# Where does light refraction occurs If the students do not change speed, then there is no cause factor. The Marching Soldiers analogy provides an excellent analogy to understanding the cause of light refraction. In other words, the higher the optical density, the more the light will be refracted or slowed down as it moves through the medium. A biconcave lens curves is thinner at the middle than it is at the edges. At the surface where the light enters the glass block, what do you notice about the angle of incidence compared to the angle of refraction? The fundamental feature of the students' motion that leads to this change in direction is the change in speed.

We use this to find the refractive index of the substance:.

Refraction of Light - Why does a pencil look bent in water? - #aumsum #kids #education #science

What Can Teachers Do... Refraction is nicely demonstrated when you look from above at an angle at a straw in a glass of water.

This is because the light rays leaving the straw change direction when they hit the surface between the liquid and the air. It is useful to draw ray diagrams to understand how the geometrical optics concepts we have discussed previously work. We look in Table 5. Email Us. Follow Us. Use your pencil to draw a dot at the point where the light exits the glass block and also somewhere else along the exiting ray.

## The Cause of Refraction

Isaac Newton performed a famous experiment using a triangular block of glass called a prism. This can cause the car to pull to the left, slightly changing its direction. Next Snell's Law. The speed of light, like that of all waves, is dependent on the medium through which it is travelling. Draw a dot at the point where the light enters the block and another dot somewhere else along the incident ray. When a light ray passes from air into water a similar thing occurs: Refraction with lenses The bending of a ray of light also occurs when light passes into and out of a glass lens. How would you identify what the liquid is?

Your eyes trace the light rays backwards as straight lines to the point they would have come from if they had not changed direction and as a result you see the tip of the straw as being shallower in the liquid than it really is.

The angle of refraction is the angle defined between the normal to a surface and the refracted light ray. The line of students approaching the masking tape are analogous to a wavefront of light.