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Inventor of the LED Discusses LEDs

Fifty years ago today, on October 9, 1962, physicist Nick Holonyak demonstrated the first "visible" LED (in other words, one that emitted non-infrared light). And that tiny invention has helped to light the world.

GE has released a publicity video featuring Holonyak, who invented lots of things in addition to the LED, including light dimmers. In this video, Holonyak recalls his early experience making the first visible-light LED, and how the red LED was such a breakthrough, such a practical and inexpensive source of light. About that invention, he says: "They still make 'em because they're so damn cheap!"

At the end, Holonyak holds one of GE's LED lightbulbs, a 27-watt bulb that's intended to replace 100-watt incandescents. He is pleased.

For more information, read Wired's article on Holonyak and check out this video interview.

If you're curious about the current state of LED lightbulbs for your house, check out Marco Arment's LED lightbulb review. Also relevant is this followup, discussing his new favorite bulb (it is not a GE bulb, for the record). Arment writes:

That’s the problem with being on the cutting edge of lighting: it’s easy to waste a lot of money on bulbs that aren’t quite right, and then you find a better choice long before yours have died. Anyone who has ever tried to buy CFLs is probably familiar with this.

As a guy who sunk some serious cash into CFLs (and even more in a few strategically placed LED bulbs), I can say he's right on the money.

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History
The Queen of Code: Remembering Grace Hopper
By Lynn Gilbert, CC BY-SA 4.0, Wikimedia Commons

Grace Hopper was a computing pioneer. She coined the term "computer bug" after finding a moth stuck inside Harvard's Mark II computer in 1947 (which in turn led to the term "debug," meaning solving problems in computer code). She did the foundational work that led to the COBOL programming language, used in mission-critical computing systems for decades (including today). She worked in World War II using very early computers to help end the war. When she retired from the U.S. Navy at age 79, she was the oldest active-duty commissioned officer in the service. Hopper, who was born on this day in 1906, is a hero of computing and a brilliant role model, but not many people know her story.

In this short documentary from FiveThirtyEight, directed by Gillian Jacobs, we learned about Grace Hopper from several biographers, archival photographs, and footage of her speaking in her later years. If you've never heard of Grace Hopper, or you're even vaguely interested in the history of computing or women in computing, this is a must-watch:

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science
Why Are Glaciers Blue?
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The bright azure blue sported by many glaciers is one of nature's most stunning hues. But how does it happen, when the snow we see is usually white? As Joe Hanson of It's Okay to Be Smart explains in the video below, the snow and ice we see mostly looks white, cloudy, or clear because all of the visible light striking its surface is reflected back to us. But glaciers have a totally different structure—their many layers of tightly compressed snow means light has to travel much further, and is scattered many times throughout the depths. As the light bounces around, the light at the red and yellow end of the spectrum gets absorbed thanks to the vibrations of the water molecules inside the ice, leaving only blue and green light behind. For the details of exactly why that happens, check out Hanson's trip to Alaska's beautiful (and endangered) Mendenhall Glacier below.

[h/t The Kid Should See This]

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