science light and eyeballs Flashcards
what is force
a push or pull on a object
what is a wave
a disturbance or movement that transfers energy through matter or space
what is a crest
highest part of wave
what is a trough
lowest part of wave
what is a wavelength
distance from one trough to the next, or crest to crest
whats a amplitude
height of the wave or the depth of it
what is a frequency
of oscilations that occur in a given time
what is a frequency measured in
hertz (Hz)
what is energy carried in
in a wave
what are the 2 wave types
transverse and compression
how do the transverse waves move
the waves are fairly far apart and they vibrate perpendicular to the direction of the wave
how do the compression waves move
they have extremely short wavelengths and they vibrate in the same direction of the waves
how can you remember the difference between the waves
think of compression like its in a compressed room and it causes the waves to become compressed.
what is white light made of
wavelengths
what happens when a white light goes through a prism
they refract and also become different colors.
which colors have shorter wave lengths
violet. everything up above it on the rainbow have slightly longer wave lengths.
what is the white light called when it separates into a rainbow
the visible spectrum
what is white a result of?
a mixture of all the colors
what happens when a light hits a object
it will be reflected or absorbed. only reflected light can be seen
what are the primary additive colors
red green blue combine to produce all colors of the rainbow.
what are the secondary additive colors
magenta, cyan, yellow
what does visible light cause
electromagnetic radiation and also causes the electrical and magnetic fields to vibrate
what are radio waves
the longest wavelength of EM radiation and has the lowest energy
what are microwaves (not the food heater)
have shorter wavelengths than radio waves. used in satellite talking
what are infrared rays
radiate heat, emitted by all objects ; more warm object means more infrared waves than cooler objects. they are used in remote controls and CD readers
what is ultraviolet light
very energetic and causes cancer, fluorescent materials absorb UV light and emit it as visible light, kills bacteria
explain X rays (not the machine)
have very short wavelengths and used to see bones and inside luggage
explain gamma rays
shortest wavelength and highest energy
what is light made out of
photons
how do photons travel
straight lines away from the light source
what is transparent, translucent, and opaque mean
transparent transmits light waves, translucent lets some out and some in, and opaque osorbs or reflects
how are shadows made
the light is blocked by a object forcing the photons to bounce and go anywhere but the blocking object
what is it called when a light bounced off a object
reflected
whats the incoming ray and the outgoing ray called
indecent ray and reflected ray
what happens when light moves from air to glass
it slows and changes direction
what is the angle of refraction
angle between a ray of light emerging from boundary between 2 materials
what is the normal
the middle of the material that the indecent and reflected ray is hitting
what happens when light passes through dense material
it bends towards the normal and slows
what happens when light passes through less dense material
vice versa from the dense stuff
what does refraction do to water
objects in the water seem closer.
what do mirrors do
reflect light
whats a plane mirror
flat mirror, normal image, image seems to be behind the mirror
whats a concave mirror
curved inward,
how do rays work with a concave mirror
reflected light rays meet at the focal point and come together. they are called converging rays
what do images looked like in concave mirrors
distant objects are small and inverted, closer is larger and upright
whats a convex mirror
curved outwards
what are the rays called that hit the convex mirror
lingering rays
what do images look like in a convex mirror
smaller than they really are and show a bigger area than most mirrors
what is a lens
its a curved piece of glass that bends light in a controlled way, can cause them to converge or diverge
explain concave lens
thinner in middle, rays diverge
explain convex lens
thicker in middle,rays converge, image formed depend on angle and light
where do light rays converge
focal point
what is the distance called from the focal length to to the lens
focal length
what is a pupil
black center of a eye where light enters
what is a iris
the colored part of the eye
what does the iris do
controls the amount of light going into the eye but expanding and shrinking
what is the sclera
white part of eye
whats the cornea
transparent tissue that covers the eye ball
whats behind the pupil
flexible convex lens
what does the flexible convex lens in the back of eye do
focuses light onto the retina located in back of the eye
what is the retina covered in
light sensitive cells that make light into energy
how are electric signals sent to the brain
by optic nerve
what does the cornea do
refracts light so it converges towards retina
is the image that is formed on the retina inverted
yes
what is the area that the optic nerve enters through the retina called
the blind spot
what are the 2 light sensitive cells that the retina contains called
rods and cone cells
what do rod cells look like and do
they are rod shaped and allow us to see in the dark
what do cone cells look like and do
they are cone shaped and allow us to see bright stuff
what is near-sighted vision
where you cant see distant objects
how does near sighted vision happen
lens causes light rays to converge witch makes image form in front of the retina
how is near sighted vision corrected
using a con cave lens
what is far sighted vision
can not focus on objects far away
how does far sight happen
lens converges light rays to make image form behind retna
how is far sight fixxed
convex
what is astigmatism
blurred sight
how does astigmatism happen
because of irregular shaped cornea
how is astigmatism fixxed
use eyeglasses, contacts, or laser surgery
what is blindness
any kind of vision imparment
what is legally blind
people who can see a little light such as tunnel vision
what is snow blindness
temporary blindness do to over exposure to sunlight
what is night blindness
when you cant see because of your enviroment
what is color blindness
when you can only see in gray
what is color vision deficiency
where cant distinguish certain colors
