Mammoth Memory

Refraction - water or glass to air

When light travels at an angle from water or glass to air the light speeds up and changes direction. The light turns away from the normal line.

Refraction as light travels from water to air.

Think of it as a tractor moving from a slow muddy, grassy field onto a fast moving road.

Tractor illustrating light refraction as it travels from a slow to a fast medium.

The first wheel hits the fast road and starts to speed up. The other side is still slipping in the mud. This starts to make the tractor speed up and change direction.

Ray or wave refraction as it travels from a slow to a fast medium.

(This is the same for light waves or water waves)

Light rays travel at 226,000km/s through water but when the light again reaches the air it will travel back up to 300,000km/s.

The same effect occurs from glass to air.

Refraction of a ray of light as it travels from glass into air.

When light enters a less dense substance (a lower refractive index) it bends away from the normal line.

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