October 22, 2014

Blue LEDs, Who Knew?

Sometimes curiosity is the best teacher. Admittedly, most of the time curiosity is a much better teacher than I am. However, understanding and using the curiosity of my students actually makes me a better teacher. If I can get my students curious about a topic and structure a lesson that gives them an opportunity to explore their curiosity then I have succeeded without giving any tests or worksheets. The big question is: How do you get your students curious about the topics that comply with given standards? I wish there were a magic answer to that question. The truth is that sometimes you hit it just right and sometimes you don’t. I do know that my own passion and curiosity does tend to transfer to the students as I teach. This is why I try to connect things that I personally find interesting to my lessons in the classroom.

Simple, yet capable of changing the world.

Simple, yet capable of changing the world.

In researching material for the Sonic Bloom project, I came across an article about how the Nobel Prize in physics went to the three men who invented the blue LED (Light Emitting Diode). Last year was the first year that I really starting using LEDs in the classroom. Having a 3D printer in the classroom has a way of getting you more interested in maker education which includes LEDs. LEDs are inexpensive, have high interest for students, and are fantastic learning tools.  I have been curious about what they are and how they work, but I was never interested enough to go beyond the wikipedia definition of a Light Emitting Diode. What is a diode anyway?

When I saw the article about the inventors winning the Nobel Prize I started to think that LEDs might be more than novel trinkets to play with in the classroom. So I dug a little deeper. It turns out that winning a Nobel Prize makes a topic more interesting for everyone. There were plenty of resources to check out. One of the first questions I had was “Haven’t blue LEDs been around for awhile?” Turns out they were first invented in 1993. They have been around for awhile. That led me to wonder why they are just now winning a Nobel Prize. I found this article that did a fantastic job in explaining why the inventors of the blue LED won the prize. It turns out that blue was the hardest to figure out and the last color needed to make white light. Now that scientists can create white light they can make bulbs to light anything. Before the blue LED, we were not able to have an LED bulb to use in our homes. These bulbs are efficient enough to really change the world. That is the reason they won the prize. Developing countries can now have LED lamps that are solar charged and can run for hours at night. They use so much less energy to run that using LED bulbs instead of traditional bulbs lowers electric bills and greenhouse emissions. It’s incredible if you think about it.

Learning this not only put into perspective why these gentlemen won, but it also  made this discovery relevant to the classroom. When I taught third grade I used to teach a science lesson where the students explored light with flashlights and translucent colored plastic. They would see how shining the white light from a flashlight through a material that would absorb certain colors would change the light and color of different objects. It was a fantastic exploration, and the students learned much about light and how we see colors.

White light made with red, green, and blue LEDs

White light made with red, green, and blue LEDs

Now with red, green, and blue LEDs the students can shine the colors on different surfaces and  see how the different color light interacts with different things. They will see what happens when the different colored LEDs are combined. When a blue, red, and green LED are combined you can really see how they make white light.

I’m not sure when or if I will get to this lesson in my classroom, but when it does happen I even have great material to tie it back to ecosystems. I came across this article which explains how, although LED lights are 90% more efficient than incandescent bulbs, they might have a negative affect on ecosystems because they attract 50% more insects, and could damage food chains and cause other harm. I’m now thinking that, after having studied ecosystems, this could be a rich conversation among my students.

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