue light. IDA recommends that only warm light sources be used for outdoor lighting. This includes LPS, HPS and low-color-temperature LEDs. In some areas, the white light of even a low-color-temperature LED can be a threat to the local nighttime environment. In those cases, LPS or narrow-spectrum LEDs are preferred choices.

https://www.darksky.org/our-work/lighting/lighting-for-citizens/lighting-basics/

More info: http://www.darkskiesawareness.org/faq-what-is-lp.php

[Nitram]

4. Thanks for the interesting history of the blue LED.