refraction and lenses

Refraction

bending of light waves as they enter or cross the boundary between two media with different densities

refraction

the light changes the direction of its motion and its velocity at the same time.

snell’s law

Light is only refracted when it crosses a boundary between two different media having different properties

optical density

Materials that allow light to pass through bend the light more than others

refraction

changes the direction and the velocity of light

Willebrord Snellius

The law of refraction was first observed

Willebrord Snellius

a Dutch physicist, as he described the relationship of the angle of incidence to the angle of refraction

n

index of refraction

c

speed of light in a vaccuum

v

speed of light

1.000

vaccuum

1.003

air

1.33

water

1.36

ethanol

1.47

glycerin

1.52

crown glass

1.54

quartz

1.61

fine glass

2.42

diamond

lenses

transparent materials made of either glass or plastic.

lenses

refract incoming light rays

lenses

can be either converging or diverging lenses

converging or convex lenses

thick in the middle and thin at the edges.

diverging or concave lenses

thin in the middle and thick at the edges

principal axis

the horizontal line that crosses the center of the lens

vertex

the intersection point of the vertical and the principal axis of the lens

focus

the point where the refracted light converges

focal length

distance between vertex and focus

lenses

refract light by bending it toward the thickest part of the lenses