Editing Invisible Glass (section)

== Why This Works ==

{| class="wikitable" style="color:black; background-color:#ddd; text-align: left; margin-left: auto; float:right"
|'''Material'''
|'''Index of Refraction'''
|-
|Air||1.00
|-
|Water||1.33
|-
|Clear Plastic||1.46
|-
|Glass||1.47
|-
|Corn Syrup||1.48
|-
|Plexiglass||1.50
|}
Why are some materials clear? The configuration of the atoms and their charges within a material determine how it interacts with electromagnetic radiation, such as light. When a light wave strikes a transparent material, such as glass, the charges on the atoms start to oscillate. The oscillating charges mimic the pattern of the light wave, and so they transfer the light through the material. The charges are not be able to oscillate as quickly as the incoming light wave, however, which causes the light to slow down as it passes through the material! Although light usually travels in a straight line, it undergoes refraction when it passes through transparent materials. ''Refraction'' is when a light wave will take the shortest path through a material, and so it bends, or changes direction, when it enters the material, and bends back to the original direction when it exits the material. How much light bends when it passes through a material depends on the properties of the material, and is called the ''index of refraction'' for that material.

In the table to the right you can see a list of indexes of refraction. Glass has an index of refraction of 1.47, which means that light will travel about 32% slower through glass. Water has an index of refraction of only 1.33, so light travels only 25% slower through water. This is why the glass test tubes or marbles are easy to spot in the water; The light travels faster through the water than the glass, allowing your eyes can see the difference between the materials! The index of refraction for corn syrup, however, is 1.48, which is only off from the glass by 1%. This is why the glass test tubes or marbles are much harder to spot in the corn syrup; The index of refraction for either the corn syrup or the glass is nearly the same, so your eyes have trouble telling them apart!