This document defines and provides examples of luminous and non-luminous objects, and describes the properties and behavior of light rays, shadows, reflection, refraction, color, and optical instruments like mirrors, prisms, and periscopes. Key terms discussed include transparent, translucent, and opaque materials; angles of incidence and reflection; real and virtual images; absorption and reflection of color; and how rainbows are formed by light refraction in water droplets.

1. By : Firman

2.  Luminous object is a object that can shining by
itself or emit light by itself.
 Example : Fire , sun , lamp.

3.  Non luminous object is a object that cannot
emit light itself they can only reflecting light.
 Example : Moon, Table , Chair ,etc.

4.  Light rays is a line of light.
 Light travel in all direction.
 Line of light can be seen clearly if they travel in
one direction.

5.  Transparent let light to pass on. Ex: Glass ,
windows.
 Translucent not let pass some light but pass
some light through them. Ex : Tracing Paper
 Opaque not let all light to pass through them.
Ex: wood, metal.

6.  As light cannot pass through opaque object it
will make a dark area usually behind the object
it was called shadows.
 Te size of the shadows depends on the light
source and the distance of the light source and
the object.

7.  The greater the light source there will be a
shadow that have dark in the middle and grey
surround it.
 The less the light source the darker the shadow
in the middle part.

8.  The further the distance between the object and
the light source will make small shadow.
 The shorter the distance between object and
light source it will make a big shadow.

9.  You can see object because the object is
reflecting the light and the reflected light will
be caught by our eye.

10.  Incident ray is a light that strike the surface of
something.
 Reflected ray is a light ray that is reflected from
a surface
 Normal is a line that is perpendicular at 90
degree to the surface where a ray strike.
 Angle of incidence is the angle between
incident ray and normal.

11.  Angle of reflection is the angle between
reflection ray and the normal line.
 Plane mirror is a mirror with flat surface.
 Image is appearance of an object in smooth
shiny surface.

12.  When light ray strike a smooth surface the
angle of reflection is equal to the angle of
incidence.
 When reflected light reach your eyes you will
be able to see the image.

13.  Real image
 Virtual image

14.  Real image is a image that cannot be projected
into flat surface.
 Virtual image is a image you see in a mirror
that are in the same size but only in opposite
directions.

15.  Light rays that strike the rough surface will not
have same angle of incidence and angle of
reflection.
 Because of this effect you will not able to see
your image in the rough surface thing.

16.  Refraction is light that is bend because of
different position of object and different
medium.
 The angle which the ray makes with normal is
called angle of refraction.

17.  Light travel in different speeds in different
media.
 If the light slows down it bends toward the
normal.
 A light ray can appear different direction than
the actual place example stone in water.

18.  Periscope is an equipment made by two plane
mirror

19.  If the sun light strikes the prism in certain
angle and stop by a white screen it will make a
range of color is spread out and called as
spectrum.
 The sun light contains different color because
have different wave length and travel in
different speed.

20.  Rainbow are appear because of the refraction
and reflection of the sun light by the water
droplets.
 There can be two rainbow if there is 2 reflection
occur.

21.  Absorbing color
 Reflecting color

22.  If all the colors are reflected the color will seem
to have white color
 If all colors are absorb the color of the object
will seem black.
 Usually object absorb some color and reflected
other colors.

23.  Because some object reflecting and absorb
some color so if you put blue glass the only
color that can be pass through is blue and the
other reflected.

24.  When different type of light color is mix up it
can make new color. Ex blue and red become
magenta.
 When three beams of light is shining into white
screen it will produce 3 secondary color and
white color.