Does Light Exposure Time Affect Glow in the Dark Appearance Time?
King George Secondary
Floor Location : J 230 D
In this lab, I am trying to determine whether the length of time of light exposure affects duration of the glow appearance afterward on glow-in-the-dark-vinyl. To test this I will be using a 9 Bulb Ultra Violet Blacklight as the light source and a glow in the dark vinyl sheet as my constant material.
This experiment will be a small example of how our eyes can actually see electromagnetic waves from 400 nm (blue) to 700 nm (red) in length. To our brain, we see them as colours. For this experiment, I will be using ultraviolet which has wave lengths of 400nm.
When exposed to UV light, electrons in fluorescent materials (such as post-it notes, highlighters, or apparel) get very excited and they enter a "High Energy State" caused by the UV light that we can't see. Then they enter a "Low Energy State" and create light that we can see. The invisible UV light goes in and then creates the visible light that comes out. But once the light is turned off the electrons no longer create that "glow". Phosphorescence, however, takes the same amount of light but releases its energy at a slower pace, creating the "glow-in-the-dark" look. This is why if you shine a light on both glow-in-the-dark and fluorescent paper, once you turn off the light, only the glow-in-the-dark side will keep emitting light. For this project, I will be focusing on phosphorescence which makes things glow.