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Day 6

Four ways blue LEDs can change the world

This week, the Nobel Prize for Physics went to three Japanese scientists for their work on blue LEDs - or light emitting diodes. Blue LEDs make it possible to create white LED light which illuminates smartphones, computer screens, and energy-efficient light bulbs.
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Day 64:24Four ways blue LEDs can change the world

This week, the Nobel Prize for Physics went to three Japanese scientists for their work on blue LEDs ​— or light emitting diodes. Blue LEDs make it possible to create white LED light which illuminates smartphones, computer screens, and energy-efficient light bulbs. In its announcement, the Nobel committee also nodded to the technology's great promise. Here's Christopher Hall, Professor of Materials Science, on 4 ways blue LEDs can change the world. 

A couple looks at white and blue LEDs used as Christmas decorations in Tokyo on Nov. 20, 2009. (Toru Hanai/Reuters)

#1. Lighting up developing countries

"One of the extraordinary things that follows from having a white LED which is efficient and which can produce light from a very small amount of electric power, is that we may be able to make light available to people all over the world. There are very many communities who don't have a public electricity supply... It's now possible to make a small, compact solar lantern which they can use in every aspect of their lives."

#2. "Li-fi"

"Another way in which white LED is set to change the world is in providing a completely new means of digital mobile communication using light. The reason it's possible is that you can switch on and off an LED lamp a million times a second, or even more. And this allows us to use an LED light to send digital information through the air without a fibre optic cable or without a copper wire." 

A boy carries a pot of water at Siddharth Nagar slum in Mumbai, on March 22, 2010. (Rajanish Kakade/Associated Press)

#3. Purifying Water

"If you have a blue LED, by tweaking the way you make the LED you can get violet light, and if you tweak it a little bit further you can get ultraviolet light. Now ultraviolet light is used to purify water, and the ultraviolet LED offers the possibility of sterilizing, disinfecting and purifying a wide range of materials but particularly water in parts of the world which have seriously contaminated water supplies ... It can be done at the tap at the point of supply, and it's not an industrial installation." 

#4. Lower energy consumption

A sculpture containing 7,000 recycled plastic water bottles with LED lights, measuring 20 m in diameter and 10 m in height, shines behind traditional Chinese lanterns at Hong Kong's Victoria Park, on Sept. 14, 2013. (Bobby Yip/Reuters)

"We spend about 20 per cent of all the electricity we produce on the lighting sector. White LED lighting is something like five or ten times more efficient than the old incandescent bulb technology and it's going to replace it extremely rapidly."

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