You light up my shirt!
reflection and absorption
Light does fascinating optical tricks!
Reflection and absorption are two of those tricks and are responsible for the color of your shirt, as well as the color of everything else you see. They are also responsible for whether you are going to be sweating while wearing that shirt or not.
Let me shed some light on these phenomenon by leading you through this project.
Let's do science...
The project – step by step
To start off with, you need to be reminded that white light is made up of seven different colors. It is these colors in white light that give every object, from your dad's car to your grandmother's favorite yellow polka-dot socks, their color.
As you know, light comes from the sun, which is the ultimate energy source to our earth. So white light will have energy in it, and it is this energy that will heat you up. You will either heat up a lot, or a little depending on how much energy is absorbed by your clothes.
The color of your shirt and how much energy is absorbed by it, thus heating you up, are linked.
Let's do the project to find the link and explain color and getting hot!
Let's do science...
The Questions
How do objects get their color and why do some objects heat up more than others.
The Hypothesis
The color of an object is a result of the colors of white light either being absorbed or reflected.
The amount of white light absorbed by an object will determine the amount of energy that is absorbed and changed into heat energy and so determine the temperature of that object.
The Experiments
Colors of the rainbow
Refraction of light - how to make a rainbow
Reflection makes colors
Reflection and absorption – hot shoes!
Why these experiments?
The first two experiments are simply to show that white light is made up of seven colors (the colors of the rainbow). These experiments are aimed at elementary school learners, but are suitable in this project too. You really only need to do one of these, or even adapt one of them to suit this project.
Having the foundation set by one of the first two experiments, the third and fourth experiments will give you the answers to the hypothesis.
The Conclusion
As already mentioned, the first two experiments will simply prove that white light is made up of seven colors.
The third experiment shows that an object gets it's color from the part of white light that it reflects.
The amount of energy and thus the temperature of an object will depend on the amount of white light (i.e. the number of colors) that is absorbed. The more colors absorbed, the hotter the object will become. This was shown in the fourth experiment.
“Beef up your project” facts
Here is a question:
If a white object does not absorb any white light, why does it still have a temperature?
The reason is that white light makes up about half of the
solar radiation
, or energy that comes from the sun. The rest is infrared and ultraviolet light.
Look it up
In “Beef up your project” facts I talk about solar radiation. Three parts of solar radiation were mentioned. These form part of the electro-magnetic spectrum. Do some research to find out more about the other parts of the electro-magnetic spectrum.
What are some of the dangerous rays of the spectrum?
Where has man managed to use some of the rays?
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