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Posts Tagged ‘light’

The Beauty of Science

March 25, 2011 1 comment

Scientists don’t like pseudoscience because it diverts attention away from the awesomeness of the natural world. The natural world instills a sense of wonder in scientists because of its diversity and complexity.

Pseudosciences hate real science because it points out the how ridiculous their claims are. But many people are more familiar with pseudoscience (bigfoot, UFOs, psychics etc) and it is these pseudosciences which instill their source of wonder in the world. As a result, many people feel scientists “ruin their fun” or “take the wonder out of everything” when we try to explain why these phenomena really aren’t that incredible.

I believe it was Ned Flanders who once said:

Science is like a blabbermouth who ruins the movie by telling you how it ends. Well, I say there are some things we don’t want to know. Important things.

But in fact the opposite is true. Scientists see the beauty in all things. Whether it be a mathematical proof, a chemistry demonstration, or a physics equation. (I have often hear physicists refer to Maxwell’s Equations as “beautiful”).

Maxwell's Equations. You don't have to know what they mean to know that they look cool!

If you read the xkcd webcomic, you know that I was inspired to write this post because of the comic posted today

So just because scientists spend their day in a lab or in front of a computer screen, this doesn’t mean that we can’t appreciate the world around us. We probably appreciate it more than the average person.

It is sometimes said that scientists are unromantic, that their passion to figure out robs the world of beauty and mystery. But is it not stirring to understand how the world actually works — that white light is made of colors, that color is the way we perceive the wavelengths of light, that transparent air reflects light, that in so doing it discriminates among the waves, and that the sky is blue for the same reason that the sunset is red? It does no harm to the romance of the sunset to know a little bit about it.  – Carl Sagan, Pale Blue Dot: A Vision of the Human Future in Space (1994)

Physics Christmas Carols

December 24, 2010 Leave a comment

Continuing with the Christmas theme of recent posts, I stumbled upon this awesome little collection of Christmas Carols re-written with physics-related lyrics. Pure gold!

My favourite: Phrosty the Photon (sung to Frosty the Snowman)

Phrosty the Photon was quite a quantum sight,

with a zero mass and an endless life,

and a speed approaching light.

There must have been some magic in a physics lab one year,

for when they studied X-ray beams

ole Phrosty did appear, Ohhhhhh,

Phrosty the Photon says he knows he’s not that large,

but he said one day if he comes this way,

he’ll give us all a charge.

Thumpity thump thump, thumpity thump thump, moving fast as light.

Thumpity thump thump thumpity thump thump, Phrosty’s out of sight!!

The Physics of Solar Power

July 6, 2010 2 comments

In my previous post, I discussed how President Obama is helping to fund the development of Solar Energy. I thought I would then take the opportunity to explain a bit of the physics behind solar power.

Don’t worry, you won’t find any equations here :)

First, lets start with the sun. That big bright thing up in the sky.

The sun generates light, and light can be thought of as a bunch of tiny packets of energy. These packets are called “photons”. The different amounts of energy in a photon will correspond to the colour of the light that is emitted. For example, photons of the colour blue have more energy than photons of the colour red.

Energy increases from left to right (Source: Opensource Handbook of Nanoscience and Nanotechnology)

 

So how do we harness the energy in these photons? We can use Photovoltaic cells. Put simply, they convert solar energy into electricity. Let’s see how…

A photovoltaic cell is made of special materials called semiconductors, which are made of things like silicon (Yes, that stuff used to make fake boobs. Isn’t science awesome?).

Now, all atoms are made up of a nucleus (which is made of protons and neutrons) and electrons which circle around the nucleus.

Electrons can actually absorb the energy from a photon, but this happens only if the photon has a very specific amount of energy (a specific colour). When an electron does absorb a photon, it causes the electron to “jump”, and sometimes even break free of the entire atom! Electricity is a constant flow of electrons, which we refer to as an electric current.

Silicon structures like to hold onto their electrons. They don’t normally let them move around which makes silicon what we call an insulator. But in a Photovoltaic cell we add impurities, little bits of stuff that doesn’t belong there. The impurities will actually encourage the silicon to release its electrons and let them move around.

Now the magic happens. So a photon (those little packets of energy from the sun) hits the Photovoltaic cell. If the photon has just the right energy, it will knock loose one of the electrons in the silicon atoms. And, because of the impurities, that electron will move around.

If you get enough electrons moving around, you get an electric current which we can then use to power all of our awesome toys!

Thats it in a nutshell. If you want to read about this stuff in a bit more detail, check out the links spread all through this post, or some of the cool sites below.

Hooray for Physics!

Further Reading:

http://science.howstuffworks.com/solar-cell.htm

http://www.physlink.com/Education/AskExperts/ae451.cfm

http://science.nasa.gov/science-news/science-at-nasa/2002/solarcells/