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Red LEDs for Green Groceries

Of all the colors of the rainbow, red is lettuce's favorite

1 min read

Of all the colors of the rainbow, red is lettuce's favorite. Chlorophyll, the electrochemical engine of photosynthesis, runs on red photons, which it uses to kick electrons along a chemical pathway that leads to the production of sugar. So if you are growing the vegetable indoors in a factory, why waste energy on colors you don't need? Using a red-LED-based growth process developed by Cosmo Plant Co., in Fukuroi, Japan, instead of a fluorescent-lighting-based one, cuts a factory's electric bill by 60 percent, the company told Agence France Press.

Fifty kilometers east of Tokyo, one of Cosmo's customers uses the technology to produce 7000 heads of lettuce per day all year round in a 10-floor building on just 1000 square meters of space. The lettuce matures more than three times as fast under the LEDs than outdoors. While growing lettuce in an open field is still less costly, growing it inside under LEDs means you don't have to worry about crop-decimating typhoons and other nasty weather.

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The Transistor at 75

The past, present, and future of the modern world’s most important invention

1 min read
A photo of a birthday cake with 75 written on it.
Lisa Sheehan
LightGreen

Seventy-five years is a long time. It’s so long that most of us don’t remember a time before the transistor, and long enough for many engineers to have devoted entire careers to its use and development. In honor of this most important of technological achievements, this issue’s package of articles explores the transistor’s historical journey and potential future.

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