1. Refraction
The bending of light

2. Refraction (p )
When light travels from one substance to another its speed changes. This speed change can cause a ray of light to change its direction (refract or bend) if the ray is at an angle to the surface.

3. Demonstration: Fast to slow: Slow to Fast: normal fast : AIR
slow: WATER
fast : AIR
slow: WATER

4. Demonstration: Fast to slow: Slow to Fast:
from a FASTER to a SLOWER medium, it will bend TOWARDS the normal
normal
fast : AIR
slow: WATER
fast : AIR
slow: WATER

5. Demonstration: Fast to slow: Slow to Fast: Toward the normal
fast : AIR
slow: WATER
 from a SLOWER to a FASTER medium, it will bend AWAY from the normal
fast : AIR
slow: WATER

6. Total Internal Reflection
Sometimes when light is going from a slow to a fast medium it refracts so much it doesn't escape.
This is called TOTAL
INTERNAL
REFLECTION
(Prisms are used as
mirrors = 99% reflected)
E.g. Fibre optics
1 min
2 min

7. demo

8. Practical Applications:
Fibre Optics

9. Practical Applications:
Diamond Cut

10. Practical Applications:
Reflectors
Reflect light back in the direction it came from

11. Practical Applications:
Binoculars
contains four prisms whose job it is to produce a final upright image for the user

12. Practical Applications:
Endoscope
A tube that is passed into the body to observe the intestines or stomach.
This contains glass fibres and light travels along it by total internal reflection!

13. Review (This has a lot of extra stuff)
10 min