One of the best places to learn about the electromagnetic spectrum is to step outside where the sun is shining! The sun gives off almost the entire spectrum, all the way from the long waves, to the short waves. And, that's why when we come outside, we can feel the heat from the sun, that's why we get a suntan or a sunburn on our skin, because the sun is giving off all of the different types of electromagnetic radiation.
Maybe, back when you were a kid, you'd go out on a sunshiny day and you'd get out a magnifying glass, and you let the sunshine in one side and make a little, sharp, beam of light on the grass and that light might have started the grass on fire. That's because you're focusing all of that visible light, that infrared light, all into one spot. Imagine if you could do that with a magnifying glass the size of a door!
We can actually do that experiment using a fresnel lens. Old projection televisions have a fresnel lens inside the screen that takes the small picture behind it and turns it into a "big screen" image. I took one off of the front of a 51-inch big-screen TV to see what would happen. (Click here to learn more about the Beals Science fresnel lens Solar Cooker)
I took the lens outside when the sun was up high on a beautiful, 90 degree day. The lens took the sun's rays and focused them into one small spot, just like a magnifying glass would do, but on a much larger scale.
The first experiment was to put a piece of wood into the beam of light. It took three seconds to burst into flames! So I figured the rays were probably hot enough to cook food - and If I am going to cook food with the sun, I figured I should start with bacon, America's favorite food.
Smell that? Of course you can't, you are reading this, but that smell you are thinking the sizzling of bacon protein undergoing a reaction called the, "Maillard Reaction". That's when meat and protein undergo a chemical reaction that denatures the protein and gives cooked meat that distinct look, smell and texture.
Other experiments with the sun in this video:
The important thing to understand is that the suns rays harness a exceptional amount of energy, energy that we take for granted here on earth.
To prove the power of the sun, we placed a toy of Kylo Ren from Star Wars in the focused light of the Satellite Dish Parabolic Mirror (more info and instructions for how to make one here) and gave Kylo Ren, a villain who used the sun's rays to destroy enemies, a taste of his own medicine.
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