light ray
a narrow beam of light that travels in a straight line
medium
medium
material through which a wave travels
opaque
materials that let no light pass through them
translucent
material you can see clearly through such as glass and clear plastic that allows nearly all the light that strikes them to pass through
transparent
material that allows some light to pass through. Objects behind material are visible but not clear
law of reflection
the angle of incidence is equal to the angle of reflection. This is true for any surface no matter what material it's made of
focal point
light rays that travel parallel to the optical axis and strike the mirror are reflected so that they pass through a single point on the optical axis
focal length
the distance along the optical axis from the center of the mirror to the focal point
lens
a transparent object with at least one curved side that causes light to bend
concave lens
a lens that is thicker at the edges than in the center
refracting telescope
uses two convex lenses to form an image of a distant object. Light passes through an objective lens that forms an image
reflecting telescope
have a concave mirror instead of a concave objective lens to gather light from distant objects
light ray
a narrow beam of light that travels in a straight line
medium
medium
material through which a wave travels
opaque
materials that let no light pass through them
translucent
material you can see clearly through such as glass and clear plastic that allows nearly all the light that strikes them to pass through
transparent
material that allows some light to pass through. Objects behind material are visible but not clear
law of reflection
the angle of incidence is equal to the angle of reflection. This is true for any surface no matter what material it's made of
focal point
light rays that travel parallel to the optical axis and strike the mirror are reflected so that they pass through a single point on the optical axis
focal length
the distance along the optical axis from the center of the mirror to the focal point
lens
a transparent object with at least one curved side that causes light to bend
concave lens
a lens that is thicker at the edges than in the center
refracting telescope
uses two convex lenses to form an image of a distant object. Light passes through an objective lens that forms an image
reflecting telescope
have a concave mirror instead of a concave objective lens to gather light from distant objects