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Tuesday, January 29, 2013

Dear Readers,
It has been so long since I updated, but I knew what I was going to do for a while. I am posting my first article for that fifth-grade newspaper I told you about. I couldn’t update sooner because there were a lot of things in question previously, but hopefully the first issue will be published this week. I would like to dedicate this article to my Step-grandmother Martha, one of the most compassionate, forgiving people I knew, who has just recently passed away. Here is my article:

Science, Math and Technology

The Photoelectric Effect

1905... a very important year in science, with all sorts of breakthroughs from the idea of golf ball dimples to The Third Law of Thermodynamics by lesser known Walther Nernst. But, 1905 was most important for our favorite stereotypical scientist dude: Albert Einstein. He came up with Special Relativity (coming up with General Relativity ten years later in 1915) and Brownian motion.

There is one more major discovery he came up with: yep, you guessed it; the photoelectric effect. “Photo” is the Latin root for light, and electric has to do with electricity and the flow of electrons.This is exactly what the photoelectric effect is about. (Always trust Latin to decipher a really science-y word!) Here’s the main idea. Some physicists wre experimenting with light waves by shooting them at metal plates and trying to coax the particles that spin around the center ball (the nucleus) of an atom: electrons. They found that they couldn’t get electrons to come out until they started experimenting with higher energy waves in the ultraviolet spectrum of light. 

We can only see a small fraction of light waves because our eyes evolved to our necessities. Lower and higher frequencies of light, like microwaves, gamma waves, and ultraviolet waves are some examples of waves we can’t see because their frequencies are too high or too low. A thermal camera can “see” ultraviolet radiation and use its program to convert the image into a color coded image in our visible light spectrum. 

Some animals, like snakes, see higher frequencies too because they’ve had to adapt to being able to find small prey, so it helps to have a built-in thermal camera. What the scientists found was that when they bombarded the plates with higher energy ultraviolet waves, the plate surprisingly emitted electrons, unlike their unsuccesful experiment with lower frequency light. Furthermore, if they shot 1000 lower-frequency light waves the plate didn’t emit electrons, but even with a few ultraviolet waves the plates did emit electrons. They were stymied. 

Of course Einstein heard about this, and he started working on it. He eventually figured it out and published a paper about his findings in the magic year of 1905. He basically said that no matter how many low-frequency waves you shoot, there isn’t any sufficient energy to knock the electrons out of their orbits. Once you take out the big guns (ultraviolet waves), there’s definitely enough energy to make some electrons go flying. 

In my words, if you poke my brother in the morning, he will fail to wake up, no matter how many times he is poked. If you give him a nice, crisp thwack though, he will definitely wake up. (You can rest reassured: no brothers were harmed in the writing of this article.) The physicists confirmed Einstein’s work.  An example of the photoelectric effect is when soldiers use night-vision goggles at night. Photons (particles of light) hit a metal in the visor such as gallium arsenide and create photoelectrons. These photoelectrons then hit a phosphor coated screen and turn back into photons, making the soldiers able to see. Next time, I think we’ll be talking about Vedic division, and I’ll see you then.

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