The document describes various phenomena related to sight and waves. It discusses the anatomy of the eye including the cornea, pupil, lens, retina, optic nerve, fovea, rods and cones. It then covers topics such as vision in low light, color detection, color blindness, the lens and its focusing abilities, diffraction, resolution, polarization, Brewster's law, the Doppler effect, and gives examples of calculations related to these concepts.

1. Sight and Wave
Phenomena
Option A

3. Cornea – a transparent membrane through
which light enters
Pupil - an
aperture through
which light enters
the eye’s lens
- the pupil can
increase in size to
adjust the
intensity of light
entering the eye.

4. Ciliary muscle – ligaments that control the curvature of
the lens
Retina – located
at the back of
the eye
- light is focused
by the lens on the
retina where rods
and cones convert
the light into
electrical signals
Optic nerve –
transmits these
electric signals to
the brain

5. Fovea – an area
of exceptionally
acute vision
- each cone is
connected to a
different nerve
fiber
Cones are
concentrated at
the center and
rods are found
primarily along the
edges of the
retina

6. Rods detect light, dark and grays.
Scotopic vision – used at night or in low light
rods are used
distinguishes shapes but not colors, little detail
Cones detect color and are
only sensitive to bright
light.
Photopic vision – used
during the day, cones are
mainly used, shaped and
colors are distinguished

7. There are three types of cones, for short, medium and long
wavelengths.

8. The lens of the eye is a converging lens which means it
focuses the light at a point (focal point). It cannot focus
on two objects at different distances at the same time.
Depth of vision Near point
The range of The closest point on which the human eye
can focus without straining. About 25 cm
distances that can
but depends greatly on age.
be seen clearly.
Far point
The largest distance
the eye can focus on
without straining.
Considered to be
infinityfor a normal
eye (a few meters)
Accomodation
The ability of the
lens to change its
shape to focus on
different distances.

9. Cones are sensitive to the primary colors:
red, blue and green.
Secondary colors (cyan, magenta and yellow)
are composed of the primary colors two at a
time.

10. Color blindness – most common kind is the inability to
distinguish between red and green.
Partial color blindness – one type of cone is not
functioning and only those colors dependent on that
cone cannot be distinguished.
Complete color
blindness – two
types of cone
are not
functional and
no color can be
distinguished.

11. Diffraction
Diffraction is the spreading
out of a wave as it goes past
an obstacle or through an
aperture.
When the wavelength is small
compared to the aperture the
amount of diffraction is
minimal.

13. b
is the angle to the first minimum (radians!)
is the wavelength of the light used
b is the size of the opening

14. A single slit of width 1.5 m is illuminated
with light of wavelength 500.0 nm. Find
the angular width of the central
maximum.
= 39o

15. Resolution
The ability to distinguish between two
objects.
Because light diffracts, two
distant stars that are close
together may appear to be
one object.

16. The Rayleigh criterion
Two sources are just resolved
if the central maximum of one
source falls on the first
minimum of the other.

17. Just resolved Unresolved

18. Well resolved

19. Diffraction pattern due to a
circular opening
b
Useful in optical devices where b is the diameter of the opening.

20. The camera of a spy satellite orbiting at 200 km
has a diameter of 35 cm. What is the smallest
distance this camera can resolve on the surface
of the earth (assume a wavelength of 500 nm).
b
1.22 x 5 x 10-7)/0.35
= 1.74 x 10–6 rad
S=R = 2 x 107 x 1.74 x 10-6
= 0.34 m

21. The headlights of a car are 2 m apart. The
pupil of the human eye has a diameter of about
2 mm. Suppose that light of wavelength 500
nm is being used. What is the maximum
distance at which the two headlights are seen
as distinct?
b = 3 x 10–4 rad
R = s/ m

22. Polarization
Only light that is oriented on the same
plane as the filter will pass through

23. Polarization by reflection
When light reflects off a
surface, the reflected ray is
partially polarized (“glare”).
The degree to which it is
polarized depends on the
angle of incidence.

24. Brewster’s Law
The Brewster angle is the angle of incidence that will create
reflected light that is 100% polarized.
n = tan
Calculate the Brewster angle for light incident
on the surface of water (n = 1.33).
= 53.1o

25. A polarizer is a material with a molecular
structure that only allows a specific
orientation to pass through.
An analyser is a polarizer that is used to
determine if light is polarized.

26. The intensity (brightness) of light passing
through an analyzer is dependent on the
angle the polarizer makes with the
orientation of the light.
I = Iocos2
Calculate in terms of Io the intensity of light passing through an
analyzer when = 40o.
I = .6 Io
Graph of Intensity vs angle.

27. Doppler effect
• The frequency of a wave changes when the
source of the waves is in motion or the observer
is in motion
• Higher pitch when the source is
approaching, lower pitch when the source is
moving away
• Higher pitch when the observer is
approaching, lower pitch when the observer is
moving away

28. Moving source
The frequency of a car’s horn is 200 Hz when the car is at rest. What
frequency will be heard if the car is approaching the observer at 30
m/s? The speed of sound in air is 330 m/s
f = 220 Hz

29. The frequency of a car’s horn is 200 Hz when the car is at rest. What
frequency will be heard if an observer is approaching the car at 30
m/s? The speed of sound in air is 330 m/s
f = 218 Hz

30. Light from distant stars is also affected by
the Doppler Effect.
v/ f
f= c
f = change in freq f = emitted freq
v = speed of source c = speed of light
Hydrogen in a distant galaxy emits light of wavelength
658 nm. The light received on earth is measured to be
689 nm. Find the speed of the galaxy.
v = 1.4 x 10 7 m/s