Explaining Refraction

Explaining Refraction

First we need a Perspex or glass block set at an angle

The Perspex block is denser than air, but allow light to travel through it (i.e. it is transparent)

Explaining Refraction

Explaining Refraction

Explaining RefractionTo understand refraction, we need to think of light as a wave travelling at 90o to the light ray

Explaining RefractionTo understand refraction, we need to think of light as a wave travelling at 90o to the light ray

Explaining Refraction

Imagine different points along that wave

Explaining Refraction

Imagine different points along that wave

Explaining Refraction

As light travels towards the Perspex block, the wave moves forward

Explaining Refraction

As light travels towards the Perspex block, the wave moves forward

Explaining Refraction

As light travels towards the Perspex block, the wave moves forward

Explaining Refraction

As light travels towards the Perspex block, the wave moves forward

Explaining Refraction

As light travels towards the Perspex block, the wave moves forward

Explaining Refraction

•As the light hits the Perspex block it slows down because Perspex is more dense than air

•To light, the Perspex is like walking through treacle

•The slower light does not travel as far in a given time

Explaining Refraction

•As the light hits the Perspex block it slows down because Perspex is more dense than air

•To light, the Perspex is like walking through treacle

•The slower light does not travel as far in a given time

Explaining RefractionBut the light that is this travelling through air is still moving quickly, so it travels further in a given time

Explaining RefractionBut the light that is this travelling through air is still moving quickly, so it travels further in a given time

Explaining RefractionBut the light that is this travelling through air is still moving quickly, so it travels further in a given time

Explaining RefractionIn the Perspex, all the

light travels at the some speed

Explaining RefractionIn the Perspex, all the

light travels at the some speed

Explaining RefractionIn the Perspex, all the

light travels at the some speed

Explaining RefractionIn the Perspex, all the

light travels at the some speed

Explaining RefractionIn the Perspex, all the

light travels at the some speed

Explaining RefractionIn the Perspex, all the

light travels at the some speed

Explaining RefractionIn the Perspex, all the

light travels at the some speed

Explaining Refraction

As the light hits the air again it speeds up because air is less dense than Perspex

Explaining Refraction

As the light hits the air again it speeds up because air is less dense than Perspex

Explaining Refraction

As the light hits the air again it speeds up because air is less dense than Perspex

Explaining Refraction

As the light hits the air again it speeds up because air is less dense than Perspex

Explaining Refraction

As the light hits the air again it speeds up because air is less dense than Perspex

Explaining Refraction

As the light hits the air again it speeds up because air is less dense than Perspex

Explaining Refraction

As the light hits the air again it speeds up because air is less dense than Perspex