Optics Flashcards
What is light and electromagnetic waves
Light is the only form of energy that can travel like a wave through empty spaces and some materials. Light behaves like a special kind of wave called an electromagnetic wave. Electromagnetic waves are like water waves that involve the movement of one place to another. They do not need particles to travel. Electromagnetic waves can travel through some vacuums such as space at the speed of light which (3.00x10*)
What is the crest
Crest is the highest point of the wave
trough
The lowest point of the wave
Resting position
Is when there is no waves.
Wavelength
The distance between one point of the wave to a smiliar place on the wave. It is measured in nanometers and repesented in Lambda.
Amplitude
Is the waves height from the resting position to the crest of the wave or the depth of the resting position to the trough. The intensity of the wave depends on the amplitude. Having shorter waves means more energy trasnffered.
Frequency
The rate of repetition in a wave. The energy of a wave depends on the frequency.
Light and its properties
Light is an electromangetic wave that is transmitted through radiation. So, this means that it does not need a medium to be transmitted. Visibel light is the light that humans can see.
Types of Electromagnetic waves
- Gramma rays
- x rays
- Radio waves
- Microwaves
- Infrared light
- Visible light
- Ultraviolet light.
Uses Radio waves
- Fm/am radio
-Cellphone communications
-Radar - Astronomy (discover pulsars)
- tv signals
Microwaves
- Telecommunication
- Microwave ovens
- Astronomy (discover addition radiation that was associated with the big bang)
Infrared light
- Physiotherapy
- Remote controls
- Lasers
- heat detection
Visible light
- light that is visible to the human eyes
- Rainbows
- Theater/concert light
- visible lasers
- Astronomy (optical telescopes)
Ultraviolet rays
- Increase the chances of getting skin cancer
- Causes sunburn and tan
- Sterilization
- Ultraviolet rays
- “Black light”
- Increases production of Vitamin D
- Astronomy
X- rays
- Cancer treatments
- Security imaging
- Medical imaging
- Astronomy study of black holes and the middle of space.
Gramma Rays
- Cancer treatment
- Astronomy
- Production of nuclear decay
Incandenscence
- When light is emmited by a rise in temperature and then glows
Electrical discharge
ligth is emmited when a electric current passes through air or another gas
Fluorescence
Light is emmited when exposed to electromagnic radiation. The electrons collide with te gas producing ultraviolet ligth
Phosphourences
the light is stored and then emmited over a long period of time
Chemiliumineses
- When loght is produced in a chemical reaction withou the rise in temperature
Bioluminescence
Light is produced by a plant or animal
Triboluminescences
when light is produced by friction, the breaking of chemical bonda when somghing is ripped pulled or strecheted apart
LED
Semiconductor device, which emit light when an electric current is passed through.
What is Luminescences
Emmision of light by a substances by anything other then rise in temperature.
Cornea
The outer surface of the eye where light enters
Pupil
A dark circular opening which allows the light to enter the eye
Iris
- The colored of the eye
- Composed of ciliuar band of mucles that form the pupil
Retina
The inner lining at the back of the eye that acts as a projection screen for the ligth entering yours eyes. It sends a message to the optic nerve and creates a imagine in you brain
What happens when the ciliary muscles contract
The lens becomes more thicker and more spherical and then the focal length decreases allowing the eye to see nearby object more clear
What happens when the ciliary muscles relax
Teh lesns becomes more thinner and flat which increases the focal length and allows the eye to see distant objects more clearly
Two types of photoreceptor cells
- Rod cells
- Cone cells
Rod cells
-Can detect movement and shape in low lught but cannot detect color.
- Only see shades of grey
- These cells are located in the side regions of the retina
Cone cells
- Can dectect colour
- Humans have three types that are sensitive to the colors red, blue, and green
-Found in the center of the retina
Blindspot?
A place on the retina which has no photoreceptors and cannot detect light.
Hyperopia
Far sighed
Image forms behind retina
eyeball is too short
cure is converging lens
Myopia
Near sighted
Image forms infront of the retina
eteball is too long
cure is diverging lens
Astigmatism
The cornea is a irreguular shape so cant form image on retina
Cure: torodial lens with two focal point
Presbyopia
Condition appers in everyone as you get older
- The lens hardens and becomes less flexible. and the ciliary muscles become weaker
- less able to see near distances
- Converging lens is cure
