Refraction and the broken pencil
Background
Refraction
, that mystical magician, takes something like an ordinary pencil and changes it, just like that. But here is the interesting part – it hasn't changed at all. It's all just an illusion...
Let's do science...
The Experiment
The Aim
To use refraction to make a pencil seem like it is broken.
Equipment Needed
A pencil (not one that has about one page of writing left in it – it needs to be fairly long)!
Water.
A drinking glass.
Method
Put water in the glass so that it is half to three quarters full.
Stand the pencil in the glass.
Look at it from the side of the glass.
Then look at the pencil from above the glass.
Results
This is what you should see happening...
From the side of the glass, the pencil seems broken (check out the photos below – the first photo was actually a photo of the same experiment using a glass bowl with a straight side. The second photo shows the pencil in the glass). Notice the difference in the two photos? The curved glass and water act as a magnifying glass!
When looking from above, the pencil seems like it is bending at the surface of the water.
If you move your eyes up and down from the side of the glass to the top you will get to a point where you will see what seems to be another pencil in the water.
The Conclusion
Check out the photo on below. You can see all the effects mentioned in the results. The different effects are simply because you are looking at the pencil from different angles. From above the bent light will make the pencil look like it is “above” the real pencil and so give the impression that the pencil is bent. From the side, the bent light will lower the image of the pencil, but because you are looking at it from the side, it will seem to be broken. The largeness of the pencil is because of magnification caused by the curved glass.
And just to help you out in your project a bit more, here are the refraction diagrams...
The bent pencil...
and the broken pencil...
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