light Flashcards
absorb
Taken into a material.
angle of incidence
The angle between the incident ray and the normal line.
angle of reflection
The angle between the reflected ray and the normal line.
brain
The organ in the human body that processes signals from receptors.
charge-coupled device (CCD)
A grid of pixels at the back of a digital camera that absorbs light and produces an image.
continuous
A variable that has values that can be any number.
converging
Bringing rays of light together.
convex
A lens that produces converging rays of light.
cornea
The transparent layer at the front of the eye.
diffuse reflection
Reflection from a rough surface.
dispersion
The splitting up of a ray of light of mixed wavelengths by refraction into its components.
emit
To give out.
endoscope
A medical instrument for seeing inside the human body.
eye
Organ of sight, which focuses and detects light.
filter
A piece of material that allows some radiation (colours) through but absorbs the rest.
focal point
The point at which the rays refracted by a convex lens cross over.
focus
Another name for the focal point.
frequency
The number of complete waves or vibrations produced in one second (measured in hertz).
image
The point from which rays of light entering the eye appear to have originated.
incident ray
The ray coming from a source of light.
inverted
Upside down.
iris
The coloured part of your eye
law of reflection
The angle of incidence is equal to the angle of reflection.
lens
A device made of shaped glass that focuses light rays from objects to form an image.
light-time
Distance measured in terms of how far light travels in a given time.
luminous
Gives out light.
medium
The material that affects light or sound by slowing it down or transferring the wave.
non-luminous
Objects that produce no light.
normal
An imaginary line at right angles to a surface where a light ray strikes it.
opaque
Objects that absorb, scatter, or reflect light and do not allow any light to pass through.
optic nerve
A paired sensory nerve that runs from each eye to the brain.,
photoreceptors
Specialised cells that are sensitive to light.
pinhole camera
A simple camera made of a box with a small hole at the front and a screen at the back.
pixel
A picture element found at the back of a digital camera.
plane
A mirror with a flat, reflective surface.
primary colour
The colours red, blue, and green.
prism
A triangular-shaped piece of glass used to produce a spectrum of light.
pupil
The hole in the front of your eye where light goes in.
real (image)
An image that you can put on a screen; the image formed in your eyes.
reflect
Bounce off.
reflected ray
The ray that is reflected from a surface.
refraction
The change in direction of a ray or wave as a result of its change in speed.
retina
The layer of light sensitive cells at the back of the eye.
secondary colour
Colours that can be obtained by mixing two primary colours.
source
Things that emit (give out) light or sound.
spectrum
A band of colours produced when light is spread out by a prism.
specular reflection
Reflection from a smooth surface.
translucent
Objects that transmit light but diffusing (scattering) the light as it passes through.
transmit
When light or other radiation passes through an object.
transparent
Objects that transmit light and you can see through them.
vacuum
A space in which there is no matter.
virtual
An image that cannot be focused onto a screen.
wave
A vibration that transfers energy.
