# Refracting Light with LASERs

LASERs make almost anything better, and that includes refracting light in physics lessons.  Here's a guide to refracting LASER light, and some calculations you might need to do afterwards.
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## Step 1: Just a bit on theory

As a beam of light enters an optically more dense medium it slows down.  If a beam of light is traveling diagonally, some parts will slow down before others. This causes the light ray to bend towards the normal (the normal is a line drawn perpendicular to the surface where the beam of light hits).  The opposite happens when a light ray leave a more dense medium.

## Step 3: Draw around the perspex block

Place the block on the paper and draw all the way around it with the pencil.  This rectangle (unless you have a differently shaped perspex block) will serve as a guide to show you where the block was when it is removed for measuring the angles.

## Step 4: Turn the LASER on

This is probably my favourite step:
Plug in and turn on the LASER!

(Seriously though, DO NOT SHINE THE LASER AT OTHER PEOPLE)

## Step 5: Start refracting!

Place the perspex block and paper in the path of the laser, making sure that the block is still aligned with the rectangle you drew.  It should look something like the picture.

## Step 6: Marking out the LASER's path

When trying to draw out the line formed by the LASER, you can't simply trace it with your pencil, because that wouldn't be a properly straight line so it would be difficult to measure the angles for calculations, and placing a ruler down would break the laser beam and you wouldn't know where it is.

To mark out the beam, you take your pencil (make sure it is sharpened) and mark one dot at one end of the line, one near the middle, and one at the other end of the line.  Do this for the beams either side of the block, being careful that you don't move it.
amandaghassaei2 years ago
cool! this reminds me of a demo I saw at the smithsonian that was showing how different types of telescopes work. kind of like this.
wilgubeast2 years ago
YES! Lasers make math more fun. Cool project. Hope you can find a camera that allows you to take better photos in the dimness required for laser-visibility.
sherd030 (author)  wilgubeast2 years ago
Yeah, I know about the camera, all the pictures were actually taken at school for a guide we're supposed to make (this is it). Unfortunately, i don't have a LASER.