Sunday, April 25, 2010

In this picture, I placed a pole into the water.  The pole looks like it is at first straight, then bends just as it hits the water.  In reality, the pole is completely straight.  The water seems to bend the pole becuase of the physics property of refraction.  Refraction is the bending of a ray as it passes from one medium into another.  In this photo, the two mediums are air and water.  In the air, the speed of light travels at a higher speed than the speed of light in a material such as water.  In water, light will generally travel about three-fourths of its velocity in the air.  Therefore, the incident angle created by the straight side of the pole will be different than the refracted angle created by the bended part of the pole.  I measured the angle of incidence at 42 degrees and with the equation from Snell's Law, the refracted angle in the water is 30.2 degrees. 


  1. Hi Jonathan,

    I've always been interested in this phenomena; thanks for addressing it and offering an explanation!

    I'm curious now that you've finished your project-- are you finding that you are learning more when you are asked to relate what you've learned to something you actually see and then having to explain that to all of us?


  2. Very good picture, it really shows the pole as if it was bent!
    Your physics explanation is clear and I particularly applaud your effort to taking it to the next level as you measured the angles.
    Great job!